Calf diarrhea

Question 1

What is the agent that causes enteric colibacillosis?

Answer 1

Enterotoxigenic E. coli

Question 2

What are the characteristics of enterotoxigenic e.coli

Answer 2

2 main virulence factors -> pilus formation, K99, K88 and f41 pilus or fibria which allows attachement to enterocytes
-heat stable enterotoxins, heat labile enterotoxins

Question 3

What is the epidemiology of enteric colibacillosis?

Answer 3

a) most frequently isolated pathogen in diarrheic neonates
b) most commonly seen in calves, lambs, kids, and piglets from 1-4 days of age
c) associated with lack of colostrum and or contamined environment
d) often complicates viral or parasitic enteric diseases

Question 4

What are the CS of enteric colibacillosis?

Answer 4

a) profuse watery diarrhea, no straining, dehydration, weakness
b) course is rapid - death may occur 6-12 hours after onset
c) temperature - normal to subnormal
d) heart rate -> may be elevated. normal or decreased
e) respiratory rate - may be elevated depending on degree of acidosis

Question 5

What is the pathophysiology of secretory diarrhea

Answer 5

1) cell structure is not affected
2) Enterotoxins are secreted which increase intestinal secretion
3) the SI and LI absorptive cells remain capable of absorbing nutrients and fluid, the amount of fluid secreted, however, exceeds the absorptive capacity of these cells resulting in diarrhea

Question 6

What can we see from lab results with enteric collibacilosis

Answer 6

-hypoglycemia, hyperkalemia, acidosis, prerenal azotemia, dehydration

Question 7

How do we diagnose enteric collibacilosis?

Answer 7

Culture of E.coli with presence of pilus antigen, PCR isolates
ELISA or latex agglutination test on feces
Florescent antibody testing of intestinal tissues

Question 8

What do we see on necropsy with enteric collibacilosis

Answer 8

no gross lesions

Question 9

What do we see on histopath with enteric collibacilosis

Answer 9

minimal inflammatory reaction in the SI, some mild vilous atrophy. Sheets of gram negative bacilli adhere to the villous enterocytes of the SI mucosa

Question 10

How do we treat enteric collibacilosis

Answer 10

-fluid therapy, colostrum feeding
-antimicrobials early in the disease : ceftiofur, spectinomycin, sulfas

Question 11

How do we prevent enteric collibaclosis

Answer 11

a) proper colostrum managment
b) birth in a clean environment
c) vaccination of the dam with pili antigen
d) monoclonal antibody

Question 12

What agent causes cryptosporidosis

Answer 12

Cryptosporidium parvum

Question 13

What are the characteristics of cryptosporidiosis

Answer 13

a) zoonotic potential
b) oocysts sporulated at time of passage, infective immediately. Autoinfection
c) oocysts do not survive freezing but are hardy in the enviornmen. Build up in the environment over time

Question 14

CS of crypto

Answer 14

a) disease occurs in calves 1-3 weeks of age
b) diarrhea, tensmus, anorexia, weight loss, depression
c) dehydration is ocassionaly present but usually occurs when other pathogesn complicate infection

Question 15

Pathophysiology of crypto

Answer 15

a) does not invade the cytoplasm but attaches in the brush border at the cell surface resulting in malabsorption
b) distal SI is mostly affected

Question 16

How do we diagnose crypto

Answer 16

a) fecal floation
b) histopath- organisms can be seen in the border. May see blunting and mild fusion of the vili

Question 17

How do we treat crypto

Answer 17

a) fluids, vitamin A, supportive care

Question 18

How do we prevent crypto

Answer 18

a) sanitation - clean with undiluted bleach
-5% ammonium
b) drying decreases infectivity
c) movement of calving and housing areas

Question 19

How do they get salmonellosis

Answer 19

a) acquired from the environment- capable of surviving in the enviornment for long periods of time, sunlight kills it. Exposure to contaminated manure - rodent, birds, infected cattle
b) acquired from cattle- recrudencsce at times of stress
c) acquired through feed - contamination by feces
d) acquired through water- run off sources

Question 20

Pathophysiology of salmonellosis

Answer 20

secretory and malabsorptive diarrhea
Secretory -> prostaglandin syntehsis from endotoxin effects
Malabsorptive -> destruction of microvillous and inflammaotry reaction in the bowel

Question 21

What are the CS of salmonellosis

Answer 21

a) calves are usually between 10 days to 3 months of age but all ages are affected
b) enteritis, fever, inappetence, depression, and dehydration
c)intiially diarrhea is watery but as disease progresses, diarrhea may contain shreds of mucosa, fibrin, casts or frank blood. Putrid foul odor
d) signs of septicemia predominate
e) acute protein losing enteropathy and extreme weight loss
f) abortions

Question 22

What do we see on necropsy with salmonellosis

Answer 22

a) fibrin tags on the intestine along with excessive peritoeal fluid
b) mesenteric lymph node are enlarged and often hemorrhagic
c) bowel contents may contain mucus, blood, fibrin
d) fibirin and mucosal casts are often found in the SI and LI

Question 23

How do we treat salmonellosis

Answer 23

fluids, oral or IV
Antibiotics (ceftiofur, TMS)- parenteral treatment more effective than oral
NSAIDS- banamine

Question 24

How do we prevent salmonellosis

Answer 24

Clean the environment, proper nutriton, reduce stress

Question 25

What therapy do we do for the diarrheic patient?

Answer 25

Goals of fluid therapy
1 correct dehydration
2. electrolyte deficit
3. acid-base balance
4. energy supplementation
5. provide maintenace fluid

Question 26

How can we assess dehydration?

Answer 26

6-7% -> sight enopthalmos, skin turgor slightly increased, mm moist
8-9%-> eyes obviously sunken, skin turgor obviously increased, mm tacky, 4 meg/k, bicarb deficity
10-12% -> eyes deeply sunken in orbits, skin tents and does not return, mm dry, depression or comatose 8meg/k bicarb deficit

Question 27

How do we calcuate the amount of fluid needed to resotre volume deficit

Answer 27

percentage of dehyration x body weight in kg= volume of fluid in liters

Question 28

How do we replace Na and CL deficit

Answer 28

-an isotonic saline solution is adequate to replace Na and Cl
-to replace K, can give 20 mE/i fluid if glucose and bicarb are in teh fluid

Question 29

In diarrheic calves less than 1 week of age for acid base imblance?
In diarrheic calves older than 1 week

Answer 29

assume a 10-15 meg/l deficit
15-29 meq/l deficit

Question 30

Energy supplementation in diarrheic animals

Answer 30

Most neonates with diarrhea are hypoglycemic
glucose will enhacne potassium resorption from the extracellular space to the intracellular space
supply by giving a 1-2% IV solution

Question 31

How do we provide maintenace fluid

Answer 31

50-100 ml/kg, 40 ml /lb

Question 32

When do we give IV fluids?

Answer 32

a) if calf has severe diarrhea
b) abscence or depression of suckle reflex
c) severe dehydartion of 8% or greater
d) unwillingness to stand
e) weak or absent pain reflex

Question 33

What rate do we give IV fluids?

Answer 33

50-80 ml/kg/hr, can rehydrate over 4-8 hour period

Question 34

When do we give oral fluids?

Answer 34

use when the neonate readily suckles electrolyte solution

Question 35

Oral fluids rule of thumb?

Answer 35

1. let animal nurse from bottle if it will
2. provide calf with fluids as often as possible
3. if using a stomach tube/ esophageal feeder in ruminants do not give more than 3-5% body weight at a time.
4. if tubing, space feedings 2 hours apart
5. leave electrolye solutions available for animals either in waterer or buckets between feedings

Question 36

When do we give sq fluids

Answer 36

-when they suck but have a high fluid loss
when the suckle reponse is poor and the owner is delivering therapy

Question 37

What are the sq fluids rule of thumb?

Answer 37

1. 80 ml/kg total volume
2. use isotonic solution
3. no more than 10-20 ml/kg per site
4. should be absorbed in 4 hours

Question 38

When do we give antibiotics?

Answer 38

a) patient has fevers or bacteremias
b) patient has concurrent infections

-can alter the normal flora of the gut
-tetracycline and neomycin may interfere with healing of the gut linign
-better to give parenterally

Question 39

How do we know how much buffer to give?

Answer 39

body weight x volume of distribution x deficit

Question 40

how do we know how much potassium to give

Answer 40

.1 unit change in the pH