FAC10-11: Enteric Problems of Young Calves

Question 1

How does age impact the possible cause of calf diarrhoea?

Answer 1

<7 days: bacteria

7-21 Days: Virus

>1 month: Parasite

Question 2

Which causes the most acidosis: Bacteria, Virus, Parasite?

Answer 2

Most: Virus

Least: Parasite

Question 3

What are the two syndromes to neonatal diarrhoea?

Answer 3

Dehydration and acidosis

Question 4

What is happening in the gut when calves have diarrhoea?

Answer 4

Increased osmolality

Increased secretion

Decreased absorptive area

Deranged motlity

Question 5

How do E. Coli cause diarrhoea?

Answer 5

1. K99 adheres bacteria to intestine
2. Then enterotoxin is released
3. Activated guanylate cyclase
4. Leads to net Na+ and Cl- secretion
5. Draws water into lumen

Question 6

How do viruses cause diarrhoea?

Answer 6

1. Infects brush border of villi
2. Leads to sloughing of cells
3. Crypt cells cannot mature quickly enough
4. Cilli become stunted
5. Reduced surface area
6. Malabsorption

4b. Enzymatic Loss
5b. Maldigestion
6b. Changed osmotic potential
7. Diarrhoea

Question 7

How much fluid does the GIT usually re-absorb?

Answer 7

99% of fluid

Question 8

What is maintenance for a 50kg calf?

Answer 8

80-100ml/kg/day

OR

250ml/hr

Question 9

What are the signs of fluid loss? At what percentage fluid loss do these signs appear?

Answer 9

Question 10

What are the clinical signs of acidosis in calves?

Answer 10

Mental obtundation

Decreased suck reflex

Muscle weakness

Gut stasis

Cardiac arrhythmia

Question 11

What are the clinical signs of dehydration in calves?

Answer 11

Activation of the sympathetic NS

Decreased venous return

Hypothermia

Low RT

Tachycardia

Question 12

How do you correct dehydration in a calf?

Answer 12

Oral Therapy

• Give 1-2L every 4-6 Hours
• Continue to allow access to milk

IV therapy

• Use isotonic
• DO NOT USE Lactated Ringers
• Maintenance + Deficit
  
  • Bolus 3L first and then give the rest over 6-8 hours at 250-500ml/hr

Question 13

How do you correct acidosis?

Answer 13

You dont (the issue is d-lactate, which you cant do anything about), but you give bicarb to stop the clinical signs

Total Base Deficit = Body weight x % as ECF (0.6) x Base Deficit

Amount of Bicarb to give = Total Base Deficit / 12/mmol/g

Question 14

What are the common bacterial causes of diarrhoea in calves?

Answer 14

E. coli

Salmonella

Question 15

What are the common viral causes of diarrhoea in calves?

Answer 15

Rotavirus

Coronavirus

BVD

Question 16

What are the common parasite causes of diarrhoea in calves?

Answer 16

Cryptosporidia

Coccidiosis

Nematodirus

Strongyles

Question 17

What are the common non-bacterial, non-viral, or non-parasitic causes of diarrhoea in calves?

Answer 17

Dietary change

Intussusception

Torsion

Grain overload

Necrotic enteritis

Poisoning

Question 18

How do you diagnose the cause of diarrhoea in calves?

Answer 18

History

SNAP Test - E. coli, Rota, Corona, Crypto

Faecal Culture - Salmonella

McMasters - Strongyle, Coccidia