Immunotherapy for Dogs with Cancer
Harnessing the Body’s Own Defences to Fight Disease
Immunotherapy is one of the most exciting advances in veterinary oncology. Instead of directly attacking cancer cells with drugs or radiation, immunotherapy works by stimulating your dog’s own immune system to recognise and destroy those cells. For many cancers, it offers new hope — sometimes used on its own, and often alongside traditional treatments like surgery or chemotherapy.
What Is Immunotherapy?
The immune system constantly protects the body against infections and abnormal cells. Cancer, however, can hide from or suppress these natural defences. Immunotherapy is designed to “wake up” the immune system, helping it recognise cancer cells as threats and mount a stronger, targeted attack. In dogs, this may involve:
- Cancer vaccines – These teach the immune system to recognise specific tumour proteins. Vaccines may target common proteins that are mutated in a cancer or may be specific to an individual dog’s cancer. Our vaccine is a individualised (autologous) vaccine made for each patient.
- Monoclonal antibodies – Laboratory-made antibodies that attach to unique markers on cancer cells, flagging them for destruction by the immune system. Whist common in human medicine, these treatments are only starting to be produced for veterinary patients.
- Immune stimulants – Substances that boost immune activity more generally, sometimes given by injection or incorporated into treatment protocols. Our injectable immunostimulants Neostim and Neostim Plus go directly into the cancer and help trigger an immune response, drawing cells in to target the tumour.
- Cell-based therapies – These expensive treatments are currently available in human medicine but not yet in veterinary medicine. They in involve cells that are activated or modified in the lab and then returned to the body to seek and destroy the cancer.
- Check point inhibitors – In dogs and other animals, cancers can hide from the immune system by switching on the “brakes” that stop immune cells from overreacting. Checkpoint inhibitors work by releasing these brakes, boosting the animal’s own immune defences to target the tumour. They are increasingly being explored in veterinary oncology to improve outcomes while using the body’s natural disease-fighting mechanisms.
How It Differs from Chemotherapy
Chemotherapy uses cytotoxic drugs that kill rapidly dividing cells, both cancerous
and healthy. Immunotherapy, in contrast, focuses on immune balance and
precision. It does not usually cause the side effects and nausea sometimes seen with chemotherapy, and most dogs maintain normal energy, appetite, and quality of life. Immunotherapy also does not produce toxic residues, making it safe for the pet and the whole family. With chemotherapy, toxic residues are shed in the dogs urine and faeces and can pose a risk to family members, especially children.
However, immunotherapy is not a replacement for all other treatments. It is often
combined with surgery, chemotherapy, or radiation to reduce tumour size first, then prevent recurrence by training the immune system to keep fighting residual cancer cells.
Which Cancers May Benefit?
Immunotherapy is being studied or used clinically for several canine cancers,
including:
- Mast cell tumours
- Oral and digital melanoma
- Lymphoma
- Osteosarcoma (bone cancer)
- Transitional cell carcinoma (bladder cancer)
- Soft tissue sarcomas
Each cancer behaves differently, and not every dog will respond in the same way.
Your veterinarian or a veterinary oncologist will evaluate whether immunotherapy is appropriate based on the cancer type, stage, and your dog’s overall health.
What to Expect During Treatment
Treatment schedules vary depending on the therapy used. Cancer vaccines and
immune stimulants are typically given by injection, often in a series of doses spaced weeks apart. Some dogs may receive boosters over several months to maintain immune response. Monitoring involves follow-up visits, physical exams, and sometimes blood or imaging tests to track progress.
Side effects are generally mild, if they occur at all. Some dogs experience
temporary fever, soreness at the injection site, or fatigue for a day or two. Severe
immune reactions are uncommon. However, it’s vital that dogs suffering from mast
cell tumour receive antihistamines during their treatment to prevent histamine
release syndrome. Your vet will monitor closely and adjust treatment as needed.
The Benefits — and the Limits
Immunotherapy can improve survival times and quality of life for certain cancers. It may delay or prevent recurrence after surgery, slow the spread of disease, or shrink tumours that resist other treatments, and extend survival. Perhaps most importantly, it offers a gentler approach that supports your dog’s natural defences rather than overwhelming them.
That said, not all tumours or dogs respond, and results can vary widely. Research is ongoing to understand why some dogs experience dramatic responses while others do not. In some cases, immunotherapy extends life but does not eliminate the cancer entirely. Your veterinary team will provide realistic expectations and tailor a plan that aligns with your goals.
The Future of Cancer Care for Dogs
Veterinary immunotherapy is an active field of innovation. New vaccines and cell-
based treatments are being developed in universities and biotechnology companies around the world. Many mirror breakthroughs seen in human oncology, offering a glimpse of a future where cancer care is personalised, targeted, and minimally toxic.
Supporting Your Dog Through Treatment
Throughout therapy, your dog’s comfort and happiness remain the top priorities. Maintain regular routines, provide good nutrition, gentle exercise, and lots of affection. Most dogs tolerate immunotherapy very well and continue to enjoy normal activities while receiving treatment.
In summary:
Immunotherapy is changing how we approach cancer in dogs — turning the immune system into an ally rather than a bystander. By working with your veterinary team to explore this option, you can make informed, compassionate choices that help your dog fight cancer with strength and dignity.
