Effects of trazodone on behavioral signs of stress in hospitalized dogs.

OBJECTIVE To determine the effects of trazodone treatment on behavioral signs of stress in hospitalized dogs. DESIGN Prospective observational study. ANIMALS 120 client-owned dogs. PROCEDURES Hospitalized dogs administered trazodone (n = 60) were observed for stress-related signs or behaviors ≤ 45 minutes after the drug was administered (time 1) and approximately 90 minutes later (time 2). Dogs that did not receive trazodone (n = 60) were selected to serve as controls for environmental stimuli that could affect behavior and were observed at the same times. Signs or behaviors (scored as present or absent) were assessed individually and grouped into behavioral summation categories (frenetic [lip licking, pacing, panting, spinning, trembling, wet dog shake, whining, and yawning], freeze [averting gaze, pinning back ears, and whale eye sign], or fractious [growling, lunging, showing teeth, and snapping], with lifting of a forelimb and pupil dilation included in all categories). Results were compared between groups and within groups over time. Logistic regression was performed to assess associations between reduction in stress-related signs or behaviors and trazodone administration while controlling for environmental influences. RESULTS Lip licking, panting, and whining were reduced (defined as present at time 1 and absent at time 2) in trazodone-treated but not environmentally matched dogs. The median number of stress-related behaviors and of frenetic and freeze behaviors was significantly lower at time 2, compared with time 1, in trazodone-treated dogs. Odds of reduced panting and reduced frenetic behaviors at time 2 for trazodone-treated dogs were > 2 times those for environmentally matched dogs. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that trazodone administration reduced stress-related signs and behaviors in hospitalized dogs and may thereby improve patient welfare.

Inner ear histopathology in "nervous Pointer dogs" with severe hearing loss.

Ten puppy dogs (82, 131 or 148 days-old) from a Pointer cross-colony, exhibiting a juvenile severe hearing loss transmitted as an autosomal recessive trait, were used for histopathological characterization of the inner ear lesion. Immunostaining with calbindin, Na,K-ATPase, cytokeratins, S100, S100A1 and S100A6 antisera were helpful in identifying the different cell types in the degenerated cochleae. Lesions, restricted to the Corti's organ and spiral ganglion, were bilateral but sometimes slightly asymmetrical. Mild to severe lesions of the Corti's organ were unevenly distributed among the different parts of the middle and basal cochlear turns while the apical turn remained unaffected at 148 days. In 82 day-old puppies (n = 2), severe lesions of the Corti's organ, meaning that it was replaced by a layer of unidentifiable cells, involved the lower middle and upper basal turns junction area, extending in the upper basal turn. Mild lesions of the Corti's organ, with both hair and supporting cells abnormalities, involved the lower middle turn and extended from the rest of upper basal turn into the lower basal turn. The outer hair cells (ohc) were more affected than the inner hair cell (ihc). The lesions extended towards the basal end of the cochlea in the 131 (n = 5) and 148 (n = 3) day-old puppies. Additionally, the number of spiral ganglion neurons was reduced in the 131 and 148 day-old puppies; it is earlier than observed in most other canine hereditary deafness. These lesions were interpreted as a degeneration of the neuroepithelial type. This possible animal model might provide information about progressive juvenile hereditary deafness and neuronal retrograde degeneration investigations in human.