Dog pheromones: do they work?


Photo credit: Gatorgoon via Foter.com / CC BY-ND

To follow up from my post about the efficacy of cat pheromones, I wanted to delve into the scientific literature looking into the effects of pheromonotherapy (the therapeutic application of pheromones to treat behavior problems) on dogs.

What is pheromonotherapy?

Scientists have demonstrated that many animals utilize pheromones (chemical communication signals emitted by animals) for a purposes as varied as sexual receptivity to spatial orientation to appeasement of infant animals. The idea behind pheromonotherapy is pretty simple: use synthetic pheromones to communicate a useful message to a pet displaying a behavior problem. While no side effects or toxicity to synthetic pheromones are known, the application of pheromonotherapy is complicated by the fact that animals do not passively intake pheromones (as far as scientists and veterinarians understand) – rather, animals must actively suck in pheromones through a specialized organ in the nasal cavity called the vomeronasal organ (VNO). Unfortunately, there are typically environmental or behavior signals that induce an animal to engage the VNO and these signals may or may not be present when synthetic pheromones are applied. Synthetic pheromones are available from many pet retailers in the form of plug in diffusers, impregnated collars, sprays, and wipes.

What can pheromones do for dogs?

The only dog pheromone that I have found on the market is Dog Appeasing Pheromone (DAP), which is supposed to be a synthetic copycat of the pheromone mother dogs produce to enhance attachment and promote emotional stabilization in her puppies. The common application for this pheromone is, unsurprisingly, to mitigate a undesirable dog behavior resulting from stressors  such as loud noises, being left alone, meeting/living with another animal, going to a veterinary office, etc.

So…do pheromones work for dogs?

I separated studies that I found in my literature review of pheromonotherapy efficacy in dogs into two broad categories: those considering dogs in “social” situations (i.e. where many other animals are present: shelters, veterinary clinics, or training classes) and those looking at dogs in a more private home setting. My motivation for this division is the probable increase in the engagement of the VNO in social situations vs. when dogs are just sitting in their familiar environment.

Interestingly, the general consensus is: YES, pheromones are very effective in reducing anxiety and displacement behaviors (barking, panting, avoidance behaviors, destruction, excessive licking, etc.) while promoting relaxed and social behaviors (social greetings of strangers, laying down, normal appetite, etc.) in dogs. In social settings, results have been reported in as little as 4-7 days, while the treatment period for dogs in home settings is typically longer (4+ weeks). One study even found that DAP application had comparable results to an antidepressant medication, clomipramine, on reducing anxious behaviors.  That’s pretty impressive, considering that DAP has no side effects while clomipramine can have serious side effects including GI upset, elevation of liver enzymes, convulsions, and confusion.

Nearly every study that I read included the stern limitation that more research is needed to confirm these positive results. Furthermore, serious canine behavior problems are unlikely to be fully ameliorated by pheromonotherapy alone: behavior modification programs and psychopharmaceutical drugs should be applied as determined by a veterinarian and/or behaviorist.


Photo credit: Bekathwia via Remodel Blog / CC BY-SA

What does the manufacturer have to say about pheromone efficacy in dogs?

I contacted Ceva Animal Health, the company that produces a popular dog pheromone, Adaptil because their products/website purport to have data on file about the effectiveness of Adaptil. A veterinary technician in their customer service section got back to me with three pieces of literature: one was an actual study of pheromonotherapy and socialization in puppies [1], one was a well-referenced summary of pheromonotherapy studies [2], and the final piece was (probably?) a selection from a book that had no references and a single author [3]. Since I expected some data generated internally from Ceva or at least a Ceva-funded study, I was pretty disappointed in this response – all of this information is available publicly, so what’s with the “data on file” statement? I suspect that Ceva (and other animal product manufacturers) are not all that interested in selling an effective product – they just want to sell any product.

TL;DR

Dog Appeasing Pheromone (DAP) is pretty well established as an effective treatment for stress-induced behavior problems in dogs. Pheromonotherapy has been demonstrated to reduce anxious behaviors and increase relaxed behaviors in dogs in especially short timeframes (4-7 days) in situations where other animals are present, which appears to hold up in more private home settings over longer periods (4+ weeks). Dogs with serious behavior problems should be evaluated by a veterinarian and/or dog behaviorist because pheromonotherapy is likely only one piece of the behavior modification and treatment program that the dog will need.

References

  1. Denenberg, Sagi, and Gary M. Landsberg. “Effects of dog-appeasing pheromones on anxiety and fear in puppies during training and on long-term socialization.” Journal of the American Veterinary Medical Association 233.12 (2008): 1874-1882.
  2. Landsberg, Gary. “Why Practitioners Should Feel Comfortable with Pheromones – The Evidence to Support Pheromone Use.” Presented at The North American Veterinary Conference. (2006)
  3. Mills, Daniel S. “Pheromones and Pheromonatherapy.” The Henston Small Animal Veterinary Vade Mecum. Part IV: 316-323
  4. Frank, Diane, Guy Beauchamp, and Clara Palestrini. “Systematic review of the use of pheromones for treatment of undesirable behavior in cats and dogs.” Journal of the American Veterinary Medical Association 236.12 (2010): 1308-1316.
  5. Tod, Elaine, Donna Brander, and Natalie Waran. “Efficacy of dog appeasing pheromone in reducing stress and fear related behaviour in shelter dogs.” Applied Animal Behaviour Science 93.3 (2005): 295-308.
  6. Kim, Young-Mee, et al. “Efficacy of dog-appeasing pheromone (DAP) for ameliorating separation-related behavioral signs in hospitalized dogs.” Canadian Veterinary Journal 51.4 (2010): 380.
  7. Gaultier, E., et al. “Comparison of the efficacy of a synthetic dog-appeasing pheromone with clomipramine for the treatment of separation-related disorders in dogs.” Veterinary Record-English Edition 156.17 (2005): 533-537.
  8. Mills, Daniel Simon, et al. “A triple blind placebo-controlled investigation into the assessment of the effect of Dog Appeasing Pheromone (DAP) on anxiety related behaviour of problem dogs in the veterinary clinic.” Applied animal behaviour science 98.1 (2006): 114-126.
  9. Sheppard, G., and D. S. Mills. “Evaluation of dog-appeasing pheromone as a potential treatment for dogs fearful of fireworks.” Veterinary Record: Journal of the British Veterinary Association 152.14 (2003).

Cat pheromones: do they work?

I can’t speak for all pet owners but pet pheromone products have been pushed at me from all quarters – pet shop associates, veterinarians, trainers, and even other pet owners! I was initially recommended pheromone products due to car- and moving-induced stress in my pets but if you pick up any brand pheromone dispenser and you will discover a  multitude of potential applications. (Urine marking, inappropriate scratching, multicat tension, excessive barking, hiding, etc.) These products cost a pretty penny too – around $30 for a diffuser or spray, $15 for a pheromone-infused collar. So it begs the question: do pheromone products work?

Photo credit: Trish Hamme via Foter.com / CC B

What are pheromones anyway?

Pheromones are a means of chemical communication. Although not completely understood, it is thought that animals perceive pheromones through a specialized receptor in roof animal’s snouts called the vomeronasal organ (VNO). The VNO does not always pick up pheromones, however – it has to be activated by the animal. Have you ever seen a cat, intrigued by a new smell or etc., open her mouth and “pant” with her tongue out? That behavior is called “flehmen” and it’s function is to suck pheromones into the VNO.

Animals use pheromones to communicate a wide array of messages: territorial marking, sexual receptivity, spatial orientation and emotional stabilization, assertion of social status, alarm marking during fear reactions, appeasement of infant animals – and those are just the pheromones that scientists understand (and there are loads whose functions are unknown).

Scientists and pet product companies have developed synthetic pheromones that can be purchased at many pet stores and veterinary offices. Several types of pheromone dispensation products are available: passive diffusers that are plugged into a wall outlet, pheromone-infused collars, pheromone-infused wipes, and pheromone sprays.

What could pheromones do for cats?


Photo credit: Sander van der Wel via Foter.com / CC BY-NC-SA

Considering that our pets live in a world full of smells, veterinarians and behaviorists have  been exploring the application of pheromones to treat animal behavior problems because, when used correctly, they are completely non-toxic, have no side effects, and involve little effort on the part of owner or pet. The therapeutic use of pheromones to treat behavior problems in pets is called pheromonotherapy.

The principle of pheromonotherapy is pretty simple: use synthetic pheromones to communicate a useful message to a pet displaying a behavior problem. Many behavior problems are the result of fear and anxiety in pets, so using a pheromone with an emotional stabilization function – like the pheromone cats release when they rub their chin on something to distinguish it as “known”. Reduction of feline spraying has been a target of numerous pheromonotheray studies – no doubt because this is a common and extremely aggravating behavior problem for cat owners. Scientists have also evaluated cat pheromones in calming cats during transport, prior to intravenous catheterization, in preventing stress-induced anorexia, and facilitating the peaceful introduction of unsocialized cats.

So…do pheromones work?

There are real barriers to the success of pheromonotherapy. First, animals generally do not communicate by pheromones alone. Usually there would be a multitude of body signals or vocalizations that would accompany (and emphasize) the pheromone message and open up the VNO so that the animal perceives the message.  Secondly, pheromones may “prime” an animal’s emotional state to be receptive to a behavior modification program but it is unlikely that pheromones alone will completely address behavior problems.

Thus the importance of the scientific evaluation of pheromonotherapy! All of the studies that I read about the use of pheromones for emotional stabilization, i.e. for behavior problems like urine marking, inter-act aggression, transport-induced stress, stress-induced anorexia (see Sources below), were all suggestive of a positive effect. The general consensus is that the longer pheromones were used (4+ weeks), the better the effect. Additionally, many cats maintained improved behavior after pheromones were removed.

I did find a very critical meta-analysis, which is a study of studies. This meta-analysis looked at all available pheromone studies and found that most studies had significant problems with design and/or analysis, such as small sample size, the absence of blinding or randomization, and the lack of a control sample. These problems prevented the authors from agreeing with the positive findings of the individual studies. However…I had problems with the meta-analysis’s problems! The principles of “robust” clinical research aren’t always ethical – especially in a situation where, say, you’ve got an owner whose cat is spraying all over the house and euthanasia is seriously on the table. Furthermore, the funding opportunities for these studies don’t seem to be abundant so gathering huge sample sizes may not be possible. I did not find any study over stating its findings and hopefully the examination of pheromonotherapy will continue to provide additional information.


Photo credit: jenny downing via Foter.com / CC BY

TL;DR

We have reasonable evidence to suggest human-applied pheromones (or pheromonotherapy) can be helpful as part of a behavior modification program for a cat displaying certain behavior problems, especially urine marking and inter-cat aggression. Best results have been seen in prolonged use (4+ weeks) of pheromonotherapy.

 

 

Sources

  1. Frank, Diane, Guy Beauchamp, and Clara Palestrini. “Systematic review of the use of pheromones for treatment of undesirable behavior in cats and dogs.” Journal of the American Veterinary Medical Association 236.12 (2010): 1308-1316.
  2. Mills, Daniel S., Sarah E. Redgate, and Gary M. Landsberg. “A meta-analysis of studies of treatments for feline urine spraying.” PloS one 6.4 (2011): e18448.
  3. Griffith, Cerissa A., Elizabeth S. Steigerwald, and CA Tony Buffington. “Effects of a synthetic facial pheromone on behavior of cats.” Journal of the American Veterinary Medical Association 217.8 (2000): 1154-1156.
  4. Mills, D. S., and C. B. Mills. “Evaluation of a novel method for delivering a synthetic analogue of feline facial pheromone to control urine spraying by cats.” RIVISTA DI ZOOTECNIA E VETERINARIA 30.1 (2002): 50-51.
  5. Kronen, Peter W., et al. “A synthetic fraction of feline facial pheromones calms but does not reduce struggling in cats before venous catheterization1.”Veterinary anaesthesia and analgesia 33.4 (2006): 258-265.
  6. Gunn-Moore, D. A., and M. E. Cameron. “A pilot study using synthetic feline facial pheromone for the management of feline idiopathic cystitis.” Journal of feline medicine and surgery 6.3 (2004): 133-138.
  7. Frank, D. F., H. N. Erb, and K. A. Houpt. “Urine spraying in cats: presence of concurrent disease and effects of a pheromone treatment.” Applied Animal Behaviour Science 61.3 (1999): 263-272.
  8. Pageat, Patrick, and Emmanuel Gaultier. “Current research in canine and feline pheromones.” Veterinary Clinics of North America: Small Animal Practice 33.2 (2003): 187-211.

Journal Article: Can you measure stress in dogs?

Title: Manifestations of chronic and acute stress in dogs

Authors: Bonne Beerda, Matthijs B.H. Schilder, Jan. A.R.A.M. van Hooff, Hans W. de Vries

Published: 1997 in Applied Animal Behaviour Science

General overview:

The researchers sought to review the behavioral, physiological and immunological stress reactions that had been previously published and add to that knowledge base with their own researcher. The authors applied auditory stimuli to 6 beagle dogs (3 “test” dogs and 3 “control” dogs) in a variety of intensities and length. Additionally, the authors used 10 beagle dogs to test for stress reactions during 50 minutes of transport and in an unfamiliar environment. The dogs had behavioral and physiological measurements taken throughout travel to the testing facility or during the auditory stress or control situations. The authors found a wide range of physiological responses to supposed stressful events. The researchers suggested that more research into stress parameters for various behavioral, physiological and immunological reactions is needed. Furthermore, the authors recommend recording a variety of stress reactions in order to reduce differences between individuals, breeds, age, gender or previous life experiences when attempting to quantify the welfare of animals exposed to stress.

My comments:

Because this paper was about 50% literature review and 50% novel data, and because it was relatively old (17 years), I found this to be a highly, erm, fascinating read. Behavior researchers used to do some pretty sadistic things to dogs (i.e. shocking a dog with such a high voltage that the dog would, “urinate, defecate, scramble rapidly and vigorously around the compartment, emit high-pitched screeches, salivate profusely and roll their eyes rapidly with dilated pupils…”)! However flawed our currently animal research welfare laws are, they really are an improvement over…you know, no animal research welfare laws.

The literature review of this piece explained the historical efforts of animal behavior researchers to define which behaviors, physiological and immunological reactions in dogs were associated with stress. This research was probably fueled by the desire to define “stress” in dogs without any anthropomorphic influences. I thought it really highlighted the importance of “baby steps” in research: if you want to study stress in dogs, you must first define stress, determine how stress in manifested in the general population of dogs, and define measurable parameters of stress. Furthermore, if you want to say that stress is bad for dogs, you must first determine whether or not stress decreases the welfare of a dog! While these components might seem maddeningly insignificant, they are a requirement of understandable, reproducible, rigorous science.

The actual findings of novel research from this paper were not altogether interesting – which isn’t entirely surprising on account of the incredibly small sample sizes (6 and 10 dogs, respectively). The authors found a great variety in potential stress behaviors in these dogs, so they’re able to determine ranges for stress responses in any of the behaviors or physiological samples they measured. The authors also did not provide information about the dogs in regards to age, gender, neuter status, previous life experiences, etc., which could have offered some potential explanations for the variable stress reactions. It does highlight the need for more research into how individual differences between dogs could impact stress reactions and its welfare implications, I suppose.

Stress is an unavoidable part of canine life. If we can reduce stress on dogs, does this make their lives and thus welfare better off? This paper focused on the importance of linking stress to welfare implications. I am interested to read more about measurable stress reactions in companion animals!