Exam 3 - Calf Scours Flashcards
what are the 6 major causes of calf diarrhea?
- ETEC
- rotavirus
- coronavirus
- cryptosporidium
- salmonellosis
- nutritional (improperly mixed ration)
what animals are typically affected by clostridium perfringens type a & type c?
type a - dairy cattle
type c - beef cattle
what is the pathogenesis of ETEC causing diarrhea in calves?
bacteria are ingested & they multiply in the ileum & ascend into the small intestine where the fimbriae of the bacteria attach to the F5/K99 cell receptor which has an age dependent attachment (<5 days old)
toxin released causes hypersecretion of chloride, inhibition of the Na-Cl transporter on the luminal surface, & loss of Na, Cl, & HCO2 into the lumen
what pathology does ETEC cause in the gi tract? what kind of diarrhea does ETEC cause?
minimal to no villous damage - secretory type diarrhea
what is the pathogenesis of rotavirus causing diarrhea in calves?
calves ingest the organism & they infect the mature brush border epithelial cells of the small/large intestines & slough the infected cells
villous atrophy will cells replaced from the crypts (cuboidal or squamous cells with decreased lactase activity) resulting in a maldigestive diarrhea & a longer repair time because the crypts are involved
what age are calves typically affected by rotavirus?
5-7 days in beef calves & earlier breaks in dairy calves
are colostral antibodies protective against coronavirus?
only during ingestion
what kind of diarrhea does rotavirus cause?
maldigestive diarrhea & secondary malabsorptive diarrhea
what are the main sources of infection for coronavirus?
calves!!!!!! environment, cows - shed more at parturition
how can you decrease parturition shedding of coronavirus?
vaccination of cows
T/F: coronavirus calves may have respiratory signs
true
what pathogens that cause calf scours are zoonotic?
cryptosporidium & salmonellosis
what is the pathogenesis of cryptosporidium?
multiply in the brush border of the ileum & colonic epithelium - intracellular but extracytoplasmic organism
causes villus atrophy & villus fusion in the small intestines & hyperplasia of the crypts
persistent clinical signs!!!
what salmonella is host adapted to cattle?
salmonella dublin
T/F: infection caused by salmonella is dose dependent
true
what kind of diarrhea does salmonella cause?
malabsorptive/maldigestive diarrhea
what are the clinical signs of salmonellosis?
malabsorptive/maldigestive diarrhea, lymph node colonization, bacteremia, & fever
what is the pathogenesis of salmonellosis?
organism is ingested - causes invasive enteritis in the ileum, cecum, & colon
protein, fluid, & electrolyte loss into the lumen
how is clostridium perfringens spread?
organisms are ubiquitous - ingested with subsequent proliferation/commensal
milk primarily digested in abomasum & SI
what predisposes an animal to developing clostridium perfringens?
organism overgrowth - poorly developed flora
abrupt change in feeding pattern, stress, toxin production
toxin - local & systemic effects
what is typically the nutritional problem that causes diarrhea in calves?
poor quality milk replacer - plant protein is trash
what are 6 common disorders of neonatal calves?
- dehydration
- acidemia
- hypoglycemia
- sepsis
- hypothermia
- congenital abnormalities
what diagnostics & treatment should be done for ETEC, rotavirus, coronavirus, & cryptosporidium?
no diagnostics
rehydrate, correct acid/base & electrolyte derangements
what diagnostics are used for salmonellosis? what treatment?
fecal culture & CBC
antibiotics & anti-inflammatories
why is it important to run diagnostics such as culture & histopathology for calves with suspected clostridium perfringens quickly before/after death?
overgrowth is common after death!!!
what diagnostics & treatment are used for clostridium perfringens?
culture - histopathology for toxin ID
antibiotics, anti-inflammatories, & anti-toxin
how is septicemia diagnosed & treated in calves?
blood culture & cbc
antibiotics & anti-inflammatories
what makes up visual appraisal in a calf with scours?
diarrhea staining, demeanor, BCS, stance, & abdominal contour
if you see a toxic line in a calf with diarrhea, what disease process do you suspect?
salmonellosis
what percentage dehydration does a calf have a comatose demeanor & dry mucus membranes?
11-12%
what 3 things should you not forget to check in a calf with diarrhea?
umbilicus, joints, & rectal temperature
what clinical signs are seen in a calf with undifferentiated diarrhea?
loose-watery diarrhea, dehydration, weakness, depression, metabolic acidosis, hyperkalemia, & death
what are the diagnostics & corrections made when approach a calf with diarrhea?
minimal to no diagnostics - guide specific intervention
correct hydration, acid/base problems, & electrolytes - give antibiotics if sick
what is the maintenance fluid therapy needed for calves?
60-120 ml/kg/day - need more than an adult
what is the shock/maximum fluid rate for a calf?
90 ml/kg/hr
what is the maximum sustained fluid rate for a calf with diarrhea?
80 ml/kg/hr
what is the conservative replacement fluid rate for calves?
30-50 ml/kg/hr
what is the maximum potassium administration rate in calves?
0.5 mmol (mEq/kg/hr)
what is the daily fluid requirement of calves?
deficit + maintenance + ongoing loss
how is fluid deficit calculated?
% dehydration * body weight (kg)
what is the equation used for base deficit?
body weight (kg) * base deficit mmol/L * 0.6 = base deficit mEq/L
154 mEq bicarbonate/L isotonic fluid
( # mEq bicarb) / 12 = g HCO3
13g HCO3/L = isotonic HCO3
how is calf diarrhea managed?
fecal oral contamination & knowing that infected calves are the reservoir
how is calf diarrhea controlled?
minimize exposure to pathogen, ensure adequate colostral intake, boost specific/non-specific immunity, & promote biosecurity
what are some risk factors for calf diarrhea?
calving pens, lack of colostrum ingestion, dirty teats, unsanitary equipment, group/intensive housing, continuous rearing, overcrowding, & sick calves
how is cryptosporidium prevented?
good hygiene
how is coronavirus infection prevented?
vaccinating cows & good hygiene
how is rotavirus infection prevented?
good hygiene, vaccinate cows, & cellular entry slowed with age
how is ETEC infection prevented?
cows - vaccination with purified K99 fimbrial antigen
calves - oral fimbrial Ab pre colostrum
how is salmonellosis prevented?
cull carriers, good hygiene, milk replacer
how is clostridium diarrhea prevented?
good hygiene, enhance immunity, manage feeding practices, proper mixing of food
what recommendations are made for preventing dairy calf diarrhea?
ensure adequate colostral intake, disinfect feeding utensils, treat healthy before sick
hutches - decreased contamination, 15% more than needed, separate hutches, clean/disinfect/move hutches
what recommendations are made for preventing beef calf diarrhea?
calving hygiene - clean, well drained pastures, gestation based calving groups, shorten the season
ensure adequate colostrum intake, hygiene in problem areas (waterers & feeders)
what is the demeanor scoring system used for calves?
score 1. standing, strong suckle, base deficit 0 if < 8 days & 5 if > 8 days
score 2. standing, weak suckle, base deficit 5 if < 8 days & 10 if > 8 days
score 3. sternal recumbency, base deficit 10 if < 8 days & 15 if > 8 days
score 4. lateral recumbency, base deficit 15 if < 8 days & 20 if > 8 days
