Geographical, clinical, clinicopathological and radiographic features of canine angiostrongylosis in Irish dogs: a retrospective study

Abstract

BackgroundAngiostrongylus vasorum infection is associated with high morbidity and mortality in dogs. Although recognised in Ireland, there are no large series of cases reported. The aim of this retrospective study was to identify pertinent clinical and geographical features in Irish dogs.ResultsThe case records of dogs presenting to the University College Dublin Veterinary Hospital (1999-2010) were reviewed. A contemporaneous review of external faecal parasitology and post mortem submissions was also performed. A positive diagnosis of angiostrogylosis was identified in 49 dogs including 24 clinical, 10 post mortem and 15 external faecal sample cases. The majority (n = 44 (90%)) resided on the East Coast.In the clinical cases, the median age was 20 months, 29% of cases were older than 2 years. Clinical features included cardiorespiratory (63%), coagulopathic (71%) and other (63%) signs. Cough (n = 10), dyspnoea (n = 5) and tachypnoea (n = 3) were the most common cardiorespiratory abnormalities. Of animals with evidence of coagulopathy, excessive haemorrhage from a wound (n = 5), airway haemorrhage (n = 9), epistaxis (n = 3), haematoma (n = 4), suspected haemarthrosis (n = 3), neurological signs (n = 2) and haematuria (n = 1) were found. Ten dogs were anaemic, of which two were severe (haematocrit ≤ 0.20 L/L). Ten animals had thrombocytopenia, with four severely affected (≤50 × 109/L). PT and APTT values were prolonged in 4 (24%) of 17 and a BMBT was prolonged in 5 (63%) of 8 cases. Vague signs of exercise intolerance (n = 6), lethargy (n = 6) and weakness (n = 2) were identified, with two (8%) animals having only these signs. In one animal the diagnosis appeared to be incidental. Thoracic radiographs (n = 19) identified abnormalities in 100% of cases. Four (17%) animals died before or within 24 hours of treatment and post mortem examinations confirmed angiostrongylosis. Fenbendazole was administered in 19 cases, 18 (95%) recovered. Two animals were euthanised, one which failed to respond to therapy and another in which an ante mortem diagnosis had not been made.ConclusionsAngiostrongylosis is not uncommon in Ireland, is not confined to young dogs or the East Coast and can present with a wide variety of signs, particularly coagulopathic, respiratory or neurological signs.

Canine angiostrongylosis: recent advances in diagnosis, prevention, and treatment

“…71 Furthermore, this latter study supports the theory that thrombocytopathy and/or thrombocytopenia may indeed play a relevant role in most infected dogs showing hemorrhages. 71 Dogs may present neurological manifestations due to embolism of larvae or eggs in the central nervous system 29,73,88 or to intracranial, subdural bleeding. 77,87,89 Depression, ataxia, seizures, 12,82 central vestibular signs, forelimb or hind limb paralysis, and acute lumbar pain can be observed.…”

“…In fact, infected dogs may show prolonged prothrombin and activated partial thromboplastin times and decreased factors V, VII, and VIII activities or alterations. 71,[83][84][85] Immune-mediated thrombocytopenia and von Willebrand's factor deficiency have been described 86,87 and, in particular, thrombocytopenia has been described in naturally infected dogs that did not show alterations in specific prothrombin time and activated partial thromboplastin time, thus supporting the hypothesis of an immune-mediated thrombocyte destruction. 71 Furthermore, this latter study supports the theory that thrombocytopathy and/or thrombocytopenia may indeed play a relevant role in most infected dogs showing hemorrhages.…”

“…71,[83][84][85] Immune-mediated thrombocytopenia and von Willebrand's factor deficiency have been described 86,87 and, in particular, thrombocytopenia has been described in naturally infected dogs that did not show alterations in specific prothrombin time and activated partial thromboplastin time, thus supporting the hypothesis of an immune-mediated thrombocyte destruction. 71 Furthermore, this latter study supports the theory that thrombocytopathy and/or thrombocytopenia may indeed play a relevant role in most infected dogs showing hemorrhages. 71 Dogs may present neurological manifestations due to embolism of larvae or eggs in the central nervous system 29,73,88 or to intracranial, subdural bleeding.…”

“…Indeed, an alveolar infiltrate has been described in at least 50% of dogs examined in clinical case series, and its features (eg, diffuse, multifocal, or peripheral) depend upon the duration of infection. 71,92 Also, interstitial infiltration is commonly observed in case series, and pleural fissures may be present in about the half of examined cases with several cases of concurrent interstitial pattern, which could reflect a chronicity of the infection. 71 Interestingly, animals may show radiographic evidence of lung lesions despite presenting with no overt respiratory signs.…”

“…71,92 Also, interstitial infiltration is commonly observed in case series, and pleural fissures may be present in about the half of examined cases with several cases of concurrent interstitial pattern, which could reflect a chronicity of the infection. 71 Interestingly, animals may show radiographic evidence of lung lesions despite presenting with no overt respiratory signs. Hence, the importance of thoracic radiography in investigating angiostrongylosis should not be disregarded even in the absence of cardiorespiratory signs.…”