The down sheep

Question 1

What are the differentials for a down sheep?

Answer 1

• hypocalcaemia
• pregnancy toxaemia
• scrapie
• lameness
• respiratory disease
• listeria
• hypomagnasemia

Question 2

What differentials for a down sheep can happen at any tine and will have slow onset to the point of recumbency?

Answer 2

• scrapie
• resp disease
• listeria

Question 3

What are risk factors for hypocalcaemia in a sheep?

Answer 3

• Occurs in late pregnancy
• Older and thinner ewes more prone
• Carrying multiple foetuses increases risk
• Any stressor can trigger the condition

Question 4

How does milk fever affect a sheep’s digestive system?

Answer 4

Ruminal stasis and bloat

Question 5

How would you manage hypocalcaemia in sheep?

Answer 5

• 25-40ml 40% Calcium Borogluconate over 30-60 seconds I/V
• Typically eructation seen after 1-2 minutes, stand after 5 minutes then urinate / defecate and re-join the flock.

Question 6

Why are hypocalcaemia and pregnancy toxamia often confused?

Answer 6

They have the same risk factors and have the same consequence - down sheep

Question 7

How can we distinguish pregnancy toxaemia and hypocalcaemia in sheep?

Answer 7

In pregnancy toxaemia
* Ewe is separated from the mob
* Ewe is drowsy or comatose
* Ewe is not eating
* Nervous system signs – tremors, blindness
* Lying on their side – long duration (3-4 days)
* Die a few days later

Question 8

Why is nutrition so important in late pregnancy in sheep?

Answer 8

• Developing foetus
• Udder development and colostrum production
• Prevent milk fever
• Compensation for reduced feed intake

Question 9

Why can’t we just feed sheep lots and lots in late pregnancy?

Answer 9

• Perversely increases pregnancy toxaemia risk as deregulates insulin response
• Increases milk fever risk as deregulates parathyroid hormone response
• Vaginal prolapses more likely
• Dystocia more likely – fat in pelvic canal with oversized foetus
• Feed = money

Question 10

How can we manage pregnancy toxaemia?

Answer 10

I/V glucose
Oral glucose
Induce parturition (Steroids & PGF2a)

Encourage eating
- minerals in molasses
- Yeast and propylene glycol drench
- Vitamin B12
- Consider minerals

Question 11

When does staggers occur in sheep?

Answer 11

• Is more common post partum.
• Seen when moved onto fast growing spring pasture - sometimes pasture with high Potassium fertiliser which inhibits uptakes

Question 12

How can you manage staggers in sheep?

Answer 12

• Increasing gut transit times, by feeding higher fibre diet can help to increase absorption of available magnesium, and reduce the incidence of disease.
• Routine soil analysis shows the Magnesium level of soil. Use of Magnesian limestone rather than Calcium limestone, maintains the levels.
• Modify bagged fertiliser applications so K applications are carried out later in the season.
• A regular supply of Magnesium in the diet e.g. offer free access minerals.