There are an enormous number of unregulated over-the-counter remedies marketed to pet owners, often for serious health problems, and most of them have never been scientifically tested to see if they are safe or effective. It is difficult to evaluate these products objectively when there is no real evidence. There are always, of course, plenty of anecdotes and testimonials, but while people frequently find these persuasive, I have explained many times in detail why they do not actually tell us much at all about the safety or effectiveness of such products.
Often, the best pet owners and veterinarians can do is consider whether the claims made for such products are reasonable or fanciful, whether the theoretical justifications for how they might work make sense or not, and whether there is any obvious danger. This is not a very reliable or satisfactory way to evaluate healthcare products, but in the absence of regulatory requirements to prove any claims manufacturers make or any ethical commitment on the part of these manufacturers to back up their own claims, this is sometimes the best we can do.
Even when there is some research on a product, however, often the evidence is of limited reliability. And of course, companies never accept any negative reports on their products, and they tend to exaggerate or even mislead consumers regarding the strength of the evidence for their products. I recently ran across a nice study on an herbal product called Pet Remedy, which led me to look at the company marketing materials. Not surprisingly, the marketing does not reflect the evidence for this product.
What Is It?
Pet Remedy is a mixture of several plant extracts. According to the manufacturer, these include extracts from valerian root, vetiver, sweet basil, and Spanish sage. The exact amount of these ingredients, unfortunately, is not disclosed, though the company indicates the valerian content is “very low,” suggesting enough to have the purported benefits of relaxation without the potential. The product comes in a variety of forms, including sprays and plug-in diffusers. The advertising material provides this information about the development of Pet Remedy:
Developed as a result of one of our directors having a cat with behavioural issues! Pet Remedy sorted the problem so effectively that Pet Remedy was then created as a marketable product with a range of plug diffuser, calming sprays, and battery operated atomiser. Pet Remedy was developed with the help of a team comprising several vets, nurses, a psychiatrist and using our own experience in the aromatherapy and essential oil markets.
The company makes broad and sweeping claims for it including:
Clinically proven to calm pets without sedating
Pet Remedy is 100% safe for all mammals and birds, including dogs, cats, rabbits, guinea pigs, hamsters, parrots and horses.
Regular readers will be familiar with my views on claims of significant benefits with absolutely no risk, which I have codified into McKenzie’s Law:
The company quite explicitly claims scientific support for their product. They propose a mechanism of action based on previous studies of valerian extracts:
…the active ingredients in the special Pet Remedy blend will sit on the cell receptor as if a GABA molecule was sitting on it, and that activates (excites) the receptor into giving the cell the message to calm.
The other ingredients are presented in terms of their traditional use, with a lot of vacuous language and extravagant claims that sound like they were copied out of herbal medicine books:
This plant has been appreciated for its calming properties since records began.
Basil oil is a good tonic for the treatment of nervous disorders and stress related headaches, migraines and allergies. It is used to clear the mind and relieve intellectual fatigue, while giving clarity and mental strength.
The therapeutic properties of sage oil are anti-inflammatory, antibacterial, antiseptic, antispasmodic, astringent, digestive, diuretic, emmenagogue, febrifuge, and hypertensive,.There also seems to be a more general relaxant effect, so that the plant is suitable in the treatment of nervousness and excitability. It helps to fortify a generally debilitated nervous system.
The company is also quite specific about the strength of the purported scientific evidence behind their product:
We have already conducted three major clinical Trials…The results of all trials are consistent with pet remedy being an effective natural aid to calm stressed pets.
They also list a number of other studies in progress and offer to send copies of the study reports upon request. Needless to say, I sent such a request since I was otherwise only able to find the one study I had initially run across.
Does It Work?
Valerian has been claimed to be useful as a sleep aid and anxiety reducing herb. The evidence for these claims is limited and mixed in humans (e.g. 1, 2), suggesting there may be some benefits but without definitive proof of these. As usual, there is virtually no good scientific research on the use of this herb in veterinary patients. It is plausible that this herb might have some calming effects in the species the company markets it for, but this does not obviate the need for actual clinical studies of the product itself.
When I requested copies of the studies the company uses to promote Pet Remedy, I received two unpublished reports from a statistical analysis firm hired to analyze data collected in two studies and also a draft report of the published study I had already seen. Interestingly, the company did not direct me to the published report of this last study, even though that is available freely through the journal. The company representative also sent me the unpublished results of a survey of groomers suggesting that, when asked, many reported they would be willing to recommend the product. This, of course, amounts to no better evidence than the many testimonials and anecdotes available on the company web sites.
The first unpublished study involved 60 dogs receiving behavior modification therapy who were alternately exposed to Pet Remedy or a placebo. The report doesn’t indicate that important controls for bias were included (randomization, blinding, etc.), and it reports vague and subjective outcome measures: “excitement” on a 5-point scale from “not excited” to “very excited” and “behavior” on a similar scale from “poor/unacceptable” to “better/good.” These are certainly not the hallmarks of good-quality behavioral research, which likely explains why the study has not been published.
The company statistician appears to recognize that the design disallows any meaningful conclusions about the efficacy of the product. Despite reporting some differences in the outcome measures for the dogs when exposed to Pet Remedy or placebo, several cautionary statements are included, such as:
It was noted that as no data were available on the baseline (pre-study intervention) behaviour scores and excitement levels for the dogs, it would not be appropriate to compare the August outcomes between the dogs receiving the Pet Remedy and the placebo in the first month. This would fail to take into account the baseline excitement level and behaviour score of the dogs when they entered the study.
It is important to acknowledge that, due to the design of the study, it is not possible to directly attribute the changes observed to the study treatment received in the current month in each case. As each dog was switched between placebo and Pet Remedy from month-to-month, it is not possible to rule out the possibility of so-called carryover or lagged effects of the treatments received in previous months.
It should be reiterated that, due to the design of the study, it is not possible to directly attribute the changes observed in the trial to the study treatment received in the current follow-up month in each case. This is because of the possibility of so-called carryover or lagged effects of the treatments received in previous months.
We would recommend running another study to replicate the effect with a study design that would allow us to determine whether this was indeed due to the study treatment. Select would be more than happy to provide advice on how best to design the study from a statistical point of view.
I was sent another report from the same statistical company that was named as reporting a different study. The date on the report was different, but the content was exactly the same, so I suspect this may have been an error, but I was not able to evaluate the report from this trial. Information from the company web site indicates both trials used the same design and outcome measures, so it seems likely the caveats of the one I was able to review apply to the one I was not, especially given neither have been published.
I was also sent a couple of Excel spreadsheets with data and notes about the subjects in the two studies. These were surprisingly revealing. In fact, they contain individual identifying information for study subjects and owners, which is typically not supposed to be shared outside of the study team. The study was conducted at a private training facility, not an academic institution, which may explain the failure to follow standard study design or ethics guidelines.
These spreadsheets do seem to confirm the lack of blinding and randomization, and support the subjective nature of assessments and potential for bias. A note from one of the investigators, for example, indicates that dogs in one of the studies who were exposed to Pet Remedy in the first month were switched to placebo in the second month, as per the study design, but that those owners who thought the remedy was helpful the first month and asked to switch back to it were allowed to do so. This would be a pretty serious violation of basic study design procedures.
One of the spreadsheets also contains notes about the prognosis for the dogs. These show that the evaluators make judgements about whether or not the dogs could be helped as part of their initial assessments. Some were described positively (e.g. “this one will be easy to resolve” and “can’t wait to work with this little man.”) and others quite negatively (e.g. “Not all together put together this dog has brain issues… This dog needs to be PTS ASAP he has mental health issues” and “This dog is a menace.”).
A rather large number of these comments, in fact, suggest the dogs are very dangerous or should be euthanized. This both indicates this is not a typical population of dogs whose owners are likely to want an over-the-counter herbal remedy and also that, in the absence of blinding and randomization, there is a significant risk of individual bias in how the dogs and the treatments were evaluated. In any case, neither of these studies has been published or appears to meet the basic criteria for a reliable controlled scientific study.
The final study was the one I originally found published in the journal Animals.
Taylor, S. Madden, J. The Effect of Pet Remedy on the Behaviour of the Domestic Dog (Canis familiaris) Animals 2016, 6(11), 64; doi:10.3390/ani6110064
The published study had much better methodology than the other two, including appropriate randomization and blinding. It involved exposing 28 dogs (a pretty small number) to either Pet Remedy or a placebo in an unfamiliar and evaluating for behavioral signs of anxiety. Dogs were chosen whose owners had indicated that they showed signs of anxiety or aggression in unfamiliar places. The study concluded that the product had no effect:
In the current study, no statistically significant differences in behaviour were found in either the Pet Remedy or placebo condition. A lack of a discernible effect under either condition suggests that Pet Remedy did not affect behaviour of dogs’ placed in a potentially stressful non-familiar environment.
This is a pretty clearly negative result in a study that did a much better job controlling for bias than the unpublished studies the company publicizes. In fact, I initially thought it pleasantly surprising that the company would direct consumers to scientific evidence that does not support their claims. However, it turns out the company is doing everything it can to present this study as a success despite the lack of any actual effect.
For one thing, the company lists and describes the study on its web page but leaves out the fact that it found no benefit. The site even says say, “The results of all trials are consistent with pet remedy being an effective natural aid to calm stressed pets.” This is clearly not true. The reality is that the two unpublished studies are unreliable and the published study showed no effect.
The misleading attempt to spin weak and even negative evidence even extended to sending me an unpublished preliminary version of the study report that differed from the published version, even though the published paper is freely available. This was done because the preliminary version presents a much more positive interpretation of the data. In the initial version, two of the many outcome measures evaluated were reported as showing a statistical difference between Pet Remedy, and then this was presented as suggestive of a benefit despite the lack of any difference on all the other measures.
Pet Remedy also significantly decreased overall yawning behaviour; indicative of reduced anxiety although overall heart rate did not significantly differ between treatments. Pet Remedy also significantly affected rates of change in locomotory behaviour but not change in heart rate, with activity decreasing more slowly in comparison to a placebo. The results suggest that Pet Remedy may be a useful tool for reducing canine stress and anxiety in dogs that display suppressed behaviour by increasing activity whilst reducing anxious behaviour. Reduced anxiety may also lower the number of dogs being relinquished to shelters as a result of anxiety related behavioural problems. In turn, Pet Remedy may have potential value in enhancing the welfare of these individuals.
The final paper in published form was apparently edited as a result of the peer review, resulting in the removal of these likely spurious findings and a conclusion more clearly reflecting the lack of any real effect in the data.
Is It Safe?
As pointed out already, the claim of 100% safety can only be true if there is no effect at all, since any treatment which has beneficial effects will almost certainly have potential undesirable effects as well. The company acknowledges that some such effects have been reported with valerian, but of course they claim that their product is perfectly designed to reap the benefits without these side effects:
Many Valerian preparations are too potent and can sedate rather than calm. Pet Remedy is a low concentration valerian blend and the diffuser delivers a constant slow release, which is very kind and gentle in its effect on the metabolism.
No evidence is provided to substantiate this claim.
Given the limited veterinary research available on this product and its ingredients, the question of safety remains unanswered. It seems unlikely that small amounts of these substances volatilized through a diffuser would have serious risk, just as it seems unlikely they would have dramatic benefits, but in the absence of good evidence, we can only speculate.
Pet Remedy is an example of the tremendous number of herbal products marketed to pet owners with extravagant claims but little real evidence to support these. This company explicitly claims strong scientific support for their dramatic claims of safety and efficacy. However, the evidence consists only of anecdote, poor-quality unpublished studies funded by the company, and one reasonably good published study that shows no effects, despite the company’s attempts to imply otherwise.
Like the purported benefits, the claimed absolute safety of the product is also not supported by good scientific evidence. There is little reason to think it is especially dangerous, just as there is little reason to think it has significant benefits, but the marketing claims for both safety and efficacy are not, as the company claims, supported by good science.
The company claims a number of additional studies are in progress. If these turn out to have appropriate design and execution, they may clarify whether there are any benefits to this product. If, however, the company persists in exaggerating the significance of poor-quality unpublished studies and ignoring negative results from more reliable research, then these additional studies will do nothing but create the false appearance of scientific legitimacy where it does not exist.