Pheromone Therapy for Dogs and Cats–What’s the Evidence?

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.

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55 Responses to Pheromone Therapy for Dogs and Cats–What’s the Evidence?

  1. Josie says:

    I’m using a Feliway infuser for my two cats who fight a fair bit and it’s a real problem. I’ve found it does take the edge off, and they play gentle rather than rough when it’s on. I notice a difference anyway, but it’s difficult to be objective about these things. I found whatever area it states it can cover is exaggerated and you should at least halve that (so if it says it can cover 20 square metres, it’s only really effective for 10
    etc). You have to close of the doors and windows, pretty much seal the place shut, and lastly it takes a few hours to build up. If I put it on overnight for example by morning they’re snuggling together, which is something they never do otherwise. I use it PRN. It’s not really practical to use all the time.

  2. chihuahualover says:

    http://veterinaryrecord.bmj.com/content/early/2015/08/26/vr.103172.full#F4

    What do you think about this study? (besides the missing allocation scheme…)

  3. skeptvet says:

    Interesting, thanks for bringing it up. Overall, it is a reasonable design for the subject. Behavioral signs of anxiety and fear are inherently subjective and difficult to evaluate, but the protocol seemed to be reasonable. Methodologically, the use of placebo controls and blinding of most personnel was encouraging. However, there were a number of methodological issues.

    1. It isn’t clear if the subjects actually have clinical thunderstorm phobia. A group of lab beagles was exposed to recorded thunder (27), and all but the 3 least reactive were chosen for the study. However, their scores were quite low (1.25-2.75) on a 6-point scale. These dogs may not be representative of a clinical population that have naturally occurring noise/thunderstorm phobia, so their responses may not fairly represent what would happen with treatment of real patients. In particular, if real patients are considerably more fearful, any small effects that could be detected in this group might be irrelevant or undetectable. Repeating the study with actual noise phobia patients would be a good step.

    2. As you point out, alternate allocation was used rather than randomization, and the only person not blinded was responsible for allocation. This introduces a pretty big risk of bias, which requires cautious interpretation of results

    3. The placebo group was tested 5-6d after the first thunder exposure and the treatment group 8-9 days after. One might expect the fear induced by the original exposure to diminish with time, so it is possible the treatment group could be less reactive due in part to having had more time to recover from the initial stimulus.

    4. The differences between placebo and treatment groups were statistically significant but quite small. Most differences were less than 1 point on a 6-point scale. This raises the question of whether or not these differences would be clinically significant. Would actual patients experience enough improvement to matter?

    5. There is, as always, the issue of financial bias to consider. The study was funded by the manufacturer of the product tested, and the test was done by a company that specifically focuses on testing so-called “natural” products and supplements, and which tends to produce positive results (I haven’t yet seen a negative study published by the group, though there may be some out there. Again, this doesn’t mean the results can be automatically dismissed, but it is an additional factor to consider since in human medicine it has been shown that industry funding does influence the likelihood of positive results.

    Overall, since there is little reason to think the product does harm, trying it based on relatively weak evidence is reasonable. But I do think this study, while encouraging, would need to be independently replicated, ideally with real thunderstorm-phobia patients, in order to have high confidence in the conclusions regarding efficacy.

  4. Bee says:

    I agree with your point here, but what about this unmet medical need of problems with cat behavior? Is the answer for the frustrated owner to actually put the cat down or re-home it?

  5. skeptvet says:

    Behavioral problems are often complex and difficult to resolve, and every individual and situation is unique, so there is unlikely to be a single answer that consistently helps different pets and their people. Ideally, an in-depth consultation with a veterinary behaviorist and a comprehensive behavior modification and environmental management strategy, with the addition of medications in some case, would be possible for everyone, and while even this would not solve all problems, it would give people and their cats the best chance. Unfortunately, this is not available to everyone, for various reasons. I wish something easy and cheap like pheromones was more effective because, as you point out, there are many cats and people who could use something like that, but so far it hasn’t been much help, and the best chance is still out of reach for many. Truly a frustrating situation, but we have to do the best e can with the tools and knowledge we have.

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