20. large animal med- diarrhea in sheep and goats

how is diarrhea in sheep/goats often noted?

because of extensive spiral colons for water conservation, diarrhea is often noted as softened fecal pellets rather than passage of watery feces

what is peste de petite ruminants?

a viral cause of diarrhea in sheep and goats

virus is related to rinderpest, and found in africa, india and middle east

which animals does peste de petite ruminants cause more severe disease in?

goats get severe disease

can cows become infected with peste de petite ruminants?

yes, cows can be infected, but do not develop clinical signs

how is peste de petite ruminants transmitted?

oculonasal secretions, respiratory droplets, feces

indirect contaminated feeders (but virus is short lived in environment)

viral shedding start before onset of clinical signs, so spread is often thru transport of shedding animals (often sheep or cattle)

what are clinical signs of peste de petite ruminants?

-fever

-anorexia

-depression

-clear nasal discharge which progresses to thick, yellow discharge with crusts and occludes nostrils

-eyes may develop similar thick, matting discharge

-ulcers and inflammation on all oral MMs, and throughout GI tract

what are common disease sequelae to peste de petite ruminants?

-diarrhea with tenesmus

-pneumonia

-abortion

which animals is morbidity/mortality higher in with infections of peste de ruminants?

younger animals

death occurs 5-10 days after onset of fever in most cases, can also see peracute death

how are acute infections of peste de petite ruminants diagnosed?

PCR or ELISA on swabs of lesions or blood

how can peste de petite ruminants be differentiated from bluetongue and foot and mouth disease (FMD)?

bluetongue and FMD also cause oral ulcerative lesions, but either of these rarely cause diarrhea

-bluetongue rarely affects goats

-FMD only causes mild dz in small ruminants

what is the most important viral cause of diarrhea in young small ruminants?

rotavirus

what are clinical signs of rotavirus in small ruminants?

similar to bovine analogue, causing watery diarrhea due to damage to absorptive epithelium

which age of animals is rotavirus most common in?

most common in lambs <1 month old

occasionally see in kids <3 months old

how is rotavirus treated in small ruminants?

self-limiting with fluid treatment

what type of diarrhea is seen in small ruminants infected with coronavirus/adenovirus?

mild diarrhea

does caprine herpes virus commonly cause diarrhea in goats?

no- CHV has rarely been associated with ulcerative GI lesions and diarrhea in goats

what is the common disease seen in lambs due to e. coli infections?

ETEC due to K99 pilus adhesion and enterotoxin-stimulated secretory diarrhea in young lambs

what is the common disease seen in kids due to e. coli infections?

enteropathogenic e.coli is more common than ETEC in kids

how do e. coli infections differ in lambs vs kids?

kids tend to be sicker, with more blood in the feces and evidence of systemic toxemia

what is the most common salmonella serotype isolated from small ruminants?

salmonella typhimurium (likely spread by non-clinical shedders)

s. dublin and others also isolated, but are rarely endemic

what are the clinical signs of goats infected with salmonella typhimurium?

goats typically have profuse, watery foul diarrhea with high fever and leukopenia

death is common

how do salmonella infections differ in small ruminants (goats) vs cattle?

bloody diarrhea is extremely rare in goats, unlike in cattle

which small ruminants are more commonly infected with yersinia?

disease is seen more in goats than sheep

kids less than 6 months old get enteritis and bacteremia (get very sick and can die fairly quickly)

what type of diarrhea is seen in young goats (kids) infected with yersinia?

watery diarrhea (not bloody)--> causing dehydration

what are other clinical signs of yersinia infections in goats/small ruminants?

younger animals: severe toxemia and sudden death

older animals: chronic diarrhea and weight loss (seen due to gut wall and abdominal abscesses)

what other lesions are seen with yersinia infections?

multiple microabscesses in gut wall and mesenteric lymph nodes

how are yersinia infections diagnosed?

culture of lesions or demonstrating rising antibody titer

what is the most commonly used drug to treat yersinia infections?

tetracycline (organism is gram-negative, and sensitive to tetracycline)

is it common for a healthy ruminant with an appropriately functioning gut microbiome to get clostridium perfringens infections?

no

if in contact with these organisms, they are usually in small numbers and a properly working gut microbiome/peristalsis should just flush these organisms out

how do clostridium perfringens infections occur?

at times of abnormal motility or passage of fermentable feed into their environment

--> causes clostridia to proliferate, and their toxins to cause damage

how are clostridium perfringens infections diagnosed in small ruminants?

diagnosis often confounded by post-mortem or secondary proliferation of clostridial organisms

ie clostridia is a very common post-mortem overgrowth, so can be difficult to determine if sole cause of death/illness

what toxin does clostridium perfringens type B produce?

beta-toxin

what substance in the body inactivates beta-toxin produced by clostridia type B?

trypsin

why is clostridia type B most damaging in very young lambs or kids (less than 3 days old)?

in kids/lambs under 3 days old, trypsin production has not yet started

because the beta-toxin is inactivated by trypsin, and these animals lack trypsin== more susceptible to type B

what is the disease name for clostridia types B and C in neonates?

type B: lamb dysentery

type C: struck

what are the characteristic lesions of clostridia type B in lambs?

characteristic lesion: small ulcers in the small intestine surrounded by hemorrhage, as well as hemorrhagic gut contents

what is the pathogenesis of clostridia causing lesions in small intestine?

once in the gut, clostridia create permeable lesions in gut wall and induce a severe inflammatory response (neutrophils, pain, colic, tender abdomen, intestine distended with gas)

what are peracute/acute clinical signs of clostridia type B in lambs?

sudden death (peracute)

or

splinting/tenderness of abdomen with yellow-brown diarrhea (acute)

most lambs with clinical disease die

what is the result of lambs in a naive flock exposed to clostridia type B?

on first exposure, many lambs may suddenly die or get severe, rapidly progressing disease

how is clostridia type B diagnosed?

characteristic lesions seen at necropsy

lab assay can also be used to ID the beta-toxin

when should pregnant ewes be vaccinated against the beta-toxin of clostridia type B?

vaccines against toxin reduce morbidity and mortality when given to ewes several weeks before lambing

what is the treatment for clostridia type B?

antitoxin, fluids, NSAIDs, antibiotics (penicillin)

which clostridia perfringens type can cause peracute colic and death in adult sheep?

type C

how are clostridia types B and C infections prevented?

through toxoids and antitoxin

what toxins does clostridia perfringens type D secrete?

alpha-toxin and epsilon-toxin

epsilon-toxin is trypsin resistant (why this is also seen in adult animals)

what are causes of clostridia type D infections?

-feed and weather changes

-high concentrate diets

-overeating (clostridia love carbs)

-weaning

-combining groups

-confinement

-tapeworms

-basically any change in routine/alteration of gut microbiome

in addition to pneumonia, what is one of the main causes of death in feedlot lambs?

clostridiosis

what effects does the epsilon toxin of clostridia type D have on tissues?

toxin increases vascular permeability, which facilitates its own absorption from the gut

it is necrotizing to tissues, especially neurons

which animals tend to get a neurologic form of disease caused by clostridia type D? what are the clinical signs?

sheep get neuro form, will see:

-depression

-neurologic signs

-death with minimal diarrhea or gut lesions

what disease is seen more frequently in goats infected with clostridia type D?

localized enteric form; enterotoxemia or pulpy kidney disease

what is the peracute form of enterotoxemia/pulpy kidney dz seen in goats?

sudden death in fast growing young kids

or

rapid development of painful abdomen with vocalization, depression and bloody diarrhea

--> most die

what is the acute form of enterotoxemia/pulpy kidney dz seen in goats?

less severe pain than peracute form

-feces gradually change from pasty to watery

-the goats (often older than peracute form) develop abnormalities associated with diarrhea

-if not treated, die within 3-4 days

what is the chronic form of enterotoxemia/pulpy kidney dz seen in goats?

intermittent bouts over several weeks

-goats are dull with loose feces

-hard to recognize w/o aforeknowledge of acute form on farm

what clinpath changes are seen with clostridia infections in small ruminants?

leukocytosis

hyperglycemia and glucosuria at the end

how can clinpath changes differentiate clostridia infections from most gram-negative/viral infections?

clostridial dz: leukocytosis

viral/gram-negative bacteria: leukopenia

what lesions are seen with clostridia infections in small ruminants?

-fibronecrotic enteritis (goats)

-pulpy kidneys (sheep or goats)

-hemorrhage on many organs

how are clostridia infections in small ruminants treated?

-fluids

-NSAIDs

-antitoxins

-penicillins or sulfas

how are clostridia infections prevented?

vaccines- should be given every 6 months

what type of disease is seen in small ruminants infected with johne's disease? is diarrhea common?

in small ruminants, johne's primarily causes a weight loss syndrome

diarrhea is only intermittent or terminal

what is the most common cryptosporidium species isolated from kids less than 1 month old?

cryptosporidium parvum (and ubiquitum)

what type of disease does cryptosporidium parvum cause in young kids?

watery diarrhea (similar to calves)

what is the most common cause of diarrhea in lambs and kids between 3 weeks and 5 months old?

infections with eimeria species

most eimeria strains are species specific

when are eimeria infections most commonly seen?

-during hot weather

-when animals are put into group pens

-or at weaning

what are clinical signs of eimeria infections?

-diarrhea and tenesmus

-severe untreated infections can be fatal

-bloody diarrhea with more invasive eimeria species

how are eimeria infections in small ruminants treated?

similar to cattle (can use decoquinate, or monensin)

**remember that small ruminants are more sensitive to monensin toxicosis than cattle

if animals are infected with giardia, will clinical signs always be seen?

no, giardia can be isolated from symptomatic and asymptomatic animals

giardia E is what generally affects hoof-stock

how is giardia transmitted?

primarily from fecal-contaminated water sources or (seasonally) wet pasture

oocysts can survive 3 months in water at 4C

is clinical disease commonly seen in animals after the weaning period?

no, clinical disease is rare after the weaning period

how are giardia infections treated?

metronidazole (not for food animals) and fenbendazole

how are parasitic causes of diarrhea in small ruminants diagnosed?

fecal flotation

flock management

necropsy

what are possible non-infectious etiologies of diarrhea in small ruminants?

similar to cattle: indigestion, grain overload, overfeeding, copper deficiency

which animals are toxins especially an important cause of diarrhea in?

goats

what are examples of plants that can cause diarrhea in goats if ingested?

S³O²MBC

• spurges

• senna

• selenium-accumulating plants

• oleanders

• oaks

• morning glory

• bladderpod

• crab apple

how are goats with plant toxicities treated?

removal from source is often sufficient

though, more aggressive tx is required if the goat is showing systemic signs (as seen with oleander)