Studio funzionale dell'orecchio medio mediante esame timpanometrico nel cucciolo di cane

Abstract

Tympanometry is a testing methodology that is used to evaluate the function of the middle ear. Veterinary tympanometry applications have been reported but all previous studies have used high-priced devices and tests were performed under sedation or general anesthesia which represent an additional risk. The availability of a low-cost method of assessing the tympanum would be a significant tool for practitioners.

The objective of this study is to present normative data for clinical use of this equipment to enable assessment of the tympanum, middle ear and auditory tube in puppies. A secondary purpose was to verify whether congenital sensorineural deafness affects middle ear function.

Tympanometry was performed on 76 purebred puppies, (44 females), aged 6 to 15 weeks. After sedation and cleaning of the ear canal, dogs were tested using a handheld device. Both ears were tested in all puppies. Data output with the tympanogram included the following: the peak compliance (in millilitres); the peak pressure (in decapascals); the gradient (in decapascals); the ear canal volume (in millilitres).

Recordings were obtained from both ears in 74 dogs; in the other two animals, data was collected from one ear only, resulting in data from 150 ears (98,7 %). Among tympanometric measures, the peak compliance significantly positively correlates with age. Sensorineural deafness has proven to have no effect on middle ear function.

Results of this study established reference range values for impedance audiometric measurements in clinically normal puppies under sedation. Timpanometry may be a useful noninvasive screening test to assist in the evaluation of the middle ear structures in puppies.