Icterus in Horses Flashcards Preview

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Flashcards in Icterus in Horses Deck (26):
1

What is important to remember about a horses biliary system? How does this affect bile acid analysis?

They have no gall bladder and thus secrete bile acid constantly. Therefore there is no need to take two measurements for bile acids.

2

How common is pre-heatic icterus in horses?

Relatively uncommon

3

What can cause heamolysis in horses?

Neonatal isoerythrolysis
EIA
drugs
Toxins
Autoimmune HA

4

What are common hepatic reasons for icterus in horses?

ANNOREXIA, acute hepatocellular disease

5

What is uncommon post-hepatically in horses?

Shunts

6

When should one think about liver disease in an icteric horse?

When it is still eating, not a foal and not pale.

7

What are the main clinical signs of liver failure in horses, are they specific?

Depression and annorexia - non specific

Colic - hepatocellular swelling, biliary obstruction (often will see a mild colic)

Weight loss

8

What is a cardinal sign of HE in horses?

Head pressing

9

What is the cause of photosensitization in icteric horses?

Phylloerythrin is no longer conjugated and excreted by the liver. Cells are then more responsive to UV

10

What needs to be done to diagnose liver disease?

Clinical signs
Bloods
Ultrasound
Biopsy

11

What tests are specific for the liver?

Increased bile acids
Increased SDH
Increased GGT

12

Why is abdominal ultrasound not that helpful in diagnosing liver disease?

It can only view ~20% of the liver as most of the liver is covered by lung tissue.

13

What can findings from a hepatic biopsy be used for?

Dx, Px, Treatment

14

What are the general principles of liver disease treatment in horses?

Suportive - maintain liver until regeneration. If fibrosis is severe this is less likely :

-Fluids/Acid base
-Glucose
-ABs????
-Anti-inflammatories

15

What are the priniciples of HE treatment?

-Sedate
-Mannitol/hypertonic saline - brain oedema
-Oral lactulose - limitis ammonia absorption
-Oral BCAAs (no evidence of efficacy)

16

What antiinflammatories can be used in liver disease? What should be remembered with corticosteroid use?

NSAIDs
DMSO
Cortico - link between these and laminitis
Pentoxifylline

17

What is the pathogenesis of Pyrolizidine alkaloid toxicity?

Meabolized by liver to toxic pyrrole derivatives . These are antimitotic and xlink DNA and bind to nucleic acid and proteins within hepatocytes. Cells cant divide and become megalocytes which will die and fibrose.

18

What can cause cholelithiasis?

parasites
Ascending biliary infection/inflammation
Biliary stasis

19

What clinical signs are strongly suggestive of cholelithiasis?

Fever+Icterus+Colic

20

How is cholelihiasis diagnosed?

Liver enzyme activity, ggt, shd, ast

Ultrasound (maybe)

Biopsy

21

How is cholelithiasis treated?

Antimicrobials
Suportive care
DMSO
Anti-inflammatoris
Others

22

When should hyperlipeamia be strongly suspected?

Obese pony breeds/ minature horses.

23

What causes hyperlipaemia?

Negative energy balance

24

How does hepatic lipidosis differ in horses compared to cats?

Horses very good at producing TGs and these are over produced so build up

25

How can HL be diagnosed?

Breed
History
Clinical signs
Serum TGs
(liver biopsy)

26

What are the principles of hyperlipaemia treatment?

1.Reverse te NEB
2.Treat hepatic disease
3.Eliminate stress/primary disease treatment
4. Inhibit fat mobilisation (insulin)
5.Increase uptake by peripheral tissues
(heparin - although likely that lipoprotein lipase is already maximally active)