Why Might My Dog Or Cat's APPT Time Be Delayed ?













Ron Hines DVM PhD

To see what normal blood and urine values are for your pet, go here

For an explanation of causes of most abnormal blood and urine tests go here

To see how tests are often grouped, go here

For an extensive list of health problems that can delay blood clotting in your pet, go here

Activated Partial Thromboplastin Time


When your veterinarian is suspicious that your dog or cat has a blood-clotting problem that is leading to internal or external bleeding or , perhaps, unexplained anemia; one of the most sensitive examination to detecting a blood-clotting defects is the APTT test.



Because the clotting of blood is such a complex process (coagulation cascade) with many different stages or steps and the interplay of many chemicals and cells; a series of tests on your dog or cat may be required to determine exactly what is wrong. The other tests are its thrombocyte count, prothrombin time (PT), partial thromboplastin time (PTT), Fibrinogen level, the d-dmer test and thrombin clot time TCT.

Problems That Can Cause Abnormally Long APPT Time In Your Pet :

Shock (DIC), Liver failure, certain rodent poisons, Hemophilia in dogs and cats and FIV in cats can all delay blood clotting and lengthen the pet's APPT time.

Extended APPT times also occur on rare occasions in cats subsequent to vaccinations. Extended APPT times also occur in some Bernese Mountain Dogs due to unknown genetic causes.