ABR Pretty Dog-Gone Versatile

As hearing professionals, we have a distinct interest in our patient's hearing. But what if your patient was your own dog?

Dr. Peter Scheifele encountered this very scenario as he noticed that his Australian shepherd, Belle, did not respond to his calls. Dr. Scheifele has spent several years at the University of Connecticut's Department of Animal Science developing auditory brainstem response (ABR) protocols for canines who show signs of hearing loss. Of course, Belle was his first subject and was diagnosed with a profound hearing loss.

As an audiologist, Scheifele studied human ABR responses, and simply adapted the ABR to work for dogs. He used insert earphones that were more appropriate for doggie ears, as well as electrodes fixed on the scalp (Figure 1). In addition, he used subdermal electrodes in a non-sedated setting. When asked how canine waveforms compare in relation to adult human waveforms, he said, "A majority of the time the latencies are early by so much as 3 milliseconds. The morphology is not unlike that of a human, and many times Wave IV does not show up either" (Figure 2).

Just as in a human ABR interpretation, ABR tests performed on dogs can offer conclusive results, as opposed to the black-and-white line of "hearing" or "not hearing." This information can be useful to breeders by providing knowledge concerning the possibility of a litter of puppies inheriting deafness. Congenital deafness has been reported in at least 60 breeds of dogs.

The University of Connecticut clinic is one of the only sites in the United States that offers such testing for canines. As an animal audiologist, Dr. Scheifele hopes that his testing and headway will provide opportunities for the practice to expand nationwide. As quoted in the Hartford Courant, he said, "The ultimate goal is to train animal audiologists. If we can start people to become audiologists, veterinarians will eventually be able to rely on audiologists the same way MDs do."

Peter Scheifele's work concerning the canine ABR was recently presented at the Acoustical Society of America's National Meeting, and is currently awaiting publication:

Scheifele, P.M., Musiek, F.M., Pinto, M.G., Darre M., Preece, J. (2006). Comparative analyses of canine hearing using auditory evoked potentials." Journal of the Acoustical Society of America (presented at 151st national meeting and now in submission).

To read to the complete story, go to www.courant.com/news/local/northeast/hc-animalnoises0820.artaug20,0,7098909.story?coll=hc-headlines-northeast.



Figure 1. Doggie ABR Setup. "Belle" is the white Australian Shepherd.



Figure 2. Wave V Latency-Intensity Function for a Normal Hearing Dog