Peer-reviewed veterinary case report
How aging changes dog inner ears and hearing tests
By Ter Haar, G et al.·Published in Journal of veterinary internal medicine·2009·Department of Clinical Sciences of Companion Animals, Netherlands·View original on PubMed →
PetCaseFinder translated the abstract of this peer-reviewed paper into plain English so pet owners can read it. We do not publish original research — every detail traces back to the citation above. How we work →
Original publication title: Effects of aging on inner ear morphology in dogs in relation to brainstem responses to toneburst auditory stimuli.
- Species:
- dog
Plain-English summary
A group of older dogs, averaging 12.7 years, showed signs of age-related hearing loss, which is common in both dogs and humans. The study found that these dogs had significant damage to the cells in their inner ears, which affected their ability to hear higher frequency sounds. This damage was similar to what is seen in older humans with hearing loss. Understanding these changes can help veterinarians better diagnose and manage hearing issues in aging dogs.
People also search for: dog hearing loss symptoms · how to help an older dog hear better · signs of deafness in dogs
Abstract
BACKGROUND: Age-related hearing loss (ARHL) is the most common form of hearing loss in humans and is increasingly recognized in dogs. HYPOTHESIS: Cochlear lesions in dogs with ARHL are similar to those in humans and the severity of the histological changes is reflected in tone audiograms. ANIMALS: Ten geriatric dogs (mean age: 12.7 years) and three 9-month-old dogs serving as controls for histological analysis. METHODS: Observational study. Auditory thresholds were determined by recording brainstem responses (BERA) to toneburst auditory stimuli (1, 2, 4, 8, 12, 16, 24, and 32 kHz). After euthanasia and perfusion fixation, the temporal bones were harvested and processed for histological examination of the cochleas. The numbers of outer hair cells (OHCs) and inner hair cells (IHCs) were counted and the spiral ganglion cell (SGC) packing density and stria vascularis cross-sectional area (SVCA) were determined. RESULTS: A combination of cochlear lesions was found in all geriatric dogs. There were significant reductions (P .001) in OHC (42%, 95% confidence interval [CI]; 24-64%) and IHC counts (21%, 95% CI; 62-90%) and SGC packing densities (323, 95% CI; 216-290) in the basal turn, SVCA was smaller in all turns. The greatest reduction in auditory sensitivity was at 8-32 kHz. CONCLUSIONS AND CLINICAL IMPORTANCE: ARHL in this specific population of geriatric dogs was comparable histologically to the mixed type of ARHL in humans. The predominance of histological changes in the basal cochlear turn was consistent with the large threshold shifts observed in the middle- to high-frequency region.
Find similar cases for your pet
PetCaseFinder finds other peer-reviewed reports of pets with the same symptoms, plus a plain-English summary of what was tried across them.
Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/19645839/