Leptospira spp

From Ferret
Leptospira under light microscopy

Leptospirosis is a relatively rare zoonotic bacterial disease of mustelids.

Although ferrets are reportedly refractory to leptospira infections, occasional cases present with acute infections characterised by icterus and acute hepatitis.

Sporadic outbreaks of renal disease has been observed in otters and minks[1].

Species which are pathogenic to ferrets include:

  • Leptospira interrogans (6 serogroups - Australis, Autumnalis, Icterohæmorrhagiæ, Grippotyphosa, Panama, Sejroe)

Serological testing has also revealed exposure to leptospira in badgers[2], martens and polecats[3].

Mustelids are primarily infected by predation of mice, rats and other rodents which harbor a renal nidus of spirochaetes.

Secondary infections also occur through contact with infective urine passed by wildlife vectors such as cattle, raccoons, foxes, bobcats and opossums.

Although most mustelids are asymptomatically affected when infected experimentally[4], clinical disease is reported as a result of other factors such as concurrent bacterial or viral infections, or other causes of immunosuppression.

Diagnosis is based on urinalysis, with culture of the leptospire by specialist laboratories, or ELISA or PCR assay confirmation of antigens[5].

Treatment regimen focuses on antimicrobial therapy, usually with tetracyclines, but aggressive therapy is required to minimise renal damage.

Commercial vaccines (bacterins) are available for cats residing in areas endemic for leptospirosis.


  1. Goldstein T et al (2011) Assessment of clinical pathology and pathogen exposure in sea otters (Enhydra lutris) bordering the threatened population in Alaska. J Wildl Dis 47(3):579-592
  2. Hathaway SC et al(1983) Infection of free-living carnivores with leptospires of the Australis serogroup. Vet Rec 113(11):233-235
  3. Moinet M et al (2010) Leptospirosis in free-ranging endangered European mink (Mustela lutreola) and other small carnivores (Mustelidae, Viverridae) from southwestern France. J Wildl Dis 46(4):1141-1151
  4. Larsson CE et al (1985) Laboratory and clinical features of experimental feline leptospirosis. Int J Zoonoses 12(2):111-119
  5. Gaydos JK et al (2007) Does human proximity affect antibody prevalence in marine-foraging river otters (Lontra canadensis)? J Wildl Dis 43(1):116-123