Effects of aspirin and propranolol alone and in combination on hemostatic determinants in the healthy cat.

The effects of aspirin (75 mg orally/average-size cat) and propranolol (5 mg orally every 8 hours/average-size cat) alone and in combination on hemostatic determinants in healthy cats were studied. In cats, aspirin alone did not cause a significant effect in platelet numbers, plasma fibrinogen, activated partial thromboblastin time, prothrombin time, thrombin time, or platelet aggregation response to adenosine diphosphate. Aspirin did, however, significantly reduce the degree of aggregation induced by acid soluble collagen. Propranolol alone or in combination with aspirin did not cause a significant effect on platelet numbers, plasma fibrinogen, activated partial thromboblastin time, prothrombin time, thrombin time, or platelet aggregation in response to acid soluble collagen, adenosine diphosphate, or adrenaline. It was concluded that aspirin alone at the recommended dosage of one-quarter of a 5-grain tablet (1.25 grains or 75 mg) every other day will significantly affect platelet function and may be of value in the prevention of thromboembolic disease in the cat.