Evaluation of coagulation and platelet activation state and function in heartworm‐infected dogs

• Published in: Veterinary clinical pathology 2024-06, Vol.53 (2), p.186-195
• Main Authors: Fraser, Carisa, Wallace, Mandy L., Moorhead, Andrew, Tarigo, Jaime, Brainard, Benjamin M.
• Format: Article
• Language: English
• Subjects: canine; coagulation; Dirofilaria immitis; Dogs; hypercoagulability; microfilaremia; viscoelastic coagulation monitoring
• ISSN: 0275-6382; 1939-165X
• DOI: 10.1111/vcp.13358

Background Enhanced platelet responses have been demonstrated in heartworm‐infected (HWI) dogs; however, the cause and clinical implications of altered platelet function have not been fully elucidated. Objective This study evaluated platelet function in HWI dogs. Methods Anticoagulated whole blood collected from eight HWI and eight uninfected dogs was evaluated using turbidometric platelet aggregometry, a platelet function analyzer (PFA‐100), a total thrombus analysis system (T‐TAS), tissue factor‐activated and tissue plasminogen activator modified thromboelastography (TF‐ and tPA‐TEG), CBC, von Willebrand Factor activity, and fibrinogen concentrations. Platelet activation state and the presence of reticulated platelets were assessed via flow cytometric expression of P‐selection (CD‐62P) and thiazole orange staining. Results Platelet aggregation responses to adenosine diphosphate (ADP, 10 μM) or collagen (20 μg/mL), PFA‐100 closure times, and T‐TAS occlusion times did not differ between groups. TEG values TF‐R, tPA‐R, TF‐K, and TF‐LY60 were decreased (P = .025, P = .047, P  = .038, P  = .025) and TF‐MA, tPA‐MA, TF‐G, tPA‐G and TF‐alpha angle were increased (P