Exam 3 - Calf Scours

Question 1

what are the 6 major causes of calf diarrhea?

Answer 1

1. ETEC
2. rotavirus
3. coronavirus
4. cryptosporidium
5. salmonellosis
6. nutritional (improperly mixed ration)

Question 2

what animals are typically affected by clostridium perfringens type a & type c?

Answer 2

type a - dairy cattle

type c - beef cattle

Question 3

what is the pathogenesis of ETEC causing diarrhea in calves?

Answer 3

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

Question 4

what pathology does ETEC cause in the gi tract? what kind of diarrhea does ETEC cause?

Answer 4

minimal to no villous damage - secretory type diarrhea

Question 5

what is the pathogenesis of rotavirus causing diarrhea in calves?

Answer 5

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

Question 6

what age are calves typically affected by rotavirus?

Answer 6

5-7 days in beef calves & earlier breaks in dairy calves

Question 7

are colostral antibodies protective against coronavirus?

Answer 7

only during ingestion

Question 8

what kind of diarrhea does rotavirus cause?

Answer 8

maldigestive diarrhea & secondary malabsorptive diarrhea

Question 9

what are the main sources of infection for coronavirus?

Answer 9

calves!!!!!! environment, cows - shed more at parturition

Question 10

how can you decrease parturition shedding of coronavirus?

Answer 10

vaccination of cows

Question 11

T/F: coronavirus calves may have respiratory signs

Answer 11

true

Question 12

what pathogens that cause calf scours are zoonotic?

Answer 12

cryptosporidium & salmonellosis

Question 13

what is the pathogenesis of cryptosporidium?

Answer 13

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!!!

Question 14

what salmonella is host adapted to cattle?

Answer 14

salmonella dublin

Question 15

T/F: infection caused by salmonella is dose dependent

Answer 15

true

Question 16

what kind of diarrhea does salmonella cause?

Answer 16

malabsorptive/maldigestive diarrhea

Question 17

what are the clinical signs of salmonellosis?

Answer 17

malabsorptive/maldigestive diarrhea, lymph node colonization, bacteremia, & fever

Question 18

what is the pathogenesis of salmonellosis?

Answer 18

organism is ingested - causes invasive enteritis in the ileum, cecum, & colon

protein, fluid, & electrolyte loss into the lumen

Question 19

how is clostridium perfringens spread?

Answer 19

organisms are ubiquitous - ingested with subsequent proliferation/commensal

milk primarily digested in abomasum & SI

Question 20

what predisposes an animal to developing clostridium perfringens?

Answer 20

organism overgrowth - poorly developed flora

abrupt change in feeding pattern, stress, toxin production

toxin - local & systemic effects

Question 21

what is typically the nutritional problem that causes diarrhea in calves?

Answer 21

poor quality milk replacer - plant protein is trash

Question 22

what are 6 common disorders of neonatal calves?

Answer 22

1. dehydration
2. acidemia
3. hypoglycemia
4. sepsis
5. hypothermia
6. congenital abnormalities

Question 23

what diagnostics & treatment should be done for ETEC, rotavirus, coronavirus, & cryptosporidium?

Answer 23

no diagnostics

rehydrate, correct acid/base & electrolyte derangements

Question 24

what diagnostics are used for salmonellosis? what treatment?

Answer 24

fecal culture & CBC

antibiotics & anti-inflammatories

Question 25

why is it important to run diagnostics such as culture & histopathology for calves with suspected clostridium perfringens quickly before/after death?

Answer 25

overgrowth is common after death!!!

Question 26

what diagnostics & treatment are used for clostridium perfringens?

Answer 26

culture - histopathology for toxin ID antibiotics, anti-inflammatories, & anti-toxin

Question 27

how is septicemia diagnosed & treated in calves?

Answer 27

blood culture & cbc antibiotics & anti-inflammatories

Question 28

what makes up visual appraisal in a calf with scours?

Answer 28

diarrhea staining, demeanor, BCS, stance, & abdominal contour

Question 29

if you see a toxic line in a calf with diarrhea, what disease process do you suspect?

Answer 29

salmonellosis

Question 30

what percentage dehydration does a calf have a comatose demeanor & dry mucus membranes?

Answer 30

11-12%

Question 31

what 3 things should you not forget to check in a calf with diarrhea?

Answer 31

umbilicus, joints, & rectal temperature

Question 32

what clinical signs are seen in a calf with undifferentiated diarrhea?

Answer 32

loose-watery diarrhea, dehydration, weakness, depression, metabolic acidosis, hyperkalemia, & death

Question 33

what are the diagnostics & corrections made when approach a calf with diarrhea?

Answer 33

minimal to no diagnostics - guide specific intervention correct hydration, acid/base problems, & electrolytes - give antibiotics if sick

Question 34

what is the maintenance fluid therapy needed for calves?

Answer 34

60-120 ml/kg/day - need more than an adult

Question 35

what is the shock/maximum fluid rate for a calf?

Answer 35

90 ml/kg/hr

Question 36

what is the maximum sustained fluid rate for a calf with diarrhea?

Answer 36

80 ml/kg/hr

Question 37

what is the conservative replacement fluid rate for calves?

Answer 37

30-50 ml/kg/hr

Question 38

what is the maximum potassium administration rate in calves?

Answer 38

0.5 mmol (mEq/kg/hr)

Question 39

what is the daily fluid requirement of calves?

Answer 39

deficit + maintenance + ongoing loss

Question 40

how is fluid deficit calculated?

Answer 40

% dehydration * body weight (kg)

Question 41

what is the equation used for base deficit?

Answer 41

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

Question 42

how is calf diarrhea managed?

Answer 42

fecal oral contamination & knowing that infected calves are the reservoir

Question 43

how is calf diarrhea controlled?

Answer 43

minimize exposure to pathogen, ensure adequate colostral intake, boost specific/non-specific immunity, & promote biosecurity

Question 44

what are some risk factors for calf diarrhea?

Answer 44

calving pens, lack of colostrum ingestion, dirty teats, unsanitary equipment, group/intensive housing, continuous rearing, overcrowding, & sick calves

Question 45

how is cryptosporidium prevented?

Answer 45

good hygiene

Question 46

how is coronavirus infection prevented?

Answer 46

vaccinating cows & good hygiene

Question 47

how is rotavirus infection prevented?

Answer 47

good hygiene, vaccinate cows, & cellular entry slowed with age

Question 48

how is ETEC infection prevented?

Answer 48

cows - vaccination with purified K99 fimbrial antigen calves - oral fimbrial Ab pre colostrum

Question 49

how is salmonellosis prevented?

Answer 49

cull carriers, good hygiene, milk replacer

Question 50

how is clostridium diarrhea prevented?

Answer 50

good hygiene, enhance immunity, manage feeding practices, proper mixing of food

Question 51

what recommendations are made for preventing dairy calf diarrhea?

Answer 51

ensure adequate colostral intake, disinfect feeding utensils, treat healthy before sick hutches - decreased contamination, 15% more than needed, separate hutches, clean/disinfect/move hutches

Question 52

what recommendations are made for preventing beef calf diarrhea?

Answer 52

calving hygiene - clean, well drained pastures, gestation based calving groups, shorten the season ensure adequate colostrum intake, hygiene in problem areas (waterers & feeders)

Question 53

what is the demeanor scoring system used for calves?

Answer 53

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