Bovis ISSN 2398-2993

Trichophyton spp

Synonym(s): Ringworm, Dermatophytosis

Contributor(s): Catherine Fraser , Alan Murphy

Introduction

Classification

Taxonomy

  • Genus: Trichophyton.
  • Species: equinum, erinacei, mentagrophytes, quinckeanum, simii, verrucosum.

Etymology

  • Gk:trikho- hair; phyton- plant.

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Clinical Effects

Epidemiology

Habitat

  • Trichophyton species inhabit mammalian hosts (zoofilic dermatophytes).
  • Can transfer to in-contact humans  .

Transmission

  • Direct and indirect (fomite) contact.

Pathological effects

  • Antibody-mediated and cell-mediated hypersensitivities involved in pathogenesis.
  • Antibodies not important in resistance.
  • Recovered animals are resistant to reinfection, but may show severe local reactions on exposure.
  • Proteolytic enzymes   →   virulence.
  • Infectious conidium enters through skin defect   →   germination   →   mycelium develops in cornified epithelium   →   hair invasion   →   ectothrix arthroconidial accumulation.
  • Site of lesions depends on reservoir and transmission, eg T. verrucosum in calves often facial, spread through bucket feeding and licking at other pen mates .
  • T. equinum survives in fomites such as halters, calf jackets and housing, particularly wood and permeable housing materials, where cleaning may not be as effective Ringworm: disease.

Other Host Effects

  • Some species have become adapted for survival in the skin of specific host species, ie they are zoophilic, eg T. equinum (horses), T. erinacei (European hedgehogs), T. mentagrophytes (rodents),  T. verrucosum (cattle).

Control

  • Spontaneous regression without treatment is common. Ringworm likely to be killed by UV light so often regresses at turnout.
  • Topical treatment does not shorten the course of disease but may limit spread of infection
    • Miconazole.
    • Tolnaftate. 
    • Thiabendazole. 
    • Sodium hypochlorite. 
    • Tamed iodine.
    • Lime sulfur 2%.
    • Enilconazole 0.2%.
    • Natamycin spray 100 ppm. 
  • Of the above only enilconazole is licensed in the UK.
  • Topical treatment may decrease spread.

Control via environment

  • Avoid contamination of fomites.
  • Thorough cleaning eg steam cleaning of buildings between batches of livestock.

Vaccination

Diagnosis

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Further Reading

Publications

Refereed Papers

Other sources of information

  • Van Cutsem J & Rochette R (1991) Mycoses in Domestic Animals. Janssen Research Foundation.
  • Biberstein E L (1990) Dermatophytes. In: Review of Veterinary Microbiology. Eds: Biberstein E L & Zee Y C. Blackwell Scientific, Boston. pp 272-279. ISBN: 0 86542 085 8.

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