Image source: Wyoming State Vet Lab
Healthy eye color
Club lamb fungus
Congenital defect: no rectum
Dying lamb (cause unknown)
Colorado State University Extension
Image source: Wool is Best
Foot rot or scald
Hairy Shaker disease
Image source: TeAra.govt.nz
Foot rot (maggots)
Image link: TeAra.govt.nz
Milk goiter (healthy)
Passing a tapeworm
Image source: Dept. of Ag Western
Healthy pregnant yearling ewe
Pulpy kidney disease
Image source: TeAra.govt.nz
Scrotal hernia (congenital)
Scrotal hernia (acquired)
Image source: Cornell University
"Sloppy mouth" - cause unknown
Septic pedal arthritis
Looks like soremouth
Enough tapeworms to cause
intestinal blockage and death
Image source: NADIS
White muscle disease
Image source: North
Carolina State University
Listing of sheep diseases, A-Z
This chapter is meant to provide an overview of the diseases that can affect sheep and lambs. For more information, including more detailed treatment options, you need to consult an animal health reference or seek advice from a qualified veterinarian or other animal health professional.
Sheep can be affected by a variety of infectious and noninfectious diseases. Some diseases that affect sheep are contagious to people. These are called zoonotic diseases or zoonosis. Some diseases, such as scrapie, must be reported to government authorities. Reportable diseases vary by state and country. Certain diseases prevent the import and export of livestock or have requirements for entry.
G H I
J K L
M N O
P Q R
S T U
V W X Y Z
Abomasal bloat is mostly a disease of artificially-reared lambs, especially those that are hand-fed warm milk. It seldom affects lambs that are self-fed cold milk. Abomasal bloat is believed to be caused by a build-up of bacteria in the stomach of the lamb. Clostridial bacteria and species of Sarcina have been implicated in the US. Affected lambs have swollen bellies and abdominal discomfort. Treatment (sodium bicarbonate) is not always rewarding. The addition of yogurt or probiotics to milk replacer has been shown to reduce the incidence of abomasal bloat. It is especially important to vaccineate artificially-reared lambs for the enterotoxemias.
Read article on abomasal bloat=>
Abomasal emptying defect (AED)
Abomasal emptying defect is a disease that primarily affects Suffolk sheep and is characterized by distension and impaction of the abomasum. Symptoms include anorexia and progressive weight loss. There is no known cause or curative treatment. The disease occurs sporadically and is considered rare.
Abortion is when a ewe's pregnancy is terminated, and she loses her
lambs, or she gives birth to weak or deformed lambs that die shortly
after birth. There are many causes of abortion in sheep, both infectious and non-infectious. In the US, the most common infecious causes of abortion in
sheep are Chlamydia (Enzootic abortion), Campylobacter (Vibrio),
and Toxoplasma gondii (Toxoplasmosis). It is important to note that these organisms may also cause abortion (miscarriage)
in women. As a precaution, pregnant women should not handle fetuses or placental fluids.
Read Infectious Causes of Abortion in Ewes =>
Brucellosis is an infectious disease caused by bacterium of the
genus Brucella. Various Brucella species affect
sheep, goats, cattle, pigs, dogs, and other animals.
In infected ruminants, brucellosis commonly causes abortion
during the second half of gestation. Sheep are less susceptible
than cattle, and brucellosis is not considered a common cause of abortion in sheep.
Ovine brucellosis mainly affects rams, causing lesions in their
reproductive organs (called epididymitis).
Cache Valley Virus
Cache Valley Virus is a bunyavirus that occasionally causes abortion storms in sheep. The virus is spread by mosquitoes to pregnant ewes. If a ewe is infected at less than 28 days
of gestation, the embryos usually die and are reabsorbed. If
a ewe is infected after 45 days of pregnancy, there are usually no adverse effects.
If infection occurs between 28 and 45 days of gestation, the
fetuses usually develop the "A-H syndrome," resulting
in various congenital abnormalities (birth defects) affecting the central nervous
system. Ewes that are infected usually show no signs of disease
and develop good immunity that lasts for several years. Cache
Valley virus is similar to Akabane Disease except that it only
Campylobacterisis is a common cause of abortion in ewes.
Abortion during the last month of pregnancy, stillborn lambs,
and the birth of weak lambs are common signs of vibrio abortion.
The organisms which cause abortion are Campylobacter
jejuni or Campylobacter fetus. Ewes are infected
by oral ingestion. The incubation period from the time of infection
and abortion is only two weeks.
Vaccination can be effective
in the face of an outbreak.
Feeding of antibiotics has also been shown to be effective at reducing abortions caused by vibrio.
Disease spread can be prevented by isolating the aborting ewe,
disposal of the fetuses and membranes, and disinfecting the affected
area. Infected ewes usually recover after aborting and are immune
to re-infection. A vaccine is available. It should be administered
prior to breeding and repeated in 60 to 90 days, then annually.
(enzootic abortion, EAE)
In the U.S., Chlamydia is the most common cause of abortion
in ewes. It is transmitted from aborting sheep to other susceptible
females. Ewe lambs are usually the most susceptible on farms
where the organism is present. The bacteria which causes enzootic
abortions in ewes is called Chlamydia psittici. Chylamydia causes abortion during the last month of pregnancy and may also
result in the birth of lambs that die shortly after birth.
The organism may also cause pneumonia in young lambs, but the
chlamydia species that causes abortion is not associated with
conjunctivitis or arthritis. Chlamydia abortions can usually
be stopped or reduced by treating the entire flock with tetracycline.
A vaccine is available. It should be administered 60 days prior
to breeding and repeated in 30 days, then annually just prior
Sheep are generally more resistant to leptospirosis than cattle,
swine, and most other domestic animals. Abortion due to this
disease may occur during the last month of pregnancy. A blood
test of aborting sheep will confirm diagnosis. The problem can
be prevented with annual vaccination with a 5-strain leptospirosis
Q Fever is a disease caused by the bacteria Coxiella burnetti.
The disease is found worldwide except for New Zealand. Sheep,
goats, and cattle are most likely to get Q fever. The most common
sign of Q fever is abortion during late pregnancy. However, most
animals do not show any signs. Animals get Q fever
through contact with body fluids or secretions. Q fever is zoonotic
(transmissible to people). It causes influenza-like symptoms.
Rift Valley Fever
(infectious enzootic hepatitis)
Rift valley disease is a viral disease of sub-Saharan Africa.
The virus attacks the liver and causes symptoms ranging from
fevers and listlessness to hemorrhage and abortion rates approaching
100%. It is transmitted by mosquitoes. There
is no specific therapy for infected animals.
Vaccination of animals against RVF has been used to prevent
disease in endemic areas and to control epizootics. Rift Valley
fever has not occurred in the United States. However, there
has been concern that it could become permanently established
in the U.S. if it does enter the country. Rift Valley fever
is more deadly than West Nile virus.
In the US, salmonella abortion is a less common cause of abortion in sheep, but probably occurs more often
than recognized. The two major factors determining whether a
pregnant ewe will abort from Salmonella are stress on the ewe
and the number of Salmonella bacteria the ewe ingests.
Abortions may occur earlier in gestation but are most common
in the last month of gestation. Most of the ewes show diarrhea
and some will die from metritis, peritonitis, and septicemia.
Healthy lambs may also contract the disease and die.
Toxoplasmosis is another common cause of abortion in ewes. It is caused
by Toxoplasma gondii, a protozoan parasite which causes
coccidiosis in cats. Thus, cats are the carrier for the causative organism. Toxoplasma abortion in ewes follows ingestion
of feed or water that has been contaminated with oocyte-laden
cat feces. The organism migrates to the placenta and fetuses,
causing their death and expulsion. Ewes will abort during the
last month of pregnancy or give birth to dead or weak lambs
that usually die from starvation.
Infection in the first two months of gestation results in embryonic
death and re-absorption. There is some evidence that Rumensin®
and Deccox® will partially prevent toxoplasmosis in pregnant
ewes. Limiting cat populations (spay and neuter farm cats) and preventing contamination
of sheep feed and water with cat feces will help to prevent
disease outbreaks. There is no vaccine available in the U.S.
(lactic acidosis, ruminal acidosis, grain overload,
Acidosis is a common metabolic disease. It is caused by excess consumption of grain or pellets to which animals are unaccustomed to. The feeds are rapidly fermented in the gut, resulting in large quantities of lactic acid being produced, which lowers the pH in the rumen.
Affected sheep appear depressed and listless and
may have abdominal pain. Acidosis can be a life-threatening condition. Affected sheep should be drenched with an antacid
such as carmalax, bicarbonate of soda (baking soda), or products containing
magnesium carbonate or magnesium hydroxide.
Acidosis can be prevented by proper feeding management. Concentrates
(grain) should be introduced to the diet slowly and increased
incrementally to give the rumen time to adjust.
Whole grain feeding reduces the risk of acidosis, as does feeding grains that are higher in fiber, e.g. oats and barley.
Arthritis in sheep is an inflammation of the joints of the legs,
resulting in loss of production, loss of carcass value, and deaths.
The main cause of arthritis in sheep is when bacteria enter the
body via broken skin. The common times when sheep will be susceptible
to arthritis are: 1) at or soon after birth with infection
through the umbilical cord; 2) during docking, castration, and
ear tagging; 3) through shearing wounds; and 4) other wounds.
There are several bacteria that may be implicated in arthritis.
The most common is Erysipelothix rhusiopathiae. Signs appear 2
to 14 days after infection. Affected joints become swollen, hot,
and painful, resulting in the lamb becoming reluctant to move.
For most types of arthritis, the only treatment is a course of
massive doses of antibiotics. Prevention is the result of good
sanitation and hygiene.
Bacterial meningitis occurs sporadically in lambs. It most commonly affects lambs 2 to 4 weeks old. The entry point of the bacteria is not clearly understood. Inadequate transfer of passive antibodies predisposes lambs to infection. Early clinical signs include depression, hunger, and failure to follow dams. Affected lambs may have abnormal gait. Their head is often held lower in a rigid extension. Response to treatment with antibiotics and corticosteroids is usually poor.
(a form of rickets)
Bent leg is a form of rickets and is due to a malfunction of
bone metabolism during growth. It occurs during the rapid growth
phase of the lamb, usually between 6 and 12 months of age. It
occurs primarily in rams but can occur in ewes. It is more
common in Rambouillet and related breeds. Similar conditions
occur in cattle, horses, dogs, poultry, and people.
It can be prevented by 1) feeding balanced rations; 2) avoiding
the use of too much high energy or high protein feeds (rapid
growth and nutritionally "pushing" animals for growth
is a factor in all species for increased incidence of rickets);
3) providing a calcium to phosphorus ratio of at least 1.5 to
1; 4) supplementing the ration with 300 IU of vitamin D (per
100 lbs. of body weight per day); 5) providing adequate magnesium;
6) shearing young rams in early winter to allow more skin surface
for vitamin D conversion; and 7) providing housing that provides
good exposure to sun during the winter.
Bloat is a common metabolic disease of ruminants. It occurs when rumen gas production exceeds the rate of gas
elimination. Gas then accumulates causing distention of the
rumen. The skin on the left side of the animal behind the last
rib may appear distended. Bloat can be a medical emergency,
and timely intervention may be necessary to prevent death.
Bloat is a common cause of sudden death in livestock. It usually results
from nutritional causes.
There are two types of bloat: frothy
and free gas.
Frothy bloat is usually associated with the consumption of leguminous
forages but may also occur in sheep grazing lush cereal grain
pastures or wet grass pastures or consuming grain that is too
finely ground. Animals with frothy bloat can be treated with
anti-foaming agents such as cooking oil or mineral oil or a
commercial product such as Poloxalene.
Free Gas Bloat
(feed lot bloat)
Free grass bloat is associated with grain feeding and occurs
when animals were not given enough of an adjustment period.
Many of the same factors causing acidosis are associated with
free-gas bloat. Simple passage of a stomach tube may be effective
at relieving free gas bloat. Inserting a trochar or needle (14 gauge) into
the abdomen is a life-saving procedure that should only be attempted
as a last resort.
Bluetongue is an insecttransmitted, viral disease of sheep,
cattle, goats, and other ruminants, such as whitetailed
deer and pronghorn. It is particularly damaging in sheep; half
the sheep in an infected flock may die. In cattle and goats,
however, bluetongue viruses cause very mild, selflimiting
infections with only minor clinical consequences. A bluetongue
virus infection causes inflammation, swelling, and hemorrhage
of the mucous membranes of the mouth, nose, and tongue.
Inflammation and soreness of the feet also are associated with
bluetongue. In sheep, the tongue and mucous membranes of the
mouth become swollen, hemorrhagic, and may look red or dirty
blue in color, thus giving the disease its name. Bluetongue
viruses are spread from animal to animal by biting gnats. In
the United States, the disease is most prevalent in the southern
and southwestern States.
Animals cannot directly contact the disease from other animals.
The bluetongue vaccine for sheep is only effective against certain
serotypes, will not prevent the disease, and may cause adverse
reactions. Pregnant ewes should not be vaccinated.
(hair-shaker disease, fuzzy lamb syndrome,
Border disease is often seen in the newborn lamb which has a
hairy coat and trembles uncontrollably. It is caused by a virus
and causes a wide variety of symptoms depending upon the stage
of pregnancy when the ewe becomes affected. Sheep affected by
border disease are characterized by open ewes, abortion, weak
and frail lambs, abnormal hair coat, and nervous symptoms that
cause the lamb to shake.
The most common clinical symptom is abortion of macerated or
mummified lambs. Border disease is usually brought into a flock
by new additions that are carriers or when sheep are mixed with
cattle that are shedding the Bovine viral disease virus. Bovine
viral diarrhea vaccines for cattle cannot be recommended for
use in sheep because border disease viruses most commonly isolated
from sheep are antigenically distinct from bovine viral diarrhea
viruses most common in cattle. There is no treatment and the
disease will not respond to antibiotics.
(CLA, CL, boils, abscesses, cheesy gland)
Caseous lymphadenitis is an infectious, contagious disease that
primarily affects the lymphatic system, though other organs
can be affected. It is caused by the bacteria Corynebacterium
pseudotuberculosis. Infection results in abscess formation
in the lymph nodes which when cut or ruptured, discharge pus
containing the bacteria into the immediate surroundings. When
the nodes spread internally, affected ewes slowly lose weight
and eventually become emaciated.
CL is the third leading cause of carcass condemnation in the US.
The disease is controlled by culling visible infected animals and practicing
good hygiene at shearing time. There is a vaccine licensed for
sheep. It has been shown to both decrease the number of abscesses
in sheep and the number of sheep that develop abscesses.
Clostridial organisms of various types are found in the soil,
where they can survive for a very long time. Most clostridial
organisms also occur quite naturally in the gut of healthy
animals. Sheep can be infected with various clostridial diseases
black leg, botulism, malignant edema, red water disease,
enterotoxemias (several types), and tetanus. The most
common are enterotoxemia types C & D and tetanus.
Enterotoxemia type C
(hemorrhagic enteritis, bloody scours)
Enterotoxemia type C is caused by Clostridium perfringins
type C and affects lambs during their first few weeks of life,
causing a bloody infection of the small intestine. It is often
related to indigestion and predisposed by a sudden change in
feed such as beginning creep feeding or sudden increase in milk
supply. Treatment (antitoxin injected under the skin) is usually
unrewarding. Vaccination of pregnant ewes 30 days before lambing
is recommended as prevention. The antitoxin can be given to provide immediate short-term protection.
Enterotoxemia type D
("classic" overeating disease, pulpy kidney disease)
Overeating disease is one of the most common sheep diseases
in the world. It is caused by Clostridium perfringins
type D and most commonly strikes the largest, fastest growing
lambs in the flock. It is caused by a sudden change in feed
that causes the organism, which is already present in the lamb's
gut, to proliferate causing a toxic reaction.
It is most commonly observed in lambs that are consuming high
concentrate rations but it can also occur when lambs are nursing
heavy milking dams. It usually affects lambs over one month
of age. It is characterized by sudden deaths, but can also be chronic in nature. Treatment (antitoxin injected under the skin) is usually
unrewarding. Vaccination of pregnant ewes 30 days before lambing
is recommended as prevention. Lambs should be vaccinated twice at approximately 6 to 8 and 10 to 12 weeks of age. Pasture-fed lambs that are brought in for feeding should be vaccinated.
Tetanus is caused by Clostridium tetani, a soil inhabitant
that is a prolific spore producer. This disease is usually related
to docking and castrating by elastrator bands, though any wound
can harbor the tetanus organism.
Signs of tetanus occur from about four days to three weeks or
longer after infection is established in a wound. The animal may
have a stiff gait, "lockjaw" can develop, and the third
eyelid may protrude across the eye. The animal will usually go
down with all four legs held out straight and stiff and the head
drawn back. Convulsions may occur.
Treatment consists of the tetanus anti-serum and antibiotics.
It is usually unrewarding. Tetanus can be prevented by vaccinating
pregnant ewes 30 days before lambing. If pregnant ewes were not
vaccinated for tetanus, the tetanus anti-toxin can be administered
to lambs at the time of docking and/or castrating. The tetanus
anti-toxin provides immediate short-term immunity and can be used
during high risk periods to prevent disease outbreaks.
Less common Clostridial Diseases
Enterotoxemia type B
Clostridium perfringins type B causes lamb dysentery. It
usually affects strong lambs under the age of 2 weeks. Symptoms
include sudden death, listlessness, recumbency, abdominal pain,
and a fetid diarrhea that may be blood-tinged. On post-mortem,
intestines show severe inflammation, ulcers, and necrosis. The
mortality rate approaches 100 percent. Cl. perfringins type
B is not common in the U.S., but is frequently found in England,
Europe, South Africa, and the Near East.
Black disease occurs in sheep in areas where liver flukes are
known to occur. Infections are caused by the bacterium Clostridium
novyi, which becomes active in the liver tissue damaged by
the liver fluke. Control relies on vaccination and elimination
of liver flukes.
Blackleg is disease of cattle and less frequently of sheep. It
is caused by the soil-borne bacteria Clostridial chauvei.
The disease develops rapidly in affected animals and often deaths
occur before the owner has noticed any sickness. Vaccination is
the only means of protection against blackleg.
Malignant edema is caused by the bacterium Clostridium septicum.
In sheep, blackleg and malignant edema are indistinguishable.
The disease is not common in sheep in North America. In areas
where the disease is known to occur, lambs can be vaccinated.
Cobalt deficiency (vitamin B12 deficiency)
The only known animal requirement for cobalt is as a constituent
of Vitamin B12, which has 4% cobalt in its chemical structure.
This means that a cobalt deficiency is really a vitamin B12 deficiency.
Microorganisms in the rumen are able to synthesize vitamin B12
needs of ruminants if the diet is adequate in cobalt. Ruminants
must consume cobalt frequently in the diet for adequate B12 synthesis.
Cobalt deficiency causes lack of appetite, lack of thrift, severe
emaciation, weakness, anemia, decreased fertility, and decreased
milk and wool production. Weeping eyes, leading to a matting of
wool on the face, is another common symptom. Sheep are more susceptible
to cobalt deficiency than cattle. Cobalt deficiency also impairs
the immune function of sheep which may increase their vulnerability
to infection with worms.
The diagnosis of cobalt deficiency is usually based on blood (serum)
vitamin B12 concentrations, which reflect immediate cobalt intake.
Short-term supplementation of sheep with cobalt is usually achieved
through oral drenching with cobalt sulfate or vitamin B12 injections.
Congenital defects are abnormalities of structure or function present at birth. They may be caused by genetic or environmental factors or combinations of both. The causes of many defects remain unknown. Developmental defects may be lethal, semi-lethal, or have little effect on the health and performance of the animal. If the cause is genetic, inbreeding will increase the frequency of deleterious genes.
In sheep, copper deficiency is not diagnosed nearly as frequently as copper toxicity, but it may occur in regions where soils and forages are low in copper or have elevated levels of molybdenum. Some feedstuffs may also contain mineral levels that are antagonistic to copper absorption. In adult sheep, signs of copper deficiency are usually sub-clinical and hard to identify. Severe deficiencies may result in "steely" or "stringy" wool that lacks crimp and tensile strength.
Young animals are more susceptible to copper deficiency, as milk is a poor source of copper. Affected lambs may show signs of "swayback" or have difficulty standing or walking (known as ataxia). Oral administration of copper sulfate or other chelated forms of copper is the usual treatment for copper deficiency.
Sheep are ten times more susceptible to copper toxicity than
cattle. When consumed over a long period of time, excess copper
is stored in the liver. No damage occurs until a toxic level
is reached at which time there is a hemolytic crisis with destruction
of red blood cells. Most outbreaks of copper poisoning in sheep
can be traced to feeding supplements containing copper levels
that have been formulated for cattle or swine.
Copper is closely related to molybdenum, and copper toxicity
occurs when the dietary ratio of copper to molybdenum increases
about 6-10: 1. Affected animals suddenly go off feed and become
weak. An examination of their mucous membranes and white skin
will reveal a yellowish-brown color. Their urine will be a red-brown
color due to hemoglobin in the urine.
Treatment of copper toxicity involves the use of ammonium molybdate and sulfate compounds.
Read Copper Toxicity in Sheep =>
Diarrhea is defined as an increased frequency, fluidity, or
volume of fecal excretion. There are many causes of diarrhea:
bacterial, viral, parasites, diet, and stress. It is not possible to
definitively determine the infectious organism by looking at
the color, consistency, or odor of the feces. A definitive identification
requires a sample for microbiological analysis. Diarrhea is a complex, multi-factorial disease involving
the animal, the environment, nutrition, and infectious agents.
Diarrhea should not be considered an illness in and of itself
but rather a symptom of other more serious health problems in
sheep and lambs. Diarrhea is not always the result of an infectious
disease. It can be induced by stress, poor management, and nutrition.
Before treating an animal for diarrhea, it is essential to determine
why the animal is scouring. Many of the common causes of diarrhea
are self-limiting, and the major goals of treatment are to keep
the animal physiologically intact while the diarrhea runs its
In some animals, rehydration and other supportive care may be necessary. Over-the-counter medications such as Pepto Bismal (Bismuth subsalicylate) and Kaopactate (Kaolin pectin) can be used to treat non-infectious causes of diarrhea. Probiotics or yogurt are always a good treatment option for scouring animals.
Diarrhea (scours) in small ruminants =>
Dystocia (lambing difficulty)
Most ewes deliver their lambs without assistance; however, there
are instances when producers must be prepared to assist with difficult
deliveries. Difficult births can be caused by 1) abnormal presentation
of the lamb(s); 2) an unusually large lamb; 3) a fat ewe;
4) a small pelvic area; and 5) disease.
The normal delivery position for a lamb is the head and two front
feet being delivered first. If lambs cannot be delivered after
a reasonable amount of time and effort, competent assistance should
be sought. A caesarean section is sometimes necessary to deliver
lambs that cannot be delivered normally.
E. Coli scours
E. coli scours is an opportunistic disease that is usually associated
with sloppy environmental conditions and poor sanitation. It
generally occurs as a diarrhea problem in two to four-day-old
lambs. Affected lambs salivate and have a cold mouth; thus,
the common name, "watery mouth." Dehydration, coma,
and death usually occur within 12-24 hours following the onset
of clinical signs of scours.
Treatment of E. coli scours usually involves rehydrating
the lamb with oral, subcutaneous, or intraperitoneal fluids and
treatment with appropriate antibiotics. Prevention of E.
coli scours in lambs should really be the key focus for
any flock. Lambing barn sanitation and creating a clean, dry
environment for newborn lambs are the key factors related to
preventing outbreaks of E. coli scours.
Entropion (inverted eye lid)
Entropion is a heritable trait in which the lower eyelid is
inverted, causing the eyelashes of the lower lid to brush against
the eye. Entropion should not be left untreated. The constant
irritation results in tearing and can lead to corneal ulceration,
scarring, and blindness. It may affect one or both eyes.
cases of entropion can be treated by injecting a long acting
antibiotic under the skin of the affected eyelid. Sometimes,
staples, sutures, or clips will need to be applied to the skin
surface of the affected eyelid. Rams carrying this trait should
not be used for breeding.
Epididymitis is a venereal disease of rams caused by the bacteria Brucella
ovis. Epididymitis means inflammation of the epididymitis,
the tubular portion of the testicle that collects the sperm
produced by the testes and stores it until it is ready to transport.
Severely affected rams will often have at least one enlarged
epididymis and may show pain when the testicle is manipulated.
Epididymitis causes varying degrees of damage. It may cause
infertility by affecting the ram's ability to produce viable
sperm. It is the number one ram fertility problem seen in the
sheep industry. Epididymitis is contagious and is transmitted
during homosexual activity or during the breeding season via
the ewe. Only about half of the rams affected by epididymitis
respond to antibiotic treatment. Damage is usually permanent.
Prevention is to buy virgin or disease-free rams, to subject
rams to diagnostic testing, and to cull affected rams.
External Parasites (ectoparasites)
External parasites that affect sheep include keds, ticks, lice,
mites, and flies. Mange (sheep scab) in sheep is rare and
a reportable disease in the U.S.
(blowflies, wool maggots, fleece worms, myiasis)
Fly strike is the infestation of the flesh of living sheep by
blowfly maggots. Of all domestic animals, sheep are most often
affected because of their wool, as particularly dirty wool attracts blowflies.
Blowfly populations are greatest during the summer months.
Docking, shearing, and removal of dags (wool contaminated with
feces) will help to prevent flystrike. Insecticides are another
control measure. Hair sheep are less susceptible to fly strike
due to their absence of wool. Blowflies are also attracted to
wounds, foot rot, weeping eyes, or sweat around the base of
the horns of rams.
Sheep keds are wingless, reddish brown biting flies that resemble,
and are sometimes called, ticks. They use piercing- sucking
mouthparts to feed on blood. High ked populations cause unthriftiness
and emaciation and make animals more susceptible to diseases
and other stresses. Sheep keds are readily controlled with insecticides.
Treatment is recommended immediately after shearing. Keds can
only survive off the animal for about a week. Keds do not thrive
well on the short hair of hair sheep.
Lice are quite small, ranging from 1/20-inch to 1/10-inch long.
They spend most of their time next to the skin and are difficult
to see within dense wool or hair. Three species of lice are
found on sheep. The primary animal reaction to lice is itching.
Severe infestations can cause anemia. Various insecticides can
be used to control lice on sheep.
(bot flies, head bots)
The sheep bot fly is a fuzzy, yellowish-gray, or brown fly that
deposits tiny larvae on the muzzles or nostrils of sheep. The
larvae migrate into the nostrils and head sinuses and develop.
A snotty nose is the most common symptom. Animals will hold their heads
down or in a corner to escape the flies. Weight reductions of
up to 4 percent have been attributed to bot infestations in
some studies. The highest bot levels are seen in November and
December. A systemic insecticide formulation containing ivermectin
is effective against larval stages of the nasal bot.
(sheep scab, psoroptic mange, wet mange)
Sheep scab is a very contagious disease, caused by mites feeding
on the surface layers of the sheep's skin. Severe itching occurs,
wool or hair falls out in patches, and the skin becomes reddened,
crusted with scabs and sore. Positive diagnosis can be made
only by scraping lesions and examining the scrapings microscopically
for mites. The preferred method of treatment is dipping with
insecticides. Scabies has been eradicated from the
Facial eczema is a condition of severe dermatitis in cattle, sheep,
and goats caused by a toxin in spores of the saprophytic fungus
Pithomyces chartarum, which lives in dead vegetative material
in pastures, especially perennial ryegrass. Facial eczema is an
example of "secondary photosensitization," in which
the skin lesions are really the secondary result of liver damage,
rather than the direct result of a plant toxin. The liver damage
in facial eczema is caused by the toxin sporidesmin in the fungus
Facial eczema is relatively common in areas of New Zealand and
has also been observed in Australia, South Africa, and in irrigated
perennial ryegrass fields in the United States (Oregon). Perennial
ryegrass is the grass species most associated with facial eczema.
P. chartarum as does not grow well in legumes. The occurrence
of facial eczema is also influenced by livestock genetics.
Performance testing programs in New Zealand have identified genetic
lines of sheep that can tolerate relatively high toxin situations.
Animals suffering from facial eczema should be removed from the
contaminated pasture and provided with shade, cool water, and
a good diet. Feeding high levels of zinc may help prevent facial
Most Tall Fescue (Festuca arundinacea) is infected with
a fungal endophyte. The endophyte produces toxins that cause a number of problems for grazing animals, though sheep
appear to be less affected than cattle and horses.
However, sheep are prone to "fescue foot," hyperthermia,
poor wool production, and reproductive problems, as well as lowered
feed intake and the resulting poor weight gains. Diluting Kentucky
31 tall fescue with legumes and supplementing with other feeds
will reduce the toxic effects of fescue on livestock. Alternative
tall fescue cultivars are also available. Stockpiled fescue is less toxic.
(FMD, hoof-and-mouth disease)
Foot-and-mouth disease is a severe, highly communicable viral
disease of cattle and swine. It also affects sheep and goats and
other cloven-hoofed animals. The disease is characterized by fever
and blister-like lesions followed by erosions on the tongue and
lips, in the mouth, on the teats, and between the hooves.
While many affected animals recover, the disease results in
a weakened state, loss of weight, and reduced production of milk
and meat. Foot-and-mouth disease in adult sheep and goats is frequently
mild or unapparent but can cause high mortality in young animals.
Sheep and goats are sometimes the reservoir of infection. The disease
is virtually never harmful to humans but is highly contagious
among those animals which are vulnerable to this virus.
The United States has been free from foot-and-mouth disease since
Footrot is one of the most economically devastating diseases in
the sheep industry. It is caused by the interaction of two
anaerobic bacteria: Bacteroides nodosus, which can only
live in the animal's hoof; and Fusobacterium necrophorum,
which is a normal inhabitant of soil and sheep manure.
Lameness in one or more feet is the most common symptom of footrot,
though not all lame sheep have footrot. Footrot has a characteristic
foul odor. Footrot can be controlled and/or eradicated by a combination
of hoof trimming, vaccination, foot bathing and soaking and culling.
Zinc sulfate is considered to be the most effective foot rot treatment.
Footrot is highly contagious.
Foot Scald (benign footrot and ovine interdigital dermatitis)
Foot scald causes the tissues between the sheep's toes become
blanched or white, or red and swelled. It is caused by a soil
bacteria that is present in most environments and manifests itself
during wet conditions. It is easier to treat than foot rot. Placing
sheep in a dry area away from mud may clear the condition. Individual
animals can be treated with Koppertox. Groups of animals may be
treated with a zinc sulfate foot bath.
Goiter is an enlargement or swelling of the thyroid gland. Affected
lambs have a swollen throat. They are often born with little or
no wool. They are weak and often die of starvation. Treatment
is usually unrewarding. But if the condition is not advanced,
the lamb may survive.
Goiter in newborn lambs is due to a deficiency
of iodine in the pregnant ewe's diet. It can be prevented by providing
iodized salt in the diet of gestating ewes. The salt mixture should
contain 0.007 percent of available iodine. An iodine deficiency
may also result in reduced yield of wool and reduced conception
rate in the flock.
Well-fed hair sheep lambs often display a throat swelling that resembles goiter. It is not. It is often called "milk goiter."
Grass tetany (grass staggers, magnesium deficiency)
Grass tetany is a complex disease traditionally associated with
a magnesium deficiency. All ruminants are susceptible. Magnesium
deficiency in sheep most commonly occurs in an acute form during the last 4 to 6 weeks of pregnancy. Affected ewes exhibit sensitivity to touch
and trembling of the facial muscles; some are unable to move,
others move stiffly; extreme cases collapse and show repeated
tetanic spasms with all four limbs rigidly extended.
Low blood magnesium can be caused by low levels of magnesium in
lush spring grass or by mineral imbalances such as high potassium
and nitrogen or low calcium in the diet. Ewes with grass staggers
are often low in calcium as well as magnesium. It is therefore
wise to use a combined treatment of calcium borogluconate and
magnesium hypophosphite. Producers can add about 10 to 20 grams
of commercial or homemade supplemental magnesium to livestock
diets to prevent grass tetany. Magnesium oxide is one of the best
and cheapest magnesium sources.
Hypothermia is a leading cause of death in neonatal lambs. Mild to moderate hypothermia is characterized by a body temperature between 98° and 102°F. Severe hypothermia occurs when body temperature is below 98°F. Hypothermia is caused by excess body heat loss combined with reduced heat production. Newborn lambs are unable to regulate their body temperature during their first 36 hours.
Severely hypothermic lambs need to be removed from the ewe for treatment. If they are less than five hours old, they should receive an intraperitoneal injection of a warm 20 percent dextrose (glucose) solution. Wet lambs should be towel dried and supplemented with heat or put in a warming box using dry heat (heat lamp or hair drier). Colostrum should be tube fed at a rate of 20 to 25 ml per pound of body weight. Once rectal temperature is normal, lambs may be returned to their dams.
Losses due to hypothermia can be prevented by providing ewes with adequate shelter for lambing, shearing ewes prior to lambing, confining ewes and lambs for one or two days to promote bonding, checking ewes for adequate milk production, and helping lambs suckle to ensure adequate colostrum intake. Coats or covers can help to prevent heat loss, but they should be removed once the lamb is capable of regulating its own temperature.
There are three broad types of internal parasite that can cause
significant health issues in sheep: worms, flukes, and protozoa.
Cryptosporidiosis (Cryptosporidium sp.)
Cryptosporidium species are tiny protozoan parasites closely
related to coccidia. One major species, Cryptosporidium parvum,
infects both farm animals and humans. C. parvum has a rapid,
direct life cycle and infection occurs when viable oocysts in
the environment are ingested by susceptible hosts, usually lambs
under a month old.
Lambs as young as 3 days can be affected.
Lambs are depressed and reluctant to suck while the diarrhea
lasts. Very young lambs soon become dehydrated and die. In poor
weather conditions, lambs may die of hypothermia. The illness
may last for up to 10 days, and relapses after apparent recovery
Coccidiosis (Eimeria sp.)
Coccidia are single-cell protozoa that are naturally in the sheep's digestive system. Young lambs are particularly susceptible
to coccidia especially during periods of stress (e.g. weaning).
Coccidia damage the lining of the small intestine, affecting
absorption of nutrients. The most common symptom of coccidiosis
is diarrhea. The diarrhea may be bloody or smeared with mucous.
The diagnosis of coccidiosis cannot be confirmed by identification
of oocysts in fecal samples. Coccidiosis is mostly a management-related
disease, caused by overstocking and poor hygiene. Coccidiosis
can be prevented by including Lasolocid (Bovatec®), Monensin
(Rumensin®), or Decoquinate (Deccox®) in the feed or
mineral. Coccidiosis should be treated with Amprolium or sulfa
and Ostertagia sp.)
The internal parasites of greatest concern in sheep are usually
the stomach worms, with the barber pole worm (Haemonchus
Contortus) being of primary concern and the small brown
stomach worm being of secondary concern. The barber pole worm
is a blood-sucking parasite that pierces the mucosa of the abomasum,
causing blood and protein loss.
The primary symptom of barber pole infection is anemia (blood
loss). Anemia can be observed in the sheep by examining its
lower eyelid, which will become paler (whiter) with increasing
infestation. An accumulation of fluid under the jaw, called
"bottle jaw" is also a tell-tale of barber pole infection.
The small brown stomach worm also burrows into the lining of
the abomasum, but it causes typical digestive symptoms, especially
diarrhea. Microscopically, it is difficult to differentiate
between the barber pole worm and the brown stomach worm. The
eggs only differ in size not appearance.
The life cycle and transmission of Nematodirus differs from
that of other sheep worms. Infective N. battus larvae generally
don't survive for long on pasture when weather conditions are
warm and dry but can survive for several months during cool
and damp weather. The symptoms of nematodirus are scours, weight
loss, and sudden death.
Tapeworms (Moniezia sp.)
There is disagreement as to whether tapeworms cause serious
problems in sheep. They are generally considered to be non-pathogenic,
though they can cause weight loss, diarrhea, and ill-thrift. A heavy infestation may cause an intestinal blockage and result in death. Heavy infestations may also predispose lambs to enterotoxemia.
Tapeworms infect mostly suckling lambs. The only anthelmintics that are effective
against tapeworms are the benzimadazoles (fenbendazole and
albendazole) and Praziquantel (available extra-label in Quest® Plus or Zimectrin® Gold). Most research shows no benefit to treating lambs for tapeworms. Tapeworms are the only parasite that is visible in the feces and for this reason, they tend to cause concern among producers.
Read Tapeworms: Problem or Not? =>
Lungworm larvae are passed in the feces, but travel to the
respiratory system once they enter the sheep system. The symptoms
of lung worm infection are not obvious unless the problem is
severe. Lungworm infestations are most commonly diagnosed at necropsy or slaughter. The same anthelmintics that are effective against stomach
worms are also effective against lung worms.
Liver flukes (Fasciola hepatica)
Liver flukes can be problematic in wet areas. They are spread by snails and slugs. As the name would suggest, liver flukes damage the liver of the host animal. They cause blood loss, diarrhea, weight loss, and death. The only drugs that
are effective against liver flukes (the adult form) are clorsulon (contained in Ivomec® Plus) and albendazole
(Paralaphostrongylus tenius, deer
worm, brain worm)
The meningeal worm is a parasite of the White Tail deer. Sheep,
goats, llamas, alpacas, horses, and other animals are abnormal hosts for the
parasite. After the host ingests the larvae, the larvae travel to
the spinal cord causing gait abnormalities and other neurological symptoms and eventually paralysis and death.
When the parasite reaches the sheep's brain, it will kill them.
Meningeal worm infection cannot be detected in the live animal, except from spinal fluid.
When meningeal worm is suspected, high doses of anthelmintics
and anti-inflammatory drugs are recommended. Fenbendazole (SafeGuard®) is the anthelmintic of choice, as it can cross the blood-brain barrier. Cornell University has recently validated treatment protocols. Infections can
be prevented by limiting exposure to deer or by controlling
snail populations, since the parasite requires snails to complete
its life cycle.
Read Meningeal Worm =>
Johne's Disease (paratuberculosis)
Johne's Disease (pronounced "Yo nees") is a disease
that affects the intestines of mostly ruminants. It is most commonly observed in dairy cows, but may also affect
beef cattle, sheep, and goats. It is caused
by a hardy bacteria called Mycobacterium paratuberculosis.
The strain that affects sheep is different than the one that
affects cows, though there is an intermediate strain that sheep
are susceptible to.
While cattle experience diarrhea, in sheep,
Johne's tends to be more of a wasting disease. Control of the disease in infected flocks is difficult due to the lack of a reliable live animal test. No Johne's vaccine is available for sheep in the US. Colostrum from other sources (cows, goats) could be a source of infection in sheep flocks. The is no treatment for Johne's disease.
While Johne's disease has been linked to Crohn's disease in people, no causative association has been confirmed.
Download Johne's Disease Q & A for Sheep Owners =>
Joint or navel ill
Joint ill occurs in lambs up to one month of age. Affected lambs
are often lame in several joints, usually limb joints, including
fetlocks, knees, hocks, and stifles. Affected joints are hot and
painful. The lambs are dull, feverish, and clearly unthrifty. Some
may have swollen, infected navels, while others may have symptoms
of pneumonia or meningitis.
The infection is usually caused by strains of streptococci,
though coliforms and occasionally Actinomyces pyogenes
may be isolated. Affected lambs should be treated with a long-acting
penicillin. Joint ill is prevented by good hygiene and using a
navel dip, such as betadine or gentle iodine.
It has been estimated that 80 percent of the flocks in Great Britain
have lame sheep. Lameness can be a sign of several foot conditions
some of which are very serious as well as some other
problems. These include foot rot and scald, strawberry foot,
foot abscess, foot-and-mouth disease, bluetongue, ovine interdigital
dermatitis (looks like scald), sore mouth, arthritis, nutritional
deficiencies, mineral excesses, and physical injuries. The more
common foot problems can be avoided or minimized if good husbandry
practices are followed. Regular hoof inspection and foot paring
will prevent many problems.
Download Lameness in Sheep =>
Lameness related to laminitis is caused by an inadequate
flow of blood in the foot. Signs are heat in the feet. Laminitis is normally associated
with digestive problems resulting from excessive intake of grain
(grain overload/acidosis), which usually masks the effects on
the feet. Such animals usually die before the feet become involved.
Recovered animals may exhibit foot growth and/or permanent lameness.
Feeding management is key to the prevention of laminitis/founder.
Listeria monocytogenes, the bacteria that causes listeriosis,
is widely distributed in nature and is found in soil, feedstuffs,
and feces from healthy animals. Listeriosis is most commonly associated
with the feeding of moldy silage or spoiled hay, but because the
organism lives naturally in the environment, listeriosis may occur
Listeriosis usually presents itself as encephalitis (inflammation of the brain) but may also
cause abortion in ewes. Sheep with the neurological form of the
disease become depressed and disoriented. They may walk in circles
with a head tilt and facial paralysis. Mortality is high and treatment
(high doses of antibiotics) is generally not effective.
(hard bag, blue bag)
Mastitis is an inflammation (or infection) of the mammary gland (udder) which
is usually caused by a bacterial infection. The bacteria that most commonly cause
mastitis in ewes are Staphylococcus aureus and Pasteurella
hemolytica. There are two types of mastitis: acute and chronic.
The glands of ewes with acute mastitis may be discolored and dark,
swollen and very warm. The affected ewe may be reluctant to walk,
may hold up one rear foot, and may not permit her lambs to nurse.
Ewes with chronic mastitis often go undetected.
While no drugs are approved for sheep, mastitis is usually treated
with intramammary infusions of antibiotics, systemic antibiotics, and anti-inflammatory drugs.
There is no vaccine for mastitis. It is best prevented by good
management and sanitation. Heavy milkers are more prone to mastitis. There is also a genetic component.
Read Mastitis in Ewes and Does =>
(sheep measles, cysticerosis)
Sheep measles (Cysticercus ovis) is the intermediate or
larval stage of the cestode (tapeworm) Taenia ovis, the adult
stage of which is found in the small intestine of dogs (sheep
host the larvae stage). Sheep measle lesions are found in the
heart, diaphragm and other muscles of sheep and goats. Although
not considered to be a human health hazard, carcasses can be condemned
on account of sheep measles.
There are no clinical signs of cysticerosis in sheep. Currently
diagnosis is only made by finding the cysts at slaughter. To prevent
sheep measles, dogs and other canines should not be allowed to
feed on sheep or goat carcasses. Dogs should be dewormed for tapeworms.
Any dog given access to the farm should be required to be dewormed.
Milk fever (hypocalcemia, parturient paresis)
Milk fever is a metabolic disease affecting mostly pregnant ewes
near term when calcium requirements are the highest. It is most commonly
caused by an inadequate intake of calcium, but can also be caused
by a ewe's inability to mobilize calcium reserves prior to or
after lambing. Milk fever presents similar symptoms as pregnancy
toxemia but can be differentiated by the affected ewe's response
to calcium therapy.
Ewes in the early stages of milk fever can be administered calcium
gluconate subcutaneously. More seriously affected ewes will require
intravenous calcium and other supportive therapies. Milk fever
can be prevented by providing proper levels of calcium in ewe
diets, especially during late gestation.
Read Milk Fever Strikes =>
Ovine progressive pneumonia (OPP, lunger disease. Maedi-Visna)
Ovine progressive pneumonia is a slow developing viral disease
that is characterized by progressive weight loss, difficulty in
breathing and development of lameness, paralysis, and hard bag.
It is very closely related to caprine arthritis-encephalitis virus
(CAE) and is caused by a retrovirus. The OPP virus closely resembles
Maedi-Visna which is a similar slow or retrovirus found in other
parts of the world.
OPP is transmitted laterally to other susceptible animals or to
offspring through ingestion of infected milk and colostrum. Veterinary
diagnostic laboratory assistance is required for diagnosis. There
is no treatment, but OPP can be eliminated from the herd using
annual blood testing and removal of positive animals and removal
of the lambs from the ewes prior to suckling.
It is estimated that over 50% of the flocks in the U.S. are infected
with OPP with the number of sheep infected within a positive flock
anywhere between 1% to 70%. However, the vast majority of infected
sheep will never show respiratory disease or a wasting syndrome.
Pink eye (infectious keratoconjunctivitis)
Pinkeye is a highly contagious disease affecting the eyes of sheep.
Pinkeye may result from many different infective agents: Chlamydia,
certain viruses, and mycoplasma. The disease will usually complete
its course in three weeks in individual sheep. The use of eye
medications containing antibiotics may be helpful in individual
cases. There are no effective vaccines available, as the agent that
causes pinkeye in sheep and goats is different from the one that
causes it in cattle.
Infectious Keratoconjunctivitis (Pinkeye) =>
Pizzle Rot (sheath rot)
Pizzle rot is an infection in the sheath area of the ram. It is
caused by the bacteria, Corynebacterium renale or one from that
group. The other factor is high protein diets (>16 percent).
Ammonia produced by the excess urea in the ram's urine can cause
severe irritation and ulceration of the skin around the preputial
opening. The debris from the ulcer form a crust which may block
the opening to the prepuce. Pizzle rot can affect a ram's desire
and ability to mate.
It is important to consider plant toxicities when diagnosing death losses. Many plants are toxic or potentially toxic to sheep. Some plants accumulate toxins during specific times of their growing cycle or after periods of environmental stress. The incidence of plant poisoning in livestock tends to increase when normal forages are scarce, causing animals to eat plants that they would not normally eat.
The signs of plant poisoning are as varied as the plants themselves and may mimic other diseases. Many poisonous plants cause sudden death. Some plants cause photosensitization (a severe skin reaction). Other poisonous plants affect the nervous system. Some plant poisonings can be treated if signs are recognized early. For many plant toxins, there are no treatments.
(respiratory disease complex, pasteurellosis, shipping fever)
Pneumonia is second in importance to diseases of the digestive
tract. Pneumonia is a respiratory complex with no single agent
being solely responsible for the disease. The most common bacteria
isolated from respiratory infections is Pasteurella haemolytica
or Pasteurella multocida or both. Affected animals become
depressed and go off feed. They may cough and show some respiratory
distress. Temperatures are usually over 104°F. The disease
may be acute with sudden deaths or take a course of several days.
Pneumonia is treated with antibiotics. There is a vaccine for Pasteurella.
Polioencephalomalacia (PEM, CCN, polio, cerebrocortical necrosis)
Polioencephalomalacia is a disease of the central nervous system,
caused by a vitamin B1 (thiamine) deficiency. Since the rumen
manufactures B vitamins, polio is not caused by insufficient thiamine,
but rather the inability to utilize it. The most common symptom
of polio is blindness and star-gazing.
Polio most commonly occurs in lambs that are consuming high concentrate
diets. Polio can also occur in sheep that consume plants that
contain a thiamase inhibitor. Excessive use of amprolium (Corid) can cause polio. Polio symptoms mimic other neurological
disease conditions, but a differential diagnosis can be made based
on the animals' response to injections of vitamin B1.
Polyarthritis is an infectious disease of nursing lambs, recently weaned lambs, and feedlot lambs. Symptoms are stiffness, reluctance to move, depression, loss of body weight, and conjunctivitis. Clinically the disease is primarily characterized by stiffness and by conjunctivitis. Body temperatures over 104°F are common. Lambs can be treated with several different broad-spectrum antibiotics or tetracycline drugs.
(ketosis, twin lamb disease, lambing paralysis,
Pregnancy toxemia is a metabolic disease that affects ewes during
late gestation. It most commonly affects ewes, overfat ewes,
older ewes, and/or ewes carrying multiple fetuses. It is caused by an
inadequate intake of energy during late pregnancy, when the majority
of fetal growth is occurring.
Treatment is to increase the blood sugar supply to the body by
administering glucose intravenously or propylene glycol or molasses
orally. In extreme cases, removal of the fetuses is the only recourse
to save the ewe and lambs.
Pregnancy toxemia can be prevented by providing
adequate energy to ewes during late gestation, usually ½
to 1 lb. of grain per head per day, more for high producing ewes.
Adequate feeder space is also necessary to ensure all ewes are able to
consume enough feed.
Read Pregnancy Toxemia in Ewes and Does =>
Rabies is a viral disease of the central nervous system of mammals,
spread by contact with saliva from an infected animal, usually
through bites or scratches, abrasions, or open wounds in the skin.
Domestic animals may become exposed during normal grazing or roaming.
Sheep have symptoms similar to cattle, and sometimes vigorously
pull their wool. Livestock and horse owners may decide to vaccinate
their animals if they are often exposed to potentially rabid wild
or domestic animals.
Generally, production animals, such as dairy cow herds and sheep
flocks, are not vaccinated because the potential risks are usually
lower than the annual costs of vaccination and because human contact
with individual animals is low. Small groups of valuable purebred
animals may be an exception. Producers who lease their animals for grazing or use their animals for exhibition should consider vaccinating. In recent years, a few states have
required vaccination for rabies before an animal (including some
livestock) can be exhibited publicly.
A rectal prolapse is protrusion of the rectal tissue through the
exterior of the body. It usually begins as a small round area
that sticks out when the lamb lays down or coughs. In extreme
cases, the intestines can pass through the opening and the disease
can be fatal. There are many predisposing factors to rectal prolapses,
including genetics, short tail docks, coughing, weather, stress,
and high concentrate diets.
Rectal prolapses tend to occur more in ewe lambs than wether lambs
and more in black-faced sheep than white-faced sheep. It is a heritable trait, about 10 percent. Lambs on high concentrate diets are more prone. In fact, a link
between ultra-short tail docking and concentrate feeding has been scientifically established. Usually,
lambs with prolapsed rectums are prematurely slaughtered or sent
to market. It is possible to repair a rectal prolapse by amputating
the prolapsed part of the rectum. These lambs should not be kept for breeding.
Read Rectal prolapses: a complex problem with many contributing
Ringwomb is when the cervix fails to dilate sufficiently to allow
delivery of the lamb(s). While sometimes the cervix of affected ewes
can be opened with gentle pressure or the injection of hormones,
usually such efforts prove futile and a caesarian section to remove the
lambs is the only option that will produce a successful outcome for both ewes and lambs. Unfortunately, little
is known about the cause of ringworm and how to prevent it. There
is some evidence to suggest that ringwomb has a genetic component.
Ringworm (club lamb fungus, wool rot, and lumpy wool)
Club lamb fungus is a highly contagious fungal infection of the
skin of sheep. It is primarily a problem with show lambs that
are frequently slick sheared. Club Lamb Fungus is caused by fungus
of the genus Trichophyton. Infection occurs when the fungus
invades the skin and hair (wool) follicles. Fungal spores are
transmitted by contaminated clippers, blankets, combs, bedding,
bunks, and pens. Lesions can appear anywhere, however, most are
found on the head, neck, and back. The infection is susceptible
to anti-fungal agents. Club lamb fungus causes a nasty ringworm
infection in people.
Ryegrass staggers is a disease of grazing animals that causes
muscle spasms, loss of muscle control and paralysis. It is caused
by a group of toxins that accumulates in the leaf sheaths of perennial
ryegrass. The toxins are produced by a native fungus called ryegrass
endophyte, Neotyphodium lolii, that grows within the leaves,
stems and seeds of perennial ryegrass. Sheep and cattle are most
commonly affected but horses, alpaca. and deer are also susceptible.
Ryegrass staggers has not been recorded in goats. Affected animals
have a stiff gait or are unable to walk. They may injure or kill
themselves in transit. The toxins can induce high body temperatures
thus animals will try to cool themselves. Younger animals tend
to be worst affected. The symptoms of ryegrass staggers usually
develop 7-14 days after livestock stock start grazing the toxic
parts of the plant. Prolonged exposure to toxic pasture can lead
to permanent neurological damage.
Scrapie is a degenerative, fatal disease affecting the central nervous system
of sheep (and goats). The causative agent is believed to be a prion, a misshapen protein. The disease is spread via placenta, from the dam to her offspring and other lambs (and kids) that come into contact with her birthing fluids, placenta, and bedding soiled with birthing fluids. There is no treatment for scrapie. Affected animals always die.
While the occurrence
of scrapie in the U.S. sheep flock is low and getting lower all the time, it is a disease of regulatory concern. This is because
scrapie is a member of a family of diseases called "transmissible
spongiform encephalopathies (TGE's), which also includes chronic
wasting disease (in mule deer and elk), mad cow disease (bovine
spongiform encephalopathy) and classic and new variant Creutzfeldt-Jacob's
Disease (in humans).
Producers of breeding stock are encouraged to enrolled in the
voluntary scrapie flock certification program, which after five
years of scrapie-free monitoring, enables a flock to be certified
"scrapie-free." Furthermore, while scrapie is not a
genetic disease, a sheep's genetic make-up influences its susceptibility
to scrapie if exposed to the infective agent. Therefore, sheep
can be tested for scrapie resistance.
an Update on Scrapie =>
A scrotal hernia is when the ram's intestines slip through the inguinal rings into the scrotum. The condition causes an enlargement of the scrotum. Scrotal hernias may be congenital or acquired. They are thought to be caused by trauma. While it may be possible to surgically repair a scrotal hernia, a more practical option would be harvest them for meat. Since heredity probably plays a role in the occurrence of a scrotal hernia, it is probably prudent to cull rams that sire lambs that develop hernias.
Septic pedal arthritis
Septic pedal arthritis is a bacterial infection that usually gains entry to the distal interphalangeal (pedal) joint from an interdigital legion which then tracks across the joint to discharge above the coronary band. The foot is swollen with obvious widening of the interdigital space and a discharging sinus(es) above the coronary band. In chronic cases, there is considerable widening of the interdigital space and loss of hair around the coronary band. Chronic cases usually do not respond to antibiotic therapy. Digit amputation by a veterinarian is usually necessary.
(contagious ecthyma, scabby mouth, pustular dermatitis,
Soremouth is the most common skin disease affecting sheep (and
goats). It is a highly contagious viral infection that can also
produce painful lesions in people. The virus causes scab formation
on the skin, usually around the mouth, nostrils, eyes, mammary
gland, and vulva. It first appears as tiny red nodules, usually
at the junction of the lips. Treatment is usually unrewarding, though WD-40 has been advocated as a treatment. The disease will usually run its course in 1 to 4 weeks.
Effective vaccines are available. The vaccine is applied to a
woolless area in the inside of the ear or under a leg where it
cannot spread to the mouths of other animals. Once the vaccine
is used on the premises, it should be continued yearly. Flocks
that have not experienced soremouth should not vaccinate
for soremouth since the vaccine introduces the virus to the farm.
Soremouth (orf) in sheep and goats =>
(spider lamb disease, ovine hereditary chondrodysplasia)
Spider lamb syndrome is a genetic condition that causes lambs to have severe malformations of the skeletal system. These animals have
very fine bone, crooked legs and a crooked spinal column, and a distinct
lack of muscular development. They usually do not survive to full
The cause of the condition appears to be genetic alteration due
to selection for extreme length and height in show sheep. The
disease is found predominantly in black-faced lambs: 75% Suffolk
and 25% Hampshire. In order to have this disease, lambs must inherit
a recessive gene from each parent. Several labs offer genetic testing for spider lamb disease.
Urinary calculi (water belly, urolithiasis, calculosis)
Urinary calculi is a metabolic disease of wethers and rams characterized
by the formation of calculi (stones) within the urinary tract.
Blockage of the urethra by calculi causes retention of urine,
abdominal pain, distention and rupture of the urethra or bladder. Left untreated, it can cause death.
The most common cause of urinary calculi is feeding rations with
high phosphorus levels. Grain and oilseeds are usually high in
phosphorus and low in calcium, whereas forages, especially legumes, have a much more desirable
ratio. The ratio of calcium to phosphorus in the ration should
be at least 2:1. Providing the proper balance of minerals in the
ration is preferred to offering minerals free choice, since there
is no guarantee animals will consume adequate amounts of free
Sheep rations should always include roughage, ideally long-stemmed forage. The addition of ammonium chloride (a urine acidifier) to the ration will aid in preventing
urinary calculi. It is also important that animals have an ample
supply of clean, potable water. The addition of salt to the ration
will increase water intake and decrease stone formation.
Ram lambs that are castrated at an early age are at increased risk for developing urinary calculi, as their urethras do not develop as fully. However, for animal welfare reasons, late castration is not advocated, as almost all cases of urinary calculi can be prevented with proper nutrition.
Read Urinary Calculi in Sheep and Goats =>
A uterine prolapse is when the womb (uterus) is turned inside out and pushed
through the birth canal by abdominal strainings of the ewe.
It may occur immediately after lambing or several days later. A uterine prolapse is life-threatening. Before the prolapsed uterus can be put back into
the ewe, the ewe's hindquarters should be raised. The uterus should be cleaned with a warm, soapy, disinfectant
solution prior to replacement and should be replaced before the
tissues become dry or chilled. Pouring water into the uterus will help to ensure that the tips of the horns are unfolded. Affected ewes should be given antibiotics and oxytocin. Unlike ewes that prolapse their vaginas, it is okay to keep a ewe that has prolapsed her uterus.
Vaginal prolapses (protrusion of the vagina) are most commonly
observed during the last month of pregnancy or shortly after lambing.
Many factors have been implicated in the cause of vaginal prolapse,
such as hormonal/metabolic imbalances, overfat/overthin body condition,
bulky feeds, lack of exercise, dystocia in previous pregnancies,
increased abdominal pressure and fetal burden. Prolapses often
recur in subsequent pregnancies.
The exposed vagina of affected ewes should be washed with soapy
disinfectant solution and forced back into the ewe. A bearing
retainer or "spoon" can be inserted and secured in the
ewe to prevent further prolapsing. There are harnesses that can be put on ewes to prevent further prolapses. Sutures are another option. Sutures must be removed in order for the ewe to lamb. The ewes can lamb with the spoon or harness in place, but it is better to remove them. Affected ewes and their offspring
should probably not be kept in the flock for breeding animals
due to the hereditary nature of the problem.
White muscle disease
(WMD, nutritional muscular dystrophy, nutritional myopathy, stiff
White muscle disease is a degeneration of the skeletal and cardiac
muscles of lambs. It is caused by a deficiency of selenium, vitamin
E, or both and can be a problem wherever selenium levels in the
soil are low or the diet is deficient in selenium. Symptoms are stiffness of the hind legs with an
arched back and tucked in flanks. Treatment is the administration
of selenium and vitamin E by injection.
Feed rations should be evaluated to determine if they are providing
adequate levels of selenium and vitamin E. If dietary levels of selenium are inadequate, lambs can be given an injection of selenium
and vitamin E shortly at birth. Dietary supplementation of selenium
is usually preferred to selenium injections. There is a narrow margin between selenium deficiency and selenium toxicity.
Read White Muscle Disease in Sheep and Goats =>
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