Contributors: Rosanna Marsella, Ian Mason, David Scarff
Species: Feline | Classification: Diseases
Introduction Pathogenesis Diagnosis Treatment Outcomes Further Reading
Introduction
- An uncommon feline dermatosis (except subcutaneous abscessation Abscess which is common!).
- Cause: surface, superficial and deep bacterial infections.
- Signs: pustules, nodules and draining tracts +/- a range of other primary and secondary lesions.
- Diagnosis: microscopic examination of stained smears, bacterial culture and histopathology.
- Treatment: antibiotics; surgical resection of nodules.
- Prognosis: good for surface and superficial infections, poor for some deep infections.
Presenting Signs
Pathogenesis
Etiology
- Staphylococcus intermedius Staphylococcus intermedius.
- Staphylococcus aureus Staphylococcus aureus.
- Staphylococcus hyicus Staphylococcus spp.
- Pasteurella multocida Pasteurella multocida.
- Streptococcus spp. Streptococcus spp.
- Nocardia spp. Nocardia spp.
- Actinomycoses spp. Actinomyces pyogenes Actinomyces viscosus.
- Mycobacterium spp. Mycobacterium lepraemurium.
- Escherichia coli Escherichia coli.
- Pseudomonas spp Pseudomonas spp.
- Proteus spp.
- Dermatophilus Dermatophilus congolensis.
- Yersinia pestis Yersinia pestis.
- Bacterial L-forms.
- Mycoplasma spp Mycoplasma and Ureaplasma.
Predisposing Factors
General
- Superficial pyoderma: unclear.
- Surface and deep pyoderma: trauma.
Pathophysiology
- Unclear.
Diagnosis
Presenting Problems
- Discharging sinuses.
- Pustules.
- Pruritus.
- Alopecia.
Client History
Clinical Signs
Typical lesions
- Nodules.
- Discharging sinuses.
- Ulceration.
- Pustules.
- Papules.
- Crusts.
Typical clinical forms
- Pruritus.
- Lymphadenopathy.
- Alopecia.
- Surface pyoderma .
- Superficial pyoderma
(folliculitis).
- Deep folliculitis and furunculosis
.
- Feline acne
.
- Subcutaneous abscess Abscess
.
- Cellulitis.
- Mycobacterial infections Mycobacterium tuberculosis Skin: panniculitis due to rapidly growing mycobacteria Feline leprosy .
- Actinomycosis Actinomyces viscosus Actinomycosis.
- Nocardiosis Nocardia spp Nocardiosis.
- Feline mycoplasmal Mycoplasma and Ureaplasma and bacterial L form-induced abscesses L-form bacteria.
Diagnostic Investigation
Microbiology
- Pathogenic bacteria.
- Microscopy - Diff-Quik or Gram-stained smears of exudate, fine needle aspirate or impression smear Skin: impression smear. Modified Ziehl-Nielsen Stain for acid test bacilli.
- Superficial pyoderma: cellular exudate comprising primarily healthy and degenerative neutrophils with intracellular and extracellular bacteria.
Bacteriology
- See Bacteriology overview Bacteriology.
- If deep pyoderma suspected.
- Culture from biopsy sample or discharge from draining tracts if tissue granules present.
- Special stains Histopathology: special stains required for certain bacteria.
Histopathology
- If deep pyoderma or mycobacterial disease or pseudomycetoma suspected.
Differential Diagnosis
Causes of nodules, ulceration and discharging sinus
- Neoplasia Skin: neoplasia.
- Foreign body reaction.
- Immune-mediated skin disease Skin: immunological disease - overview.
- Physical causes.
- Ectoparasites Parasitic skin disease: overview.
- Eosinophilic granuloma complex Eosinophilic granuloma complex.
- Arthropod-bite granuloma.
- Panniculitis.
- Xanthomatosis.
- Sterile nodular granuloma and pyogranuloma.
- Parasitic skin disease Parasitic skin disease: overview.
Causes of pruritus, pustules, papules and crusts
- Flea bite hypersensitivity Flea bite hypersensitivity.
- Ectoparasites Parasitic skin disease: overview.
- Dermatophytosis Dermatophytosis.
- Feline pox virus Cat pox disease.
- Food hypersensitivity Food hypersensitivity.
- Atopy Skin: atopic dermatitis.
- Contact irritant dermatitis Skin: allergic contact dermatitis.
- Collagenolytic granuloma (linear form).
- FIV Feline immunodeficiency virus disease, FIP Feline infectious peritonitis, FeLV Feline leukemia virus disease.
- Tail-gland seborrhea Stud tail.
- Cutaneous neoplasia Hair follicle: neoplasia.
- Immune-mediated skin disease Skin: immunological disease - overview.
- Drug eruption Drug eruption.
- Solar dermatitis Dermatitis: solar.
- Contact hypersensitivity Skin: allergic contact dermatitis.
- Mosquito hypersensitivity.
- Essential fatty acid deficiency Skin: fat responsive dermatosis.
- Hypereosinophilia.
- Malassezia dermatitis Malassezia pachydermatis.
- Lentigo.
- Linear IgA dermatosis.
- Primary keratinization disorders.
- Nutritional disorders Skin: disease - malnutrition.
- Low humidity.
Alopecia
- Other causes of alopecia.
Treatment
Initial Symptomatic Treatment
- Topical and systemic antimicrobial therapy Therapeutics: antimicrobial drug Therapeutics: skin .
- Surgical excision of solitary nodules.
Subsequent Management
Monitoring
- Subsequent history and clinical findings.
Outcomes
Prognosis
- Surface and superficial pyoderma: good.
- Deep pyoderma: good to poor.
Expected Response to Treatment
Reasons for Treatment Failure
- Concurrent corticosteroid therapy.
- Inappropriate use of antibiotics, eg underdosing - dose +/- duration.
Further Reading
Publications
Refereed papers
- Recent references from PubMed and VetMedResource.
- Kennis R A, Wolf A M (1999) Chronic bacterial skin infections in cats. Comp Contin Educ Pract Vet 21 (12), 1108-1115 VetMedResource.
- Ihrke P J (1984) Therapeutic strategies involving antimicrobial treatment of the skin in small animals. J Am Vet Med Assoc 185 (10), 1165-1168 PubMed.
- Thoday K (1981) Skin disease of the cat. Vet Rec 109 (21), 22-35 PubMed.