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The design of the Cornell study merits closer attention because cross-sectional surveys of this kind occupy a distinctive position in the hierarchy of clinical evidence. Unlike case-control designs, which begin with affected animals and work backward to identify exposures, a cross-sectional snapshot captures both the outcome of interest and its candidate determinants at a single moment in time. This makes the approach well suited to estimating prevalence, because the denominator—the full population presenting for non-neurologic reasons—is sampled directly rather than reconstructed from referral patterns. The tradeoff is temporal ambiguity: a delayed paw replacement response observed during a single appointment cannot reveal whether the deficit has been present for years, whether it emerged gradually, or whether it reflects a transient state such as fatigue or mild discomfort during the examination itself. Longitudinal follow-up of the same cohort would be required to distinguish these possibilities, and the authors appropriately frame their findings as prevalence estimates rather than causal claims.

The enrollment window between May and July 2025 introduces a seasonal dimension that is rarely discussed in neurologic screening studies but may influence results in subtle ways. Dogs presenting to specialty services during a summer quarter may differ systematically from the general hospital population in activity level, body condition, and owner motivation for seeking care. Temperature can also affect examination dynamics, since dogs exercised outdoors in warm weather may show transient postural inconsistencies from fatigue. Although the standardized evaluation sheet and examiner blinding to age reduce subjective drift, the three-month convenience sample means the prevalence estimate should be generalized with care. The confidence interval reported around the headline figure—spanning roughly 21 to 32 percent—honestly conveys this uncertainty, and the true population prevalence could reasonably fall anywhere within that band.

The exclusion criteria deserve particular emphasis because they shape what the 26 percent figure actually represents. By removing dogs on gabapentin or trazodone, the investigators excluded animals in which sedative or analgesic effects could plausibly blunt postural reactions, an important confound given how commonly these drugs are prescribed to older dogs for pain or anxiety. Similarly, excluding orthopedic disease other than osteoarthritis and any history of cranial nerve abnormalities minimized the chance that structural lesions outside the proprioceptive pathway would masquerade as general proprioceptive deficits. Yet osteoarthritis itself was allowed to remain in the cohort, which is a deliberate and defensible choice: degenerative joint disease is nearly ubiquitous in senior dogs, and excluding it would have produced a study population unrepresentative of real-world practice. The consequence, however, is that some portion of the observed deficits may reflect joint pain or mechanical restriction influencing hopping performance rather than true impairment of conscious or subconscious proprioceptive signaling. The examiners attempted to mitigate this by documenting spinal reflexes and limb tone, which were normal in all deficit-bearing dogs, but pain-associated hesitation during postural reaction testing remains difficult to fully disentangle from neurologic dysfunction.

The fractional lifespan framework used for age stratification represents a methodological refinement over raw chronological age. Dogs vary enormously in lifespan across body sizes—from toy breeds frequently exceeding fourteen years to giant breeds rarely reaching eight—and dividing age by an estimated lifespan derived from weight, age, and height allows a nine-year-old Chihuahua and a six-year-old Great Dane to be compared on roughly equivalent biological footing. This approach is increasingly favored in geriatric research across species because it aligns more closely with physiological aging than calendar years. Notably, both chronological age and fractional lifespan were independently associated with deficit presence, with the fractional lifespan odds ratio somewhat larger, suggesting that biological aging stage is at least as informative as elapsed time. The finding that the association persisted after adjustment strengthens the inference that the relationship is not merely an artifact of how age was categorized.

The neuroanatomical basis of the tests employed helps explain why delayed postural reactions are so sensitive to lesions along the entire neuraxis. Hopping and paw replacement require afferent input from muscle spindles, Golgi tendon organs, and mechanoreceptors in the paw pads to ascend through peripheral nerves, dorsal nerve roots, and the dorsal columns of the spinal cord, reach the brainstem and forebrain for integration, and then descend via upper motor neuron pathways to coordinate the corrective movement. A lesion at any point along this circuit—a compressive disc extrusion, an intramedullary neoplasm, an inflammatory plaque, or a strategic infarct—can prolong the reaction time or cause limb collapse during hopping. This anatomic breadth is both the strength and the weakness of these tests: their sensitivity across lesion locations makes them invaluable screening tools, but it means a positive finding is inherently nonspecific and demands correlation with gait analysis, spinal reflex evaluation, cranial nerve assessment, and ultimately advanced imaging for localization. The observation that reflexes and tone were normal in all affected dogs places the putative lesions—or age-related changes—above the level of the lower motor neuron, consistent with either spinal cord, brainstem, or forebrain involvement.

The predilection for pelvic limb involvement in 90 percent of affected dogs aligns with several converging explanations. Proprioceptive tracts serving the pelvic limbs are located more superficially and laterally within the funiculi of the spinal cord in domestic animals, making them arguably more vulnerable to compressive forces from extruded disc material or vertebral canal stenosis. Additionally, the longer conduction distance from hindpaw receptors to forebrain means more axonal length is exposed to age-related demyelination, axonal degeneration, and microvascular compromise. Degenerative lumbosacral stenosis, a common condition in large-breed senior dogs, compresses nerve roots at the lumbosacral junction and can impair the afferent limb of the proprioceptive arc without altering withdrawal reflexes early in its course. The study’s finding that 93 percent of single-limb deficits were pelvic limb further narrows the likely anatomic distribution toward lumbosacral and caudal thoracolumbar regions, locations where age-related degenerative changes accumulate predictably.

The absence of association with chondrodystrophic status is among the more unexpected results. Chondrodystrophy, driven by a retrogene insertion on chromosome 12 that produces a premature stop codon in the FGF4 gene, predisposes affected breeds to early chondroid metaplasia of intervertebral discs and dramatically elevated risk of Hansen type I disc extrusion. If incidental proprioceptive deficits in the general population were primarily attributable to subclinical disc disease, one would predict chondrodystrophic breeds to show elevated prevalence. The null result instead nudges the etiologic needle toward diffuse, age-linked processes—axonal degeneration, cumulative microstructural changes in white matter, or generalized musculoskeletal slowing—rather than focal compressive lesions. This interpretation is consistent with the clinical observation that most deficit-bearing dogs had bilateral pelvic limb or four-limb involvement, a distribution atypical for focal disc extrusions, which typically produce asymmetric or lateralized signs.

For the practicing clinician, the most consequential application of these findings lies in calibrating diagnostic thresholds. The traditional teaching that postural reaction deficits are pathognomonic of neurologic disease remains true for young and middle-aged dogs, in whom even subtle deficits warrant investigation. The new data suggest that in senior dogs, particularly those beyond three-quarters of their estimated lifespan, a mild delay in paw replacement or hopping may fall within the population baseline and does not automatically mandate advanced imaging. The graded scoring system used in the study—distinguishing mild from severe deficits—suggests a practical hierarchy: severe or asymmetric deficits, especially when combined with altered spinal reflexes, cranial nerve abnormalities, or a history of progression, should still prompt aggressive workup, whereas mild, symmetric, pelvic-limb-predominant delays in a comfortable, reflex-normal senior dog may reasonably be monitored. The 21 percent of affected dogs with single-limb deficits form a particularly interesting subgroup, since unilateral involvement is classically more suggestive of focal lesions than diffuse aging, and these dogs may merit closer follow-up despite the study’s inclusion of them in the overall deficit category.

Several avenues for future research follow naturally from this work. Repeating the survey in a primary care rather than specialty referral population would test whether the prevalence estimate generalizes beyond a tertiary hospital, where dogs referred for cardiology, oncology, or ophthalmology may carry comorbidities affecting neuromuscular function. Objectifying the examination with quantitative measures—such as time-to-recovery during hopping measured with inertial sensors, or pressure-plate assessment of weight shifting—would reduce examiner variability and potentially reveal subclinical deficits below the detection threshold of manual testing. Longitudinal cohorts tracking deficit development alongside serial gait analysis and, where owners consent, magnetic resonance imaging would clarify whether incidental deficits predict future overt neurologic disease, degenerative myelopathy, or cognitive dysfunction. Finally, correlating deficit severity with owner-reported quality-of-life instruments and functional mobility measures would establish whether these subtle findings carry clinical weight for the dog or remain merely an examination curiosity. Until such data mature, the study provides a valuable baseline: roughly one in four dogs presenting without neurologic complaints exhibits measurable postural reaction impairment, and that proportion climbs steadily as dogs traverse their fractional lifespan.

Subject of Research: Prevalence of proprioception deficits in dogs without neurological signs

Article Title: Prevalence of proprioception deficits in dogs visiting veterinary clinics for non-neurologic reasons: a cross-sectional study

Article References: Tam, A., Carney, P., & Merbl, Y. (2026). Prevalence of proprioception deficits in dogs visiting veterinary clinics for non-neurologic reasons: a cross-sectional study. Journal of Veterinary Internal Medicine, 40(5), Article aalag236. https://doi.org/10.1093/jvimsj/aalag236

Image Credits: AI Generated

DOI: 10.1093/jvimsj/aalag236

Keywords: dogs, proprioception, veterinary neurology, aging, fractional lifespan, neurological examination, canine health, chondrodystrophy, postural reactions, veterinary medicine, Prevalence, deficits