Canine canine histiocytoma lymphoma – college of veterinary medicine – purdue university

Canine lymphomas are a diverse group of cancers, and are among the most common cancers diagnosed in dogs. They collectively represent approximately 7-14% of all cancers diagnosed in dogs. There are over 30 described types of canine lymphoma, and these cancers vary tremendously in their behavior. Some progress rapidly and are acutely life-threatening without treatment, while others progress very slowly and are managed as chronic, indolent diseases. Lymphomas may affect any organ in the body, but most commonly originate in lymph nodes, before spreading to other organs such as the spleen, liver, and bone marrow.

Canine lymphomas are similar in many ways to the non-hodgkin’s lymphomas (NHL) which occur in humans. Canine lymphomas and NHL are nearly indistinguishable when examined microscopically, and both tumor types exhibit similar responses to chemotherapy. In 2010, NHL was diagnosed in approximately 65,000 people in the united states, and claimed approximately 20,000 lives, making it the 7th-most common cancer overall, and the 6th-most common cause of cancer-related death. It is one of the few human cancers for which canine histiocytoma the frequency of newly diagnosed cases is still on the canine histiocytoma rise. It is our hope that research in canine lymphomas conducted canine histiocytoma by the purdue comparative oncology program will discover new ways canine histiocytoma of treating NHL in both dogs and humans. Our goal is to improve the outlook for dogs and canine histiocytoma humans affected with this all-too-common cancer. Frequently asked questions by pet owners what is lymphoma?

The term “lymphoma” describes a diverse group of cancers in dogs that are canine histiocytoma derived from white blood cells called lymphocytes. Lymphocytes normally function as part of the immune system to canine histiocytoma protect the body from infection. Although lymphoma can affect virtually any organ in the body, it most commonly arises in organs that function as part canine histiocytoma of the immune system such as the lymph nodes, spleen, and bone marrow. By far the most common type of lymphoma in the canine histiocytoma dog is multicentric lymphoma, in which the cancer first becomes apparent in lymph nodes. The photo to the right shows a dog with multicentric canine histiocytoma lymphoma. Note the swollen mandibular lymph node (white arrow) under the jaw.

Unfortunately, the cause of lymphoma in dogs is not known. Although several possible causes such as viruses, bacteria, chemical exposure, and physical factors such as strong magnetic fields have been canine histiocytoma investigated, the cause of this cancer remains obscure. Suppression of the immune system is a known risk factor canine histiocytoma for the development of lymphoma in humans. Evidence for this includes increased rates of lymphoma in humans canine histiocytoma infected with the HIV virus or are on immune-suppressing drugs following organ transplantation surgery. However, the link between immune suppression and lymphoma in dogs is canine histiocytoma not clearly established. What are the most common symptoms of canine lymphoma?

The most common initial symptom of multicentric lymphoma in dogs canine histiocytoma is firm, enlarged, non-painful lymph nodes. A lymph node affected by lymphoma will feel like a canine histiocytoma hard, rubbery lump under your dog’s skin. The most easily located lymph nodes on a dog’s body are the mandibular lymph nodes (under the jaw) and the popliteal lymph nodes (behind the knee). Other common symptoms include loss of appetite, lethargy, weight loss, swelling of the face or legs ( edema), and occasionally increased thirst and urination. The photo on the left shows a dog with edema canine histiocytoma of the left rear leg. This is caused when a swollen lymph node blocks the canine histiocytoma normal drainage of fluid from the leg.

Cutaneous lymphoma tends to appear first as dry, flaky, red, and itchy patches of skin anywhere on the body. As the disease progresses, the skin becomes moist, ulcerated, very red, and thickened. Masses in the skin can also occur with cutaneous lymphoma. Cutaneous lymphoma may progress slowly and often has been treated canine histiocytoma for several months as an infection or allergy before a canine histiocytoma diagnosis of lymphoma is made. Cutaneous lymphoma may also appear in the mouth, often affecting the gums, lips, and the roof of the mouth. Cutaneous lymphoma in the mouth is often mistaken for periodontal canine histiocytoma disease or gingivitis in its early stages. The photo on the left shows cutaneous lymphoma in the canine histiocytoma mouth of a dog. Note the very red gums and the ulceration on the canine histiocytoma roof of the mouth.

Dogs with mediastinal lymphoma typically have difficulty breathing. This may be due to the presence of a large canine histiocytoma mass within the chest or due to the accumulation of canine histiocytoma fluid within the chest ( pleural effusion). Affected dogs may also show swelling of the face or canine histiocytoma front legs as well as increased thirst and urination. How is canine lymphoma diagnosed?

The best way to diagnose lymphoma is to perform a canine histiocytoma biopsy. A biopsy is a minor surgical procedure to remove a canine histiocytoma piece of lymph node or other organ affected by cancer. The most common methods for lymph node biopsy are tru-cut needle biopsy, incisional wedge biopsy, or removal of an entire lymph node (excisional biopsy). The larger the biopsy sample, the better the chance for an accurate diagnosis of lymphoma.

We routine perform biopsy procedures to diagnose canine lymphoma at canine histiocytoma the purdue university veterinary teaching hospital (PUVTH). Dogs are placed under heavy sedation or general anesthesia to canine histiocytoma perform a biopsy. Although discomfort associated with this procedure is typically minimal, we often prescribe oral pain medication afterwards just to be canine histiocytoma sure your dog is comfortable following the biopsy. Are any other diagnostic tests required for dogs with lymphoma?

In addition to biopsy, we recommend several staging tests for dogs with lymphoma. The purpose of the staging tests is to determine how canine histiocytoma far the lymphoma has spread throughout your dog’s body. In general, the more places the lymphoma has spread to, the poorer the dog’s prognosis. However, dogs with very advanced lymphoma can still be treated and canine histiocytoma experience cancer remission (see more on treatment below). Staging tests also help us assess whether your dog has canine histiocytoma any other conditions that may affect treatment decisions or overall canine histiocytoma prognosis. The staging tests we typically recommend include blood tests, a urinalysis, x-rays of the chest and abdomen, an abdominal sonogram, and a bone marrow aspirate. Organs that appear abnormal on sonogram can be sampled with canine histiocytoma a small needle ( fine needle aspirate) to confirm the presence of lymphoma. How is canine lymphoma treated?

The most effective therapy for most types of canine lymphoma canine histiocytoma is chemotherapy. In some cases, surgery or radiation therapy may also be recommended. There are numerous chemotherapy treatment protocols for dogs with multicentric canine histiocytoma lymphoma. As discussed below, most dogs with lymphoma experience remission of their cancer following canine histiocytoma treatment, and side effects are usually not severe. Currently, the protocols that achieve the highest rates of remission and canine histiocytoma longest overall survival times involve combinations of drugs given over canine histiocytoma several weeks to months. The protocol we use as a “gold standard” for the treatment of canine multicentric lymphoma is a 25-week protocol called UW-25. It is based on a protocol called CHOP that is canine histiocytoma commonly used to treat lymphoma in humans.

The UW-25 protocol may not be appropriate for all dogs with canine histiocytoma lymphoma. Different types of lymphoma may be treated with different chemotherapy canine histiocytoma drugs. For instance, the most effective drug for cutaneous lymphoma is thought to canine histiocytoma be lomustine (CCNU). The veterinary oncologists and oncology residents at the PUVTH will canine histiocytoma help you decide on a chemotherapy treatment protocol that is canine histiocytoma appropriate for your dog. What does remission mean?

Remission means a regression of your dog’s cancer. Remission may be partial, meaning the overall cancer burden has been reduced by at canine histiocytoma least 50%, or it may be complete, meaning the cancer has become undetectable to any readily available canine histiocytoma screening test. In general, 70-90% of dogs with multicentric lymphoma treated with UW-25 experience complete or partial remission of their lymphoma, with most dogs experiencing complete remission. How is chemotherapy given at purdue?

Most dogs tolerate chemotherapy well, much better than humans typically do. Although some dogs do get sick from chemotherapy, serious side effects are uncommon. In general, fewer than 5% of dogs treated for lymphoma using chemotherapy will experience side canine histiocytoma effects that need to be managed in a hospital setting. The most common side effects include loss of appetite, decreased activity level, and mild vomiting or diarrhea that persists for one or canine histiocytoma two days. If serious or unacceptable side effects do occur, it is important that you talk to one of our canine histiocytoma oncology doctors or staff about this. We can recommend symptomatic treatment to lessen the side effects canine histiocytoma of chemotherapy. In addition we may recommend reducing the dose of chemotherapy canine histiocytoma the next time it is to be given.

In rare instances, dogs are apparently cured of their lymphoma by chemotherapy. Unfortunately, most dogs with lymphoma will have relapse of their cancer canine histiocytoma at some point. A second remission can be achieved in a large number canine histiocytoma of dogs, but it is usually of shorter duration than the first canine histiocytoma remission. This is because the lymphoma cells become more resistant to canine histiocytoma the effects of chemotherapy as time goes on. Eventually, most lymphomas develop resistance to all chemotherapy drugs, and dogs with lymphoma die or are euthanized when the canine histiocytoma cancer can no longer be controlled with chemotherapy. What is the prognosis for dogs with lymphoma?

Your dog’s prognosis is determined by what type of lymphoma he canine histiocytoma or she has and what type of chemotherapy is used canine histiocytoma to treat the lymphoma. The median length of survival of dogs with multicentric lymphoma canine histiocytoma treated with UW-25 chemotherapy is between 9-13 months. (the term “median” implies that 50% of dogs will survive beyond this time point and 50% of treated dogs will die before this time point.) various other factors, such the type of lymphoma your dog has or its canine histiocytoma stage of disease, may affect your dog’s overall prognosis. The oncologists and oncology residents at the PUVTH will discuss canine histiocytoma your dog’s prognosis in detail with you before any treatment decisions canine histiocytoma are made. Are there any studies at purdue involving canine lymphoma?

Yes! We are currently conducting multiple clinical trials for dogs with canine histiocytoma lymphoma at purdue. Varying degrees of financial support are available to owners who canine histiocytoma agree to allow their dogs participate in these clinical trials. To determine whether your dog may qualify for a clinical canine histiocytoma trial, please ask your dog’s primary care veterinarian to call 765-494-1107 and ask to speak with a member of our canine histiocytoma canine lymphoma clinical trials team, or you may contact our canine lymphoma clinical trials coordinator, ms.Sarah lahrman at 765-496-6289.