The picture shows proliferation of the nasal conchal mucosa in a two-year-old Beltex tup which was examined at Dumfries recently. This animal was running with ewes but was described as lazy and lying down a lot. It developed a nasal discharge in the week prior to being found dead. Disruption to air flow, the unseasonably warm weather the previous day, and a body condition score of 5 were considered to contribute to its death. No evidence of laryngeal chondritis was found. Salmonella diarizonae was isolated from the lesion and histopathology confirmed this as the cause.
Salmonella diarizonae is host adapted to sheep and is not often implicated as a cause of disease. The pathogenesis of chronic proliferative rhinitis is not fully understood, however the potential for sheep to sheep spread has been shown.
Nasal swabs were collected from 31 adult sheep in a small Texel flock where 3 animals had died of the condition. 3 were dyspnoeic, 12 had a nasal discharge, and Salmonella diarizonae was isolated from 27. 28 lambs tested negative. Experimental infection has shown that Salmonella diarizonae can be carried in the upper respiratory tract for at least one year. Shedding or invasion of the tissues may occur in stressed or immunocompromised animals.
This condition should be added to your differential diagnosis list for upper respiratory signs and/or dyspnoea in sheep.
Lacasta et al. (2012) Chronic proliferative rhinitis associated with Salmonella enterica subspecies diarizonae serovar 61:k:1,5,(7) in sheep in Spain. Journal of Comparative Pathology, 147, 406-409
Lacasta et al. (2017) Experimental infection with Salmonella enterica subsp. diarizonae serotype 61:k:1,5,(7) in sheep: Study of cell mediated immune response. Small Ruminant Research, 149, 28-33
Stokar-Regenscheit et al. (2017) Salmonella enterica subsp. diarizonae serotype 61:k:1,5,(7) associated with chronic proliferative rhinitis and high nasal colonization rates in a flock of Texel sheep in Switzerland. Preventive Veterinary Medicine, 145, 78-82