Peripheral nerve sheath tumors in cats and dogs

Peripheral Nerve Sheath Tumors in Cats and Dogs

Peripheral nerve sheath tumors are malignant tumors of nerve sheath origin and have also been referred to as
neurofibrosarcoma, malignant schwannoma, and hemangiopericytoma These tumors can affect nerves adjacent to as well
as away from the brain or spinal cord. In dogs and cats, peripheral nerve sheath tumors of the skin are found in older
animals. These tumors appear as white, firm nodules which can be either benign or malignant. In dogs, cats, and horses,
most are locally infiltrative but do not metastasize. They are similar to fibrosarcoma, most tend to infiltrate surrounding
tissues but are slow growing. Tumors that grow in the axial region may result in the compression of nerves, causing signs
of lameness, loss of muscle, paralysis and pain. They can invade the spinal cord but local disease usually limits survival
before metastasis occurs. Complete surgical removal is the treatment of choice, and in cases where the tumor could not be
completely removed, follow-up radiation therapy is recommended to kill any remaining cancer cells left behind by the
surgery.

Does cancer cause pain in pets?
Pain is common in pets with cancer, with some tumors causing more pain than others. In addition to pain caused by the
actual tumors, pets will also experience pain associated with cancer treatments such as surgery, radiation therapy or
chemotherapy. Untreated pain decreases the pet's quality of life, and prolongs recovery from the illness, treatment or
injury. It is, therefore, essential that veterinary teams that are taking care of pets with cancer should also play a vital role in
educating pet owners about recognizing and managing pain in their pets. The best way to manage cancer pain in pets is to
prevent it, a term referred to as preemptive pain management. This strategy anticipates pain ahead of time and
administers pain medication before the pet actually experiences pain, thus ensuring the pet's maximum comfort.

To learn more about which tumors are likely to cause a lot of pain, how to recognize pain in pets with cancer and what
cancer pain management options are available for your pet, please visit the Cancer Pain Management section.

How important is nutritional support for pets with cancer?
Cancer cachexia (a term referring to progressive severe weight loss) is frequently observed in pets with cancer. Pets with
cancer lose weight partly because of lack of appetite and partly because of cancer-induced altered metabolism. Some of
the causes for decreased appetite are related to the cancer itself (for example, tumors may physically interfere with food
chewing, swallowing, and digestion process) and some may be related to the side effects of cancer treatment (for example,
some chemotherapy drugs cause nausea and vomiting, and radiation therapy can cause mouth inflammation).

Proper nutrition while undergoing cancer treatment is essential to maintain your pet's strength, improve survival times,
quality of life and maximize response to therapy. Adequate nutritional support was shown to decrease the duration of
hospitalization, reduce post-surgery complications and enhance the healing process. Additionally, pets with cancer need to
be fed diets specifically designed to provide maximum benefit and nutritional support for the patient. To learn more, please
visit the Cancer Nutrition section.

How do I find a qualified veterinary oncologist?
To locate a qualified veterinary oncologist worldwide who can discuss with you appropriate cancer treatment plan for your
pet's cancer condition, please visit the "Locate a veterinary oncologist" section.

Are there any clinical trials investigating new treatments for peripheral nerve tumors in pets?
Although there are no trials specifically evaluating new treatments for peripheral nerve tumors, there are several clinical
trials available for cats and dogs with any tumor type for which your pet may qualify. To learn more these trials (which are
partially or fully funded by the institutions), please visit the Dog Clinical Trials (any tumor type) or C at C linical Trials (any
tumor type ) section.

To learn more about veterinary clinical trials in general, please visit the Pet Clinical Trials section.

Sources:

www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/72219.htm
Withrow Stephen J, and David M. Vail. Small Animal Clinical Oncology. St Louis: Saunders Elsevier, 2007.
Morrison Wallace B. Cancer in Dogs and Cats: Medical and Surgical Management. Baltimore: Williams&Wilkins, 1998.