Viral Skin Disease

By | November 16, 2015

Cowpox

  • uncommon
  • mainly rural cats
  • infection may be from a rodent reservoir — not all affected cats have contact with cattle

Clinical features

  • papules, ulcers and particularly scabs develop at the site of cuts or bites, usually the head, neck or limbs
  • these lesions may become generalized to involve the entire body and oral mucous membranes, particularly if there is concurrent debilitating disease, or immunosuppressing viral infections such as feline leukaemia or feline immunodeficiency virus infection, or if glucocorticoids have been administered
  • affected cats may suffer from a transient dullness, but are not usually unwell; in a minority of cases there is dyspnoea, pyrexia, anorexia and depression
  • pruritus is commonly noted

Diagnosis

  • history
  • physical examination
  • virus isolation in tissue culture; send scabs and swabs in viral transport medium to the virology laboratory. Biopsy; eosinophilic intracytoplasmic inclusion bodies within keratinocytes
  • serological investigation, e.g. complement fixation, haema-gglutination inhibition or neutralization tests. May be of limited value in immunosuppressed cats and acutely ill cats

Differential diagnosis

  • bacterial folliculitis
  • ectoparasites
  • miliary dermatitis
  • dcrmatophyte infection

Treatment

  • supportive nursing
  • antibacterial agents to prevent secondary infection
  • glucocorticoids are contra-indicated since they may cause the infection to become generalized
  • resolution may take up to 2 months

Feline leukaemia virus (FeLV) infection

  • Feline leukaemia virus, due to immunosuppressive activity, may initiate or exacerbate a number of skin diseases; the most important of these are:
  • paronychia, particularly chronic and resistant cases
  • recurrent or chronic abscessation or cellulitis. There is frequently a history of response to antibacterial agents with rapid relapse when therapy ceases
  • seborrhoea
  • poor wound healing

Diagnosis

  • history
  • physical examination
  • bacterial and fungal culture, skin scrapings (rule-outs)
  • positive virus tests

Treatment

  • advise owner of the poor prognosis
  • euthanasia

Feline immunodeficiency virus (FIV)

FIV is associated with a multiplicity of clinical signs including gingivitis, stomatitis, neurological signs and chronic skin disease, particularly pyoderma

Diagnosis

  • positive virus tests

Treatment

  • euthanasia if severe disease
  • supportive therapy in milder cases

Feline herpes virus infection

  • uncommon
  • superficial ulceration of the skin and oral cavity
  • there is a variable course; most cases recover, a few die
  • diagnosis is by isolation of the virus from lesions

Treatment

  • supportive nursing
  • antibacterial cover

Feline calicivirus infection

  • rarely associated with cutaneous signs
  • reported cases had ulceration of the footpads, swollen painful feet and ulceration of the tongue, palate and lips

Canine distemper

  • in some cases of distemper there is a hyperkeratosis of the nose and footpads ()
  • in these dogs the planum nasale becomes hard and rough, and there may be fissures; the footpads are thickened, dry and cracked, and walking may be painful
  • recovery from distemper often leads to an improvement or resolution of the clinical signs

Diagnosis

  • history
  • physical examination
  • rule out other diseases

Differential diagnosis

  • ichthyosis
  • nasodigital hyperkeratosis
  • pemphigus foliaceus
  • discoid lupus erythematosus
  • systemic lupus erythematosus
  • zinc-responsive dermatosis

Treatment

  • trim excessive keratin
  • bathing to hydrate the keratin
  • apply petroleum jelly after bathing
  • topical antibacterial ointments

Papovavirus

Causes cutaneous and mucosal papillomas in the dog ()

Feline sarcoma virus

Causes cutaneous fibrosarcoma in young cats ()

Contagious ecthyma (orf)

  • primarily a sheep and goat disease caused by a paravaccinia virus
  • a few cases have been reported in dogs fed on sheep carcases
  • acute moist dermatitis, crusts and ulceration occur round the mouth and head

Diagnosis

  • history
  • physical examination
  • virus isolation

Treatment

  • supportive nursing
  • recovery may take up to 4 weeks

 

Selections from the book: “Skin Diseases in the Dog and Cat”. D. I. Grant, BVetMed (1991)