Hyperfibrinolysis and Hypofibrinogenemia Diagnosed With Rotational Thromboelastometry in Dogs Naturally Infected With Angiostrongylus vasorum.

BACKGROUND: The pathomechanism of Angiostrongylus vasorum infection-associated bleeding diathesis in dogs is not fully understood. OBJECTIVE: To describe rotational thromboelastometry (ROTEM) parameters in dogs naturally infected with A. vasorum and to compare ROTEM parameters between infected dogs with and without clinical signs of bleeding. ANIMALS: A total of 21 dogs presented between 2013 and 2016. METHODS: Dogs with A. vasorum infection and ROTEM evaluation were retrospectively identified. Thrombocyte counts, ROTEM parameters, clinical signs of bleeding, therapy, and survival to discharge were retrospectively retrieved from patient records and compared between dogs with and without clinical signs of bleeding. RESULTS: Evaluation by ROTEM showed hyperfibrinolysis in 8 of 12 (67%; 95% CI, 40-86%) dogs with and 1 of 9 (11%; 95% CI, 2-44%) dogs without clinical signs of bleeding (P = .016). Hyperfibrinolysis was associated with severe hypofibrinogenemia in 6 of 10 (60%; 95% CI, 31-83%) of the cases. Hyperfibrinolysis decreased or resolved after treatment with 10-80 mg/kg tranexamic acid. Fresh frozen plasma (range, 14-60 mL/kg) normalized follow-up fibrinogen function ROTEM (FIBTEM) maximal clot firmness in 6 of 8 dogs (75%; 95% CI, 41-93%). Survival to discharge was 67% (14/21 dogs; 95% CI, 46-83%) and was not different between dogs with and without clinical signs of bleeding (P = .379). CONCLUSION AND CLINICAL IMPORTANCE: Hyperfibrinolysis and hypofibrinogenemia were identified as an important pathomechanism in angiostrongylosis-associated bleeding in dogs. Hyperfibrinolysis and hypofibrinogenemia were normalized by treatment with tranexamic acid and plasma transfusions, respectively.

Unexplained bleeding as primary clinical complaint in dogs infected with Angiostrongylus vasorum.

INTRODUCTION: Unexplained bleeding was the primary clinical complaint in 15 dogs diagnosed with A. vasorum and was observed in the mouth, as external bleeding, as large subcutaneous hematoma, as hemoptysis, in the brain, post ovariectomy, as epistaxis, in the anterior ocular chamber and on a tracheal intubation tube. In 8 dogs the cause of bleeding initially was suspected to be a minor trauma or a surgical complication, and various surgical approaches had been undertaken to eliminate the problem. In only 3 dogs respiratory signs were observed before the bleeding prompted referral. The median time elapsed between the first recognized clinical signs attributed to A. vasorum until diagnosis was 2 weeks (range1 day to 4 months). Four dogs died, 3 on the day of admission and 1 dog 4 days after admission. Suspected causes of death were respiratory failure and cerebral hemorrhage in 2 dogs each. Four dogs had been pre-treated with NSAIDs; of these, 2 dogs developed severe hemoptysis (1 died), 1 dog developed brain hemorrhage (and died), and 1 dog developed a large subcutaneous hematoma with marked anemia. Bleeding at various sites may be the only recognized abnormality in A. vasorum infection. Without a high index of suspicion, the diagnosis and appropriate therapy may be delayed to the point of a fatal outcome. Tests of coagulation were quite variable and the cause of bleeding likely multifactorial.

INTRODUCTION: Un saignement inexplicable a été le symptôme clinique primaire chez 15 chiens chez lesquels une infestation à A. vasorum a été diagnostiquée par la suite. Ces saignements ont été observés sous forme d'hémorragies dans la gueule, de saignements externes, de gros hématomes sous-cutanés, d'hémoptysie, de saignements cérébraux, de saignements abdominaux après ovariectomie, de saignements dans la chambre antérieure de l'oeil ou sur le trachéotube lors d'intubations. Chez 8 chiens, on a supposé que le saignement était initialement dû à un petit traumatisme ou à une complication opératoire et diverses mesures chirurgicales ont été prises pour résoudre le problème. Chez trois chiens, des symptômes respiratoires ont été observés avant que le saignement n'amène à l'envoi dans un centre de référence. Le temps moyen écoulé entre les premiers symptômes causés par A. vasorum et le diagnostic était de 2 semaines (1 jour à 4 mois). Quatre chiens sont décédés, 3 le jour de leur arrivée et un 4 jours plus tard. Les causes probables de la mort étaient dans deux cas une déficience respiratoire et dans deux une hémorragie cérébrale. Quatre chiens avaient été traités précédemment avec des AINS; deux d'entre eux ont développé une hémoptysie massive et un en est mort, un chien a présenté une hémorragie cérébrale fatale et le dernier a développé un volumineux hématome sous-cutané avec une anémie massive. Un saignement à un endroit quelconque peut être la seule anomalie constatée lors d'une infestation par A. vasorum. Si on n'a pas d'importants soupçons de cette affection, le diagnostic et le traitement adéquat peuvent être tellement retardés qu'une issue fatale survient. La cause pathophysiologique des hémorragies est vraisemblablement multifactorielle.