Oftentimes there is no one specific cause for cancer in companion animals and the cause is often multifactorial and difficult to pinpoint. Cancer is commonly a result of genetic and environmental factors. Genetic factors include breed predispositions (i.e. German Shepherds, Golden Retrievers, Boxers, etc being overrepresented in our patient population) and spontaneous genetic mutations. Mutations can occur as a result of exposure to cancer-causing factors such as viruses, pesticides, UV light, radon, asbestos, carcinogens, etc.
One thing to make clear to alleviate our pet parents of guilt is that there is NO way to prevent cancer.
Is there a specific food I should be feeding my pet now that they have a cancer diagnosis?
Short answer: no. Long answer: There is no such thing as a “cancer diet”. While there are studies in lab mice regarding protein:carbohydrate ratios in food and cancer, that data has not been extrapolated to companion animals. Cancer metabolism is an extremely complex subject that is far more complicated than “starving the cancer of glucose”.
How do we treat cancer in companion animals?
Cancer in animals is generally treated in a multimodal fashion with a combination of treatment modalities such as chemotherapy, surgery, immunotherapy, and/or radiation therapy. Medical oncologists use chemotherapy and immunotherapy to treat cancer. Radiation oncologists use radiation therapy to treat cancer. Veterinary oncologists rely on surgical specialists or surgical oncologists to perform surgery on our cancer patients.
What is chemotherapy?
Chemotherapy is drugs that are designed to kill or slow down the growth of cancer in tumors that have a high likelihood of spreading throughout the body. Chemotherapy is also used in cancer cases where radiation therapy or surgery are not treatment options. Many chemotherapeutics we use are derived from natural substances (i.e. plants/trees, bacteria, etc). While the drugs used to treat companion animals are also commonly used in humans, the approach in companion animals is much different compared to humans. In veterinary medicine we focus primarily on the animal’s quality of life, such that we focus on limiting severe side effects and ensuring that the pet's quality of life remains as good as possible while they receive chemotherapy. There are some chemotherapeutic that are specific to veterinary patients.
What are the side effects of chemotherapy?
Chemotherapy side effects occur due to the fact that chemotherapy not only kills rapidly dividing cancer cells, nature rapidly dividing cells such as the cells that line the gastrointestinal tract (i.e. stomach, small intestines, large intestines), white blood cells, and in some breeds hair follicles. The majority of pets who receive chemotherapy experience mild side effects that are self-limiting and include gastrointestinal upset (i.e. decreased appetite, vomiting, diarrhea, etc), lethargy, and/or immunosuppression (decreased in a white blood cell called the neutrophil). In a recent study (VCO 2021) looking at severe adverse events (i.e. side effects) commonly observed in dogs during cancer chemotherapy it was found that adverse events were reported in 80% of patients and severe adverse events were reported in 32.3% of dogs. Among the 32.3% of dogs who experienced severe adverse events 14.8% experienced gastrointestinal events and 20% experienced adverse events related to red and white blood cells and platelets (i.e. immunosuppression). Approximately 24% of the severe adverse events led to hospitalization of the dogs and 7.7% of dogs with severe adverse events stopped chemotherapy due to these events. Thankfully only a small percentage of dogs who experience severe adverse events (5.8%) suffered from life-limiting consequences. It was shown that risk factors for severe adverse events include small dogs (<22 pounds) and receiving a multi-agent chemotherapy protocol.
Side effects in cats and dogs are usually controlled using over the counter or prescription medications. In general, the quality of life for patients receiving chemotherapy is generally excellent. The oncologist always keeps track of an individual patient’s tolerance for chemotherapy and can adjust their dose accordingly. In addition, prophylactic medications are always prescribed for pets receiving chemotherapy.
Hair loss is not common in companion animals receiving chemotherapy compared to humans. Breeds with continuously growing hair (i.e. Shih Tzu’s, Sheepdogs, Poodles, Westies, etc) can lose their hair. Sometimes cats lose whiskers while receiving chemotherapy. In rare cases dogs develop more pigment to their skin while receiving chemotherapy, and sometimes cats and dogs experience a haircoat change.
Blood work is checked prior to pets receiving chemotherapy to ensure they have enough white blood cells to withstand treatment. Chemotherapy can temporarily lower white blood cell counts, which can make pets susceptible to infections (from infectious agents in their environment and within their own body!).
What is a chemotherapy protocol?
Once a cancer diagnosis is obtained in a cat or dog, a chemotherapy protocol is prescribed to the patient. A chemotherapy protocol is a set schedule of drug(s) given in a specific time frame. Some protocols include one drug, while others include giving more than one drug on the same day or alternate drugs over time. Chemotherapy protocols are created using (ideally) studies with control groups and the intent is to optimize anticancer benefits of multiple chemotherapeutics. It is of the utmost importance to adhere to a protocol’s schedule (unless there are adverse side effects), or else run the risk of the cancer progressing and potentially become refractory to treatment. The veterinary oncologist will determine if/when it is appropriate to alter a chemotherapy protocol.
How is chemotherapy given?
Chemotherapy is given either within the veins/vessels (intravenously), orally, or underneath the skin (subcutaneously). In some cases the drug can be directly injected into the tumor itself. Most intravenous injections are given as a bolus (i.e. over a few minutes), though there are a few chemotherapeutics that are given as an infusion over 20-30 minutes. Most pets require gentle restraint (with love and care) while they receive chemotherapy, with some pets needing anti-anxiolytics prior to their appointment to help with restraint. In some cases, a mild sedative can be given to help facilitate a smooth and safe chemotherapy administration.
Some oral chemotherapy drugs are given at home by the owners or in the hospital prior to the pet being discharged. Chemotherapy pills cannot be crushed, split, or broken open and gloves must be worn when handling these pills. People who are pregnant or breastfeeding and people who are immunocompromised should not handle chemotherapy.
Side effect profiles of oral and injectable chemotherapy are similar. The oncology staff will discuss in detail how to keep yourself safe while your pet receives chemotherapy.
How long does it take to finish a chemotherapy protocol and how often is it given?
Many chemotherapy protocols have a set number of treatments that can last a few months in duration. Overall, treatment protocols vary such that some drugs are given daily, while others are administered once a week or every 2-4 weeks. In some cases the chemotherapy protocol is indefinite.
Once a chemotherapy protocol is complete serial monitoring is recommended to monitor progression of disease.
How can I keep myself (and others) safe while my pet undergoes chemotherapy treatment?
If your pet urinates, defecates, or vomits within 24-72 hours after receiving chemotherapy (in any form), it is recommended to clean the area (while wearing disposable gloves) with detergent/disinfectant. It is recommended to wipe up the area first (ideally with paper towels) before applying the cleaning product (ideally by pouring and not spraying), so as to not aerosolize the metabolized chemotherapy. All items that came into contact with the bodily fluids should be disposed of and the person who cleaned the area should wash their hands thoroughly. Generally it is recommended that an fabric that comes into contact with bodily fluids within 24-72 hours of chemotherapy administration be washed in hot water twice and separate from other laundry.
Pets receiving chemotherapy can interact with family members and other animals in the household. Chemotherapy pills given at home should be kept out of reach of children. People who are of childbearing age or immunocompromised should not be handling chemotherapy and should avoid cleaning up vomit, urine, or feces 24-72 hours after the pet receives chemotherapy. In addition, coming into contact with a pet’s saliva 24-72 hours after administration of chemotherapy is not recommended (i.e. no excessive licking, especially around the mouth).
Can my pet receive vaccines while they undergo chemotherapy treatment?
There is no evidence to indicate that it is unsafe for pets to receive vaccines while they are receiving chemotherapy. However, it is generally recommended to space out the administration of vaccines and chemotherapy administration. Your veterinary oncologist will guide you regarding the timing of vaccines.
How do I make an oncology appointment for my pet?
The PASE Oncology service is a referral-only service, meaning your primary veterinarian can contact our service via telephone (267-908-6888) or email (firstname.lastname@example.org) to initiate the referral process, which includes transfer of your pets records. If your primary care veterinarian referred your pet or if your pet was directed to our service after seeing another speciality service, you can call directly to set up your appointment (which will also require transfer of your pet’s medical records).
What is the cost of a new consultation appointment?
The cost for the initial consultation with PASE Oncology is approximately $290. There are additional costs associated with emergency transfers. The cost of a typical visit depends on if further diagnostics or treatment are performed (i.e. x-rays, abdominal ultrasound, CT, aspiration of lymph nodes, etc). Treatment costs vary depending on the diagnosis. An accurate financial estimate will be provided at your appointment along with a discussion regarding prognosis, pros/cons of treatment, and efficacy based on literature and clinical experience. Pet owners can expect a discussion regarding side effects.
What can I expect during my new/initial consultation appointment?
New consultation appointments are an hour and 15 minutes in duration. This consultation will consist of a complete view of your pet’s medical records including any lab work or imaging that was performed to obtain a cancer diagnosis (or suspicion). One of our veterinary technicians or assistants will initially greet you to confirm the history we have gathered from your pet’s medical records. Your pet will be escorted to the oncology exam room by the technician or assistant to then be examined by the attending oncologist. Afterward you will meet the attending oncologist, who will ask further questions about the pet’s history, clinical signs, and discuss your pet’s physical exam findings. The oncologist will make recommendations regarding further diagnostic and treatment options. Depending on the case and oncology schedule, further diagnostics and treatment can occur the same day. All information will be written down in the form of a discharge summary, handouts, and financial estimates.
You should plan for a half day (2-3 hours) to full day (5 hours) for initial consult appointments since PASE Oncology also works in conjunction with other hospital services (i.e. Surgery and Radiology etc) to offer the best care to our oncology cases. Therefore, this team-approach takes more time than is allotted for the formal appointment and we appreciate your patience.
What can I expect during recheck appointments?
Recheck appointments are 45-60 minutes in duration depending on what type of treatment your pet is given and if they are feeling well. Recheck appointments start with you checking in with reception. A questionnaire should be sent to you 24-48 hours prior to your appointment, we encourage all clients to fill this questionnaire out each visit to expedite the check-in process. A veterinary technician or assistant will greet you and your pet and briefly go over the questionnaire, if it has not been filled out then they will ask all pertinent questions at that time. They will also discuss how your pet has been doing since their last visit and review the plan for the day. Your pet will then be taken to the treatment area for diagnostics and treatment.
**Please specify what medications you need refilled at check-in and/or on the recheck questionnaire**
Some owners will choose to wait for their pet to be finished with treatment or will step out, please provide us with a contact number for that day regardless so we can contact you as needed during your pet’s appointment time.
Failure to comply with the above process will result in a delay in your pet’s discharge time. Failure to arrive at your recheck appointment on time will result in either a cancellation of the appointment (+/-late fee) and a significant delay in your pet’s discharge time.
If there is no change to your pet’s treatment plan and they are doing well, your pet will be discharged on time. However, if there is a change to your pet’s plan (i.e. additional diagnostic tests are warranted, they are not feeling well, etc), the oncologist will contact you to discuss this as soon as possible.
**You are welcome to call or email for an update during the day. However, this may result in a delay in the pet’s treatment and discharge time.**
What if I have a question after my appointment is over?
We encourage all owners with NON-URGENT questions to email us at email@example.com. Please allow 24-48 hours for a response. All URGENT questions (i.e. a pet is not feeling well, emergent care is needed) should be seen through the Emergency Service or called in at (267-908-6888) realizing that a message will be taken by a receptionist and for expedited callback we require a detailed message be left for our oncology team. Emergent calls will be returned within 1-2 hours. All calls deemed to be NON-URGENT will be returned within 24-48 hours.
Medication refill requests should NOT be called in and emailed to us at firstname.lastname@example.org. Please plan accordingly as it will take 48-72 hours to fulfill refill requests.
What is a veterinary (medical) oncologist?
A veterinary oncologist is a board-certified specialist who undergoes rigorous and extensive training throughout their career to become fluent in all things small animal cancer. To become an oncologist a veterinarian must go through 4 years of veterinary school (and pass the National American Veterinary License Exam [NAVLE] to become a veterinarian), 1 year of a rotating internship, and then 3 years of a medical oncology residency. During residency, while spending 60+ hours a week on clinics the oncologist is required to develop a scientific study and publish the data successfully and pass two board exams prior to becoming a diplomate of the American College of Veterinary Internal Medicine (with the subspecialty of oncology). Veterinary oncologists then have to maintain their credentials every decade by attending conferences, giving lectures, publishing scientific articles or textbooks/chapters, etc.
What is a veterinary technician?
A veterinary technician is the pillar of the veterinary team such that they assist veterinarians in day to day patient care. Veterinary technicians must complete a postsecondary program in veterinary technology. They usually need a 2-year associate's degree and must pass a credentialing exam to become registered, licensed, or certified depending on the state in which they work. Veterinary technicians are required to pass the Veterinary Technician National Examination (VTNE) offered by the American Association of Veterinary State Boards. Veterinary technicians have a vast array of skills including communication, phlebotomy, anesthesia, manual dexterity, emotional intelligence, etc. Veterinary technicians also need to maintain their credentials through continued education (at least 16 hours) every 2 years. The biggest difference between veterinarians and technicians is that technicians are not allowed to diagnose, prescribe, or give a prognosis for veterinary patients. With all this said, veterinarians cannot do their job without technicians!
What is a veterinary technician?
Veterinary assistants are non-licensed veterinary professionals who assist technicians and veterinarians with day-to-day patient care. Most veterinary assistants have a high school diploma and/or bachelor’s degree.
What is radiation therapy?
Radiation therapy is a type of cancer treatment performed by radiation oncologists. This treatment uses high energy x-ray or other particles to kill cancer cells. A radiation protocol consists of a specific number of treatments given over a set period of time determined by the radiation oncologist. Radiation treatment and chemotherapy are not performed simultaneously. If the medical oncologist recommends radiation therapy for your pet, they will refer you to a speciality hospital that has a radiation oncologist.
Can I give my pet supplements for their cancer?
While holistic medicine has some benefits in animals with cancer, it is generally not recommended to be used instead of evidence-based medicine (aka standard of care chemotherapy protocols). Instead, it is recommended to use holistic care as a supplement to standard of care not as a replacement. Just like in human medicine, supplements for animals are not well regulated therefore it is unclear what harm these supplements pose for pets in general. Therefore, it is recommended to hold off on supplemental therapy when pets are initially starting their chemotherapy regimen. Overall, it is recommended to give your pet holistic care under the guidance of a holistic veterinarian. Your oncologist can refer you to some reputable holistic veterinarians.
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