Theses and Dissertations

Issuing Body

Mississippi State University


Thomason, John M.

Committee Member

Mackin, Andrew J.

Committee Member

Bulla, Camilo

Committee Member

Langston, V. Cory

Date of Degree


Document Type

Graduate Thesis - Open Access


Veterinary Medical Science

Degree Name

Master of Science (M.S.)


College of Veterinary Medicine


Veterinary Medical Science Program


Low-dose aspirin therapy in dogs inconsistently inhibits platelet function, termed ‘aspirin resistance’. There are no established diagnostic tests that can predict aspirin resistance in dogs prior to therapy. Platelet function was evaluated in healthy dogs prior to and during low-dose aspirin therapy using turbidimetric and impedance aggregometry, PFA-100, and urine 11-dehydro-thromboxane-B2 concentration. Following a washout, platelet-rich plasma from the dogs was incubated with aspirin and evaluated via turbidimetric aggregometry. After aspirin, the majority of dogs were classified as ‘aspirin responders’ with 81% responding after 7 days. Platelet dysfunction was not consistent in all dogs at all times. Compared to turbidimetric, impedance and PFA-100 results were inconsistent when run concurrently, suggesting turbidimetric is the preferred technique. There was poor agreement between in vitro aspirin incubation and all other tests. Unlike in people, platelet function in dogs is consistently inhibited by aspirin incubation, making this a poor technique for predicting aspirin resistance.