Discover recent advances in treating cancer in dogs. Modern drugs, effective pain relief and patient-focused approach, mean your pet stays well during treatment and lives longer. When you hear the diagnosis, “I’m sorry, but your dog has cancer,” it’s a sick-to-your-stomach moment. It can be a struggle to come to terms with the news and you leave the clinic feeling helpless. But the truth is, for the majority of patients there are options for treating cancer in dogs. Perhaps at first you’d baulk at putting your best-buddy through chemo or other therapies. After all, in people, chemotherapy has distressing side effects, and this isn’t something you could bear for the dog. However, the aim of treatment is different in dogs, and maintaining a good quality of life is a priority. With this in mind, it might after all be worth weighing up the options.

A Balancing Act

  In people, the aim of cancer therapy is to cure the patient. This means high doses of drugs, chemo or radiation, and frequent treatments. It is the aggressive nature of therapy that is largely responsible for the side effects, such as hair loss and severe sickness.   In dogs, however, there is no reason to achieve, for example, a 30 years remission. Instead, the aim is to slow progression whilst maintaining a good quality of life; in other words having your cake and eating it. This is done by using lower doses of meds, less frequently, which reduces the risk of side effects. As a result side effects and sickness are less severe.   Ultimately, treating your dog is about balancing quality and length of life. The veterinarian aims for that sweet spot where deterioration is slowed but therapy doesn’t cause excessive distress.

Options for Treatment

  Your veterinarian will thoroughly assess the dog’s condition, to plan which treatment is right for your pet pal. Of these therapies, chemotherapy is the best known, but there are other choices, including surgery, radiotherapy, and new treatments that are coming on-stream.


  Chemotherapy works by using drugs that are toxic to rapidly dividing cancer cells. Chemo is a great choice for tackling ‘disseminated’ or widespread cancers, such as lymphoma in dogs, where surgery is not an option.   Chemotherapy drugs aren’t ‘cuddly’ and must be treated with respect, even at reduced dosages. For example they can suppress the bone marrow, weaken the immune system and make the dog vulnerable to infection. But again, your veterinarian will monitor response to the drugs, be alert for fever and low white cell counts, and adjust doses as necessary.   In addition, there’s now a great anti-vomiting drug, maropitant (TM Cerenia), which eliminates nausea. If even the low dose chemo does upset his stomach, Cerenia can settle it and prevent him from feeling sick.


  When caught early, localized dog tumors can often be surgically removed. ‘Early’ is the key word here because the smaller the tumor the more likely surgery is to completely remove it before any spread.   Indeed, for some cancers in dogs, such as Mast Cell Tumors, surgery is the treatment of choice. Successfully removing the whole tumor with wide margins, gives the best chance of a full recovery.   Whilst radical surgery may seem daunting, modern medicines can alleviate even severe pain. And once the dog goes home you can monitor dog pain levels and give additional pain relief as needed, to avoid unnecessary distress.  


Some dog tumors are too big or in a place (such as the jaw) that makes removal impossible. For these guys radiotherapy may be an option.   Radiotherapy uses a highly focused x-ray beam to destroy cancer cells. It has various uses, such as:
  • ‘Cleaning’ the site of a previous cancer surgery, to blitz any lingering cancer cells
  • Destroy a tumor
  • Shrink the size of a large tumor as preparation for surgery
  For the right patients radiotherapy is worth pursuing, although it does have downsides, not least of these are the practical aspects, such as travelling once a week to a special oncology center for treatments. In addition, a general anesthetic is required each time, so his overall health needs to be good.   Often times the veterinarian will recommend a combination of the above modalities in order to exploit their respective benefits while minimizing the adverse effects that come with each one.

New Treatments

New treatments for cancer in dogs appear all the time. Examples include:
  • Photodynamic therapy: This uses a combination of light, drugs, and oxygen to target cancer cells
  • Cancer vaccine: A new cancer-directed vaccine has the potential to shrink down malignant melanomas and offers hope for some patients.
  • Modern Drugs: New classes of drugs, such as the tyrosine kinase inhibitors, can make an impressive difference to dogs with widespread mast cell tumors.
  Speak to your veterinarian or consider referral to a veterinary oncology specialist for an in-depth discussion about the right treatment for your dog.

Palliative Care

Last not least, palliative care should not be overlooked as a reasonable choice in the appropriate cases..   Just because there are treatments such as chemo or radiotherapy, doesn’t mean you have to take them. Excessive stress and anxiety from frequent hospital visits, as well as side effects from treatments, may be considered when devising a specific treatment plan for your pet.   The best palliative care means learning how to read your dog’s pain and managing his symptoms. To help you do this, some veterinarians offer hospice care visits to your home, so the dog doesn’t need to travel to the clinic.   Above all, there are options for treatment, should you wish to pursue them. And whilst no-one wants to hear their dog has cancer, know things aren’t as bleak as they might at first appear. But whatever you decide, know there’s no right and wrong answer, only what’s best for your dog.