Contributors: Rosanna Marsella, David Scarff

 Species: Feline   |   Classification: Diseases

Introduction Pathogenesis Diagnosis Treatment Outcomes Further Reading

Introduction

  • One of the most common causes of dermatoses in cats.
  • Cause: exposure of skin to ectoparasites +/- allergenic nature of parasite +/- excretory products.
  • Signs: range from mild to severe skin lesions +/- systemic involvement.
  • Diagnosis: identification of parasite by naked eye, microscopy or fecal examination.
  • Treatment: parasiticides.
  • Prognosis: good.

Presenting Signs

  • Pruritus.

Pathogenesis

Etiology

Arthropods

Hymenoptera 

  • Bees.
  • Wasps.
  • Hornets.
  • Moths.
  • Ants.
  • Caterpillars.

Helminths

  • Ancylostoma braziliense, Ancylostoma caninum, Uncinaria stenocephala (ancyostomiasis and uncinariasis, hookworm dermatitis).
  • Pelodera strongyloides (pelodera dermatitis).
  • Anatrichosoma cutaneum (anatrichosomiasis).
  • Schistosomiasis.
  • Dracunculus spp. (dracunculiasis).
  • Lagochilascaris major.

Rickettsia

Protozoa

Diagnosis

Presenting Problems

  • Pruritus.
  • Pruritic alopecia and excoriation.
  • Erythema.
  • Pustules and papules.
  • Crusts.
  • Hyperpigmentation.
  • Lichenification.
  • Scaling.
  • Non-pruritic alopecia.
  • Otitis externa Otitis externa.
  • Pododermatitis.
  • Lymphadenopathy.
  • Local edema.
  • Nodules.

Client History

  • Excessive grooming.
  • Scratching.
  • Localized, multifocal or generalized hair loss.
  • Dandruff.
  • Scab formation.
  • Observation of parasites (fleas, lice, ticks, Trombicula spp, flies, mosquitoes, bees, wasps, hornets, ants, caterpillars).
  • Skin lesions on owner.
  • Seasonal occurrence.
  • Head shaking.
  • Discharge from ear canal.
  • Crusts.
  • Hyperpigmentation.
  • Malodor.
  • Depression.

Clinical Signs

  • Severe to mild pruritus.
  • Excoriation and alopecia as a result of self-trauma.
  • Inflammation and edema.
  • Erythema, pustules, papules and crust formation.
  • Miliary dermatitis.
  • Hyperpigmentation and lichenification in chronic cases.
  • Scaling.
  • Observation of parasites (fleas, lice, ticks, Otodectes cynotisTrombicula spp, flies, mosquitoes, bees, wasps, hornets, ants, caterpillars).
  • Symmetrical alopecia.
  • Non-pruritic alopecia.
  • Eosinophilic granuloma complex.
  • Otitis externa.
  • Hyperesthesia.
  • Pododermatitis.
  • Regional or generalized lymphadenopathy.
  • Nodule formation.
  • Systemic signs.

Diagnostic Investigation

Other

  • Coat brushing positive for flea feces Flea feces - wet paper test .
  • Microscopy:
    • Skin scrape Scraping: skin: mites.
    • Acetate strippings: mites and/or eggs.
  • Otoscopic examination
    • Otodectes cyonitis.
  • Parasiticide therapeutic trial:
    • Regression of clinical signs of flea infestation.

Fecal analysis

Differential Diagnosis

Pruritus, pruritic alopecia and excoriation

Pustules, papules, crusts, hyperpigmentation, lichenification and scaling

Non-pruritic alopecia

Otitis externa

Lymphadenopathy

  • As for lymphadenopathy.

Nodules

Pruritus, pruritic alopecia and excoriation

Pustules, papules, crusts, hyperpigmentation, lichenification and scaling

Non-pruritic alopecia

Otitits externa

Pododermatitis

Lymphadenopathy

  • Lymphadenopathy.

Nodules

Pruritus, pruritic alopecia and excoriation

Causes of pustules, papules, crusts, hyperpigmentation, lichenification and scaling

Non-pruritic alopecia

Pododermatitis

Local edema

Nodules

  • Xanthomatosis.
  • Panniculitis Skin: panniculitis.
  • Sterile nodular granuloma and pyogranuloma.
  • Leishmaniasis Leishmaniasis.
  • Spider bite.
  • Dracunuliasis.
  • Cuterebra larvae.

Treatment

Standard Treatment

Outcomes

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Messinger L M (1995) Therapy for feline dermatoses. Vet Clin North Am Small Anim Pract 25 (4), 981-1005 PubMed.
  • Noxon J O (1995) Diagnostic procedures in feline dermatology. Vet Clin North Am Small Anim Pract 25 (4), 779-799 PubMed.
  • Power H T & Ihrke P J (1995) Selected feline eosinophilic skin diseases. Vet Clin North Am Small Anim Pract 25 (4), 833-850 PubMed.
  • Foley R H (1991) Parasitic mites of dogs and cats. Comp Contin Educ 13 (5), 783-800 VetMedResource.

Other sources of information

  • Nesbitt G H and Ackerman L J Dermatology for the Small Animal Practitioner. Veterinary Learning Systems Co, 1991. p 32. (Excellent Table of common parasitic diseases with history, clinical signs and diagnosis.)
  • Scott D W, Miller W H and Griffin C E Muller and Kirk's Small Animal Dermatology. 5th edn. Philadelphia: W B Saunders Company, 1995. pp 392-468. (Detailed dermatology text book for in-depth reading.)
  • Guaguere E & Prelaud P (2000) Guide Pratique de Dermatologie Feline Lyon: Merial.

Other Sources of Information