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.
- Erythema and edema.
- Alopecia Alopecia: overview.
- Miliary dermatitis Dermatitis: miliary
.
- Eosinophilic granuloma complex Eosinophilic granuloma complex.
Pathogenesis
Etiology
Arthropods
- Ticks :
- Mites :
- Dermanyssus gallinae Dermanyssus gallinae.
- Lynxacarus radovsky Lynxacarus radovsky.
- Trombiculaspp (trombiculiasis) Neotrombicula autumnalis infestation.
- Otodectes cynotis Otodectes cynotis.
- Cheyletiella blakei (cheyletiellosis) Cheyletiellosis.
- Demodex cati (demodicosis) Demodectic mange also short Demodex species.
- Notoedres cati (notoedric mange) Notoedres cati (head mange).
- Sarcoptes scabiei (sarcoptic mange) Sarcoptic mange.
- Spiders Spider bites .
- Insects :
- Lice (pediculosis) Pediculosis.
- Fleas Flea bite hypersensitivity.
- Fly dermatitis.
- Mosquito dermatitis.
- Myiasis Myiasis.
- Cuterebra spp infestation.
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
- Haemobartonella felis (feline haemobartonellosis) Mycoplasma haemofelis, 'Candidatus Mycoplasma haemominutum' and 'Candidatus Mycoplasma turicensis'.
Protozoa
- Toxoplasma gondii (toxoplasmosis) Toxoplasmosis.
- Leishmania spp (leishmaniasis) Leishmania donovani.
- Sarcocystis spp (feline sarcocystosis).
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 cynotis, Trombicula 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
- 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
- Hookworm eggs Fecal analysis: parasites.
Differential Diagnosis
Pruritus, pruritic alopecia and excoriation
- Fleabite hypersensitivity Flea bite hypersensitivity.
Pustules, papules, crusts, hyperpigmentation, lichenification and scaling
- Fleabite hypersensitivity Flea bite hypersensitivity.
- Dermatophytosis Dermatophytosis.
Non-pruritic alopecia
- As for alopecia Alopecia: overview.
Otitis externa
- As for otitis externa Otitis externa .
Lymphadenopathy
- As for lymphadenopathy.
Nodules
- Foreign body reaction.
- Neoplasia Skin: neoplasia.
- Infection Bacterial skin disease: overview.
Pruritus, pruritic alopecia and excoriation
- Feline poxvirus Cat pox disease.
- Bacteria Bacterial skin disease: overview.
- Atopy Skin: atopic dermatitis.
- Food hypersensitivity Food hypersensitivity.
- Contact irritant dermatitis/hypersenstivity Skin: allergic contact dermatitis.
Pustules, papules, crusts, hyperpigmentation, lichenification and scaling
- Feline pox virus Cat pox disease.
- Bacteria Bacterial skin disease: overview.
- FIV Feline immunodeficiency virus disease, FIP Feline infectious peritonitis, FeLV Feline leukemia virus disease.
- Feline acne Feline acne.
- Atopy Skin: atopic dermatitis.
- Food hypersensitivity Food hypersensitivity.
- Contact irritant dermatitis/hypersensitivity Skin: allergic contact dermatitis.
- Tail-gland seborrhea Stud tail.
- Cutaneous neoplasia Skin: neoplasia.
- Immune-mediated skin disease Skin: immunological disease - overview.
- Drug eruption Drug eruption.
- Solar dermatitis Dermatitis: solar.
Non-pruritic alopecia
- As for alopecia Alopecia: overview.
Otitits externa
- As for otitis externa Otitis externa.
Pododermatitis
- Infection Bacterial skin disease: overview.
- Trauma and foreign bodies.
- Irritant contact dermatitis Skin: allergic contact dermatitis.
- Acral lick dermatitis.
- Bacteria Bacterial skin disease: overview.
- Hypersensitivity Skin: immunological disease - overview.
Lymphadenopathy
- Lymphadenopathy.
Nodules
- Eosinophilic granuloma complex Eosinophilic granuloma complex.
- Arthropod-bite granuloma.
Pruritus, pruritic alopecia and excoriation
- Neoplasia Skin: neoplasia.
- Contact irritant dermatitis/hypersensitivity Skin: allergic contact dermatitis.
- Mosquito hypersensitivity.
- Essential fatty acid deficiency Skin: fat responsive dermatosis.
- Hypereosinophilia Hypereosinophilia.
- Malassezia dermatitis Malassezia pachydermatis.
- Collagenolytic granuloma (linear form).
Causes of pustules, papules, crusts, hyperpigmentation, lichenification and scaling
- Contact irritant dermatitis Skin: allergic contact dermatitis.
- Lentigo.
- Impetigo.
- Drug eruption Toxic epidermal necrolysis.
- Primary keratinization disorders.
- Nutritional disorders.
- Low humidity.
Non-pruritic alopecia
- Alopecia Alopecia: overview.
Pododermatitis
- Plasma cell pododermatitis Plasma cell pododermatitis.
- Autoimmune diseases Skin: immunological disease - overview.
- Drug eruption Drug eruption.
- Hookworm dermatitis.
- Neoplasia Skin: neoplasia.
- Anatrichosomiasis.
Local edema
Nodules
- Xanthomatosis.
- Panniculitis Skin: panniculitis.
- Sterile nodular granuloma and pyogranuloma.
- Leishmaniasis Leishmaniasis.
- Spider bite.
- Dracunuliasis.
- Cuterebra larvae.
Treatment
Standard Treatment
- Antiparasitic drugs Therapeutics: parasiticide.
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.