Dog Owner's Home Veterinary Handbook.pdf - Mr. Walnuts

530 •DOG OWNER’S HOME VETERINARY HANDBOOK
Common Surface Tumors
Skin tumors are common in dogs. It is often impossible to determine whether
a skin tumor is benign or malignant by appearance alone. The only conclusive
way to make a diagnosis is by biopsy, a procedure in which tissue or cells are
removed by your veterinarian and examined under a microscope by a veterinary
pathologist.
For small tumors it is best for your veterinarian to remove the growth and
present the entire specimen to the pathologist. For tumors larger than 1 inch
(2.5 cm) across, it may be advisable for your veterinarian to obtain a tissue
sample by fine needle aspiration. In this procedure, a needle connected to a
syringe is inserted into the tumor and cells are obtained by pulling back on the
plunger. Alternatively, the vet can use a cutting needle to obtain a core sample.
An open biopsy, in which an incision is made, is preferred for suspected
sarcomas and tumors that present diagnostic problems for the pathologist.
Additional information on the size of the tumor and the extent of local
involvement may be important in planning treatment. Ultrasonography, available
in many veterinary clinics, provides diagnostic information that cannot
be obtained through conventional X-rays. CT scans and MRI are used to diagnose
some internal cancers and determine the extent of local involvement.
They are available at veterinary medical centers.
SKIN PAPILLOMAS
Skin papillomas are benign wartlike growths that occur on the skin of the
body, on the foot pads, and beneath the nails. They are caused by the canine
oral papilloma virus and tend to occur in older dogs, especially older Poodles.
Treatment: They do not need to be removed unless they are causing a
problem because of their location on the body. Rarely, these will become
injured and bleed or get infected. In these cases, removal is recommended.
HEMATOMAS
A hematoma is a blood clot beneath the skin, caused by a blow or contusion.
These are not cancers. Large ones may need to be drained. Ear flap
hematomas require special attention (see Swollen Pinna, page 210).
Calcifying hematomas are hard masses that resemble bone. They tend to
occur at fracture sites, and may be found as a bump on the skull of a tall dog
who strikes her head on the underside of the dining room table.
Treatment: Calcifying hematomas do not need be removed but may have
to be biopsied if there is a question of bone tumor. They are difficult to treat
and often recur.