Page 1125 - Problem-Based Feline Medicine

53 – THE CAT WITH PAW OR PAD PROBLEMS 1117

or secondary. Secondary neoplasia results from metas- Bacterial or fungal infections, especially the rarer
tasis of primary neoplasia in other organs. opportunistic ones, can look very similar. Biopsy for
histopathology and culture will distinguish between
Squamous cell carcinoma.
these.
● Rare primary tumor arising from the nail bed
epithelium.
● Appears to be more aggressive than squamous cell Treatment
carcinomas in other parts of the body.
Radical surgical excision is the treatment of choice for
● On clinical examination it may be mistaken for
tumors without evidence of metastasis.
paronychia or pyoderma.
Mean survival for metastatic digital carcinoma was 67
Metastatic digital (ungual) carcinoma.
days.
● Usually presents as lameness associated with multi-
centric digital carcinoma.
● Seen in aged cats (average age 13 years) with
asymptomatic bronchogenic carcinoma or squa- PEMPHIGUS*
mous cell carcinoma of the lung.
● Lesions can involve a number of digits and more Classical signs
than one paw. Typically there is swelling of the
● Crust, scales, alopecia in a symmetrical
digit, ulceration of the skin or purulent discharge,
pattern.
and either fixed exsheathment, deviation or loss of
● Areas usually involved are face, ears,
the nail.
trunk, feet and mucocutaneous junctions.
Fibrosarcoma. ● Occasionally have only foot lesions.
● Seen in older cats and is not associated with feline
sarcoma virus.
Pathogenesis
● Lesions are usually solitary and can involve the digits.
● The area is alopecic, ulcerated and the tumor has Pemphigus is an immune-mediated disease, with
rapid infiltrative growth. auto-antibodies directed against intercellular cement in
the epidermis causing loss of cohesion between ker-
Undifferentiated sarcoma.
atinocytes and resulting in the formation of bullae.
● Seen in older cats and involves the footpads of one
● Bullae are very transient in cat skin due to the thin
or more feet.
epidermis, and may not be observed.
● Affected pads are soft, mushy, painful and maybe
ulcerated. What initiates the auto-antibodies is unknown, but
drugs and chronic skin disease have been implicated
Malignant fibrous histiocytoma.
in some cases.
● Seen in older cats.
● The lesions are solitary, firm, poorly circumscribed, Different types of autoimmune dermatitis may involve
variable in size and shape and locally invasive. cats’ paws but the most common is Pemphigus foli-
● Legs, especially the paw, and shoulders are the aceus.
most common sites.
Clinical signs
Diagnosis Erythema, oozing, crusts, scales and alopecia occur
Biopsy of representative areas and histopathology. with a symmetrical pattern on the face, ears, trunk,
feet and mucocutaneous junctions.

Lesions commonly involve the feet and footpads, caus-
Differential diagnosis
ing hyperkeratosis and ulceration. Some cats are pre-
Plasma cell pododermatitis also has swollen mushy sented with only footpad lesions and sometimes
pads, which may be ulcerated. lameness.