Avian Hemostasis (Schalm 95)

Question 1

In addition to microtubules, vacuoles, and a canicular system similar to platelets, what are some other proteins and activities expressed by chicken thrombocytes?

Answer 1

MCHII, CD40, CD80, CD86
Phagocytic ability to engulf foreign material

Question 2

What receptors are found in lower levels on avian thrombocytes compared to platelets?

Answer 2

Lower levels of GPIIb/IIIa
Less GPIba (which binds to VWF) - may reduce aggregation strength

Question 3

What coagulation pathways are absent in birds?

Answer 3

The contact pathway of prekallikrein, Factors XII and XI

Question 4

What variable factor influences the PT test in birds?

Answer 4

The source of the thromboplastin - mammalian thromboplastins yield prolonged endpoints and avian-sourced thromboplastins are preferred. Incubation may still be performed at 37C

Question 5

How do APTT’s in birds differ from mammals?

Answer 5

APTT’s are often prolonged in birds since they lack factors XII and XI

Question 6

What may act as vitamin K antagonists in chickens?

Answer 6

Sulfonamide antibiotics

Question 7

What injectable treatment has been implicated as a cause of fatal hemorrhage in birds?

Answer 7

Polysulfated glycosaminoglycans for DJD
(these are synthetic heparinoids)