Pet cancer types and treatments
Every year, more than 12 million dogs and cats are diagnosed with cancer. The main culprit seems to be the manner in which we have treated our environment and the lifestyle of convenience that we have adopted. We look for ready-made, quick solutions for everything — for ourselves and for the pets we bring home.
Signs of cancer in pets
It is imperative that due attention is paid to even subtle behavioral and physical changes in pets for ruling out or confirming the prevalence of cancer. Many types of cancer can be effectively treated if they are attended to in the early stages.
Some of the signs that may indicate cancer as an underlying cause are easily shortlisted for 10 symptoms:
- an abnormal swelling that refuses to go away even after treatment;
- a sore, lesion or a wound that does not heal within a reasonable time period;
- weight loss despite sufficient diet;
- incessant bleeding or discharge from an opening in the body;
- difficulty in urinating or passing stools;
- chronic diarrhea or vomiting;
- loss of stamina and difficulty in breathing;
- subtle changes like increased sleep, lack interest and refusal to play;
- bad smell;
- refusal to eat for more than two days.
Most of the symptoms can be observed while grooming your pet. Any abnormal sign that was not there when you last groomed your dog or cat should be brought to the notice of the veterinarian. Nine times out of ten it may turn out to be a minor ailment but that should not reason to be negligent. Remember that early detection can save the life of your pet.
Types of cancer in dogs and cats
Lymphoma, one of the four major types of cancer, is a neoplasm (an abnormal growth that serves no purpose) of the lymph tissue. It is commonly known as lymph cancer or lymphosarcoma and is almost always malignant. Lymph cancer usually occurs in middle-aged dogs and cats and one of the major indications is the prevalence of one or more lumps just under the skin. A physical examination would normally reveal that the peripheral lymph nodes are enlarged and firm.
While there is no evidence of a link between the leukemia virus and canine lymphoma, feline cancer of the lymphatic system is normally associated with the leukemia virus. The fact that lymphoma is more prevalent in certain breeds is indicative of a genetic predisposition for this type of cancer. Besides this, like all other types of cancers, there is no specific cause known for lymph cancer in dogs.
The most common form of lymphoma is multi-centric and therefore it appears at several sites at the same time. In normal conditions, lymph nodes are difficult to feel under the skin. The indication of lymph cancer comes in the shape of enlarged lumps that can be felt easily under the skin.
In some cases, the symptoms of lethargy, loss of appetite, increased thirst and urination and loss of energy appear before the lumps can be felt. Multi-centric lymphoma can potentially spread to the liver and demonstrate the symptoms of liver cancer in dogs.
Other types of lymphomas present different symptoms:
- Lymphoma in the alimentary canal is associated with diarrhea, vomiting, weight loss, and lethargy. Cutaneous lymphoma is rare and affects the skin.
- Lymph cancer in the mediastinal, the part of the thoracic cavity between the lungs that contains the heart, aorta, esophagus, trachea, and thymus, shows as a tumor in the front part of the chest leading to fluid retention and difficulty in breathing.
- Extra-nodal lymphoma pertains to other parts of the body including eyes, the central nervous system, bones, heart, kidneys, bladder and the nasal cavity where the lymphatic system can be potentially affected by cancer cells.
Aspirates from the lymph nodes are sent to the pathological lab to establish the malignancy of the lumps Blood tests, x-rays and a biopsy of the lymph tissues are some of the other tests that may have to be performed for effective diagnosis.
Without treatment, lymph cancer results in the death of the dog or cat within four to six weeks. Chemotherapy protocols are well defined for treating lymphomas as they are the most commonly treated cancer in pets. Most pets respond favorably to anti-cancer drugs and there is an approximately 84 percent chance of abatement and increase in the survival time.
Intestinal cancer throws up symptoms that are similar to symptoms caused by inflammation or obstruction in the intestinal passage. This makes early detection a difficult task. Although they form a small percentage of all feline cancers and cancers in dogs, prognosis ranges from poor to very poor depending upon the location of the tumor.
The common types of cancers that can develop in a pet’s intestines include:
- Lymphoma — neoplasm of lymph tissue that is most predominant in cats.
- Mast Cell Neoplasia — cancer that causes single or multiple lesions in the small intestines.
- AdenocarcinomaCancer that begins in glandular (secretory) cells. Most cancers of the breast, pancreas, lung, prostate, and colon are adenocarcinomas. — a malignant tumor that originates from the glandular epithelium.
- Other intestinal neoplasms such as rectal and colon tumors.
Lymphoma is the most common form of intestinal tumors in pets followed by carcinomas and mast cell tumors. Like the symptoms of liver cancer, intestinal tumors also remain concealed due to the general nature of symptoms.
Canine and feline urinary tract infection is a common occurrence. In some cases, however, the symptoms may indicate bladder cancer. The important signs of the prevalence of growth in the bladder are similar for urinary tract infections in dogs and cats. This hampers an early detection of the tumor. Usually, it is severe infections that do not respond to antibiotics that end up under further investigation, leading to late detection.
Benign tumors of smooth muscle and polyps that occur in the bladder are very rare. These can be removed surgically and usually do not recur. Small masses that do not invade healthy tissue can also be removed surgically.
But in the case of cancerous growths, the cancer is found in parts of the bladder from where it is difficult to remove due to the fact that bladder cancer is invasive and affects the bladder walls. In addition, by the time it is diagnosed the cancer cells are found to have metastasized or spread to other parts of the body.
Treatment rarely cures bladder cancer and the fundamental goal is to provide temporary relief for the temporary periods to give a better quality of life to the dog. Although bladder cancer is more common among older dogs, UTI in puppies should also be investigated thoroughly to be on the safe side.
The skin is the biggest organ in the body. It is also the most common organ that can develop carcinoma.
The name skin cancer is a general classification of different types of tumors that include any uncontrolled growth of cells in:
- the skin;
- skin glands;
- hair follicles;
- supportive fat and connective tissues.
MetastasisThe spread of cancer cells from the place where they first formed to another part of the body. In metastasis, cancer cells break away from the original (primary) tumor, travel through the blood or lymph system, and form a new tumor in other organs or tissues of the body. The new, metastatic tumor is the same type of cancer as the primary tumor. For example, if breast cancer spreads to the lung, the cancer cells in the lung are breast cancer cells, not lung cancer cells. that occurs in the skin as a result of cancer in other parts of the body is not termed as skin cancer because it originates elsewhere. Skin cancer in dogs is less likely to be malignant than in cats. Even in cats skin cancer is most likely to be seen in older cats between 6 to 14 years of age.
The known causes of skin cancer are:
- light or white color of the skin;
- excessive exposure to sunlight;
- feline immunodeficiency virus (FIV);
Skin cancers appear mostly as lumps under the skin or as lesions that do not cure. This often leads to abnormal behaviors like scratching or chewing the affected area. Squamous cell cancer, a type of skin cancer, often leads to redness of the area and crusty skin.
Detection of skin cancer is relatively easier as compared to other cancers because the symptoms are easily visible. For example, looking for the symptoms of liver cancer in dogs and cats is a tedious process of keen observation to identify multiple signs.
Regular examination needs to be made of your pet’s skin to be able to notice certain signs like:
- tumors or lumps under the skin;
- blemishes, scaly areas or change in color;
- the progress of the above changes noticed earlier;
- color changes and irregular areas in the cat’s eyelids, lips and the mouth’s interior.
An occasional massage and grooming with a fine comb help in being able to catch the abnormality immediately.
Diagnosis involves laboratory examinations of:
- an aspirate of the tumor;
- a piece cut off from the tumor;
- blood and urine;
- X-Rays to establish if metastasis has occurred.
If your pet is white in color or has a white nose and ears you can minimize the risk by protecting the animal from sunlight. You can also ask your veterinarian about the use of sunscreens on light colored ear tips or patches of white on its coat.
While a serious nasal discharge may only be a sign of infection caused by bacteria or viruses, a mucoid, purulent or bloody nasal discharge can be indicative of nasal cancer in your pet.
The nasal cavity in dogs and cats is a complex structure consisting of nostrils that open up in two air passages that are lined with scrolled spongy bones called turbinates. A clear serous discharge coming out from both the nostrils may also be caused by the presence of small mites, but mucoid and purulent discharges need to be investigated since they can be signs of any of the following:
- foreign matters such as grasses or weeds that may have entered the nose while sniffing;
- dental infections, especially in the roots of upper teeth;
- fungal infection;
- nasal cancer.
If blood is present in the discharge, it is almost certain that the cause is either a fungal infection or nasal cancer that is taking root in the passage. Cats with a fungal infection in the nose must be checked for the prevalence of feline cancer or the leukemia virus. A final diagnosis is done only after ruling out that the bleeding is not caused by violent sneezing since that can also result in temporary bleeding.
Nasal cancer usually occurs as paranasal sinus fibrosarcomas (a sarcoma derived from fibroblast cells, often able to generate collagen) or paranasal sinus chondrosarcomas (a malignant neoplasm of cartilage cells). Both types of sarcomas grow slowly but are progressive and invasive in nature.
Diagnosis of nasal cancer involves routine blood and urine tests, biochemical profiling, biopsy, and CT scans.
Apart from the nasal discharge and bleeding, other symptoms that dog owners should keep a watch out for include:
- excessive sneezing;
- bad breath;
- loss of appetite for a long period;
- facial deformity;
- bulging eyes;
- seizures that indicate metastasis to the brain.
Nasal tumors usually do not respond to chemotherapy and other anti-cancer drugs. Surgery is also a difficult procedure since the structure of the nose is extremely complex making it difficult to remove the tumor from the nose. Radiation therapy is available in select cities and veterinary schools but this method usually reduces the size of the tumor only.
It is dangerous to ignore treatment as nasal tumors can spread to the brain and cause seizures and the condition may also breakout through facial bones and distort the pet’s appearance permanently.
Like all types of tumors, the cause behind nasal tumors is also not known. As with the symptoms of liver cancer in pets, your observation of the symptoms and detection are the only ways to institute medical intervention in early stages to manage nasal cancer in pets.
Additional Types of Pet Cancer
Cancer can occur in almost any organ of the body. The most common cancers that have been found to afflict pets are cancerous tumors (solid mass of abnormal cells) and leukemia (blood cancer).
- Basal cell tumors can be malignant or benign and start from the epithelial (membranous tissue covering internal organs and other internal surfaces of the body) layer of the skin. It requires invasive surgery for removal of the tumor and, in most cases, it usually cures the pet.
- Chondrosarcoma is a malignant tumor of cartilage cells. It can occur in the nasal and paranasal passages and nearby concavities or in the larynx and trachea. This type of cancer is more prevalent in dogs than cats and requires chemotherapy, radiation therapy or surgery for effective treatment. Tumors in the larynx sometimes require the removal of the entire larynx. A passage is then created through the neck that opens in the trachea.
- Eyelid tumors — Pets are also prone to develop tumors on the eyelids although it is less common in cats than in dogs. Outdoor pets, white pets, and pets that remain in the sun fall under the high-risk category. Eyelid cancer usually originates from the lymphocytes. They can also form into mast cell tumors. Eyelid tumors rub against the cornea and lead to frequent conjunctivitis and excessive eye discharge.
- Fibrosarcoma (fibroblastic sarcoma) is a malignant tumor derived from fibrous connective tissue and is characterized by immature multiplication of different types of cells. It affects the connective tissues of the skull, pelvis, and ribs. Fibrosarcoma is very rare and different from the commonly known bone cancer (osteosarcoma).
- Tumors associated with the ear can be of different types. Some may be malignant while the others can be basal cell tumors also. They are commonly seen in middle-aged or older pets.
- Hemangiosarcoma is a rare, rapidly growing and highly invading variety of cancer. It is malignant cancer in which the tumor is filled with blood. This tumor finally ruptures causing the pet to bleed to death. Hemangiosarcoma has mostly been observed in the spleen and the heart but it can also invade the bones.
- Hepatic Neoplasia (another name for liver tumor) is actually quite rare in cats, not so in dogs. Exposure to carcinogens increases the risk of liver cancer. The symptoms of liver cancer in dogs and cats usually indicate the prevalence. Some of the signs of liver cancer that you may notice are excessive vomiting, reduced appetite, pale gums, distended stomach, jaundice or breathing disorders.
Treating cancer in your pet
There are two ways in which cancer treatment in pets can be approached. The first is the conventional treatment. Conventional treatment is typically invasive. Cancer treatment is toxic and options like chemotherapy, radiation, and surgery are beset with side effects.
Treating cancer, including canine and feline cancers, with chemotherapeutic drugs is beset with dangers. Most veterinarians are against the use of these drugs since the effects are sometimes worse than the ailment. Most veterinarians suggest chemotherapy if the dog owner insists and is adamant to prolong the life of his dog, irrespective of its quality.
The other approach is the holistic approach, which targets the underlying cause of the disease and attempts to cure it. A holistic approach is suggested to help in uprooting the disease from its roots. The basic principle behind a holistic approach is that no disease occurs without a cause. A holistic approach treats symptoms as reflections of the body’s effort to heal itself or as the results of the causes of the disease.
Conventional pet cancer treatments
The most common therapies for cancer treatment include:
- Surgery, partial or total excision of a tumor, has limited success ratio in cases where cancer has spread to various organs in the body.
- Chemotherapy, the use of drugs to kill cancer cells, has serious toxic side effects.
- Radiation therapy, the use of high-intensity radiation, cannot guarantee that only cancer cells will be targeted.
There has been a significant development in the field of discovering newer therapies for treating cancer. Drugs and techniques that target only cancerous cells and spare the normal cells are in different stages of development and are being termed as ‘magic bullets’. Some of these therapies include the following:
This is a process of introduction of foreign DNA into a cancerous cell. After the foreign gene is incorporated and expressed by cancerous cells, it attempts to kill cancerous cells, attract substances from the immune system to fight cancer cells, suppress formation of tumors and make normal cells resistant to drugs that are used to kill cancer cells.
These drugs work on the theory that cancer cells are dependent on a process called angiogenesis. Angiogenesis is a process of formation of blood vessels which facilitates the division of cancerous cells. It also allows the tumors to attain a solid structure. For this purpose, many cancerous cells excrete molecules to activate angiogenesis. Natural and synthetic inhibitors that restrict the formation of blood vessels are in the process of preclinical studies and have been found to be extremely effective.
Not all types of cancers give prior noticeable indications, the way the symptoms of liver cancer in pets surface as diarrhea, vomiting, bloated stomach and lethargy. Pet cancer, including feline cancer, is a fatal disease and even a seemingly successful treatment can have a debilitating effect on the quality of life of the pet during and after treatment.
There are also some more complicated therapies in the process of development, but it appears that it will be quite sometime before an ideal cure for cancer is found. However, there is still a lot of scope in developing existing modes of treatment so as to at least limit side effects and provide a non-recurring cure for one of the most dreaded diseases.
A significant limitation of conventional drugs is in the field of recurrence. There is a great amount of heterogeneity within the cells of a single tumor. As the tumor increases in size, some of the cells get lesser blood supply causing them to divide at a reduced pace compared to others in the same tumor. This results in making some cells resistant to drugs and they can survive even after the patient is cured of the disease. These cancerous cells remain dormant for a time and lead to recurrence of cancer at a later stage.
On the other hand, surgery has a different set of limitations. Pet cancer has the uncanny property of surfacing when it has already metastasized to neighboring, distant and even vital organs. This either rules out surgery or, at best, results in partial excision of a tumor making chemotherapy and radiation necessary.
Total excision is only possible in cases of a benign tumor, which is, in most cases, harmless. On the other hand, any increase in the dosage of chemotherapeutic drugs or time of radiation exposure has an accompanied and corresponding risk of an increase in toxicity.
Pet owners need to make an educated decision based on the general health of the dog and the risks involved. In fact, owners have to strike a balance between compassion, quality of life after treatment and benefits likely to be derived from treatment.
Alternative pet cancer treatments
Clear environmental toxins
The first step should be to clear the pet’s environment of all potentially carcinogenic materials and chemicals. Change his environment so that there is no contact with harmful pesticides, chemicals, and toxic materials. Clean the household where remnants of these tend to accumulate. Throw out the plastic feeding bowl and use ceramic or metal. Start giving filtered water to the pet.
If you are looking for a better quality of life rather than just adding to the number of years, you may look toward a holistic treatment for cancer. Some natural, holistic treatments for pets include:
- Essiac Tea is a cancer treatment that we have noticed that is frequently used with pets. You can order Essiac Tea.
- The Kelmun Protocol (baking soda and maple syrup) has done very well at shrinking tumors. It is both a highly alkaline protocol and it contains a “trojan horse” (maple syrup) to allow the baking soda to target cancer cells. The dose of baking soda should be 1 teaspoon for pets over 60 pounds and for pets less than 60 pounds a proportionately lower dose. It should be combined with juicing (e.g. carrot juice with a tablespoon of beet juice) and “green drinks” and hopefully an electromedicine protocol, such as the High RF Frequency Generator with plasma amplifier (which does not need “skin” to make a connection).
- Herbs including astragalus, mistletoe, withania somnifera (ashwagandha), and milk thistle.
Strengthening your pet’s immune system
The real defense against cancer and for that matter any other disease is the body’s immune system. If the immune system is strong, it follows that these cells are killed or reabsorbed before they can cause cancer or threaten overall health. If the immune system is weak, treatment only results in temporary remission of the disease only to reoccur.
If the reason behind cancer was known then it would have helped a great deal in finding a definite cure for the deadly disease. But apart from the fact that there are certain carcinogens that cause cancer, very little is known about what causes cancer. In recent years, there has been a significant increase in the incidence of cancer in dogs and the feline cancer-causing lot of concern to pet owners.
It has been suggested that there is a high probability of some cancer cells present in a body. A perfectly conditioned and healthy body does not let cancer take root. It is the immune system of the body that inhibits these cancer-causing cells from multiplying.
When the body is unhealthy, the immune system triggers off certain changes in the body to fight back. When cancer takes root, the immune system causes certain symptoms to appear in the body. These symptoms are basically the body’s mechanism to fight back in order to self-heal.
As cancer progresses, the self-healing process can go awry. The body cannot handle the constant “war” situation. With changing priorities of the body system, the normal growth processes are compromised. A diet that can strike a balance in priorities of attending to cancer and the routine growth processes can be of great help in prolonging the life of a pet.
Nutrition for pets with cancer
Your pet’s body requires a typical diet that is compatible with his structure and needs. It should be kept in mind that human food is not always good for the animal. A pet who suffers from cancer requires specific nutrition that can allow him to fight back the disease and continue the other regular body functions.
It is not too optimistic to believe that the right nutrition can help in treating cancer in pets. And a certain combination of nutrients can also help in preventing cancer. Additionally, it can help ensure a better quality of life if cancer has already set in.
There is a strong correlation between nutrition and cancer. Commercial foods available in the market contain a preservative and synthetic substances that may be carcinogenic and may cause harm to the process of healthy cell multiplication. Home cooked and organic food is best for your pet’s health. If home food is not an option, opt for healthy foods for pets that are available in health stores. Before buying make sure that they do not contain hormones, pesticides or antibiotics.
You may also choose to give therapeutic level supplements of antioxidantsProtects cells from damage caused by free radicals (unstable molecules made by the process of oxidation during normal metabolism). Free radicals may play a part in cancer, heart disease, stroke, and other diseases of aging. Antioxidants include beta-carotene, lycopene, Vitamins A, C, and E, and other natural and manufactured substances., Vitamin C and Vitamin A. Many herbs also help in fighting cancer and can be given directly or along with a meal. Discuss with your veterinarian and select a few herbs and natural foods that are rich in zinc, selenium and Omega 3 fatty acids. Fish oil or flaxseed oil have anti-cancer properties and increase oxygen uptake to cells.
Not much research has been conducted to understand how diets can manage or prevent cancer from occurring in pets. Whatever research is available suggests that a diet that provides the following substances in sufficient quantities can be of help:
- Vitamins C, D, and E along with beta-carotene and chemical compound of Vitamin A known as retinoids;
- minerals like selenium, copper, zinc, magnesium, calcium, lead, iron, potassium, sodium, iodine and germanium;
- enzymes that help in immunization against cancer-causing pathogens. These are available as oral preparations;
- green and black tea is believed to have cancer-inhibiting properties and can be introduced in the pet’s meal.
Cancer treatments and surgery can drain the energy out of a patient. If the energy levels dip to extremely low levels a condition known as cancer cachexiaWeakness and wasting of the body due to severe chronic illness, also known as Wasting Syndrome, is a sign of diseases, such as advanced chronic obstructive pulmonary disease (COPD), AIDS, cancer, or heart failure. occurs. One of the symptoms of liver cancer in pets is a loss of appetite and extreme weight loss. Managing the amount of energy spent and supplementing with a healthy diet are the best ways of countering the condition.
Supplements for the immune system
Cod liver oil is usually favored by veterinarians for its high Vitamin A, D, and Omega 3 fatty acid content. Vitamin A is essential for maintaining healthy mucous membranes in eyes and ears. It also keeps the gastrointestinal and urogenital tracts in proper operable conditions. Vitamin D, on the other hand, helps in the effective metabolism of calcium, which is essential for maintaining bone density.
Fish oils like cod liver oil are natural sources of Omega 3 fatty acids, which are necessary to maintain overall health. Many commercial diets for dogs and cats contain Omega 6 fatty acids in higher than recommended proportions, which can prove to be harmful. The Omega 3 fatty acids in cod liver oil act as a balancing factor and counters the harmful effects of Omega 6 acids.
Fatty acids, to be effective, should be in the form of EPA (Eicosapentaenoic Acid) and DHA (Docosahexaenoic Acid) and are thus termed as essential fatty acids. Fish oils, including cod liver oil, are natural sources of these forms of fatty acids. Plant-based oils need to be converted from Alpha-linolenic Acid (LNA), a process that requires huge amounts of LNA for the required amount of EPA and DHA.
Essential fatty acids are necessary for some critical functions the body must perform to maintain health:
- transport and metabolism of cholesterol and triglycerides;
- normal brain development and functioning;
- maintaining vision;
- adrenal functioning;
- regulate the immune system.
Herbs like aloe vera, Echinacea, astragalus, goldenseal, elder, and garlic are suggested to play a role in maintaining a healthy immune system. A healthy immune system helps in preventing certain diseases that often cause problems in the health of your dog or cat.
It is important for pet owners to learn more about this aspect of animal health so that early treatment may be given to avoid further complications.
The natural and holistic approach to maintain immune system health is always preferred as natural remedies can be included in the routine diet without fear of major side effects. Despite this, some herbs are not recommended in certain conditions and in undiluted form. It is better to use herbs after gathering full information or under the supervision of a certified herbalist.
Pet Cancer Sites
Tony Isaacs has a website for pet cancer (primarily for dogs). He does NOT recommend oleander products because they are too hard on their digestive tracts.
General pet cancer sites:
- http://www.katberard.com/healthcare.htm (see Essiac Tea warning)
Pet cancer discussion sites: