Angiostrongylosis in The United Kingdom. Clinical Characteristics of an Increasingly Frecuent Pathology: Description of 5 Cases

Abstract

Angiostrongylus vasorum infection has been considered endemic in different regions of the United Kingdom and it is wide spread in Europe. It is caused by a metastrongyloid nematode and mainly affects wild carnivores and dogs and they are affected usually due to the ingestion of gastropod molluscs (slugs or snails). The objective of this study was to describe the clinical presentation of the disease, diagnosis and treatment. To this aim, 5 dogs between 8 month and 10 years old, 3 males and 2 females,were presented in consultation with a history of tachypenoea, dyspnoea, coughing, exercise intolerance and epistaxis. None of them was receiving preventive treatment against lungworm for more than 2 years. Physical exam showed not evident signs of illness in 1 of them (asymptomatic); the rest of the patients showed sinus tachycardia, crackles and broncoalveolar noises in auscultation. One of the dogs presented right heart murmur without presence of jugular pulses or hepatojugular reflex. After reviewing history details and physical exam data, blood samples were collected to perform an inhouse serological assay for the detection of antigens (Angio Detect, IDEXX Laboratories)TM and three different days of faeces samples in order to do a coproscopic examination. All the dogs tested positive to serological assay and the diagnosis was confirmed by the faeces Baermann test were all dogs were positive. After diagnosis, further investigation as blood test, including haematology, chemistry and coagulation test, thorax xrays and echocardiography were performed to assess treatment and prognosis. Haematology abnormalities were found in 2 dogs including mild anaemia, eosinophilia and trombocytopenia. Biochemical results were normal and coagulation parameters were altered in 1 dog. Radiographic findings included alveolar infiltrate and bronchial thickening and increased sternal contact, indicating right heart enlargement, truncated pulmonary arteries and increased Vertebral Heart Score. Echocardiography exams demonstrated dilation of the right ventricle and atrium in 1 dog, dilated vena cava with clot formation in 1 dog and moderated tricuspid valve regurgitation in 2 of the dogs studied.Treatment was started with milbemycin oxime in combination with praziquantel tablets once weekly for four weeks against A. vasorum, and supportive treatment including pimobendan and sildenafil for pulmonary hypertension. Anti-inflammatory steroids doses was used to moderate respiratory signs. In conclusion, to improve the understanding and diagnosis of angiostrongylosis, new endemic areas should be defined in the United Kingdom as diagnosis of Canine Angiostrongylosis could be challenging for veterinary surgeons due to variability of clinical signs. Mechanisms leading coagulopathies need to be identified, however supportive treatment is necessary to reduce chronic cardiovascular disease.