Hearing loss is a complex problem not only in humans, but also in animals. In fact, deafness and hearing loss are also very common in dogs, but the hidden genetic variants in the inherited form that lead to disability were unknown to date.
A group of researchers from the University of Helsinki (Finland) and the Folkhalsan Research Center have analyzed a rare type of hearing loss seen in Rottweiler puppies.
It usually begins during the first stage of life (when they are still puppies) and progressively progresses to deafness when they are several months old. They have also seen a similar hearing loss in mixed breed dogs, most of which were of Rottweiler ancestry.
Investigation Development
The scientists identified the variant in the LOXHD1 gene, which plays a fundamental role in the function of the cilia (cellular structures that can move and allow the movement of various fluids and particles) of cochlear sensory cells. And while the exact mechanism that causes deafness is still unknown, researchers have been able to conclude that variants of the same gene cause inherited hearing loss in both humans and mice.
According to Docent researcher Marjo Hytonen, this hearing impairment (caused by the LOXHD1 gene defect) is a recessively inherited trait. This means that, to develop the disorder, the dog must have two copies of the defective gene (one from the father and one from the mother).
The team also analyzed the prevalence of the genetic variant in a data set of about 800,000 dogs, the largest study to date. In addition, during the screening they were able to identify nine dogs that had inherited the genetic defect (and that were also deaf).
Study results
As the researchers point out, thanks to this discovery it will be possible to prevent pets from being born with this genetic defect. To do this, they should only avoid combinations that result in puppies with hearing loss.
On the other hand, according to Marjo Hytonen, both hereditary congenital hearing loss (previously unknown) and hearing loss during adulthood occur in various breeds of dogs, which could help to avoid this problem in other animals.
The preliminary findings also open new avenues to investigate inherited hearing defects in humans.
