Page 1122 - Problem-Based Feline Medicine

1114 PART 13 CAT WITH SKIN PROBLEMS

Pathogenesis Transmission

Infection is caused by a virus from the orthopoxvirus The natural reservoir for infection is not known, but is
genus. The origin of the virus is unclear. It was attrib- thought to be small wild animals and the cat is infected
uted to the cow-pox virus, but now it is thought there whilst hunting them.
could be a feline pox virus.
Transmission of cow pox virus from infected milk has
Reported infections are from England and Europe. also been blamed.
The pox virus can be transmitted to in-contact cats,
Clinical signs dogs and humans; immunocompromised individuals
are more at risk. Warn in-contact people of the zoonotic
Skin lesions occur on the face, ears, limbs and paws
potential.
with multiple papules, vesicles, plaques or crusts
and ulcers. The virus is killed by most disinfectants, particularly
chlorine-based ones.
On the feet there can be paronychia and sloughing of
the footpads.
Prevention
Diagnosis Prevent the cat from hunting or contact with an infected
cat.
Biopsy and histologic examination of the crust or
affected skin demonstrates eosinophilic intracytoplas-
mic inclusion bodies within keratinocytes.
INSECT BITE HYPERSENSITIVITY**
Specialist tests that may be available also include a
serologic test for virus-neutralizing antibodies, electron
Classical signs
microscopy of crusts or affected skin to detect the virus,
and virus isolation. Virus isolation is currently the only ● Erythematous, crusted, pruritic lesions.
method for making a precise diagnosis. ● Symmetric lesions on ear tips, face, nose
and footpads.
Differential diagnosis
Bacterial and fungal infections, eosinophilic granu- Pathogenesis
loma and neoplasia may all cause similar lesions but
Hypersensitivity resulting in skin lesions is associated
can be differentiated on biopsy and histological exami-
with flying and biting insects.
nation.
It is most often seen in cats that go outdoors when
mosquitoes or midges (Lasiohelia townsvillensis) are
Treatment
present.
Treatment is not thought to affect the outcome of the
disease, and is not regarded as necessary as most cats Clinical signs
recover spontaneously within 1–2 months.
Thinly haired areas are most commonly affected, espe-
Secondary bacterial infection should be treated with
cially the bridge of the nose, ear tips and the junc-
antibiotics.
tion of haired skin and the footpad (“ears, nose and
Glucocorticoids are contraindicated. toes syndrome”).
Lesions have a symmetrical pattern, and begin with
Prognosis erythematous papules to plaques.

Prognosis is good as cats recover spontaneously, however, Lesions are pruritic, and the cat traumatizes itself, so
there may be permanent scarring. that the affected areas become ulcerated and crusted.