Chemotherapy Plan for Lymphoma Treatment in Canines & Felines
Dogs treated with chemotherapy live significantly longer than untreated dogs, and chemotherapy is generally well tolerated in most dogs. Multi-agent protocols, such as the protocol listed below are the most successful, with a complete remission rate of > 80% and remission durations of 6-11 months. Mean survival time with this protocol is 1 year (CHOP), with 20-25% living up to two years. Mean survival time with steroids only is 4 to 6 weeks.
University of Wisconsin-Madison CHOP-19 Protocol
This chemotherapy protocol is considered the first-choice treatment of most oncologists for most types of lymphoma. Drugs included in this protocol include vincristine, cyclophosphamide, doxorubicin, prednisone, and L-asparaginase. Modifications are made to the published protocols for individual patients, depending on preexisting conditions, response to treatment, and other factors.
To begin treatment: Blood samples will be run and will serve as a baseline to compare treatment response and monitor adverse side effects in the coming weeks. In addition, we may recommend MDR1 testing for certain breeds of dogs. MDR1 is a genetic mutation well known in border collies and several other breeds that makes them much more sensitive to the chemotherapy drugs used in this protocol.
Procedure: This protocol includes a cocktail of chemotherapy medications including intravenous and oral treatments. Each treatment will commence with a check of blood counts. This will help determine whether the chemotherapy is showing adverse side effects of bone marrow suppression, anemia and suppression of the immune system. Generally, if the white cell count falls below 4,000, treatment will be postponed for one week and rechecked.
Schedule: Generally, this program begins with weekly treatments that continue for 9 weeks. Some weeks may be postponed due to unacceptable bloodwork. This allows the body more time to recover from the chemotherapy treatment before starting another treatment. The chemotherapy appointments may be scheduled early in the morning to expedite treatment. Doxorubicin treatments will require admission for several hours to complete treatment.
Chemotherapy Program Schedule
| Week 1 | Vincristine given intravenously* Prednisone by mouth every 24 hours |
| Week 2 | Cyclophosphamide given by mouth. Furosemide given by mouth. Reduce dose of Prednisone given by mouth every 24 hours |
| Week 3 | Vincristine given intravenously* Reduce dose of Prednisone given by mouth every 24 hours |
| Week 4 | Doxorubicin given intravenously as a slow infusion** Reduce dose of Prednisone given by mouth every 24 hours for 7 days. |
| Week 5 | Discontinue Prednisone |
| Week 6 | Vincristine given intravenously* |
| Week 7 | Cyclophosphamide given by mouth. Furosemide given by mouth. |
| Week 8 | Vincristine given intravenously* |
| Week 9 | Doxorubicin given intravenously as a slow infusion** |
| Week 11 | Vincristine given intravenously* |
| Week 12 | Cyclophosphamide given by mouth. Furosemide given by mouth. |
| Week 13 | Vincristine given intravenously* |
| Week 14 | Doxorubicin given intravenously as a slow infusion** |
| Week 16 | Vincristine given intravenously* |
| Week 17 | Cyclophosphamide given by mouth. Furosemide given by mouth. |
| Week 18 | Vincristine given intravenously* |
| Week 19 | Doxorubicin given intravenously as a slow infusion** |
*VinCRIStine treatment will require an intravenous catheter and is given quickly as a bolus.
**Doxorubicin treatment will require an intravenous catheter and a slow infusion over approximately 60 minutes.
Adverse Effects:
• Vomiting & Nausea are the primary side effects noted with all three treatment types.
• Bloody Urine (Hemorrhagic cystitis) is common after treatment with doxorubicin.
• Injection site reactions can occur and be severe at the catheter site. Please monitor catheter sites for pain, inflammation and development of wounds.
• Dark or tarry stool
Please notify us if any of these side effects occur at any time during the treatment. Increased thirst and increased urination can be expected during the first few weeks of therapy.
Management at Home
1. Wear gloves when handling animal waste (vomit, urine or feces) particularly for the first 5 days after treatment. Most chemotherapy drugs are broken down into inactive metabolites that are then excreted in urine and feces, but there likely will still be a small amount of intact drug in both urine and feces. The area should be cleaned with soap and water. Dilute bleach solution may be used if it is suitable to the surface. Many of the drug residues break down quickly in sunlight, so waste outside is less of a risk.
2. Any soiled bedding should be washed separately with regular detergent. A second wash cycle with regular bedding can then be performed to more thoroughly remove contaminants. Any urine/feces/vomit on the floor should be cleaned with soap and water. Dilute bleach is OK if it can be used on the affected surface.
3. Avoid being licked after oral dosing. If the pet takes pills easily, there should be minimal chemo in the oral cavity. If the pill does not go down easily and begins to dissolve in the mouth, there likely will be small amounts of drug in the saliva. If there are children in the house, it is prudent to recommend that the pill be given at night after they go to bed, or in the morning after they leave for school. Exceptions to these rules exist (e.g., after-bedtime administration might be inappropriate with cyclophosphamide, as it would be better to provide the dog with free access to water and plenty of opportunity to urinate after administration of this drug to reduce the risk of sterile hemorrhagic cystitis).
4. If there are multiple pets in the household, it is not routinely recommended that they be isolated. The other pets likely will be exposed to minimal amounts of drug residue when using shared litter boxes and other areas. The risk of complications from this is minimal (after all, we are giving the full dose to the affected pet. In reality, the risk to owners is very low as well. But with the above guidelines we essentially can make that risk almost zero). Looking to balance quality of life, most owners agree that the decreased quality of life from separating the pets is not acceptable. However, if non-treated pets in a household are coprophagic, they should be prevented from ingesting feces, as this might lead to inadvertent exposure to chemotherapeutic agents or metabolites.
Diet & Supplements
Omega-3 fatty acids (fish oils) have been shown to have significant anti-inflammatory effects and may have some effect to slow growth and slow spread of certain cancers. A 2019 study (New England Journal of Medicine) did not find any benefit in human cancer patients. For dog and cats, the best source of omega 3 fatty acids is cold water fish oils. We recommend Welactin or Nordic Naturals brand. Supplementation in cancer patients is generally 1 extra-strength capsule (500-600 mg of DHA and EPA) per 10-20 lbs of body weight.
Medications
Several anti-nausea medications will be prescribed and may be given as a preventative prior to treatment and as needed after treatment. In addition, we may prescribe anti-anxiety medications.
