Abstract
Dear Editors, – My colleagues and I read with interest the recent article in JFMS from the European Advisory Board on Cat Diseases (ABCD), ‘Prevention of infectious diseases in cat shelters’. 1 Within the ‘stress reduction recommendations’ section, just after the overall guidance on environmental enrichment for a shelter housing system, the authors included a paragraph on ‘Pheromones’. This did not surprise us as we know how common it is for many shelters and big catteries in the world to routinely use feline facial pheromones in their facilities, to provide those cats with a sense of safety and security. For example, Wood Green (one of the leading UK charities, which rehomed more than 2500 cats last year) systematically includes Feliway spray in each cat unit and Feliway diffuser in its vet check rooms, as stated in its ‘procedures for feline welfare’ at intake. Indeed, cats in a shelter environment do not find their familiar marks, and have to cope with a new and unknown environment, which is potentially stressful. Even cats staying for a while in a shelter, which might be considered as accustomed to this environment, have the territorial marks they spread in their environment (while rubbing their face against walls, doors, provided enrichment devices, etc) regularly removed during cleaning processes (as do hospitalised cats in a vet practice environment). The removal of those familiar marks (which cats in private homes are less subjected to) is believed to lead to an increase in anxiety in cats.
For all these reasons, providing cats with synthetic pheromones, which reproduce the familiar marks they naturally deposit into their environment when they feel safe, will help them feel confident at the shelter.
In addition to the catteries and shelters routinely using pheromones, several behaviourists and veterinarians working with catteries also recommend their use. For example, the Maddie’s Shelter Medicine Program at Cornell University College of Veterinary Medicine states in its ‘stress reduction protocol’ for cats: ‘Feliway has been shown to reduce anxiety in cats. A plug-in diffuser should be used in each cat room. Additionally, the spray can be used to help individual cats who continue to exhibit signs of stress. To use the spray properly, spray the cat’s bedding when the cat is not in the cage or spray a washcloth and place it in the cage with the cat.’ 2 Use of synthetic pheromones (Feliway diffuser or spray) as an enrichment means for cats has also been recommended to those attending an international congress on shelter medicine. 3
In the recent JFMS article, we were thus surprised that the paragraph on pheromones stated that there was insufficient evidence of their efficacy, a statement based solely on a single reference. 4 This completely disregarded the clinical trials (14 in 2013) 5 performed with Feliway and published in reputable scientific journals or presented at international conferences. No other stress-relieving product available on the market for use in cats relies on so many published trials to support its efficacy. Most of them do not have even one.
The article referred to in that reference, by Frank et al, although presented as a ‘Systematic review of the use of pheromones for treatment of undesirable behavior in cats and dogs’, does not comply with the recommended guidelines for conducting a systematic review. The authors only focused on the material and methods described in each trial, and did not evaluate the outcome parameters such as mean and median efficacy rates. As has already been pointed out in a further publication in JAVMA, 6 this article is incomplete, inaccurate and misleading (for example, it falsely claims that Valeriana is present in all formulations and therefore may explain the efficacy). Also, according to the guidelines for conducting a systematic review, only comparable papers should be included for analysis (eg, all publications on the different treatments available for one particular disease). Here, we can question the scientific appropriateness of including studies that assessed one single product but in a variety of situations and for different indications. Moreover, we can question the inclusion of studies whose objectives were not in accordance with the title of the paper: neither idiopathic cystitis nor IV catheterization can be considered ‘undesirable behaviors’.
Aside from the scientific content of Frank et al’s review, the tone used was consistently negative rather than impartial. Systematic review guidelines emphasize the importance of respect for selected publications. All the trials quoted have been published in reputable, peer-reviewed, scientific journals, and although not perfect, they can inform an evaluation of efficacy. The review failed to highlight the lack of good evidence, according to the authors’ own standards, for the management of most of the conditions evaluated (beyond the use of Feliway) and thus ignores the inevitable conclusion that some evidence is better than none. Thus, as written, the Frank et al review offered no constructive advice for readers.
In summary, using the Frank et al review (with its flawed methods and debatable conclusions) as the basis for evaluation of, and advice on, the efficacy of pheromone therapy in cat shelters is very regrettable. We would urge readers to take a broader view and evaluate the primary literature for themselves before making a judgement. We believe that there is much more evidence that can be highlighted already, but also that this is an area that deserves further field trials in the future.