Vet-Insights: Essential Guide to Cat Cancer Treatment Options
If your cat has been diagnosed with cancer and you are wondering what the best treatment option is, know that your veterinarian determines the type of treatment based on several factors. As a result, your vet will present you with the treatment options based on the type of cancer, its location, and your cat's general health. In addition, your financial capacity will also be taken into account when determining treatment because these treatments can be quite expensive. It is also essential to clearly define your goals and expectations regarding the treatment your cat will receive.
Conventional treatment options include surgery, chemotherapy, radiation therapy, cryotherapy, or immunotherapy. Furthermore, in cases where conventional treatment cannot be applied or administered, symptomatic treatment will be recommended to alleviate your cat's suffering and improve their quality of life. In this article, we will talk about chemotherapy and radiation therapy in cats: differences, types of cancer they are used for, side effects, costs, and much more.
What Are The Treatment Options For Your Cat With Cancer?
In most cases, cancer in cats is a serious and often fatal disease with no definitive cure. However, the primary goal of treatment is to control or reduce the cancer, thereby extending the cat's survival time and enhancing their quality of life.
As previously mentioned, the treatment methods your veterinary oncologist will recommend for your cat will depend on several factors:
- Type of tumor
- Location of the tumor
- Degree of distant spread (whether it has metastasized in the body or not)
- Your cat's general condition
Conventional treatments can be administered or applied as such or in combination (for example, veterinarians usually prefer surgical removal of the tumor, when possible, followed by several sessions of chemotherapy or radiotherapy to neutralize any remaining cancer cells in the body).
1. Surgery
Surgery is the preferred treatment method for cancer in cats. It is recommended when the tumor is well-defined and easy to access. In the case of bone cancer, vets usually recommend removing the affected bone (limbs, jaw, etc.). The same applies in the case of squamous cell carcinoma, an aggressive cancer that infiltrates the surrounding tissues, especially when located on the face, mouth, or jaw. When it invades the jawbone, mandibulectomy (partial or complete removal of the lower jawbone) or maxillectomy (removal of part of the upper jaw) can be recommended.
In cases where the cancer has not spread throughout the body, surgery (usually in combination with radiotherapy or chemotherapy) can be considered curative. This combination (surgery + chemotherapy/radiotherapy) is also recommended when there are metastases in the body or when the tumor cannot be completely removed (due to its location or because it is not well-defined).
2. Chemotherapy
Chemotherapy is a type of cancer treatment that uses medication to kill cancer cells. They work by targeting rapidly dividing and growing malignant cells, slowing or stopping their growth.
Chemotherapy can serve several purposes, including:
- Putting cancer into remission.
- Preventing the recurrence of cancer cells after surgery.
- Preventing cancer cells from spreading to other organs.
- Shrinking a tumor so that surgery can be performed more easily.
- Shrinking an inoperable tumor to improve quality of life and relieve the clinical signs and symptoms (it is called palliative chemotherapy).
Chemotherapy can be given on various routes, such as intravenously (most commonly), orally, or by injection (such as subcutaneous or intramuscular), depending on the selected medication and the type of cancer your cat has. It is also given in treatment cycles, which can last one or more days, followed by a rest period. Your vet will establish the treatment plan based on your cat's type of cancer, the medication used, and your pet's response to treatment.
3. Radiation Therapy
Radiation therapy uses high doses of radiation (usually high-energy X-rays) to kill cancer cells. X-rays are used in small doses for radiographs. This treatment targets cancer cells, damaging their DNA, which can either destroy the tumor (small tumors) or shrink it.
It is important to note that radiation therapy can also affect healthy cells. However, healthy cells have a high capacity for repair, and the side effects are manageable – the treated area may become red or swollen, or your cat may lose hair.
As with chemotherapy, radiation therapy serves several purposes, such as:
- Shrinking a tumor before surgery.
- Treating a tumor when surgery is not an option (e.g., nasal, spinal, or brain cancers).
- Destruction of remaining cancer cells after surgery (total or partial).
- Pain relief (especially in bone cancer).
Radiotherapy is administered in several treatment sessions under sedation or anesthesia.
4. Immunotherapy
Immunotherapy uses certain parts of the immune system to target only abnormal cells while sparing the healthy ones. This therapy method is used to combat various diseases, including cancer, and is well tolerated by pets. One of the most advanced methods is CAR-NK (Chimeric Antigen Receptor Natural Killer cell) therapies. Although still in the experimental phase, these therapies offer new hope for addressing some of the most challenging feline malignancies.
5. Cryotherapy
Cryotherapy is a treatment method for cats with cancer that uses probes to freeze malignant tissue. The goal is to destroy the cancer while causing the least amount of damage to surrounding normal tissue. Not all cancers are amenable to cryotherapy, and the location of the tumor may make this therapy impossible. Cryotherapy may be recommended by your veterinarian for squamous cell carcinoma of the face. In one study, cryotherapy was much less effective than surgery or radiation therapy in controlling the local tumor. Of 15 cats treated, 11 had local recurrences of the tumor within a median of 6 months. Another study, involving 87 cats with squamous cell carcinomas of the head treated with cryotherapy, showed a median disease-free interval of 14 months. Cats with lesions smaller than 1 cm had a much better chance of controlling the tumor. The conclusion was that tumors larger than 1 cm should be treated with methods other than cryotherapy.
6. Symptomatic treatment
Symptomatic treatment is recommended when no other conventional treatment is an option. It can help manage clinical signs (pain, nausea, and other symptoms associated with cancer) and improve the cat’s quality of life. The treatment can include:
- Pain management (NSAIDs, opioids, Gabapentin)
- Anti-nausea medication (Cerenia, ondansetron)
- Appetite stimulants (mirtazapine, capromorelin)
- Corticosteroids (prednisone, dexamethasone)
- Antacid medication (famotidine, omeprazole)
- Antifungal medication
- Antibiotics
Understanding Chemotherapy And Radiotherapy In Cats
Why is it essential to understand the importance of chemotherapy and radiation therapy if your veterinarian decides how to treat your cat? The answer is simple: when you have a basic understanding of these two treatment options, you will be able to make more informed decisions regarding the course of treatment and your cat's health. In addition, an informed decision can help you prepare yourself emotionally and financially.
Understanding Chemotherapy in Cats
What Is Chemotherapy for Cats?
Chemotherapy for cats is a treatment that uses drugs to target and destroy cancer cells, aiming to slow tumor growth and improve quality of life. It is generally well tolerated by pets and has fewer side effects than in humans. Approximately 80% of patients do not have side effects, and other reactions are mild and manageable.
Chemotherapy is the main treatment for lymphoma and leukemia. It may also be recommended after surgery to prevent metastases or for palliative purposes to reduce inoperable tumors.
How Does Chemotherapy Work?
Chemotherapy drugs work by targeting and destroying cancer cells that are actively dividing and multiplying, a process called cell mitosis. Because cancer cells divide much faster than normal cells, chemotherapy interferes with the genetic material (DNA) in their nucleus, blocking their ability to reproduce properly and triggering programmed cell death, known as apoptosis.
Although chemotherapy is particularly effective against rapidly dividing cells, it can also affect healthy cells in the body that multiply frequently, such as those in the bone marrow or mucous membranes, which explains the occurrence of temporary side effects.
In the treatment of feline cancer, chemotherapy can be administered orally, injected, or by infusion, depending on the type of drug and condition. Examples of commonly used drugs include doxorubicin, vincristine, cyclophosphamide, carboplatin, mitoxantrone, and lomustine, each of which is indicated for specific types of tumors such as lymphomas, mast cell tumors, squamous cell carcinoma, or osteosarcoma.
An interesting aspect is that, as veterinary medicine advances, targeted therapies and immunotherapies are also being developed, which, combined with chemotherapy, promise to increase the effectiveness of treatment and reduce adverse effects. This can add new perspectives to the survival and quality of life of diagnosed pets.
Moreover, dosing chemotherapy drugs in cats can be challenging due to their smaller size and weight. Since there are no approved chemotherapy or targeted agents specifically for cats, the available pill sizes are not well-suited to their weight. This issue is even more pronounced compared to small dogs, which typically weigh more than the average cat. Many chemotherapy drugs are dosed based on body surface area (BSA) in square meters rather than body weight, as BSA more accurately reflects various physiological processes, such as renal function and energy metabolism, especially for drugs with a narrow therapeutic range.
1. Oral chemotherapy drugs for cats
Toceranib (Palladia) – It is not a traditional chemotherapy drug but an antineoplastic drug. However, many veterinarians consider or present it as a chemotherapy drug. It has a different mechanism of action than chemotherapeutic drugs - it works by blocking specific molecular pathways essential for cancer growth, not by killing cancer cells. Palladia is used in cats for cancers such as:
- Mast cell tumors
- Carcinomas (squamous cell carcinoma, SCC)
- Gastrointestinal stromal tumors (GISTs)
- Pancreatic cancer
Although this drug is indicated for dogs with cutaneous mast cell tumors, it can be used in cats off-label (i.e., using a medication in a way that is not specifically approved by regulatory agencies).
Lomustine – It is a chemotherapy drug used off-label. It can be administered in:
- Mast cell tumors
- Histiocytic sarcomas
- Lymphoma
Lomustine can penetrate the blood-brain barrier, and is used to treat brain and spinal cord cancers in cats.
Chlorambucil – It is considered the most effective drug for the treatment of chronic leukemia in pets. It may also be recommended for low-grade lymphoma or other types of cancer in cats. Cats treated for lymphoma with chlorambucil have an average remission of 2 years.
Cyclophosphamide – This chemotherapy drug is often used in combination with other chemotherapy drugs to prolong survival. In cats, it is given for cancers such as lymphomas, sarcomas, and carcinomas. It is also found as an injectable drug, being preferred in some treatment protocols.
Melphalan – A chemotherapy drug used to treat certain cancers in dogs and cats, including bone marrow cancer (multiple myeloma), resistant leukemia in cats, osteosarcoma, mammary cancer, and lung cancer.
2. Injectable chemotherapy drugs for cats (IV infusions)
Doxorubicin
This drug is given intravenously (IV) slowly over 20 minutes. It is cumulatively cardiotoxic, meaning that a cat will have a maximum lifetime dose that they can receive before heart problems develop. Cats with liver disease may have reduced tolerance to this drug because it is metabolized in the liver.
Side effects in cats may include vomiting and diarrhea, which occur 2-5 days post-treatment. It is administered in cancers such as lymphoma, hemangiosarcoma, and mammary gland carcinoma.
Note that this medication is excreted in the urine for up to 21 days post-administration, so you should protect your skin with gloves and avoid handling waste directly.
Epirubicin
This drug is a stereoisomer of doxorubicin. Epirubicin is less commonly used in cats (compared to dogs) but is still used in multi-agent protocols for lymphoma (especially alimentary lymphoma) and other types of cancer. Epirubicin can be used successfully in feline injection-site sarcoma (FISS) - cancerous tumors that can arise following injections. Studies have shown that neoadjuvant chemotherapy with epirubicin and resection of the entire muscle compartment containing the tumor has had positive results on recurrence. As a result, out of 21 cats treated, only 3 had local recurrence of the tumor.
Epirubicin is administered slowly over 15-20 minutes. Side effects may include gastrointestinal upset, lethargy, and loss of appetite.
Carboplatin
This drug is a second-generation platinum antineoplastic agent. In cats, it is used in cancers such as osteosarcoma, mammary carcinoma, or sarcomas. Administration is done slowly over 20 minutes.
Side effects are more on the digestive level. In addition, some cats may lose most or all of their whiskers.
Mitoxantrone
It is a synthetic antineoplastic (anti-cancer) agent belonging to the class of drugs known as anthracenediones, which are structurally related to anthracyclines (e.g., doxorubicin). It has a reduced incidence of cardiotoxicity.
Mitoxantrone is used occasionally in cats for lymphoma, transitional cell carcinoma, mammary carcinoma, and squamous cell carcinoma. It should be administered slowly IV over 15-30 minutes.
Side effects usually include vomiting and anorexia.
Vinblastine and vincristine
Both drugs are used in cats, primarily for lymphoma and mast cell tumors. They are administered intravenously with caution. Side effects usually include gastrointestinal upset.
Chemotherapy Safety and Side Effect Management for Pet Owners
If your cat has been diagnosed with cancer and is undergoing chemotherapy, there is a good chance that you will be exposed to their waste through direct contact. Most chemotherapy drugs are eliminated in urine and feces within 3-7 days, but doxorubicin can remain present in urine, even in low concentrations, for up to 21 days after treatment.
Here is what you can do to minimize exposure to these drugs:
For IV chemotherapy, handle urine, feces, and vomit with gloves for 3-21 days (depending on the drug administered).
- For oral chemotherapy, handle your cat's waste with gloves for 7 days.
- Put their waste into two plastic bags, seal them tightly, and throw the bags and gloves in your regular trash can.
- Use a dedicated litter box for your cat undergoing chemotherapy. If possible, use disposable litter trays.
- Clean your cat's litter box once a day.
- Wash your hands thoroughly after each contact.
- Clean surfaces with detergent and diluted bleach.
- If you or someone in your household has touched or handled your cat's waste, rinse immediately with water and wash thoroughly with dishwashing detergent for at least 5 minutes.
- Consult a doctor if necessary.
- It is advisable to throw away any fabrics that your cat vomits, urinates, or defecates on (accidents can happen). If this is not possible, wash them thoroughly twice, separately from your regular laundry. Use bleach.
- Make sure that no one in your family, including other pets, comes into contact with your cat's waste.
- If you are trying to conceive, are nursing, or are pregnant, or if someone in your family is, do not handle or let them handle your cat’s waste or medications.
- Do not crush pills or open capsules. In addition, you should always wear chemotherapy-resistant gloves when handling medications. Wash your hands after handling, even if you use gloves.
- Store your cat's medications separately from other drugs, including your own, and do not store them near food or in areas where children or other pets can reach them.
How Much Does Chemotherapy For Cats Cost?
Chemotherapy for cats is expensive, especially intravenous chemotherapy. Prices often start at $100-$300 per treatment session. Treatment can last weeks or months, depending on the type of cancer and the treatment protocol elected by the vet – some protocols require weekly visits, while others can be administered once every few weeks. A full course of treatment can cost between $1,000 and $5,000. Keep in mind that additional costs will be added to this total cost for veterinary rechecks, blood tests, imaging, and medications to relieve side effects.
If your budget doesn’t allow it, keep in mind that there are helpful options such as veterinary payment plans, pet insurance (this should be done before your cat is diagnosed with cancer), alternative therapies, or clinical trials offered by universities.
Understanding Radiation Therapy in Cats
What is Radiotherapy in Cats?
In veterinary medicine, the most commonly used radiation for this type of therapy is high-energy X-rays. They target cancer cells, killing them or stopping them from growing and dividing.
In pets, radiotherapy is used for:
- Slowing down tumor growth in parts of the body where surgery is not possible.
- Shrinking the tumor before surgical removal.
- Treating the tumor (in the case of small tumors).
- Destroying remaining cancer cells after surgical removal of the tumor.
- Relieving pain (for example, pain associated with osteosarcoma).
In cats, radiotherapy can be administered for cancers of the nose, brain, and other cancers of the head and neck.
As with chemotherapy, radiotherapy requires several treatment sessions to see results. In the case of oral squamous cell carcinoma, surgery can be combined with radiotherapy, which is applied 2 weeks after surgery (to give time for healing), once or twice a day for 15-20 days. In this way, a longer survival time can be obtained for cats diagnosed with this type of cancer, up to 14 months (especially in the case of mandibular tumors). However, hypofractionated palliative radiotherapy is preferred because it involves fewer doses, reduces side effects, and relieves pain, ensuring tumor control for 2-4 months.
Radiotherapy has no significant side effects, but it can cause redness, local irritation, and even hair loss or lethargy in some patients. These side effects usually occur 2-3 days after treatment and go away on their own in 2-3 weeks.
How Much Does Radiotherapy For Cats Cost?
As with chemotherapy, the cost of radiotherapy will be determined by the type of tumor, its size, location, etc. In addition, several treatment sessions will be needed to see results. Therefore, the total cost will be between 2000 and 7000 USD. Since specialized equipment and personnel are needed, the costs will be higher than those of chemotherapy. Don't forget that this cost will include visits to the veterinarian, blood tests, imaging, sedation/anesthesia, etc.
Covering the cost of radiation therapy for your cat can be overwhelming. However, there are several ways to alleviate the financial strain, such as veterinary payment plans, pet insurance (this should be done before your cat is diagnosed with cancer), or clinical trials offered by universities.
Are There Any Alternative Treatments For Cats With Cancer?
Although chemotherapy and radiation therapy are standard, conventional treatments for cats diagnosed with cancer, and veterinarians will often recommend them, some owners prefer alternative treatments that are gentler on their cat's system. These alternative treatments usually aim to slow tumor growth, manage side effects (if conventional treatment is being pursued), and support the overall health of the ill cat. Here are some of the most common alternative treatment options:
Reishi Mushroom (Ganoderma lucidum) – Studies show that Reishi mushrooms can inhibit protein synthesis and slow tumor growth. Zumalka’s Reishi Formula is a natural, antioxidant-rich supplement known for its immune system support and ability to support normal cellular function in cats dealing with cancer or tumors in the colon or skin. In addition, it may have beneficial effects on the liver and contribute to the body's natural defenses.
Shiitake mushroom (Lentinula edodes) - According to studies, this mushroom is effective in prolonging the survival of people with gastric, colorectal, pancreatic, and liver cancer. Zumalka's SHIITAKE product supports a strong immune system and liver function in pets facing tumors in the colon, stomach, pancreas, or liver. It is rich in vitamins B2 and B12, which contribute to overall vitality and strengthen immunity. In addition, it can help protect the body against environmental stressors, thus maintaining your cat’s well-being.
Turkey Tail Mushroom (Coriolus versicolor) – This mushroom contains polysaccharides-K (PSK), which can prolong survival in cats with various forms of cancer, especially hemangiosarcoma. Zumalka's Coriolus product is a natural supplement designed to strengthen the immune system and support the overall vitality of cats facing cancer. It has antioxidant, immune-supportive, and anti-inflammatory properties, helping to maintain normal cellular function and immune response.
Zumalka’s HEPATOPET product – An excellent liver tonic for pets. It mainly contains astragalus, milk thistle, and curcumin (from turmeric), natural compounds known for their immune-boosting, antioxidant, and anti-inflammatory properties.
Zumalka’s PIPTOPET product - This natural product is a mother tincture containing Fomitopsis betulina, a mushroom known for its numerous health benefits. Studies on dogs, monkeys, and mice have shown that it possesses anti-inflammatory, antibacterial, antiviral, antioxidant, and anticancer properties. This product can help strengthen your cat's immune system, making it more able to fight cancer. To enhance the effects of this product, supplements such as TONICPET #4, #5, #7, and #10 can be used in combination.
TONICPET #4 supports your cat’s natural immune system and contributes to the efficient circulation of oxygen in the body.
TONICPET #5 promotes healthy blood flow and supports the proper functioning of all of your cat’s body systems.
TONICPET #7 strengthens the natural immune response and promotes adequate oxygenation of the deeper layers of the skin.
TONICPET #10 helps maintain a balanced pH in your cat’s body and supports healthy digestion. Since cancer cells prefer acidic environments, this product helps reduce acidity, thus supporting your cat’s overall health.
Always consult a holistic veterinarian before using any natural remedies or products.
Frequently Asked Questions (FAQs)
How successful is chemotherapy for cats?
Chemotherapy can be successful, especially in the case of lymphoma, where the remission rate is 50-70%. In addition, the success of chemotherapy depends on several factors such as the type of cancer, its location, its stage, and the general health of the affected cat. The goal of chemotherapy is to improve the quality of life and prolong survival.
How much does chemo cost for a cat?
Chemotherapy is an expensive treatment, with one session costing between $100 and $300. Multiple sessions are required for a complete treatment, which can bring the total cost to $1,000-$5,000, excluding additional expenses (vet visits, blood tests, medications to combat side effects, etc.).
How long do cats live with chemo?
Cats undergoing chemotherapy treatment generally have a survival time of 6 months to 2 years. However, this average survival time will depend on the type of cancer, its stage, and the general condition of the affected cat. For example, a cat with stage 1 cancer will have a longer survival time than a cat with stage 3 or 4 cancer.
Is cat chemo worth it?
Several factors determine whether chemotherapy is a good treatment option, such as the type and stage of the cancer, your cat's overall health, quality of life, and possible side effects. In addition, the owner's emotional and financial commitment are also factors to consider. The primary goal of chemotherapy is to improve the cat's quality of life and average survival time. Consulting with a veterinary oncologist can help you weigh the potential benefits against the challenges and make the best decision.
Is it fair to put a cat through chemotherapy?
Chemotherapy has far fewer side effects in cats than in humans. Additionally, veterinarians would not opt for this type of treatment unless it was necessary or had certain health benefits for the pet.
How long can a cat live on chemo?
Cats undergoing chemotherapy can have an average survival time of 6 months to 2 years. However, the type of cancer, its stage, and your cat's overall health will be taken into account by your veterinarian when determining the prognosis.
Is it worth treating a cat with cancer?
Treating a cat with cancer depends on several factors, including the type and stage of the cancer, the cat's overall health, and how many good days the cat has compared to the bad days. Cancer treatment aims to improve the cat's life and prolong their life. To make an informed decision, it is best to talk to a veterinary oncologist.
Is it worth giving a cat chemo?
Chemotherapy treatment aims to improve the quality of life and prolong the life of a cat with cancer. In addition, the treatment method will be determined by the vet depending on several factors such as the type, size, and location of the cancer, the stage of the disease, and your cat's general health.
What if I can't afford chemo for my cat?
If you can't afford the cost of chemotherapy for your cat with cancer, there are a few options that can help you. Most clinics have payment plans that can allow you to pay for services in installments. Pet health insurance is also an option, but this must be purchased before your cat is diagnosed with cancer. Additionally, some universities offer clinical trials at reduced treatment prices.
Is it worth treating an old cat for cancer?
Treating an old cat with cancer may be worth it as long as it improves their quality of life, prolongs their survival time, and makes them comfortable. The following should be considered in making this decision: the type of cancer, the prognosis, potential side effects, and your cat's overall health. Consulting a veterinarian can help you evaluate the best options.
How much does it cost to treat feline lymphoma?
Feline lymphoma costs range from $2,000 to $5,000 for a full course of chemotherapy. Moreover, lab tests, imaging, veterinary visits, and medications to manage side effects incur additional costs.
Should I give my cat chemo for lymphoma?
Chemotherapy is the most common treatment for feline lymphoma and can significantly improve quality of life and extend survival, with remission rates around 50-70%. The decision depends on your cat’s overall health, the lymphoma subtype, potential side effects, and your goals for treatment. Consulting a veterinary oncologist will provide the most personalized guidance.
Is chemotherapy worth it for cats?
The primary goal of chemotherapy is to enhance the quality of life and extend the lifespan of a cat diagnosed with cancer. The veterinarian will choose the most appropriate treatment approach based on various factors, including the cancer type, size, location, disease stage, and the cat's overall health.
How expensive is cat chemotherapy?
Chemotherapy can be a costly treatment, with each session ranging from $100 to $300. Since multiple sessions are typically needed for a full course of treatment, the total cost can range from $1,000 to $5,000, not including additional expenses such as veterinary visits, blood tests, and medications to manage side effects.
Is radiation for cats worth it?
Radiation therapy for cats can be worth it when the goal is to reduce tumor size, alleviate pain, or slow cancer progression, especially for tumors that are difficult to remove surgically (like nasal or brain tumors). While it can improve quality of life, the decision should consider your cat’s overall health, prognosis, potential side effects, and financial costs. Consulting with a veterinary oncologist helps determine the best approach.
How much does radiation therapy cost for cats?
The cost of radiotherapy for cats varies based on the tumor type, size, and location, typically ranging from $2,000 to $7,000. Since it requires specialized equipment and multiple sessions, it is generally more expensive than chemotherapy. Additional costs may include vet visits, blood tests, imaging, and anesthesia (for each session).
How does radiation therapy work in cats?
Radiation therapy in cats works by using high-energy X-rays to damage the DNA of cancer cells, preventing them from dividing and causing them to die (apoptosis). It is typically used to shrink tumors, control local cancer growth, or eliminate residual cancer cells after surgery.
Can you be around pets after radiation treatment?
Yes, you can generally be around pets after their radiation treatment, as external beam radiation does not make animals radioactive. However, if a radioactive implant or injectable radioactive substance (like iodine-131) was used, temporary precautions may be necessary. Always follow your veterinarian’s guidance for safety.
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