L17: Secondary Disorders of Haemostasis Flashcards Preview

Cardiovascular System > L17: Secondary Disorders of Haemostasis > Flashcards

Flashcards in L17: Secondary Disorders of Haemostasis Deck (11):
1

4x major mechanisms responsible for defective secondary haemostasis

1. Inherited deficiency of one+ coagulation factors
2. Vit K antagonism or deficiency (most common)
3. Severe acute/ chronic hepatic parenchymal Dz
4. Excessive fibrinolysis

2

Which are the K dependant clotting factors ?

2, 7, 9, 10

3

What are some clinical signs of Vit K antagonism (e.g. rodenticide) or haemophilia?

haemotoma
bleeding into body cav
epistaxis
MM petechiae
bleeding into joints

4

Which breeds have inherent Vit K disorders that predispose bleeding

Haemophilia --> Males (e.g. German shepherds) because X linked recessive
Inherited mutation of gene encoding carboxylase important for synthesising Vit K dependant factors --> Devon rex cats

5

What role does Vit K play in hepatic synthesis of coagulation factors?

required as co-factor by enzyme gamma-glutamyl carboxylase which carboxylates residues of Vit-K coagulation factors to render them functionl

6

how can large animals be exposed to coumarin type anticoagulants

Mouldy sweet clover or sweet vernal grass

7

Why is warfarin less hazardous than modern rodenticides

has shorter half life and needs platelets to be activated or something

8

in what circumstances might a dog develop Vit K deficiency???

prolonged anorexia
oral antibiotics that eliminates GIT bacteria that can synth it
Commercial diets generally contain excess vit K and GIT floral can synthesise and liver stores several days supply so normally not a wozz!

9

How much hepatic mass needs to be loss before animal is predisposed to haemorrhage???

>70%

10

In which condition is excessive fibrinolysis a contributor to defective 2ary haemostasis?

Rare except in context of DIC

11

Which conditions predispose animals to 2ary haemostasis disorders ?

Snake envenomation
Administration of plasminogen activators
Excessive endothelial release of t-PA e.g. shock, heat stroke, severe tissue trauma