In search of a safe and environmentally friendly solution to pest problems, homeowners often consider electronic devices, designed to repel rodents and insects. Theoretically, these devices work by creating high-pitched noises that pests find objectionable. Unfortunately, little empirical evidence backs up the claims made by manufacturers of such units; most independent studies have determined that pests are unaffected by the sounds or become accustomed to them. Regardless of the units' efficacy, they are unlikely to affect your dog significantly. Nevertheless, always consult your vet before making any health-related decisions for your pup.
Types of Repellents
Most electronic pest repellents produce high-pitched sounds -- called ultrasounds -- that purportedly drive away rodents, insects, spiders and other arthropods. Different units produce sounds of different frequencies within the ultrasonic range, and project these sounds at varying volumes. Other units are what manufacturers call electromagnetic repellents, but the proposed method by which these units work -- creating very low frequency sounds by utilizing the home's electrical wiring -- remains an unproven strategy.
In the majority of cases, the manufacturers claim that the devices do not harm dogs and cats, although they discourage consumers from using the devices near rodent pets, such as hamsters and gerbils. Accordingly, while few of these devices yield the advertised results, they differ greatly from one another, making it wise to evaluate the efficacy and potential for harm of electronic pest control devices on a case-by-case basis.
The Nature of Ultrasound
Ultrasound refers to sounds at frequencies above 20 kilohertz. Such frequencies are little different than lower frequencies, except they are not audible to humans and do not penetrate objects very easily. Many animals, including dogs, are capable of hearing frequencies as high as 45 to 67 kilohertz, so they can hear these sounds made by electronic repellents.
However, unless the sounds are extremely loud, they are unlikely to affect your dog, as high frequencies do not cause discomfort to the animals who can hear them. Consider, for example, that some dog trainers use ultrasonic devices in the form of dog whistles to communicate with their four-legged partners. Additionally, manufacturers have incorporated ultrasonic devices into flea collars and training devices. As with most other ultrasonic sounds your dog hears every day, your dog is likely to ignore the high-pitched sounds unless they are associated with something noteworthy.
While many manufacturers claim in-house studies support their contentions, most third-party studies have failed to show that the units were effective. A 1997 review by Stephen A. Shumake, with the Denver Wildlife Research Center, found that only six commercial units produced "marginal repellency effects," and that pests quickly acclimated to the sounds. Some studies, such as a 2010 investigation, published in the "Journal of Vector Ecology," showed that ultrasonic repellents actually attracted some pests, such as mosquitoes.
In 2014, the University of Arizona Cooperative Extension produced a report that examined a variety of empirical studies that tested the efficacy of ultrasonic pest control devices. Given the preponderance of tests demonstrating the inefficacy of the units, the extension recommends using other pest control methods in residential applications.
Devices Directed at Dogs
Some manufacturers have tried to develop devices explicitly designed to repel dogs. The specific characteristics of these units vary widely, and while some have proven anecdotally effective, empirical studies have largely shown that the best devices are only partially useful. Nevertheless, a 1989 study found that some exceptionally loud units elicited aversive reactions in 13 of 14 dogs tested.
While some dogs moved away from the source of the sound, others seemed curious, while still others remained completely indifferent to the high-pitched sound. Therefore, while it appears most pest repellents fail to trouble dogs in an appreciable way, it is theoretically possible for ultrasonic devices to irritate dogs or make them uncomfortable.
While ultrasonic pest repellents are unlikely to cause your dog harm or discomfort, discuss the issue with your veterinarian before using one in your home or yard. Additionally, if you choose to use such devices, refrain from placing them in the rooms your dog frequents. Above all else, observe your dog for signs of distress. If you see your dog reacting apprehensively, discontinue use of the repellent.