Survey of the incidence, diagnosis, clinical manifestations and treatment of Spirocerca lupi in South Africa

Abstract

A questionnaire survey of 716 veterinary practices was undertaken to determine the incidence of Spirocerca lupi in dogs in South Africa. In total, 49 % of the questionnaires were returned, indicating a possible incidence of 28 %. Fewer than 4 cases per year were recorded by 82 % of the respondents; 4-12 by 14 %; 12-24 by 3 %; and more than 48 by only 1 %. No seasonal incidence was reported by 48 % of the respondents. Large breeds were considered to be at greater risk by 43 % of respondents. No specific age or sex was identified to be at higher risk. The most common complaints by owners and clinical findings were vomition (46 %), weight loss (27 %), coughing (21 %) or regurgitation (20 %), although 14 % of respondents reported no abnormal clinical findings. Diagnostic methods used were radiology (74 %), endoscopy (27 %), post mortem examination (34 %) and faecal flotation (4 %). Complications associated with S. lupi were reported by 76 % of respondents, which included oesophageal neoplasia (41 %), hypertrophic osteopathy (38 %) and acute haemothorax (30 %). Specific treatments were used by 58 % of the respondents, whereas 42 % of the respondents either used no treatment (72 %) or recommended euthanasia (28 %). Of the treatment group, 52 % used ivermectin, 27 % doramectin, 13 % other deworming drugs (benzimidazoles, nitroscanate), and 8 % used disophenol. Sixty-three percent of the respondents considered their treatment ineffective, whereas 31 % considered it effective, and 6 % were unsure. The overall mortality rate was high.