Hemostatic Dysfunction in Dogs Naturally Infected with Angiostrongylus vasorum—A Narrative Review

Abstract

This narrative review aims to describe Angiostrongylus vasorum-induced hemostatic dysfunction of dogs with emphasis on clinical and laboratory findings as well as potential therapeutic strategies for the bleeding patient. Canine angiostrongylosis (CA) is a disease with potentially high morbidity and mortality in endemic areas and with fatal outcome often associated with either severe respiratory compromise, pulmonary hypertension and right-sided heart failure, or hemostatic dysfunction with severe bleeding. The most common signs of hemorrhage are hematomas, petecchiation, ecchymoses, oral mucosal membrane bleeding and scleral bleeding, while intracranial and pulmonary hemorrhage are among the most severe. The pathophysiological mechanisms underlying hemostatic dysfunction in these patients are presently researched. While the larval effect on platelets remains unknown, the parasite appears to induce dysregulation of hemostatic proteins, with studies suggesting a mixture of pro-coagulant protein consumption and hyperfibrinolysis. Importantly, not all dogs display the same hemostatic abnormalities. Consequently, characterizing the hemostatic state of the individual patient is necessary, but has proven difficult with traditional coagulation tests. Global viscoelastic testing shows promise, but has limited availability in general practice. Treatment of A. vasorum-infected dogs with hemostatic dysfunction relies on anthelmintic treatment as well as therapy directed at the individual dog’s specific hemostatic alterations.

Clinical bleeding diathesis, laboratory haemostatic aberrations and survival in dogs infected with Angiostrongylus vasorum: 180 cases (2005‐2019)

“…However, gingival and cutaneous bleeding diathesis and mucosal bleeding in different anatomical localisations were the most common findings. A fair number of dogs presented with neurological signs, which is in alignment with the current literature (Willesen et al ., 2022). These findings are of high clinical significance and stress the importance of canine A. vasorum infection being considered a major differential diagnosis in any dog with either unexplained coagulopathy or neurological signs A. vasorum endemic areas.…”

Comprehensive Map of Canine Angiostrongylosis in Dogs in Spain

“…In these studies, diagnoses were made based on serum antigen detection, and a prevalence similar to those in this study was reported [ 27 , 28 , 29 , 30 , 31 , 32 , 33 ], demonstrating that although prevalence is generally low, this disease is widely distributed throughout much of the continent, showing its emerging nature. Despite this, to date, there have only been two previous studies in Spain that have evaluated the presence of this disease in different regions, so an epidemiological map was needed to help determine the current status of canine angiostrongylosis in Spain [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ].…”

“…However, the most frequent clinical presentation is cardiorespiratory by nature, caused by the presence of adults and by the migration of larvae [ 8 , 9 ]. Fatal infection is often associated with severe respiratory compromise, pulmonary hypertension, right heart failure, and/or hemostatic dysfunction with fatal bleeding [ 10 ]. However, some infected animals may not show clinical signs during infection, or these infection may be non-specific, making diagnosis difficult [ 11 , 12 , 13 ].…”

Concurrent hypoadrenocorticism, immune‐mediated thrombocytopenia and immune‐mediated haemolytic anaemia in a Jack Russell Terrier dog

“…Serum biochemistry (Idexx VetTest Chemistry Analyser) demonstrated hypoalbuminaemia (albumin 16 g/L, Ref. [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39]) and hypocholesterolaemia (cholesterol 1.63 mmol/L, Ref.…”

“…The patient had no travel history outside the UK and was fully vaccinated, thus relatively excluding non-endemic infectious causes (direct or immune-mediated) of thrombocytopenia and anaemia (dirofilariasis, ehrlichiosis, babesiosis, anaplasmosis and so on). Angiostrongylosis is a differential for thrombocytopenia, as part of the bleeding diathesis caused by this parasite 26 and perhaps as a trigger for associative IMTP. 27,28 Angiostrongylosis was not supported in this patient based on negative blood antigen testing.…”