Canine lymphoma (also called lymphosarcoma) is the most common type of cancer (malignant tumors) to affect dogs. most lymphosarcoma accurs in the lymph nodes, liver, or spleen. Lymphoma can also be present in the digestive tract, as well as in the eyes and skin.
The first documented case of canine Lymphoma was in a nine-year old crossbred dog, in the late 1980’s. It was identified in the dog’s prostate, and treatment was attempted with cytotoxic drugs. Since not much was known about this condition, the dog did not survive. With today’s technology and veterinary medicine, there is a fairly high remission rate with Canine Lymphoma.
Lymphoma can affect any type of dog, but there are several breeds that are more prone to develop this type of cancer. The most commonly affected breeds include Golden Retrievers, Rottweilers, Pit Bulls, Poodles, German Shepherds, Boxers, Scottish Terriers, Beagles and Basset Hounds.
Some of these breeds have an incredibly high rate of lymphoma, which is usually documented as an inherited breed-based trait.
For example, one in every eight Golden Retrievers will develop this condition.
The life expectancy of a dog diagnosed with lymphoma is between 9 and 12 months. While this may seem discouraging, it is possible to send a dog’s lymphoma into remission with constant medical care, and regular chemotherapy.
With proper care, the survival rate of a dog diagnosed with lymphoma can be raised to 50%. With intensive chemotherapy, the average chance of remission is from 60-90%. Without treatment, most dogs will only survive for an average of two months.
Canine Lymphoma can be present wherever there is lymph tissue in your dog’s body. It can travel quickly, especially if your dog is under significant stress. Lymphoma causes death in the same way that many other cancers do: by inducing organ failure.
The cancerous tumors begin to infiltrate important organs in your dog’s system, and the damaged organ eventually fails. Some types of lymphoma that occur in the digestive tract, will prevent a dog from digesting food. This can cause death by starvation, since it is difficult to treat gastrointestinal lymphoma.
Though lymphoma may sound like a fatal condition, it actually has a much higher remission rate than some other cancers that can affect dogs. With a prompt diagnosis, as well as an intensive treatment plan, the chances of survival are moderately good.
The Four Types Of Lymphoma That Affect Dogs
Lymphoma is characterized by the growth of malignant tumors in lymph tissue. Since your dog’s body is made up primarily of lymph tissue, this type of cancer can expand to almost any area of your dog’s system. However, there are four different classifications for 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
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)
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.
Symptoms And Diagnosis Of Canine Lymphoma
Canine Lymphoma is a condition that will cause your dog to display several key symptoms. Especially if your dog is one of the breeds commonly affected by lymphoma, it is essential to identify these symptoms as soon as possible.
What Are The Symptoms Of Lymphoma?
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).
2. 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.
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.
4. 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).
How Is Lymphoma Diagnosed?
Once you bring your dog to your veterinarian, there are several tests that will give a positive lymphoma diagnosis. The first of these is a visual examination by your veterinarian. Once it is positively identified that one or all of your dog’s lymph nodes are enlarged, further tests are needed.
Typically, a urinalysis(diagnostic test of your dog’s urine) as well as a blood panel test are used to assess your dog’s state of health. After this, one of the enlarged lymph nodes needs to be biopsied to positively identify the condition to be Lymphoma. Once a biopsy is taken, a pathologist will usually examine the cells under a high-powered microscope to confirm the diagnosis. Further examination of the biopsy will give an approximation of the progression of the cancerous tissue.
Treatment Options For Canine Lymphoma
Canine Lymphoma has a very high remission rate, however, there is a much lower chance of survival without proper treatment. Without any form of treatment, the average survival rate for a dog after diagnosis is about two months.
With a combination of anti-cancer medication, as well as intensive chemotherapy, the survival rate for a dog suffering from lymphoma can be increased to 60-90%.
There are many treatment options available, each with its own risks and benefits. The most effective treatment is a combination of all or several of these treatment types.
This is the most common, and most effective treatment for canine lymphoma.
Chemotherapy generally refers to the treatment of cancer with powerful drugs that kill cells. These drugs are used to kill the cancer cells, but can harm healthy cells as well (which causes the side effects associated with this treatment). Combination chemotherapy usually involves chemotherapy drugs in addition to radiation treatment, which is usually the most effective against canine lymphoma.
The chemotherapy process for dogs is slightly less intensive than chemotherapy in humans, since the dosage ratio of the cell-killing drugs is much lower.
The veterinarian responsible for selecting chemotherapy drugs that will best help your dog is called an oncologist. Certain chemotherapy drugs are used for each type of cancer, and an oncologist is responsible for choosing the drugs that will have the lowest toxicity rate for your dog’s healthy cells.
2. Immune System Booster
Treating your dog with an immune booster in addition to chemotherapy treatments is a good way to further increase your dog’s survival rate. Most immune boosters include glyconutrients, which are required for healthy immune system function in canines.
3. Proper Nutrition
With a systemic cancer like lymphoma, proper nutrition is extremely important in increasing your dog’s odds of survival. According to veterinary studies, dog foods that are high in carbohydrates “feed” the cancer, causing visible acceleration of the tumor’s progression.
Dog foods that are high in protein are said to “starve” the cancer, while providing good support for your dog’s healthy systems.
Dog food that is enriched in Omega 3 fatty acids has proven especially effective against canine lymphoma.
In some cases, surgery to remove the malignant lymphoma tumor is suggested for a treatment option. 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.