Ferrets are predisposed to numerous respiratory diseases, the most virulent being canine distemper virus. In 2007, an outbreak of respiratory disease characterized by a dry, nonproductive cough was observed in ferrets 6–8 weeks of age at a United States distribution center; before arrival, the kits had been vaccinated for distemper at a Canadian breeding facility. The disease was characterized by high morbidity but low mortality; over the next 4 years, ~8000 ferrets were affected. Ferrets responded to supportive care with the exception of a dry cough that only temporarily decreased and sometimes persisted for up to 4 years. Postmortem findings included bronchointerstitial pneumonia with prominent hyperplasia of associated lymphoid tissue. Cytological and bacterial cultures from 12 affected ferrets were positive for fast-growing, glucose-fermenting Mycoplasma spp and negative for other bacteria. No bacteria or Mycoplasma spp were isolated from 10 healthy ferrets. While PCR and nucleic acid sequencing failed to identify the Mycoplasma spp, it was found to be most similar to M molare and M lagogenitalium. The authors suggested a causal relationship between the isolation of this Mycoplasma species and an emerging disease in ferrets. One potential trigger may be the stress of shipping.

Commentary A new syndrome of ferret respiratory disease is described, involving a Mycoplasma spp-associated chronic respiratory disease, and should be considered in any ferret with respiratory signs. Other considerations should include canine distemper virus, influenza virus, bacterial pneumonia, and heartworm disease; diagnostics should aim to rule out these conditions. If bronchoalveolar lavage samples are obtained, a Mycoplasma spp culture must be specifically requested, as it will not grow on normal bacterial media. Treatment of the newly described Mycoplasma spp-associated disease has been unrewarding,1 but a regimen similar to that used in Mycoplasma spp infections in rats (ie, combination therapy with enrofloxacin and doxycycline) may be a reasonable first choice.—Sarah Churgin, DVM

Source Mycoplasmosis in ferrets. Kiupel M, Desjardins DR, Lim A, et al. EMERG INFECT DIS 18:1763-1770, 2012. 1. Ferret respiratory system: Clinical anatomy, physiology, and disease. Johnson-Delaney CA, Orosz SE. Vet Clin North Am Exot Anim Pract 14:357–367, 2011.