Previous reports of TECA/LBO have provided a description of the surgical technique, outcome and complications in relatively small numbers of dogs. The aim of this study was to identify risk factors for complications in a large number of dogs undergoing TECA/LBO.

The medical records of 309 dogs that had undergone TECA/LBO at the RVC and CUVS from 1994 to 2004 were reviewed. Follow-up data was obtained from the owner by postal questionnaire. Univariable statistical analysis was used to identify variables associated with complications. Mantel-Haenszel odds ratios were calculated, and variables significant at the 20% level were taken forward for evaluation in multivariable models using logistic regression.

One hundred and twelve dogs (36.3%) had post-operative complications; 30.1% of all dogs had neurological complications, 7.4% had wound complications, and seven dogs (2.26%) had both. Twenty-nine dogs (9.4%) had intra-operative haemorrhage from the retroglenoid vein. Eighty-one dogs (25.5%) had cranial nerve VII dysfunction, thirty-five dogs (11.3%) had cranial nerve VIII dysfunction and one dog (0.32%) developed Horner's syndrome. Seven dogs (2.3%) had post-operative wound infection and sixteen dogs (5.2%) had post-operative para-aural abscessation.

Three risk factors were associated with the occurrence of any post-operative complication: use of post-operative antibiotics (OR= 2.31, 95% CI=1.41-3.79, p=0.006); presence of a concurrent skin disease (OR=0.59, 95% CI=0.37-0.96, p=0.0014); and being female (OR=1.86, 95% CI=1.14-3.02, p=0.0014). In the multivariable models, post-operative antibiotics (OR= 3.91, 95% CI=2.15-7.12, p<0.001), being female (OR =1.74, 95% CI=1.03-2.9, p=0.039,) and centre where operated on (OR=3.13, 95% CI=1.72-5.70, p<0.001), were associated with increased odds of post-operative neurological complications; concurrent skin disease (OR= 0.23, 95% CI=0.08-0.62, p=0.004) was associated with reduced odds of post-operative wound complications and being female (OR=2.77, 95% CI=1.27-6.04 p=0.01) was associated with increased odds of intra-operative retroglenoid haemorrhage. Intra-operative retroglenoid bleed was associated with post-operative wound complications (OR=2.78, 95% CI=1.04-7.49, p=0.0424) in the univariable model, but not in the multivariable model.

Animals with pre-existing skin disease and those in which post-operative antibiotics are deemed necessary may differ from the population as a whole, and this merits further evaluation. Intra-operative haemorrhage may cause the surgeon to abbreviate the procedure, increasing the risk of wound complications. The 2 centers had different rates of neurologic complications. Gender affects outcome in many diseases in human medicine, but this is not well-recognised in veterinary medicine.