Clinical insights to address canine strongyloidosis in daily practice

Canine strongyloidosis by Strongyloides stercoralis is a parasitic disease emerging in Europe, which represents both a veterinary clinical issue and a public health challenge because of the zoonotic potential. The disease, not yet frequent in Europe, could induce severe clinical signs in dogs; thus, an early diagnosis and appropriate treatment are desirable. The aim of the present work is to retrospectively investigate the clinical and paraclinical findings in sick dogs naturally infected by S. stercoralis, with particular attention to ultrasound (US) changes at the gastrointestinal level. Twelve dogs were included in the study. The diagnosis was made by means of larval morphological identification on faecal samples and PCR. Most dogs presented with gastrointestinal signs; diarrhea and weight loss were the most common presenting complaint. Only one dog showed respiratory signs, associated to a parasitic cutaneous nodule. Hypoproteinaemia, anaemia, leucocytosis and an increase in alpha2globulin fraction at serum protein electrophoresis were common (>50%) but not constant findings. The most reported US picture was a fluid-filled, distended, atonic small intestine mostly associated with altered wall layering, while the wall thickness commonly associated with chronic enteritis was only rarely reported. These changes, associated with other clinical and paraclinical alterations, could increase the suspicion of canine strongyloidosis and may direct clinicians to include strongyloidosis in the differential diagnosis of dogs with diarrhea. The histological examination at the intestinal level, available in five dogs, revealed the presence of parasites from the full-thickness biopsy, but not from the endoscopic biopsy. The critical points of diagnosis in clinical practice are also discussed.