Portland Veterinary Oncology Center

13655 SW Jenkins Road
Beaverton, OR 97005

(503)644-6581

portvetonc.com

CANCER, CHEMOTHERAPY, AND QUALITY OF LIFE
 
1) The first question many people ask is how chemotherapy is going to affect quality of life for their pet. Is it going to make them sick like it does in people?
 
Our goal in veterinary medicine is to keep our cancer patients comfortable and happy during treatment while controlling their disease for as long as possible.
 
If we are not meeting this goal then changes are made to re-establish good quality of life. Nobody wants your pet to be sick or to suffer during treatment.
 
2) The second question is often related to expected survival. Everyone would like to know whether a cure is possible and if not, how long they might have with their pet?  
 
This is often a very difficult question to answer but average disease-free intervals and/or survival times can usually be presented in general terms. Each patient is unique. Each case is different. Some patients will do much better than anticipated and some patients won’t do as well as expected. Prognostic factors will be discussed during your consultation.
 
3) The third question is usually related to time and financial commitments. A cost estimate will be provided to you in writing. A schedule of treatments will also be provided. Unfortunately both of these may change during treatment depending on response to therapy and any challenges encountered along the way. We do our best to estimate as accurately as possible.
 
Appointments
Although we make every effort to make our patients feel comfortable during visits, they may be a little uneasy about new people, new surroundings, and other pets. For the safety of your pet and others, we do require cats to be in a carrier and dogs to be leashed and properly controlled at all times while on the premises (including the parking/outdoor areas). Contact with other patients should be avoided. Please let us know if you would like assistance getting your pet into or out of your vehicle.
 
After the initial consultation, if your pet is doing well, you will not be meeting with the doctor at each visit.  This approach to treatment is to provide medically appropriate, cost effective treatment and to minimize your time commitment. At each of these visits you will be asked for an update, your pet will be physically examined by the doctor, any necessary blood tests will be run, and the chemotherapy will be administered as appropriate. However, if you have concerns or would like to meet with the doctor please let us know at least 24-48 hours prior to your scheduled treatment time (when possible) so appropriate scheduling of your visit can be established. If you are in need of medication refills please let us know ahead of time as well so we can try to have those ready for you.
 
The most common cancer we treat with chemotherapy is lymphoma. The current standard of care for most cases of lymphoma is a multi-agent protocol established at the UW-Madison (often referred to as a CHOP protocol – an acronym for the chemotherapy drugs administered). This protocol is administered over a 5-6 month period. A complete discussion of treatment options, including scheduling and reevaluations, will be provided at the time of initial consultation. This protocol is a general guideline. Again, each patient is unique and the protocol is adjusted and tailored to meet individual needs and to provide for the best possible outcome.
 
The time it takes to recheck lab work and administer chemotherapy treatments varies from drug to drug. Some treatments are given by mouth and are not time consuming while most others are administered by intravenous injection and require substantially more time (20-40 minutes) to administer. Other treatments require close monitoring of your pet for 2-3 hours after administration. We will help you plan your day based on the drug to be administered. Some patients (particularly cats) require light sedation to allow for intravenous (IV) catheter placement and treatment. If this is the case, we will discuss this with you and get your authorization first.
 
SIDE EFFECTS
Nearly all medications have the potential to cause side effects. Chemotherapy drugs are no different in this respect. There is approximately a 10-20% complication rate associated with antibiotic use and a similar complication rate associated with chemotherapy agents. The dose and frequency of administration can increase or decrease this potential. The risk vs. benefit is always assessed during treatment. The potential benefit of the anti-tumor effects generally outweighs the potential risk of serious complications.  
 
A list of possible side effects of many chemotherapy agents is below:
 
1) Hair loss–rare with the exception of poodles and other breeds that have hair that grows continuously–if grooming for haircuts is necessary then hair loss may occur in your pet. Cats often lose whiskers. Hair and whiskers do grow back but might not be exactly the same as before.
2) Decrease in cell counts–white blood cells, red blood cells, and platelets can all be affected by chemotherapy. If the infection-fighting white blood cells (neutrophils) drop too low your pet is at increased risk for infection. Treatment may be delayed and antibiotics prescribed. Each drug impacts the cell counts at different times. Please refer to your individual drug handouts for the most likely time the cell counts will be low.
This is one of the more common side effects but rarely poses a significant risk to your pet unless the counts are severely decreased (which we very carefully try to avoid). If your pet is not acting right, you can take a rectal temperature at home to determine whether a fever is present. If so, your pet would need immediate attention.
Normal body temperature for cats and dogs:  ~100.0 – 102.5 F.  
3) Gastrointestinal upset–similar to GI side effects sometimes experienced with antibiotic administration: loss of appetite, nausea, vomiting, diarrhea, and rarely bloody diarrhea can occur. Medications may be started in anticipation of these side effects to ward them off or they may be prescribed if/when the side effects occur. These side effects are typically experienced 2-5 days after treatment. Please contact our office if any of these symptoms are noted. If they manifest in a different time frame then there may be more cause for concern (e.g. possible infection secondary to low cell counts). Again, please notify our office right away.
4) Tissue damage–some chemotherapy drugs can be very irritating to tissues outside of a vein. If these drugs are accidentally given outside the vein then severe tissue reactions can occur. Every precaution is taken to avoid this from happening but if it does, there are medical treatments that can help decrease the amount of tissue damage and help with comfort during resolution.
5) Allergic reactions–these are uncommon for most of the chemotherapy agents in use but some drugs are more likely than others (Elspar – L-asparaginase) to cause an anaphylactic reaction and allergic reactions are always possible. If your pet has an allergic reaction it should occur relatively quickly after drug administration and be observed and treated immediately.  
6) Heart damage–some chemotherapy drugs (doxorubicin/Adriamycin), in rare instances, can cause permanent heart damage. There is a maximum dose established to try and prevent this risk from developing. Less than 5% of patients develop heart disease as a result of chemotherapy.
 
If chemotherapy treatments are meeting our goals then your pet should be living life with you as though there was no cancer. They should be enjoying their regular activities with you and getting a kick out of life!
 
You do need to be thoughtful about the following:
1) Carefully storing oral chemotherapy drugs at home, AWAY FROM CHILDREN 
2) Wearing gloves when handling drugs and washing your hands thoroughly after
3) Never breaking a chemotherapy tablet or capsule
4) Avoiding contact with your pet’s urine or feces for 72 hours after treatments 
 
Most clients are pleasantly surprised at how well their pets feel during chemotherapy! Our goal is to maximize efficacy while minimizing side effects.