Felis ISSN 2398-2950

Leprosy

Synonym(s): Feline leproid granuloma syndrome

Contributor(s): Prof Richard Malik, Severine Tasker

Introduction

  • CauseMycobacterium lepraemurium. Infection is often assumed as it is very difficult to culture. M. lepraemurium causes murine leprosy, a systemic mycobacterial infection of rats. Cats are thought to contract M. lepraemurium following bite injuries from infected rodents but infections with other mycobacterial species are also included in feline leprosy; notably an as yet unidentified mycobacterial species and M.visibile.
  • Signs: single or multiple granulomas form in the skin or subcutis in association with large numbers of acid-fast bacilli (AFB).
  • Diagnosis: cytology and histopathology. Culture rarely rewarding. 
  • Treatment: surgical excision for localized cases; combination drug therapy.
  • Prognosis: generally good.

Pathogenesis

Etiology

  • Feline leprosy comprises several clinical syndromes:
    • One tending to occur in young immunocompromised cats caused by M lepraemurium Mycobacterium lepraemurium.
    • Another in immunosuppressed elderly cats caused by a single novel mycobacterium species.
    • A syndrome (also called 'feline multisystemic granulomatous mycobacteriosis') due to M.visibile that gives rise to diffuse (rather than nodular) cutaneous disease and widespread dissemination to multiple internal organs.
  • The existence of multiple diseases in feline leprosy, rather than one, clearly has important implications for prevention, diagnosis and therapy.
  • The usual initial location of lesions around the head or limbs suggests that source of infection may be via bite wounds sustained during hunting of rodents.

Predisposing factors

General

Pathophysiology

  • The usual initial location of lesions around the head or limbs suggests that source of infection may be via bite wounds sustained during hunting of rodents - route of entry.
  • Pyogranulomatous inflammation occurs.
  • Hematogenous or lymphatic spread of organisms may account for more disparate spread of lesions in some cases.

Timecourse

  • Incubation period can vary from 2 months to 1 year or more.

Diagnosis

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Treatment

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Prevention

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Outcomes

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Lamagna B, Paciello O, Ragozzino M et al (2009) Isolated lepromatous conjunctivo-corneal grnauloma in a cat from Italy. Vet Ophthalmol 12 (2), 97-101 PubMed.
  • Courtin F, Huerre M, Fyfe J et al (2007) A case of feline leprosy caused by Mycobacterium lepraemurium originating from the island of Kythira (Greece): diagnosis and treatment. J Feline Med Surg (3), 238-241 PubMed.
  • Moriello K A (2007) Clinical snapshot. Feline leprosy. Compend Contin Educ Vet 29 (5), 256, 261 PubMed.
  • Hughes M S, James G, Taylor M J et al (2004) PCR studies of feline leprosy cases. J Fel Med Surg (4), 235-243 PubMed.
  • Appleyard G D, Clark E G (2002) Histologic and genotypic characterization of a novel Mycobacterium species found in three cats. J Clin Microbiol 40 (7), 2425-2430 PubMed.
  • Cavanagh R, Bego M, Bennett M et al (2002) Mycobacterium microti infection (vole tuberculosis) in wild rodent populations. J Clin Microbiol 40 (9), 3281-3285 PubMed.
  • Malik R, Hughes M S, James G et al (2002) Feline leprosy: two different clinical syndromes. J Fel Med Surg (1), 43-59 PubMed.
  • Rojas-Espinosa O, Løvik M (2001) Mycobacterium leprae and Mycobacterium lepraemurium infections in domestic and wild animals. Rev Sci Tech 20 (1), 219-251 PubMed.
  • Hughes M S, Ball N W, Love D N et al (1999) Disseminated Mycobacterium genavense infection in an FIV-positive cat. J Fel Med Surg (1), 23-29 PubMed.
  • Hughes M S, Ball N W, Beck L A et al (1997) Determination of the etiology of presumptive feline leprosy by 16S rRNA Gene Analysis. J Clin Microbiol 35 (10), 2464-2471 PubMed.
  • Peters D H, Clissold S P (1992) Clarithromycin. A review of its antimicrobial activity, pharmacokinetic properties and therapeutic potential. Drugs 44 (1), 117-164 PubMed.
  • Matthews J A, Liggitt H D (1983) Disseminated mycobacteriosis in a cat. J Am Vet Med Assoc 183 (6), 701-702 PubMed.

Other sources of information

  • Malik R, Hughes M S, Martin P & Wigney D (2006) Feline leprosy syndromes. In :Infectious diseases of the Dog & Cat. 3rd edn. Greene C E (ed), W B Saunders Co., Philadelphia, PA. pp 477-480.
  • Wilkinson G T, Mason K V (1991) Chapter 19: Clinical Aspects of Mycobacterial Infections of the Skin. In: August, JR, ed. Consultations in Feline Internal Medicine. WB Saunders, Philadelphia, p 129-136.


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