Complementary cancer therapies – advising your clients

More of our clients are wanting to look into all available treatment options for their loved pets, and the use of complementary medicines and treatments is an area of veterinary health that is growing. As clinicians we are taught the traditional, well established therapies, which are scientifically backed with clinically proven trials and studies. It’s not surprising that we are uncomfortable about recommending or approving the use of alternative or complementary treatments, but we need to know what is effective and working before jumping to dismiss them.

Posted: 19 March 2020

Complementary cancer therapies – advising your clients


It’s been estimated that as many as 75% of the pet population diagnosed with cancer is offered complementary or alternative medicines, so it’s time we knew a little more about them. It’s only by being aware of them and understanding the reasons they are used that we can then offer informed advice as to their use and value as well as any potential risks.

What are Complimentary and Alternative Medicines (CAM’s)?

Complementary therapies are used together with conventional medicine while alternative therapies are used instead of conventional medicine.

When we refer to complementary and alternative therapies, we can include;

  • Nutritional supplements – these are the most frequently used therapy, with nutraceuticals forming the bulk of these. Glucosamine, chondroitin and green mussel extract are very popular.
  • Herbal – use of dried extracts of herbs such as valerian, echinacea and garlic.
  • Aromatherapy – essential oils rubbed into the skin.
  • Physical – physiotherapy, massage, acupuncture and hydrotherapy are some examples of these.
  • Mental – prayer has been used by people who are deeply religious.

The reality is that few of these have shown clinical anti-cancer effects, but the enthusiasm and belief which owners have for them needs to be addressed. It’s vital that we talk with our clients and help them rationalise and adjust their expectations of success.

It’s also essential that we stress the importance of never using these therapies as a replacement for established anticancer treatment. On the other hand, they may be suitable when used as supplementary treatments to improve the side effects of conventional medications, such as nausea and pain.

What are the risks?

  • Toxicity or injury – some treatment may be totally unsuitable as they can cause direct harm to the patient. For example, garlic and cod liver oil have anticoagulant effects, so would be unsuitable for a patient with a haemangioma or haemangiosarcoma.
  • Interactions between established therapies – some CAMs may decrease the efficacy of the established therapies. For example, although antioxidants such as vitamins A, C and E are not harmful, they may reduce the efficacy of treatments that produce free radicals in their anticancer mechanism (e.g. radiation therapy, some chemotherapy).
  • Owner delays/avoids starting conventional anticancer treatment – this is one of the biggest risks, as postponing or declining evidence-based conventional treatment makes it less likely that you’ll be able to prolong or save the patient’s life.
  • Believing the Internet – we’re all used to Dr.Google, but how many sites tell the whole truth? Too many of us want to think that there is some miracle cure out there and are willing to believe without challenging all the information. Anecdotal stories just aren’t the same as clinical trials, and many claims of treatments lack the evidence.
  • It’s totally natural - one of the big selling points of alternative therapies is to claim that conventional treatments are ’toxic’ while alternative treatments are ‘natural’, implying that natural is somehow better.

Are your clients telling you the truth about their CAM use?

It’s possible that many of your clients will be using CAM therapies on their pets without telling you. The reasons may be;

  • Nobody has asked – how often do you ask if they have looked at using alternative therapies? If you don’t ask you may never know.
  • Fear of disapproval – it’s possible that they might expect to be frowned upon by the practice if they admit they have looked at using cannabinoids or herbal remedies.

It’s for this reason that opening the lines of communication between vet and client with respect to CAM use on their pet is extremely important. How you go about it is also important, as you don’t want to be too heavy handed. In order to maintain an open and compassionate level of communication;

  • Talk to your clients about CAM therapies with an open mind.
  • Make them comfortable about being honest about their use.
  • Keep them on board with potential benefit or harm of these therapies.

Discuss and persuade, but don’t argue

Try to explain that you want to establish whether a new therapy is likely to be beneficial for their pet. This can usually be broken down into 4 key questions.

1. Find out if the treatment has been peer reviewed

This is important because it confirms that the treatment has been looked at by many independent clinicians. The places you should check are all the standard veterinary online databases and literature, including PubMed Veterinary Science, IVIS, WSAVA and Trip Database. You can explain to your client that if the therapy or its active ingredient are not mentioned in any of these databases, it's unlikely to be effective.

2. How does the treatment work?

It may be that certain treatments can kill cancer cells in a petri dish but only do so at concentrations that are toxic to animals. It’s important that the treatment has shown to be effective in live animals with naturally occurring disease, rather than just reports of effectiveness in vitro.

3. Does the treatment benefit the patient?

There are really only two ways a therapy can be considered to benefit a patient with cancer, these being if;

  • There is a measurable and significant reduction in size of the tumour.
  • If a group of animals treated lived significantly longer than a group of animals that did not receive the therapy (i.e. a control group).

4.  What are the side effects or complications?

The reality is that all medical interventions will cause side effects to some degree. Whilst these risks can vary, all treatments should produce side effects with a defined frequency. Therefore, always question any treatment claiming to produce no side effects at all.

Which CAM therapies are effective?

It would be unreasonable to dismiss all CAM therapies, as there are certainly some benefits that can be gained by using them in support of conventional treatment. Three such examples are;

  • Acupuncture – this form of CAM therapy does seem to have a role in helping cancer patients as there is some evidence to show it can help reduce nausea and pain.
  • Physiotherapy – many older animals or those recovering from surgery can benefit from physiotherapy to keep their muscles conditioned. Find out more from the National Association of Veterinary Physiotherapists.
  • Hydrotherapy – the availability of hydrotherapy units around the UK is increasing, with many veterinary practices installing them in their own clinics. The warmth of the water assists with pain relief and the reduction of muscle spasm.