Lapis ISSN 2398-2969

Microsporum canis

Synonym(s): M. canis

Contributor(s): Vetstream Ltd, Susan Dawson, Anna Meredith, David Scarff, Molly Varga




  • Division: Ascomycetes.
  • Genus:Microsporum.
  • Species:canis.

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Clinical Effects



  • Dermatophytes may be geophilic (soil reservoir), zoophilic (animal reservoir) or anthropophilic (human reservoir).
  • M. canisis zoophilic.


Non-parasitic state (including culture)
  • Septate branching hyphae (the mycelium) are produced.
  • Asexual reproductive units (macro- and micro- conidia) are found in the aerial mycelium.
  • Sexual spores (ascospores) are produced.

Parasitic state

  • Hyphae and arthroconidia (also asexual reproductive units) seen.


  • Most commonly direct contact; also fomites.
  • Source most commonly an infected cat.
  • Zoonotic.

Pathological effects

  • Dermatophytes are able to hydrolyze keratin and cause some damage to the epidermis and hair follicle. Histologically hyperkeratosis and folliculitis is reported. A cell-mediated hypersensitivity reaction is then mounted and the fungus moves away from the site of inflammation to normal skin. This causes the classic ringworm circular lesion with healing at the center and inflammation at the edge.
  • Lesions may occur anywhere on the body.

Other Host Effects

  • Can cause subclinical or inapparent infection in the host animal; causes persistent sub-clinical infection in long-haired cats. Asymptomatic carrier rabbits have been identified.
  • It is believed immunosuppressed animals are more susceptible to infection.


Control via chemotherapies

  • Topical: enilconazole   Enilconazole  , clotrimazole, tolnaftate, natamycin, ketoconazole although these are not licensed for this use in the rabbit.
  • Oral: griseofulvin   Griseofulvin  , terbinafine, itraconazole, ketoconazole.

Control via environment

  • In infected rabbit colonies, in-contact rabbits should also be treated.
  • Spores can remain viable for long periods in environment so attention to hygiene is crucial.

Other countermeasures

  • Hair should be clipped from affected areas.


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Further Reading


Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Pinter L, Ellis H J, Ciclitira P J et al (1995) Production and use of monoclonal antibodies to Microsporum canis. Vet Microbiol 46 (4), 435-444 PubMed.
  • White-Weithers N & Medleau L (1995) Evaluation of topical therapies for the treatment of dermatophyte-infected hairs from dogs and cats. JAAHA 31 (3), 250-253 PubMed.
  • Sparkes A H, Gruffydd-Jones T J, Shaw S E et al (1993) Epidemiological and diagnostic features of canine and feline dermatophytosis in the United Kingdom from 1956 to 1991. Vet Rec 133 (3), 57-61 PubMed.
  • Vogtsberger L M, Harroff H H, Pierce G E et al (1986) Spontaneous dermatophytosis due to Microsporum canis in rabbits. Lab Anim Sci 36 (3), 294-297 PubMed.