What Can Slow Tumor Growth In Dogs?

Cancer is a leading cause of death in dogs, with around 1 in 4 dogs developing some form of cancer during their lifetime. Cancer occurs when abnormal cells grow out of control, forming masses called tumors. Tumors can arise anywhere in a dog’s body and can be either benign (non-cancerous) or malignant (cancerous). Malignant tumors are particularly concerning because they are able to invade nearby tissues and spread to other parts of the body (metastasize).

Some of the most common cancers seen in dogs include lymphoma, mast cell tumors, melanoma, osteosarcoma, and mammary gland tumors. The risk of developing cancer generally increases with age, but some breeds are predisposed to certain types of cancer. Obesity and environmental exposures may also contribute to cancer risk in dogs.

Slowing the growth and spread of malignant tumors is critical for improving outcomes in dogs with cancer. Early detection through regular veterinary exams allows for earlier treatment interventions when tumors are small and less likely to have metastasized. Various treatments like surgery, chemotherapy, radiation therapy, immunotherapy and dietary supplements can help slow tumor progression and prolong survival times when applied appropriately under veterinary supervision.

While most canine cancers cannot be cured, slowing their growth and spread can provide dogs with additional good-quality months or years of life. Owners have an important role to play in monitoring their dog’s health and seeking veterinary advice at the first signs of illness. With proactive and integrated treatment approaches, there is hope for slowing cancer and managing this disease in our beloved canine companions.

Diagnosing Cancer Early

Detecting cancer early is critical for providing your dog with the best chance possible for treatment and recovery. According to the ASPCA, cancer is the leading cause of death in dogs over the age of 2. That’s why it’s important to know the common signs of cancer and bring your dog in for screening if you notice any abnormalities.

Some of the most common early signs of cancer in dogs include:[1][2]

  • Lumps or bumps under the skin
  • Sores that won’t heal
  • Abnormal odors coming from the mouth, ears, or other body parts
  • Changes in bowel habits
  • Difficulty eating or swallowing
  • Significant weight loss or gain
  • Loss of energy or lethargy
  • Difficulty breathing

Since early detection can vastly improve prognosis, it’s important to monitor your dog closely and learn the subtle signs of cancer. Routine veterinary checkups are also crucial for screening. If you notice any suspicious lumps, unexplained weight changes, or other odd symptoms, don’t delay – make an appointment right away. The earlier cancer is diagnosed, the better the outcome is likely to be.


Surgery is often used to treat canine cancers, especially those that have not yet metastasized or spread to other parts of the body. The main surgical treatment for cancer in dogs is excisional surgery, which involves removing the entire tumor along with some surrounding healthy tissue to ensure all cancerous cells are eliminated (source).

The benefits of excisional surgery include removing the tumor before it can grow larger or spread to other areas. This gives dogs the best chance at a cure. Surgery also allows for biopsy and diagnosis of the cancer.

However, there are some risks as well. As with any surgery, there are anesthetic risks and the potential for infection, bleeding, or other complications. Surgery can be more complicated for large tumors or those in difficult-to-reach locations. And in some cases, excisional surgery may not remove every last cancer cell, allowing the cancer to return. So surgery is often combined with other treatments like chemotherapy.

Overall, when feasible, surgery can provide the fastest way to eliminate cancerous tumors in dogs. Consulting with a veterinary oncologist will help determine if surgery is the right option for an individual dog’s cancer diagnosis and prognosis.


Chemotherapy is the use of drugs to kill or slow the growth of cancer cells. It works by interfering with a cancer cell’s ability to grow and divide. The drugs either circulate throughout the body or target certain cancer cells directly. Chemotherapy is commonly used for cancers like lymphoma, osteosarcoma, mast cell tumors, and others in dogs. Some of the most common chemo drugs used for dog cancer include cyclophosphamide, doxorubicin, vincristine, prednisone, and others.

Unfortunately chemotherapy often causes side effects in dogs from suppressing bone marrow. Common side effects may include nausea, vomiting, diarrhea, decreased appetite, hair loss, and fatigue. However, there are medications available to help control nausea and other side effects. It’s important to routinely monitor blood levels during chemo treatment. Vets will usually prescribe chemotherapy in cycles with rest periods in between to allow the dog’s healthy cells time to recover. While chemo can often extend a dog’s life, it is not considered a cure for cancer in most cases [1].

[1] https://gooddogpeople.com/blogs/dog-talk/dog-cancer-what-do-i-need-to-know

Radiation Therapy

Radiation therapy is a common treatment option for dogs with cancer. It works by delivering targeted, high-energy radiation to the tumor site in order to damage the DNA of cancer cells, preventing them from growing and dividing (source). There are two main types of radiation used for treating dog cancer:

External beam radiation directs radiation from outside the body onto the tumor. This allows doctors to target the radiation to the specific area with pinpoint accuracy, minimizing damage to surrounding healthy tissue. External beam radiation is delivered over multiple treatments to maximize the cancer-killing effect (source).

Internal radiation (brachytherapy) involves implanting radioactive seeds or wires directly inside or next to the tumor, giving a very concentrated dose of radiation to the cancer cells. It allows radiation to be delivered directly to tumors that may be difficult to reach with external beams (source).

Radiation therapy can be used alone or in combination with other treatments like surgery and chemotherapy. Careful administration allows high doses to reach the tumor while sparing normal tissue. This makes radiation an important weapon against canine cancers.


Immunotherapy is a type of cancer treatment that uses the power of the dog’s own immune system to fight cancer. Immunotherapies work by stimulating the immune system to recognize and destroy cancer cells more effectively.

There are several types of immunotherapies used to treat dog cancers:

– Monoclonal antibodies: These are proteins that attach to specific targets on cancer cells, flagging them for destruction by the immune system. For example, the monoclonal antibody blontress (called melanoma vaccine) targets melanoma cancer cells in dogs.1

– Cancer vaccines: These work similarly to vaccines for infectious diseases, exposing the immune system to dead cancer cells or cancer-specific proteins to provoke an immune response against those cancer antigens. The melanoma vaccine is one example.

– Adoptive cell transfer: Cells like T-cells or NK cells are removed from the dog’s body, activated and expanded in the lab, then put back into the dog where they can seek and destroy cancer cells.

– Immune checkpoint inhibitors: These drugs block proteins that shut down immune responses, allowing T-cells to remain active against cancer. One example is Elsep, which inhibits PD-L1 in dogs.

Research into immunotherapies for dog cancers is ongoing, but current options stimulate the immune system to better recognize and eliminte cancerous cells in the body.

Diet and Nutritional Supplements

Diet and nutritional supplements may help slow tumor growth and enhance overall health in dogs with cancer. Some supplements to consider include:

Omega-3 Fatty Acids

Omega-3 fatty acids like those found in fish oil have anti-inflammatory properties that may inhibit cancer cell growth. Adding omega-3s to your dog’s diet or giving fish oil capsules can support their immune system during cancer treatment.


Antioxidants like vitamin E, vitamin C, and selenium help neutralize free radicals that can damage cells and contribute to tumor growth. Fresh fruits and vegetables, as well as supplements, can provide antioxidants.


Glutathione is an important antioxidant naturally produced by the body. Cranberry, turmeric, milk thistle, and alpha-lipoic acid may help boost glutathione levels.


Curcumin, found in turmeric, has anti-inflammatory and antioxidant benefits. It may help inhibit the growth and spread of cancer cells in some cases.

Consult your veterinarian about the appropriate use of supplements. A balanced diet and nutrients tailored to your dog’s needs can complement cancer treatment.

Pain Management

Managing pain is extremely important for dogs with cancer. Cancer can cause significant pain through the tumor pressing on nerves and tissue, as well as through the side effects of cancer treatments like surgery, chemotherapy, and radiation therapy. Effectively managing your dog’s pain will improve their quality of life and allow them to continue normal activities.

There are several types of medications used for dog cancer pain management:

  • NSAIDs like Carprofen, Deracoxib, Meloxicam, and Piroxicam help control inflammation and pain. These are often used for arthritis but can also help with cancer pain.
  • Tramadol is an opioid pain medication that can be used safely in dogs for moderate to severe pain.
  • Gabapentin is an anticonvulsant that can help relieve neuropathic pain from nerve damage.
  • Amitriptyline is a tricyclic antidepressant that has pain relief effects.
  • Fentanyl patches and other opiates like Hydromorphone or Morphine may be used for severe pain under close veterinary supervision.

Your vet will determine the best pain medication protocol for your individual dog. Be sure to monitor your dog closely and alert your vet if you see signs the medication is not adequately controlling their pain. Some side effects like sedation or lack of appetite may occur but can be managed by adjusting dosages. With proper pain treatment, your dog can have a good quality of life even while battling cancer.

Quality of Life

When caring for a dog with cancer, maintaining a good quality of life is extremely important. As the disease progresses, there are several things owners can do to keep their dog as comfortable as possible:

Monitor for side effects of treatment like nausea, diarrhea, and loss of appetite. Talk to your vet about medications that can help with these issues. Appetite stimulants may help get your dog to eat, and anti-nausea drugs can relieve upset stomach. Metoclopramide and ondansetron are common medications used for nausea in dogs with cancer.

Keep your dog clean, well-groomed and free of sores or wounds through gentle bathing and grooming. This will help avoid infections and skin irritation.

Make sure your dog has soft, padded bedding in their favorite resting spot. This cushions joints and bony areas.

Avoid strenuous exercise and activities that cause pain or fatigue. Short, gentle walks and playtime that your dog enjoys can help keep their spirits up.

Use harnesses and ramps if your dog is having mobility issues. This prevents falls and makes it easier for them to move around.

Give prescribed pain medications regularly. Common options include NSAIDs, steroids, opioids and gabapentin. This relieves discomfort and improves overall wellbeing.

Consider complementary therapies like acupuncture, massage and CBD oil. Research shows they can reduce some cancer symptoms in dogs.

Make adjustments as needed to your dog’s diet. Nutritional supplements or easily digestible food may help with issues like weight loss, nausea and loss of appetite.

Spend quality time together through petting, brushing and other activities your dog enjoys. This provides comfort and strengthens your bond.

Monitor your dog’s behavior for signs of depression or anxiety. Talk to your vet about anti-anxiety medications or natural calming products if needed.

Consider at-home euthanasia when your dog’s quality of life declines to a point where they are consistently uncomfortable or distressed. This allows them to pass peacefully at home.

Supporting Your Dog

When your dog is diagnosed with cancer, it can be emotionally distressing for both you and your pet. Fortunately, there are ways you can provide comfort, care, and emotional support for your dog at home while managing their cancer. According to the American Cancer Society, interacting with pets can provide important emotional benefits for cancer patients including reducing anxiety, pain, and improving quality of life (source).

Here are some tips for providing emotional support and at-home care for your dog with cancer:

  • Spend quality time together through play, walks, or just relaxing and petting your dog. This can reduce stress for both of you.
  • Consider enrolling your dog in animal-assisted therapy programs offered by hospitals, hospices, and community centers (source).
  • Ask your vet about anti-anxiety medications to help your dog stay calm and comfortable.
  • Create a comfortable space for your dog with soft bedding, their favorite toys, and easy access to food and water.
  • Stick to your dog’s normal routine as much as possible for a sense of normalcy.
  • Learn how to properly clean and dress any surgical wounds your dog has.
  • Monitor your dog for signs of pain or discomfort and alert your vet.

You can also look into special assistance programs like CancerCare’s PAW Program which provides free pet food and other support for dogs of cancer patients (source). Most importantly, shower your dog with love and affection. Your companionship provides critical emotional support during this difficult time.

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