Hearing that your dog has cancer is never good news. Some dogs, like Rottweilers, are more susceptible to certain diseases than others. One such disease is lymphoma.
What is lymphoma?
The most common cancer in dogs, accounting for 10-20% of all cancers in dogs, lymphoma can affect any dog breed at any age, though some breeds are more susceptible than others.
Lymphoma AKA lymphosarcoma (similar to non-Hodgkin’s lymphoma in humans) is a malignant cancer that attacks the lymphatic system. It is a blood-borne cancer of the lymphocytes (a specific white blood cell) which makes this form of cancer widespread. The lymphatic system is an important part of the body’s immune system, defending against viruses and bacteria. Lymphoid tissue is found across the body, including the lymph nodes, liver, spleen, skin, bone marrow and gastrointestinal tract.
Basically, the lymphocytes mutate and accumulate, causing tumours and other havoc in the body.
Dog breeds most at risk:
Breeds at increased risk of lymphoma include Boxers, German Shepherds, Scottish Terriers, Pointers, Golden Retrievers, Bull Mastiffs and Rottweilers. But lymphoma can attack any dog at any age, though it is more common in middle-aged and older dogs.
Types of lymphoma
In dogs, lymphoma has been classically characterized by body locations in which they occur:
- multicentric, which originates in multiple places; (most common, early signs include non-painful enlargement of lymph nodes)
- alimentary, which occurs in the digestive system, (uncommon, early signs include vomiting and abdominal pain)
- mediastinal, which occurs within the chest; (uncommon, early signs include enlarged thymus and lymph nodes)
- extranodal, which may involve the kidneys, lungs, eyes, central nervous system, or skin (early signs include slow-healing sores, difficulty breathing, blindness, etc. depending on organ affected).
What causes lymphoma?
The causes of lymphoma are still unknown, but environmental factors (pesticides, herbicides, strong magnetic fields, etc.) that causes cancer in humans are certain to cause cancer in canines. Advanced genetic studies will eventually shed more light on the matter.
Because lymphoma affects and weakens the immune system, fevers are often one of the first indicators of the disease. Lymphoma itself is not thought to be painful to dogs, it is the various illnesses they can succumb to that causes pain and discomfort.
Each type of lymphoma has its own symptoms.
Most common type of lymphoma, it presents with enlarged lymph nodes in the dog’s neck, chest or behind the knees (sometimes more than ten times the normal size) with no other distinctive signs of illness.
Rapid onset, affects not only external lymph nodes and immune system, but also involves the spleen, liver and bone marrow. Tends to infiltrate all other organs, leading to organ failure.
Other symptoms include: lethargy, weakness, dehydration, weight loss, difficulty breathing, depression, anaemia and even sepsis. If it metastasises to the central nervous system, seizures and paralysis can occur.
Second most prevalent form of canine lymphoma, though uncommon.
Because it is in the intestinal tract, it is difficult to diagnose. Signs include excessive urinating and thirst, anorexia, abdominal pain, vomiting, dark coloured diarrhoea, and other gastrointestinal-related signs (including malnutrition and weight loss).
The third most pervasive canine lymphoma, though uncommon
As malignant lesions develop in the lymphoid tissues of the dog’s chest (especially the cardiothoracic area – meaning the heart and lungs), the dog will have difficulty breathing, may cough, have a swollen chest, front legs and face (due to the fluid build-up). Symptoms can include increased thirst and urination.
The rarest type of canine lymphoma. “Extranodal” refers to how the cancer presents outside of the lymph nodes.
Organs affected: eyes, kidneys, lungs, skin, mammary tissue, liver, bones, mouth and central nervous system.
Symptoms depend on the organ affected. Bone fractures if the bones are involved, blindness if the eyes are involved, etc.
The most common extranodal lymphoma involves the skin (cutaneous lymphoma). Early signs include skin rash with dry, red, itchy bumps or scaly legions. These are fairly noticeable as they cause discomfort. It can be mistaken for a fungal infection or allergies, but as the disease progresses, lesions start to ooze fluids and tumours can develop.
Early detection and treatment are essential, but dogs generally feel well and have minor symptoms which means that lymphoma is usually in an advanced stage when diagnosed. Enlarged lymph nodes can even be from other diseases.
The usual route followed to diagnose lymphoma:
- Fine needle aspirate. (Using a needle to remove cells from the suspicious place and viewed beneath a microscope. Inexpensive. Not always accurate.)
- Sometimes, a biopsy of the suspicious place will be done under general anaesthesia.
- If lymphoma is suspected in a place that is not a lymph node (suspicious place in above points), x-rays/ultrasounds are done of the chest/intestines/bone marrow.
- Urinalysis (urine test) and blood chemistry panels are usually used to stage the cancer and ascertain the dog’s overall health.
After a diagnosis is made, staging of the disease takes place. The WHO (World Health Organisation) has a five-tier staging system that is the standard in staging canine cancer:
- Stage I: Single lymph node is involved.
- Stage II: Multiple lymph nodes within in the same region are affected.
- Stage III: Multiple lymph nodes in multiple regions involved.
- Stage IV: Involvement of liver and/or spleen (in most cases lymph nodes are affected but it is possible that no lymph nodes are involved).
- Stage V: Bone marrow or blood involvement, regardless of other areas affected and/or other organs other than liver, spleen and lymph nodes affected.
Staging is important as it affects treatment and prognosis.
Though it’s uncommon for lymphoma to be cured, it can be treated. Many dogs with lymphoma can outlive dogs with other diseases like kidney, heart and liver disease. It should be kept in mind that remission is the goal, to give owner and dog more quality time together, and treatment should begin immediately as this aggressive cancer can quickly change from one day to the next.
The two main treatment options:
Steroid treatment (Prednisone)
Increases average survival between one and three months. Doesn’t work in all cases. Will make subsequent treatment with chemotherapy less successful. But Prednisone destroys lymphoma cells and works well as a standalone treatment.
Using medications to hinder and stop cancer cells growing and dividing. Side-effects include vomiting, diarrhoea, decreased appetite and decreased activity levels. Increases survival between six and twelve months.
Radiation and surgery are also options.
It should be noted that the disease often stops responding to treatment.
Remission with chemotherapy lasts, at most, twelve months. A second course of treatment can be done, called a rescue protocol, which can add a further two months. This weekly dose of medicine over the course of five months should be weighed against the dog’s quality of live. Most dogs receiving chemotherapy suffer from nausea, decreased appetite, lethargy, diarrhoea, infection, blood in urine, etc.
Again, staging is important. Dogs with B-cell lymphoma undergoing chemotherapy, has a survival time of twelve months. Dogs with T-cell lymphoma undergoing chemotherapy, has a survival time of six months. If the lymphoma has spread through the intestinal tract, survival time is at most three months.
Lymphoma is always fatal.
Treatment is a personal decision – usually the patient’s. But now it’s up to you as the petparent to make informed end of life decisions, and to take your furbaby’s feelings and suffering in consideration when doing this.
- Lymphoma in Dogs: Symptoms, Diagnosis, and Treatment
- Lymphoma in dogs: Diagnosis and treatment
- Malignant Lymphoma in Dogs
- 5 Tips for Treating and Beating Canine Lymphoma
- Canine Lymphoma
- Canine Lymphoma: Risk Factors, Symptoms, Diagnosis, and Treatment
- Canine Lymphoma
- Rottweilers: What a Unique Breed!
- Lymphoma in 3 related Rottweilers from a single household
- Breed-associated risks for developing canine lymphoma differ among countries: an European canine lymphoma network study
- Canine Cancer – Lymphoma
It was the summer of 2013 (November where I am). Six-year-old Saphira loved swimming. She had jumped into the swimming pool on her own one day when she thought that I was drowning (yeah, my swimming skills drive my Rottweilers crazy) and she’d been swimming on warm days ever since. She would even lounge on the built-in steps.
One morning, I noticed a small bump on her front leg. A rat bite? We did have a rat problem at the time and she loved to hunt them. I disinfected the area, added antibiotic salve and it looked better. (No need to rush to the vet again for the same thing, right?) It was a hot summer. She swam a lot. And she lost weight. Normal summer stuff.
And then the bump that had receded became a swollen joint. I took her to the vet. I assumed it was from slipping on the wet bricks around the swimming pool. Scans and a blood test later confirmed that she had lymphoma – in an advanced phase. Despite the bump being the only sign along with minor weight loss, she was terminal.
The vet prescribed various meds (including Prednisone) to help with pain, inflammation, to help her sleep through the night, and other things to make her comfortable – and warned that if she were to break her leg or if the pain got worse (that she showed that she was in pain), it would be time to euthanise.
It went well for a little over four weeks. And then the rapid decline started. She stopped playing, she stopped swimming, she stopped barking, she stopped growling at Emmett (her Rottie playmate), and the sparkle had left her eyes. I knew that it was time.
*I don’t believe in pumping poison into someone without their consent. If you want to fight cancer by undergoing chemotherapy, that is your choice. But I won’t force an animal to suffer unnecessarily to make me feel better. Most vets agree with me.
Have you ever lost a furbaby due to lymphoma? What are your thoughts about cancer treatment in dogs?
**Legal waiver: I’m not a veterinarian, just an overprotective Rottweiler mum and pack leader. It’s always best to contact your vet if something in your dog’s behaviour is out of character.
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