Foot health and prevalence of Dichelobacter nodosus in 11 ungulate species at Berne Animal Park.

Abstract

Dichelobacter nodosus (D. nodosus) is the etiological agent of ovine footrot affecting mainly sheep worldwide, but also free-ranging wild ungulates such as Alpine ibex (Capra ibex ibex) and mufflon (Ovis orientalis orientalis). A nationwide ovine footrot eradication program is planned for the years to come, based on polymerase chain reaction (PCR)-testing of interdigital swab samples and regular footbathing. In this cross-sectional study, we clinically evaluated the foot health and analysed presence of D. nodosus in 11 different even-toed ungulate species (mainly European species) during a 13 months (2018-2019) period in Berne Animal Park. The foot lesions were scored for any clinical signs of pathologies as described in cattle and simultaneously for clinical signs of footrot as described for sheep, using a scale from 0 to 5 (while 0 describes clinically healthy feet and 5 loss of the horn capsule). From a total of 53 animals, 4-feet swab samples were taken from the interdigital cleft and subjected to real-time PCR assays to detect D. nodosus at animal level. Foot lesions were detected in five different species. In 3/5 muskoxen (Ovibos moschatus wardi), 7/12 Cretan wild goats (Capra hircus cretica) and 2/3 dwarf goats (Capra hircus aegagrus), they mainly consisted of white line disease, whereas in 9/10 European bison, dermatitis of the interdigital cleft was diagnosed. 1/3 alpaca was diagnosed with chorioptic mange of the heel area. None of the examined animals showed clinical signs of footrot (score 0), and neither benign (aprB2-positive) nor virulent (aprV2-positive) D. nodosus were detected in any of the samples. This study provides additional information to facilitate an efficient ovine footrot control program in Switzerland and suggests that captive wild even-toed ungulates do not pose a risk to the planned footrot control program.