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Flashcards in Farm animal endocrinopathies Deck (32):
1

What are potential risks as a consueqence of subclinical ketosis in a cow?

- Clinical ketosis
- Retained foetal membranes
- LDA
- Metritis
- Lameness
- Mastitis
- Culling
- Death

2

What are the potential outcomes of a negative energy balance in a cow?

- If mild: subclinical ketosis, and increased fat infiltration in the liver
- If severe: clinical ketosis and fatty liver syndrome

3

Compare ketosis in farm animals and diabetic ketoacidosis in small animals

- Ketosis is not consequence of diabetes cf. ketoacidosis
- Also different from acidosis/SARA/acute acidosis in cattle

4

What are risk factors for a cow developing ketosis?

- Long lactation
- Higher milk production
- Increased weight before drying off

5

When are cattle most at risk of ketosis?

During early lactation where milk yield increases rapidly, faster than required increase in food intake and be accomodated for

6

What is ketosis in early lactation called?

Type II ketosis

7

What is ketosis in peak lactation called?

Type I ketosis

8

Which cows are most at risk of type I ketosis?

High yielding cows - unable to eat enough to maintain energy

9

Compare the energy requirement of a normal cow and a lactating cow

- Normal: BWT/10 = MJ of metabolisable energy/day
- Lactating needs an extra 5MJ ME/litre

10

Describe the normal physiology of fat mobilisation in lactation

- Mobilise fat as normal
- Lipolysis puts fat into blood as NEFAs
- In gut, absorbed propionate, moves into liver and provide source of glucose via gluconeogenesis
- Glucose produced used to oxidise fatty acids
- Glucose enters tissues, insulin into tissues and milk to drive metabolism and lactose production
- NEFAs oxidised in liver using glucose from propionate and gluconeogenesis

11

Describe the pathophysiology of type I ketosis

- Low propionate, less glucose prod, less oxidation of FAs
- Incomplete oxidation of FFAs = ketones, enter blood stream

12

What is the most common ketone produced in ketosis?

Beta-hydroxybutyrate

13

Describe the pathophysiology of type II ketosis

- Fat cow, more adipose tissue stores, mobilisation of lots of fat at drying off - cannot eat much
- Excessive mobilisation of fat, increased NEFAs
- Elevated fat in blood, insufficient glucose to oxidise, accumulation of FFAs in liver = hepatic lipidosis and ketones
- Further ketones produced due to impaired hepatic function
- More ketones, more fat mobilised as less energy produced from liver, continues in a cycle

14

Why are fat cows more at risk of type II ketosis?

- More fat stores to mobilise
- Insulin resistance so less metabolism and less uptake of glucose into milk

15

How does the blood insulin in a type I ketotic cow differ from that in a type II ketotic cow?

- High in type II
- Low in type I

16

What are the key interventions for type I and type II ketosis?

- Type I: post-fresh feeding
- Type II: pre-fresh feeding

17

What are the clinical signs of ketosis in the cow?

- Off food
- Milk drog
- Smell of ketones
- Nervous ketosis possible

18

What is meant by nervous ketosis? What are the signs? Prognosis?

- Rare presentation of ketosis
- May be due to hypoglycaemia, ketones, other circulating chemicals
- Can become aggressive, non-stop forward movement, furious licking
- Very good prognosis and can recover quickly

19

What are the clinical signs of hepatic lipidosis in the cow?

- Off food
- Milk drop
- Immunosuppression
- Collapse
- Liver failure

20

What is pregnancy toxaemia in sheep and when does it occur?

- Twin lamb disease
- Usually before lambing

21

Explain the pathophysiology of pregnancy toxaemia in sheep

Twins not split from singles, not fed enough, energy demads too high = ketosis

22

How does pregnancy toxaemia relate to hypocalcaemia

- Clinical signs indistinguishable
- Often one will precipitate the other

23

What are the clinical signs of pregnancy toxaemia?

- Off feed
- Dull, depressed
- Nervous sings e.g blindness
- Death

24

What conditions may cause pregnancy toxemia?

- Tooth disease/lameness may pregent eating enough
- Conjunctivitis (Mycoplasma conjunctivi), often relapse, poor immunity
- Sporadic cases

25

What often triggers outbreaks of pregnancy toxaemia?

- Change in management esp. diet
- May lead to reduced DMI

26

What diagnostic tests should be used in suspected cases of ketosis?

- Blood test for ketones
- Urine ketone dipstick (small animal/human dipstick)
- Milk Rotheras's reagent, turns purple if ketones present, rare

27

What diagnostic tests should be used in suspected cases of hepatic lipidosis?

- Ketones as with ketosis (blood, urine, milk)
- Blood NEFAs
- Evidence of liver damage i..e elevated liver enzymes AST, GGT
- Assess fat in liver (biopsy, necropsy)

28

What treatments are available for an individual with hepatic lipidosis, ketosis or pregnancytoxaemia?

- Glucose precursor
- Glucocorticoid
- Glucose

29

Describe the use of glucose precursors in the treatment of hepatic lipidosis/ketosis/pregnancy toxaemia

- E.g. propylene glycol
- Enters TCA cycles and creates insulin peak
- Is the base of ketosis treatment
- 300g once daily
- Use precursor so rumen flora cannot use it up before it enters blood as would occur with glucose

30

Describe the use of glucocorticoids in the treatment of hepatic lipidosis/ketosis/pregnancy toxaemia

- Promote gluconeogenesis
- HOWEVER evidence equivocal but still commonly used

31

Describe the use of glucose in the treatment of hepatic lipidosis/ketosis/pregnancy toxaemia

- Can only be given IV
- Rapid peak and decline
- No clear evidence
- Good for use in nervous ketosis to resolve signs quickly

32

Compare energy balance disease in camelids with those in ruminants and horses

- Ketosis like a cow
- Hyperlipaemia like a horse, hepatic lipidosis may occur in extreme cases (usually fatal)
- Always hyperglycaemia
- Pregnancy toxaemia may also occur
- Measure ketones and TAGs
- Better at dealing with lower energy intake