
In areas where ticks and fleas are a concern (which is much of the world), dogs (and to a lesser degree cats) may receive regular tick prevention medications. Some people would rather not use them, whether it’s because of cost, concern about adverse effects, a desire to use more “natural” products or internet misinformation. This, along with far fewer regulations for any compounds not marketed as “drugs,” opens the door for a lot of untested, unproven or downright ineffective products and devices.
Consider ultrasonic insect repellants. These devices are based on the theory that the high frequency sounds they emit are beyond our hearing (and therefore don’t bother us, or our pets) but are discernible to pests, and help drive them away. Various such devices are available commercially, and since they are not drugs and are not marketed as medical devices, the receive very little scrutiny.
Do ultrasonic insect repellants actually work?
The short answer seems to be no. Studies have shown no effect; for example, a study comparing two ultrasonic flea collars in cats found neither was effective (Dryden et al. JAVMA 1989).
In 2016, the New York Attorney General’s Office sent cease and desist letters to companies that were marketing ultrasonic mosquito repellents with claims of efficacy, further supporting that there seems to be no compelling evidence that they work.
Yet, there are still lots of these products around making lots of claims about what they can do.
To me, not having any data for a product related to healthcare is bad (and protection from fleas, ticks and other disease vectors is an important part of healthcare for people and animals, whether drugs, pesiticides or other means are use). Unfortunately there are lots of products on the market for all kinds of things that have absolutely no evidence of effectiveness, just someone who can spin a good story about them.
What’s perhaps even worse is using crap-tastic data to market a product and over-stating its efficacy. (Worse yet is when there is testing that shows something doesn’t work, and the company buries the unfavorable results.)
Overstating efficacy is not just a problem because it misleads consumers to spend money on something that doesn’t work, but also because it can steer people away from effective approaches (tick preventive medications) and ultimately result in increased disease risk.
I got a recent question about a product called Tickless, which is being marketed with claims that it works as a tick repellant for dogs. (Full disclosure: the question came from a pharma company employee. It was a question, not a request for a post. I don’t get any funding from them and got nothing for writing this. I’m writing it because I hate to see animals get preventable diseases because well-meaning owners were misled.) My comments below are focused on this product, but would apply to any similar product.
The company claims “TICKLESS technology underwent rigorous testing and was proven effective by a clinical study at the School of Veterinary Medical Microbiology and Infectious Diseases Laboratory at the University of Camerino, Italy.”
Let’s look at what’s available to support that.
The claim seems to be based on an unrefereed study from 2012 that looked at reduction in fleas and ticks on 30 dogs at each of 2 different shelters. There’s no mention of ethics approval for the study. Dogs had to have not recently received flea/tick medication (good) and had to have at least 4 fleas or ticks on them. A standard method to evaluate them for ticks was used (also good). The each group of 30 dogs was subdivided into 3 groups:
- Activated device (n=20)
- Treatment with fipronil and lufenuron (n=5), unactivated device
- Unactivated device (n=5)
“The subjects included in the experimentation were kept in separate enclosures for the entire duration of the study, ideally in individual enclosures or with a number of other similar dogs”
- This is a bit hard to follow and potential variation in housing is really important for fleas, since dog-to-dog spread would be the big risk.
- Tick exposure risk would likely be very low in a shelter. Most ticks are acquired from outdoor environments, so for them, it would be expected that ticks would finish feeding and drop off over time, and new ones would not likely be encountered. That’s a huge factor when assessing a tick preventive.
Their results claim to “…show the effectiveness of Tickles Pet in not permitting an increase in the number of ticks and fleas in all subjects studied and experimentation and to reduce the number of parasites in some subjects.” Specific data are limited:
- Drugs and inactivated device: “drastic reduction in the number parasites” (expected since drugs work really well, but really vague. We need numbers.)
- Inactivated device and no drugs: “number of parasites remained stable in so subjects but increased considerably in others” (again… need numbers.)
- Active device: “number of parasites remained stable, and in some subjects a considerable reduction was observed” (yep… we still need numbers, and analysis!)
They concluded that the study confirmed “the effectiveness of the product in not permitting an increase of the parasites and in reducing the number of parasite (sic) in some subjects, which can therefore be used, without side effects of any kind, on subjects for which an infestation of ticks/fleas has been confirmed, so as to avoid the worsening of the situations, and in healthy subjects so as to prevent infestation.”
That’s a stretch, and it’s not hard to see why this was never published.
They also report a study done using this device at the University of Milan from 1993. It’s a hot mess. They put the device on:
- 5 parasite-free dogs
- They were still parasite free (I’m guessing after a week but it’s not clear).
- 5 “weakly infested” (not sure with fleas or ticks) dogs
- 4/5 had no parasites after a week. How many of those would have naturally eliminated the parasite, since they don’t inhabit the dog forever? It’s hard to say.
- No parasites were seen on day 35. There’s also no info about whether these dogs were treated with anything for their parasite infestation.
- 15 “severely infested” (again, not sure with what) dogs
- 76% reduction… but there were 15 dogs in the group so the numbers don’t fit. 11/15 would be 73%. 12/15 would be 80%. That’s another red flag.
- There was 97% reduction by day 35. Again, how many would have eliminated parasites themselves? Plus, 14/15 is 93%, not 97%, and 15/15 is obviously 100%. Where does 97% come from? Are these numbers real? What’s the outcome measure if it’s not dogs that had their infestation eliminated?
They also say “The control at day 15th put in evidence a 80-90% reduction in parasites”
- What control? How many dogs? What kind of infestation?
- Also, if there was an actual control group, why report results for it at day 15, and results for the test group at days 7, 9 and 35?
More red flags.
They also claim efficacy based on a 2018 study that was done by VCA, to see “whether or not the European-manufactured, ultrasonic pest-repellent technology of TICKLESS is as effective on pets in the United States as it is on the European counterparts.” But, there’s nothing published about this study, VCA personnel are not quoted in any of the study materials and I can’t see any reports by VCA about the results. That raises a few more red flags.
The content of this study also raises lots of concerns. It reportedly involved giving out collars to 100 dogs. Owners filled out a questionnaire before and after the study period. They said: “The outcome of the test gave a clear picture on the efficacy of the ultrasonic tick and flea repellent since 94% of all pets involved stayed totally free of ticks and 88% stayed totally free of fleas thru out the whole test period.” But…
- What percentage of dogs without a collar would have been tick-free in these areas anyway?
- Were any of these dogs also on tick prevention medication?
Without answering those two questions, we can’t interpret anything from this “study.” These results could mean the product worked, it did nothing, or that it was a tick magnet.
They also said that 6% of owners reported finding fewer ticks than normal and 12% reported finding fewer fleas. That’s not actually an encouraging number since there’s likely a placebo effect with subjective assessments like that.
A proper study would have had a control group of dogs with an inactive collar, randomization to provide dogs with either the active or inactive collar, specific criteria for whether or not the dog could be on tick preventive medications, and more detailed information on infestations. That’s a really basic study design, and as cheap and as easy as doing what they did. So why didn’t they do it properly? It’s hard to say… lack of understanding of the basics of study design? Not wanting to actually know whether it works? Not having confidence that it works? Just looking for something that can go on advertising materials (e.g. “scientifically tested”)? Who knows. All I can say is that this study had no hope from the start, and tells us nothing apart from the company can’t or doesn’t want to design a proper trial.
Are there concerns about overuse of anti-parasitics in pets?
- Yes, absolutely. These products are quite safe overall but no drug is 100% safe. Some animals experience adverse effects.
- There are also poorly understood but increasing concerns about the environmental impacts of these drugs (since they are excreted in urine and feces).
I’d love to have a non-pharmaceutical, safe, effective and affordable tick repellant. (I’d love one for me and my pets, especially if it kept mosquitoes away too!) But as much as l’d like this product or similar products to work, we don’t have any evidence that they do. Ticks, mosquitoes and fleas account for massive impacts on human as well as animal health. If we had a safe, effective non-pharma approach, we’d use it. That’s a multi-billion dollar market just waiting for the right product. The fact that we don’t have an effective product on the market even for people shows that we don’t have one that works.
These products themselves are likely relatively harmless, but there’s a potential harm component when people try to use them and therefore forego effective treatments.