This course provides an overview of the methods for diagnosing, treatment options and prognosis for dogs with lymphoma. This course includes a brief review of. Learn about the veterinary topic of Overview of Canine Lymphoma. Find specific details on this topic and related topics from the Merck Vet Manual. If your dog has lymphoma, you undoubtedly have many questions about how to treat it. In summary, you should be prepared to ask the following questions.
Summary – A Treatment In Lymphoma Dogs
After the first visit, I kept in regular touch with my vet by phone. As the time to start prednisone approached, I called to request the prescription and to ask for confirmation of the signs and symptoms I was seeing to make sure it was a good time to start.
A good vet will respect your decisions regarding the treatment you choose, and will help you take well-informed steps throughout the process. Vets treat dogs with cancer all the time — they see the good, the bad, and the ugly, so keeping them in the loop can do wonders for your own peace of mind. Generally speaking, the most effective treatment for canine lymphoma is chemotherapy, which involves the application of a combination of drugs given to dogs over several weeks or months.
But some dogs do, in fact, live mostly happy, healthy lives post-chemo for several years. As with all surgeries, costs vary significantly depending on the type of surgery necessary, but you can expect to spend several hundred to several thousand dollars.
Finally, if you choose not to pursue treatment, costs are minimal, but so are life expectancies. Regardless of the type of lymphoma your dog has, a typical lifespan is only four to eight weeks. You may have the option to treat symptoms as they arise, and to temporarily mask symptoms with the use of prednisone. This is the absolute hardest decision to make — when, or whether, to put your dog down. And I have to admit, we got it wrong the first time.
When our first dog was diagnosed, we wanted her to be able to die at home so that our other dogs might be able to better understand her death. I thought we could do the same thing with Billie.
Multicentric lymphoma leads to organ failure, which leads to a long, slow, and painful death. But every day she continued to live in ever-increasing discomfort and pain. Our desire for her to die at home with our other dogs prevented us from seeing that our decision was wrong for her. We did finally clue in and take her in to be put down, but we waited far too long, allowing her to suffer for days, rather than allowing her to die in relative peace.
Our choice regarding her death is one of the only things in my life that I absolutely regret. He kept eating, drinking, walking, and breathing in relative peace. He slowed down significantly, and he started experiencing some trouble breathing, but he was happy — you could see it in his eyes. Then later that night, he wanted to go on a walk with our other dog.
He had a good last day. But that night, when we arrived home from the walk, he stopped drinking, and stopped wanting to move around. For the first time, I had to carry him downstairs to go to the bathroom, then carry him back upstairs to go to bed he was a pound dog — this was no small task.
At some point I woke up and felt his lymph nodes, and I realized they had quadrupled in size in a matter of hours — they were ringing his neck, affecting his breathing, and preventing him from sleeping. I looked in his eyes and knew he was hurting. The next morning I carried him downstairs, then let him lie in the grass outside the house just to enjoy the sunshine.
Then we took him in. Seventeen dogs received doxorubicin and placebo, while 15 dogs received doxorubicin and cyclophosphamide. The combination of doxorubicin and cyclophosphamide was well tolerated, causing no increase in adverse events over doxorubicin alone. Despite a numeric improvement in outcome in cyclophosphamide treated dogs, the addition of cyclophosphamide did not result in statistically improved response rate, PFI or ST. Lymphoma is the most common haematopoietic neoplasm in dogs.
Standard of care treatment involves multi-agent chemotherapy protocols that incorporate doxorubicin. Doxorubicin is an anthracycline derived from the Streptomyces yeast.
It has multiple mechanisms of action. These include intercalation of DNA, which leads to inhibition of protein synthesis and free radical formation, and inhibition of topoisomerase enzymes. Major toxicities associated with doxorubicin are bone marrow suppression, gastrointestinal upset, including nausea, vomiting and diarrhoea, and myocardial toxicity, which is cumulative and dose limiting.
Reported remission durations range from 4. Cyclophosphamide is an alkylating agent that can be given orally in dogs, with relatively little toxicity, including bone marrow suppression and sterile haemorrhagic cystitis. The ability to administer cyclophosphamide and prednisone orally allows for these drugs to be given concurrently with doxorubicin with minimal time or effort on the part of the owner, and with little added expense.
Previously, cyclophosphamide was evaluated in combination with doxorubicin as a maintenance protocol following induction with vincristine and L-asparaginase for 28 dogs with stage III—V lymphoma.
In this study, the median remission duration was days 5. Thirty-two dogs with multicentric lymphoma that were presented to the Animal Cancer Center at Colorado State University or the University of Wisconsin-Madison School of Veterinary Medicine between September of and October of were included in the study.
The study design was prospective in nature. Dogs were eligible for the study if they were stage II—V, substage a or b and the owners elected to treat with single-agent doxorubicin. Breed, sex and age at diagnosis were recorded for each dog. The staging system of the World Health Organization for canine lymphoma was used to determine stage and substage. A complete blood count CBC , serum chemistry and urinalysis were required for entry into the study.
Thoracic radiographs, abdominal ultrasound and bone marrow aspirate were documented when performed for staging.
Immunophenotype, as assessed by Polymerase Chain Reaction for antigen receptor rearrangement, immunohistochemistry, immunocytochemistry or flow cytometry, was recorded when available.
If owners chose single-agent doxorubicin as treatment, and elected to enroll in the study, dogs were randomized to receive either cyclophosphamide or placebo.
The randomization scheme was generated by using the web site Randomization. The ST was calculated as the time from the date of the first treatment to the date of death. Toxicity was graded 1—4, and based on the Veterinary Co-operative Oncology Group common terminology criteria for adverse events.
Haematological toxicity was evaluated 7 days after the first treatment, and subsequently at the time of each treatment, if dosage adjustments were not made. Upon completion of the five treatments, it was recommended that animals be seen once monthly for rechecks involving a physical examination.
Blood work was performed at the discretion of the clinician. If lymph node enlargement was palpated, cytology was used to confirm relapse. Information regarding rescue therapy pursued following relapse was collected, and outcome information collected following relapse via recheck examinations and telephone conversations with owners and referring veterinarians. Power analysis was performed prospectively and prior to enrollment of patients. With a planned total of 32 dogs to enroll, this study was powered to detect a 3.
This test was also used to evaluate for differences between groups for substage, hypercalcaemia and T-cell immunophenotype, all of which have been associated with prognosis in previous studies.
Stage was not evaluated as a result of inconsistencies in staging tests performed between patients. A Student—s two-tailed unpaired t -test was used to compare age between groups. A log rank Mantel—Cox test was used to compare the curves. Thirty-two dogs with lymphoma were included in the study. Patient characteristics by treatment group are listed in Table 2. There were no significant differences between the two groups with regard to age, weight, sex, substage, immunophenotype or the presence of hypercalcaemia.
The overall number of doses of doxorubicin and cyclophosphamide given ranged from 1 to 5 median 5 for both groups. In the doxorubicin and placebo group, the mean starting dose of doxorubicin was In the doxorubicin and cyclophosphamide group, the mean starting dose of doxorubicin was The distribution of adverse events is outlined in Table 3.
In the cyclophosphamide group, there were three animals that did not have a follow-up CBC 1 week after the first treatment. Of these patients, there were two patients that had dose reductions, one in the patient that had grade 3 thrombocytopenia and grade 4 neutropenia, and the other in a patient with grade 4 neutropenia.
When dose reductions were made, the doxorubicin was reduced, as it was unknown whether patients were receiving cyclophosphamide or placebo. In the placebo group, there were also three animals that did not have a follow-up CBC 1 week after the first treatment. Two patients had dose reductions in the placebo group. They eat, drink, and run just as they did before they developed cancer. The length of remission depends upon many factors including the primary site of the cancer, how sick an animal is at the start of treatment and the extent of disease.
Some of the cancer cells do survive in an animal in complete remission, but the numbers of these cells are too small to detect. Eventually, these few cells will grow and the cancer will become evident again. When lymphoma returns, remission may be re-established in most dogs by restarting the original chemotherapy protocol, or by changing to a new set of chemotherapy drugs. Eventually, the cancer cells will become resistant or insensitive to all drugs and the cancer will no longer respond to therapy.
Although chemotherapy does not cure dogs with lymphoma, in most cases it does extend the length and quality of life. Keep in mind that these are average values. Each dog is an individual and will respond to treatment differently. In effect, it is a permanent state of remission. While this is a possibility, it is more constructive and realistic to focus on increasing quality of life.
It will depend upon how the cancer is behaving, how sick an animal is at the start of treatment, and any abnormalities in organ function especially important are changes in liver and kidney function. The most effective chemotherapy protocol is a multi-agent chemotherapy; several different drugs vincristine, Cytoxan and Adriamycin are alternated in order to reduce the chance that the tumor cells will become resistant and to reduce the risk of side effects.
Other protocols include chemotherapy given once every 2 or 3 weeks either oral or IV , although remission rates and average survival times may be decreased. Most dogs will tolerate chemotherapy well and have minimal side effects. As a result, the undesirable side-effects normally associated with human chemotherapy are both less common and less severe in animals undergoing chemotherapy.
The most common side-effect is bone marrow suppression, but nausea and anorexia are also occasionally noted. While whiskers are commonly lost, substantial hair loss is not experienced by animals undergoing chemotherapy for cancer. These can include nausea, vomiting, loss of appetite, diarrhea, extreme tiredness or infection. Adriamycin can cause damage to the heart muscle if given multiple times, though most dogs do not receive enough of this drug to be a concern.
Cytoxan can cause irritation to the bladder wall in a small percentage of dogs. If this occurs, you will see changes in urination blood in the urine, straining to urinate, and frequent urination. Unfortunately, the only way to know whether an animal is going to have a drug reaction is to administer the drug.
Some animals never get sick during chemotherapy, others can be very sensitive to the drugs.
Lymphoma in Dogs: A Guide for Dog Owners
Much of the information regarding efficacy of treatment for canine lymphoma has . In summary, the best protocol for lymphoma currently available for routine. Summary of Selected Rescue Protocols for Canine Lymphoma chemotherapy with multiple drugs continues to be the cornerstone of treatment for lymphoma. Learn about the veterinary topic of Treatment of Canine Lymphoma. Find specific details on Page Helpful? Yes No. Overview of Antiseptics and Disinfectants.