Congress on Demand 2021: Surgery

Nose and soft palate: In various studies, about 60% of dogs with BOAS had stenotic nares and 90% had an elongated palate. Using advanced imaging, the palate is not only long but also thickened (hyperplastic) which may be a secondary change to other areas of airway obstruction. The lesions sites are also breed specific, with nasal stenosis being more of an issue in French bulldogs and pugs than bulldogs where the hyperplastic palate is the most noticeable lesion. In an objective study of airway function the nostril status was the most significant conformational factor associated with BOAS (though we still see unaffected dogs with severely stenotic nostrils). As lesion sites vary between breeds and also between individuals of the same breed it is important to assess individuals carefully prior to surgery with a functional assessment (https://www.thekennelclub.org.uk/health-and-dog-care/health/getting-started-with-health-testing-and-screening/respiratory-function-grading-scheme/). We use a nasal grading scheme which is breed specific to assess the nostrils. Open and mildly affected nostrils are desirable (https://www.vet.cam.ac.uk/boas/about-boas/recognition-diagnosis#stenoticnares). There are a myriad of techniques described for soft palate resection and nasoplasty. This presentation covers the current surgical options for nasoplasty and soft palate resection, including alar fold resection and folding flap staphylectomy techniques along with the evidence behind them. Potential complications and outcomes (where known) are also discussed.

Laryngeal collapse and tracheostomy: Laryngeal collapse is a form of upper-airway obstruction caused by loss of cartilage rigidity that allows medial deviation of the rostral laryngeal cartilages. Although laryngeal collapse has usually been considered to be associated with progression of the BOAS, when it comes to the more advanced stages of the condition, the breed of dog is often indicative of the severity in laryngeal changes seen. Conventionally, the condition is sub-divided into three stages in the dog: in stage I laryngeal collapse there is eversion of the laryngeal saccules, in stage II there is loss of rigidity and medial displacement of the cuneiform processes of the arytenoid cartilage, and in stage III there is collapse of the corniculate processes of the arytenoid cartilages with loss of the dorsal arch of the rima glottidis. In its advanced forms, the condition is life-threatening and often very difficult to treat effectively. This presentation covers the condition and its potential management options (e.g. husbandry changes, surgical correction of primary abnormalities, sacculectomy, arytenoidectomy, cricoarytenoid and thyroarytenoid caudo-lateralisation, and permanent tracheostomy), highlighting the controversies and difficulties in its treatment.

Critical history, blood tests and urinalysis: Urinary incontinence is a common reason for presentation, particularly in neutered bitches. It is however, important to distinguish incontinence from pollakiuria, polyuria and behavioural problems. This necessitates asking the client the right questions, performing a thorough physical examination, and sometimes checking urine specific gravity. It is useful to establish the timing of the episodes, volume of urine passed and events surrounding the leakage of urine. Animals with incontinence usually present with intermittent or continuous dribbling of urine but can void normally. Potential causes of urinary incontinence include urethral sphincter mechanism incompetence (USMI), ectopic ureters, neurological abnormalities, detrusor instability and genitourinary tract neoplasia. When incontinence is confirmed, a thorough history, physical examination, neurological examination, urinalysis and aerobic urine culture should be performed. Due to the high prevalence of USMI in adult, neutered bitches and the low cost and risk of treatment, if the results of these steps are consistent, alpha-agonists or estrodiol are frequently trialled prior to further investigations. If the presumptive diagnosis is correct, this treatment is often effective. If not or if the animal does not fit these criteria, further investigations including a complete blood count, biochemistry and abdominal imaging are required to establish the diagnosis.

Imaging the urogenital tract: what test when? Diagnostic imaging can be a very powerful tool in the investigation of urogenital disease, with the differing modalities having strengths and weaknesses for the different areas of the tract. Generally, ultrasound would be recommended as the most appropriate first-line investigation for most structures in the urogenital tract, allowing clear visualisation of the internal structure of the kidneys and reproductive structures (ovaries, uterus, prostate, testes). Radiography may allow diagnosis of altered shape or size of these structures but the changes seen are usually less specific than those that can be identified with ultrasound. Ultrasound and/or contrast radiography can be used for assessment of the bladder (with ultrasound usually being more convenient (and allowing guided cystocentesis if required), but care must be taken in interpretation of the bladder wall if the bladder is not particularly distended. For the ureters and urethra, positive contrast radiography (Intravenous urography, retrograde (vagino) urethrography) often allows clearer assessment of the length of these structures. If available, Computed Tomography can be particularly useful for the assessment of ureteric anatomy (e.g. for aberrant insertion/ectopia). In many cases, multi-modality imaging may be appropriate, particularly if investigation for changes in other body areas is required (e.g. metastatic spread from a neoplastic process).

Identifying ectopic ureters – tips and tricks: Ureteral ectopia (EU) is a congenital abnormality, in which one or both ureteral openings form with their termination located distal to the bladder trigone. Intramural and extramural phenotypes are recognised, with >95% of canine cases identified as intramural, whilst the majority of feline EU are extramural. Diagnosis may be straightforward in patients presenting with significant urinary incontinence at a young age, but may be challenging in patients with a more atypical presentation, or in those with only subtle abnormalities of their urinary tracts. This session covers the variable clinical presentation of patients with ectopic ureters, explains ultrasound findings that may increase your index of suspicion for this condition, how to optimise contrast imaging to highlight an abnormal ureter and more about our current gold standard of diagnosis, cystoscopy. This information should enable you to more confidently recommend additional diagnostic tests in the correct animals and avoid unnecessary testing in those patients unlikely to have this condition. More patients can then in turn receive appropriate treatment.

USMI when medicine fails: what next? Urethral sphincter mechanism incompetence (USMI) is the commonest cause of urinary incontinence in the bitch. Medical management is the first line treatment (usually with either an adrenergic agent (e.g. phenylpronolamine) or an oestrogenic agent (e.g. estriol). The majority of bitches have a good response to these, but other treatments need consideration in a minority of cases. Before surgery is planned, the clinician should review the diagnosis and consider underlying or secondary factors (such as obesity and urinary tract infection). If the diagnosis is confirmed and these have been considered, surgical management can be offered to the owners. There are several established surgical options (colposuspension, Artificial Urethral Sphincter placement, urethral sling), endoscopic management with urethral bulking agents and some less well established procedures (vaginectomy, vaginal septum transection). The session looks at each of these and make suggestions as to their application.