This technique can be used to diagnose common causes of URT associated with poor performance in horses during normal training. This has substantial implications for future clinical diagnosis and treatment of URT pathology.

Disease of the conchal bullae should be considered as a potential cause of chronic unilateral nasal discharge in horses. Clearance of empyema within these bullae is unlikely to occur through lavage of the paranasal sinuses alone. Where necessary, fenestration of the bulla allows physical removal of infected material.

Peripheral caries is common in British horses, primarily affecting the caudal cheek teeth. There was limited evidence of an association between feeding and PC. The association between PC and concurrent dental disorders indicates that these should be addressed in affected horses.

Background: Complications, especially delayed alveolar healing, are common following equine cheek teeth extraction, however, limited objective information is available on the prevalence and nature of these problems. Objectives: To document the type and prevalence of complications that occur following equine cheek tooth extraction and to identify possible risk factors for these complications that could be used to predict their occurrence and hopefully reduce their prevalence. Study design: Retrospective cohort study. Methods: Clinical records of all cheek teeth extractions performed between February 2004 and September 2018 were examined and written questionnaires sent to owners. Details of post-extraction complications were analysed and logistic regression was used to evaluate potential associations between the likelihood of post-extraction nonhealing alveolus managed by the authors and the variables: age, breed, reason for extraction, Triadan position and extraction technique. Results: Post-extraction complications were recorded following 58/428 extractions giving an overall complication rate of 13.6%, that caused a longer term clinical problem in 34/428 (7.9%) cases, with complications being asymptomatic or quickly selfresolving in the other 24 cases (5.6%). The most frequent complication was alveolar bone sequestration, including alveolar infection. Risk of developing a post-extraction alveolar disorder managed by the authors (n = 53) increased following extraction of the mandibular 06s, 07s or 08s compared with all other cheek teeth combined (P = .001); for cheek teeth with apical infections (P = .002) compared with those without; and following repulsion or minimally invasive transbuccal extraction (MTE) than following oral extraction (P = .01 and P = .02 respectively). Main limitations: Length of time between exodontia and survey data collection for some cases, use of clinical records and survey data and biases associated with decision to treat. Conclusions: In agreement with previous studies, oral extraction had the lowest risk of complications. This study provides new information regarding the prevalence, types and risk of development of post extraction complications. Knowledge of these

The type and location of deep digital flexor tendon (DDFT) lesions may be important in predicting outcome. The objectives of this study were to determine the frequency of different types of DDFT lesions within the hoof capsule and to determine whether lesion type predicts return to athletic activity. Lesions of the DDFT were divided into: core lesions, dorsal border lesions and parasagittal splits. Lesion location was documented, and follow-up information was obtained by telephone survey at least 18 months after diagnosis. Of 168 horses with primary DDFT injury, 54 horses had dorsal border lesions, 59 had parasagittal splits and 55 had core lesions. Twenty-five per cent of all horses returned to previous levels of athletic activity within 18 months of MRI evaluation. Horses with complete splits or core lesions of the DDFT were significantly less likely to return to some level of athletic activity than horses with dorsal border lesions P<0.001. Dorsal border lesions of the DDFT appear to have a better prognosis than core lesions or parasagittal splits. This study provides additional information that may help clinicians predict the prognosis for different types of DDFT injury.

The results will facilitate the development of strategies to improve the overall safety of horses in hurdle racing in the UK.

Background There is little objective information concerning the intra‐ and post‐operative complications or the long‐term outcome of sinoscopic treatment of equine sinus disorders. Objectives To document the long‐term outcome, including intra‐operative complications, reasons for treatment failure and other complications, in horses undergoing standing sinoscopic treatment of sinus disorders. Study design Retrospective clinical study. Methods Records of sinus disease cases presented to The University of Edinburgh Veterinary School between January 2012 and July 2019 were reviewed. Follow‐up information was obtained from clinical records and a telephone questionnaire. Results Long‐term follow up for 155 cases treated sinoscopically showed that 108/155 (69.7%) fully responded to their initial treatment. Concurrent intranasal lesions were identified in 37.4% of cases. Sinusotomy was later required in 10 cases to improve surgical access or sinonasal drainage. Reasons for failure to fully respond to the initial treatment (n = 47) included: intra‐sinus bone sequestra (n = 9), inspissated exudate (n = 6) or insects (n = 2); similar material and/or infected conchal bullae in the middle meatus (n = 7); persistent oro‐maxillary fistulae (n = 4), misdiagnosed dental apical infections (n = 4); impaired sinonasal drainage (n = 4), progressive ethmoid haematoma regrowth (n = 3) and undiagnosed causes (n = 5). Further treatment of 43 of these cases (67% as outpatients) showed 34/43 cases fully responding to their second treatment. Only 4/155 cases (2.6%) required sinonasal fenestration. In the long term, 149/155 cases (96.1%) showed full and 2/155 cases (1.3%) showed partial improvement. Sinoscopy portal wound infection occurred in nine cases. Main limitations The length of time between treatment and obtaining follow‐up information in some cases. Advances in knowledge and techniques over the duration of the study. Conclusions Sinoscopic treatment is a minimally‐invasive technique causing minimal morbidity and was successful in 96.1% of cases. Meticulous care should be taken to ensure that bony sequestrae and inspissated exudate are fully removed from the sinuses and nasal cavity during sinoscopic treatments.

Computed tomography was a useful technique to establish the linear and volumetric dimensions of the nasal conchal bullae in normal horses. Both dorsal conchal bulla and ventral conchal bulla sizes increased with animal age. Relatively consistent anatomical relationships were shown between the rostral and caudal limits of the bullae and certain maxillary cheek teeth, which would be of diagnostic value with conventional radiography and act as landmarks in the surgical treatment of nasal bulla disease.