Respiratory complications in dogs with cervical myelopathies can be life-threatening and are attributed to spinal cord morbidity secondary to cervical disease or decompressive surgery causing diaphragmatic dysfunction. However, diaphragmatic dysfunction in these dogs has not been described. Thirtyive client-owned dogs were recruited with 14 control and 21 test dogs. Dogs were evaluated for the presence of diaphragmatic dysfunction using radiography, M-mode ultrasonography, and fluoroscopy (gold standard) before and after an anesthetic or surgical event. Diaphragmatic dysfunction was observed more frequently in dogs with cervical disease prior to surgery (8/21 dogs, 38.1%) compared to control dogs (3/14 dogs, 21.4%) but was not statistically significant (odds ratio, 2.3; 95% confidence interval, 0.48-10.6; P = 0.30). Further, the frequency of diaphragmatic dysfunction did not significantly increase following surgical decompression in either group. Thus, dogs in this study with cervical disease and undergoing decompressive surgery were not considered to have a higher probability of diaphragmatic dysfunction compared to the control dogs.