Behavioral problems, especially fear and aggression in dogs and elimination in the house in both dogs and cats, are a major reason for people to give up or euthanize their pets, so they represent a serious medical condition. There are many methods of treating such disorders with behavioral modification, and medications can sometimes be helpful, though our understand of which medications might help for which problems in which patients is very poor. However, the sad truth is that we have very limited success in alleviating many of these problems.
In the face of serious medical problems for which there are not strikingly effective scientific therapies, more questionable methods can become widely used. Some, like Bach flower essences, such as Rescue Remedy, or homeopathic treatments are clearly useless nonsense. Others are plausible scientifically, but not really shown to work in definitive ways. One such treatment is the use of pheromones.
Pheromones are chemicals animals produce that can affect the behavior of other members of the same species. They are believed to be common and important in coordinating social behavior in animals, especially mammals. The role, if any, that they play in human behavior is less clear, though they may be involved in the synchronizing of menstrual cycles in women living together. In any case, it is clearly reasonable that such substances might have an impact on the behavior of dogs and cats and so might be useful in managing behavior problems. Notice all the “mights” in that statement? The devil, of course, is in the details
It has become quite common for veterinarians to recommend use of synthetic pheromone analogs, that is chemicals made to be structurally natural pheromones, to help treat behavioral problems. The most common products are Feliway, and analogue of the facial pheromone cats leave behind on furniture and people the rub their faces against, and DAP, short for Dog Appeasing Pheromones, a pheromone nursing mothers release which is believed to calm puppies. These are sold with dramatic claims of efficacy for a wide range of conditions, but of course the claims of folks selling the product have to be viewed as perhaps less objective than other forms of evidence.
In the most recent issue of the Journal of the American Veterinary Medical Association, a systematic review was published which evaluated the research evidence for the use of these products.
Frank,D. Beauchamp,G. Palestrini,C. Systematic review of the use of pheromones for treatment of undesirable behavior in cats and dogs. J.Am.Vet.Med.Assoc., 2010, 236, 12, 1308-1316.
The purpose of a systematic review is to evaluate all the published data on the basis of quality, and then evaluate the results of studies that meet a reasonable minimum quality. In this review, studies were excluded that did not meet minimum quality standards or that were conducted by researchers working for the company selling the product under study. This left a total of 14 studies, 7 in cats and 7 in dogs.
In general, as is too often the case in veterinary medicine, the methodological quality of the studies overall was lower than expected in human medicine, with no studies reaching the highest standards. But as the authors wisely note, imperfect information is better than no information, so we must make our judgments based on the best available evidence even if it is prone to errors that better studies would avoid. I will spare you the interesting but complex details of the various study designs and their strengths and weaknesses, though reading the full review is recommended for anyone interested. Having read through the full report, I am convinced that unlike others I have reviewed, the conclusions of the authors of this systematic review are supported by the methods and results they detail elsewhere in the paper.
Of the 7 cat studies, none provided convincing evidence of a benefit. Some decrease in urine spraying occurred in some cats, but the significance of this was muddied by failure to follow up on cats which dropped out of studies, which were probably cats who didn’t improve with the treatment, and other methodological flaws in the studies reviewed. Pheromone therapy also was not clearly of benefit in cats with interstitial cystitis (a condition in which irritation in the bladder causes symptoms much like those of a bladder infection). The pheromone also did not seem beneficial in calming cats in the hospital or facilitating the stressful process of placing IV catheters in hospitalized cats.
In dogs, one study found some evidence that pheromone therapy might reduce anxiety in puppies during training. Other than that, no convincing evidence of benefit was found for anxiety associated with veterinary care, anxiety in shelter dogs, or barking and elimination indoors by recently adopted dogs.
The limitations in the quality of the evidence mean we cannot definitively declare that pheromone therapy doesn’t work. What we can say is that based on the best evidence to date, it does not appear to have a benefit. Further study is certainly reasonable, but as always I question the wisdom and the ethics of widespread sale and use of products which, despite years of testing, don’t seem to have much evidence that they work. These products appear harmless, and if clients wish to spend money rolling the dice on a treatment that is not well supported by the limited clinical research available that is certainly up to them. But when veterinarians recommend such products, it does tend to convey the impression that they are legitimate, validated therapies, and I think we do a disservice to our clients if we make such recommendations without a clear statement of the limitations in the evidence. Thanks to this paper, it is now easier to make such a statement.