Page 1081 - Problem-Based Feline Medicine

51 – THE CAT WITH SKIN LUMPS AND BUMPS 1073

– It is recommended that these vaccines be given in ● If a sarcoma is identified, then wide or radical sur-
a distal location when possible, so that the limb gical excision should be performed.
may be amputated if a sarcoma develops, thus
Test for FeLV to reduce the suspicion of FeSV-related
sparing the cat’s life.
sarcoma.
– Other vaccines should be given over the lateral
shoulders away from the interscapular site. Although the rate of distant metastasis is low, it is rec-
● Single-dose vial usage is recommended. ommended that thoracic radiographs be performed
– Multi-vaccine products should be avoided. prior to excisional surgery.
● When giving booster vaccinations, previous vac-
Wide surgical excision with margins of up to 5 cm has
cine sites should be avoided.
been recommended. Margins should be evaluated via
● In the past, it has been suggested that IM adminis-
histology.
tration be performed instead of SQ injection. This
may only result in more difficult detection, reduc- Wide surgical excision with less than 5 cm performed at
ing the chance of early detection and surgical cure. the first occurrence with adjuvant external beam radia-
● Monitoring for masses occurring in common vacci- tion therapy has a good chance of long term control of
nation sites should be performed by owners and this cancer.
reported to the veterinarian.
Recurrent tumors are always more difficult to manage
– Vaccine-associated granulomas are common.
than the initial tumor with adjustments external been
A recent study evaluated cats receiving rabies
radiation thoraphy.
vaccines from four different manufacturers, and
found that 100% of the cats developed local
reactions. Reactions often occurred within a few FOREIGN BODY*
weeks, and resolved by 1–2 months later.
● Do not vaccinate cats that have had a prior history Classical signs
of a vaccine-associated sarcoma.
● Mass under the skin, often with a
discharging sinus.
GUIDELINES FOR RECORDING ● Swelling may “come and go” and may be
SUSPECTED CASES OF VACCINE- chronic.
ASSOCIATED SARCOMA

The location, vaccine type, manufacturer, serial numbers Pathogenesis
of the vaccine should be recorded in each patient’s record.
Any foreign body under the skin may result in an abscess
All other medications administered subcutaneously or or chronically draining lesion. The foreign body is usu-
intramuscularly should be recorded as well. ally of plant origin such as a grass seed or awn, but may
Any vaccine response, whether inflammatory or neo- even be a tooth broken off during a cat fight.
plastic, should be reported to the vaccine manufacturer.
● Also report outcome of the case as it becomes known.
Clinical signs
Typically there is an acute onset of a soft tissue
MANAGEMENT OF VACCINE-ASSOCIATED swelling under the skin, which can occur anywhere on
SARCOMA IN CATS the body.

If a mass in a vaccine site persists for longer than The swelling may be acute or chronic.
®
1 month, or if it exhibits rapid growth, a Tru-cut ,
Purulent material sometimes drains from a sinus in
wedge or excisional biopsy should be performed.
the mass.
● If a granuloma is identified, a conservative resec-
tion may be planned, if excision was not already The swelling is variably painful, and is often less
performed. painful if chronic.