Canine lymphoma
(lymphosarcoma) is the most common type of cancer to affect dogs, seen
as malignant tumors in a dogs organs, usually in the lymph nodes, liver
or spleen. Lymphoma can also
present in the digestive tract as well as in the eyes and skin.
In some dogs, this may occur at only one or two sites in the body but,
more commonly, it is widespread involving all the lymph glands and
internal organs.
There are four different types of canine lymphoma, categorized by the
area of growth as well as the organs that are affected.
1. Multicentric Lymphoma
Multicentric lymphoma is the most common type of lymphoma to affect
dogs, accounting for about 85% of all documented cases. This type
of lymphoma shows effects in the lymph nodes, and may or may not
involve other organs. Multicentric lymphoma typically does eventually
infiltrate the organs, and the tumor may begin to replace healthy organ
tissue. This causes death by organ failure, as the organ is eventually
unable to function.
2. Gastrointestinal Lymphoma
Gastrointestinal lymphoma involves cancerous growth around the
digestive tract, most commonly being present near the stomach.
This type of lymphoma can cause lack of appetite, malnutrition, and
fatigue. A gastrointestinal tumor can become especially dangerous
if located near the small or large intestine, since it can inhibit the
proper passage of waste from your dog's gastrointestinal tract.
3. Mediastinal Lymphoma
This type of lymphoma is typically present in the chest area, involving
the thorax and possibly affecting the lungs. Dogs with mediastinal
lymphoma often experience difficulty breathing, in addition to a
visible shortness of breath. If left untreated, mediastinal lymphoma
can cause death by suffocation, as the tumor's growth progresses to
eventually completely restrict the function of the lungs. This
type of lymphoma also will put your dog in a significant amount of
pain, usually centralized around the chest area. Surgery to remove
mediastinal lymphoma tumors is usually not recommended, and
chemotherapy is the best option.
4. Extranodal Lymphoma
Extranodal lymphoma is different from multicentric lymphoma
because it first appears outside of the lymphatic system, and then can
spread to become multicentric lymphoma. This type of lymphoma has
such a broad classification, because it can appear in so many different
areas of your dog's body. The type of symptoms present in your dog can
vary from each area affected, and will usually be visible in
degenerative effects on the specific system. This is the rarest type of lymphoma,
and refers to lymphoma that is specifically affecting one of six
different areas of your dog's body. These types include:
- Breast tissue
- Cutaneous tissue (skin)
- Hepatic tissue (liver)
- Ocular or Orbital tissue (eyes)
- Osteo tissue (bone)
- Oral tissue (mouth)
Lymphoma is a progressive and ultimately fatal disease unless treated.
In the early stages, the patient may be well but the cancer can have a
profound effect on the dog causing weakness, poor appetite, loss of
weight and general poor health. Currently, the cause of canine lymphoma
is not known. However, it is not a contagious disease and there is no
chance of spread to other pets or to humans. Without treatment, the
average survival time is about 4-6 weeks. In some rare cases it may
take several months to progress. With treatment, the majority of
patients will go into remission (i.e. the tumour is reduced to such a
small size that it is no longer apparent). This remission can be long
lasting but unfortunately, lymphoma is rarely cured outright.
The
Symptoms Of Lymphoma
|
Lumps
|
This
is one of the more obvious signs of possible lymphoma, though may be
harder to detect in dogs with thick fur. Abnormal lumps may appear in
the abdomen, back, armpits, or neck. These lumps will be
characteristically round and hard (not soft, like the fat deposits that
develop in some older dogs).
|
Lack
Of Appetite, Vomiting
|
Your
dog will be feeling unwell, and may begin to show a lack of enthusiasm
for mealtime. More food will remain in the dish after eating, or your
dog may lose interest in food altogether. In addition to this, your dog
may constantly be “hacking”, or vomit on a regular basis. All of these
are signs that your dog is suffering from a serious health problem, and
should be taken to a veterinarian immediately.
|
Fever
|
Detecting
a fever in your dog as a stand-alone symptom can be difficult, though
usually in cases of Lymphoma, a fever will be accompanied by several
other symptoms. A fever that is steady, reoccurring, or lasts for
longer than 3 days is a cause for concern.
|
Weight
Loss
|
May
dogs suffering from Lymphoma will appear to be depressed, and may cease
to be excited about daily activities. Rapid weight loss in your dog is
always a good reason to worry, as is one of the key symptoms of
lymphoma (as well as several other serious health conditions).
|
Diagnosis
1. Visual examination by your
vet
2. Urinalysis as well as a
blood panel tests are used to asses your dog's state of health.
3. Biopsy of one of the
enlarged lymph nodes to confirm diagnosis and to determine the
approximate progression of the cancerous tissue.
Treatment
Treatment
possibilities vary from basic drugs to complicated protocols
using a variety of drugs. The principal and most important goal of any
treatment is to regain and maintain a good quality of life. For the
majority of dogs the drugs that are used have minimal to no side
effects. Steroids alone will achieve a partial response in many dogs
but they will relapse within 2 - 3 months due to drug resistance.
Chemotherapy
The most common
and effective treatment is chemotherapy.
Chemotherapy drugs are used to kill the cancer cells, but may harm
healthy cells. Combination chemotherapy involves the use of
radiation treatment as well as the chemotherapy drugs and is considered
the most effective protocol against canine lymphoma.
Immune
System Booster
In addition to
chemotherapy treating your dog with an immune
booster will increase his survival rate. Most boosters include
glyconutrients which are needed to maintain a healthy, functioning
immune system.
Proper
Nutrition
Proper nutrition
is extremely important in increasing survival
chances. According to research dog foods that are high in
carbohydrates "feed" the cancer, causing visible acceleration of the
tumors progression. Dog foods that are high in protein are
believed to "starve" the cancer and foods that are high in Omega 3
fatty acids have been proven especially effective against canine
lymphoma.
Surgery
Some cases
will need surgery to remove the malignant lymphoma tumor. Surgery
is usually used in combination with chemotherapy, and is generally only
suggested if the tumor is extremely large or is endangering vital
organs. Fatal complications can arise with a surgical removal of a
tumor, especially if a portion of the endangered organ is also removed.
Side
effects from the chemotherapy drugs are not common; in general, the
quality of life for most dogs receiving cancer treatment is good and
often normal. Many dogs that were ill because of the lymphoma will
actually improve dramatically as their tumour comes under
control. However there is an increased risk of infections as
chemotherapy has been shown to supress the bone marrow which is
responsible for creating new white blood cells therefore lowering the
white blood count in dogs which in turn lowers the dogs immune
response. Your dog may also develop anaemia as chemotherapy drugs
are toxic to red blood cells, so the red blood cell count of your dog
may drop dramatically. This triggers an anaemic condition
requiring treatment. This may include a transfusion and more
drugs to enable red blood cell production. Dogs that suffer from
anaemia are more likely to experience weight loss as well as a
disinterest in food. Weight can be induced by treating with hormones or
steroids which may increase the dogs appetitie. The most common side
effect associated with chemotherapy is hair loss around the face, paws
and in the area around the tumor. Chemotherapy drugs are targeted
to be the most toxic to fast-growing cells, such as cancer cells.
However, the cells in your dog's hair follicle are also fast-growing,
and are particularly susceptible to damage by cytotoxic drugs.
http://www.caninelymphoma.net
Animal Cancer Trust
