Concentrations of interleukin-6,-8,-10 and tumour necrosis factor-α in the faeces of dogs with acute diarrhoea

Aim: To compare the concentration of faecal cytokines interleukin (IL)-6, -8, -10, and tumour necrosis factor (TNF)-alpha in dogs with acute diarrhoea with clinically normal (non-diarrhoeic) dogs. Methods: A total of 14 dogs presenting with acute diarrhoea, and 25 dogs with no history of gastrointestinal signs in the 2 months prior to enrolment, were recruited from two veterinary hospitals in Melbourne, Australia. Concentrations of IL-6, -8, -10, and TNF-alpha were measured in faecal samples using canine-specific ELISA. Results: The diarrhoeic dogs were diagnosed with or managed for acute gastroenteritis (n=6), extra-intestinal neoplasia (n=2), parvoviral enteritis (n=1), hepatopathy (n=1), acute pancreatitis (n=1), hypoadrenocorticism (n=1), gastric dilatation volvulus (n=1) and myelopathy (n=1). IL-6 was detectable in the faeces of 10/14 (71%) diarrhoeic and 7/25 (28%) non-diarrhoeic dogs, and median concentrations were 10.8 (min 0.0, max54.0) and 2.0 (min 0.0, max15.0) pg/mL, respectively (p=0.01). IL-8 was detectable in the faeces of all diarrhoeic and 11 non-diarrhoeic dogs, and median concentrations were 149.7 (min 3.72, max730.1) and 3.4 (min 0.0, max22.5)pg/mL, respectively (p<0.001). TNF-alpha was detected in the faeces of two of the diarrhoeic dogs (3.4 and 15.6pg/mL) and none of the non-diarrhoeic dogs. IL-10 was not detected in the faeces of any dog. Conclusions: Faecal concentrations of IL-6 and -8 were higher in diarrhoeic compared to non-diarrhoeic dogs, and are therefore potential candidates for non-invasive biomarkers to assess the severity and resolution of acute intestinal disease in dogs. However their correlation with disease progression and severity needs to be further investigated before their full clinical application can be determined.