The BSAVA Formulary does not include details of specific ingredients included in nutritional supplements or diets which might affect behaviour due to the large variability in percentage content, the relatively unknown interactions between supplements and other component ingredients, and the difficulty in establishing ingredient bioavailability due to the impact of product preparation. These factors mean that it is unwise to associate behavioural effects with the amount of specific ingredients in products.

Instead, veterinary surgeons should refer to the published research relating to specific products. In this regard, all articles should be consulted with caution, and the following should be considered:

• Claims should be specific (e.g. ‘stress’ and ‘calming effects’ are vague terms unless specifically defined in the context of the study)
• Testimonials represent low-quality evidence. Claims should relate to specific products and not ingredients
• The representation of control populations should be carefully considered in relation to the claims made and the generalizability of the results to clinical cases
• It is preferable to use medication rather than supplements for a given behavioural indication where medication is available and a risk analysis has been undertaken with regards to health and any potential contraindications. Medication provides the clinician with additional confidence about safety, efficacy and quality. Such information is not typically available for nutraceutical products.