Distinguishing Neurological Signs of Vestibular Dysfunction in Dogs: Central Vs. Peripheral Vestibular Disease.

The present study was carried out at Madras Veterinary College Teaching Hospital on dogs (n=28) presented with head tilt, nystagmus, and strabismus, suggestive of vestibular disease. The standard neurologic examination was performed, which consisted of an evaluation of mental status (level of consciousness), gait and body posture, postural reactions, and cranial nerve examination. These animals underwent various diagnostic tests and were classified as peripheral vestibular disease (PVD, n=14) and central vestibular disease (CVD, n=14). Seventeen dogs (60.1%) out of 28 dogs irrespective of the group showed gait abnormalities such as veering or leaning, falling, circling, non-ambulatory tetra paresis, hypermetria, and wide-based stance. Among those dogs ambulatory tetra paresis was seen more with CVD dogs and leaning/veering was observed more in PVD dogs. Six dogs out of 28 dogs showed cranial nerve dysfunction irrespective of PVD or CVD with cranial V and IX dysfunction in CVD dogs. Spontaneous resting nystagmus was observed in 21 dogs out of 28 dogs while a higher percentage of horizontal nystagmus was observed in PVD dogs and vertical nystagmus was observed in CVD dogs. There were no significant differences between groups regarding prevalences of abnormalities of segmental spinal reflexes, spinal hyperpathia, alterations in muscle tone, muscle atrophy, and alterations in the cutaneous trunci reflex. Results of the present study suggested that the neurologic examination, in its entirety, allowed reliable localization of peripheral versus central neurologic dysfunction across interpreters, but no individual feature of the neurological examination bore a strong relationship to the location of the lesion. [ABSTRACT FROM AUTHOR]