Equitation and exercise factors affecting dynamic upper respiratory tract function: A review illustrated by case reports

The importance of undertaking appropriate exercise tests for the diagnosis of dynamic upper respiratory tract (URT) obstructions has been previously documented. Dynamic URT collapse is usually most severe during peak exercise; however, there are occasions when an URT collapse appears more severe during the immediate recovery period. In addition, equitation factors such as head and neck flexion and factors relating to the bit and bridle may induce or exacerbate dynamic URT collapse. The purpose of this paper was to review the literature and 5 cases within the authors' experience have also been included.     

A novel use for polyamide tie‐wraps in the surgical resolution of caecocolic intussusception in a horse

Caecocolic intussusception is an uncommon cause of colic in the horse. Surgical correction presents its own set of challenges. The affected tissue is often markedly oedematous and a partial typhlectomy through an enterotomy incision in the right ventral colon can be the only method of successfully reducing the intussusceptum. Suture ligation of the nonviable portion of caecum can result in cut through of tissue, which can lead to an insecure ligation. In addition, a right ventral colon enterotomy can result in life‐threatening peritoneal contamination. This report describes the novel use of polyamide tie‐wraps to ligate the inverted caecum, allowing for partial typhlectomy and reduction of the intussusceptum, as well as a method to minimise potential abdominal contamination. To the author's knowledge, this is the first report of the use of polyamide tie‐wraps in the gastrointestinal tract of the horse.     

Prevalence and risk factors for canine post‐anesthetic aspiration pneumonia (1999–2009): a multicenter study

ObjectiveTo determine the incidence of canine post-anesthetic aspiration pneumonia (AP) and to identify anesthetic agents, procedures and management factors associated with the development of AP.Study designMulticenter, randomized, case-controlled retrospective study.AnimalsTwo hundred and forty dogs affected with AP and 488 unaffected control dogs.MethodsElectronic medical record databases at six Veterinary colleges were searched for dogs, coded for anesthesia or sedation and pneumonia from January 1999 to December 2009. The resultant 2158 records were hand-searched to determine eligibility for inclusion. Diagnosis of AP was made radiographically. Two unaffected control dogs were randomly selected for each affected dog, from a list of dogs that underwent sedation or anesthesia in the same time period and did not develop aspiration pneumonia. Fifty-seven factors were then evaluated for association with aspiration pneumonia. Data analysis was performed using univariate Chi-square or student t-tests, then multivariate logistic regression.ResultsIncidence of post-anesthetic AP was 0.17%, from 140,711 cases anesthetized or sedated over the 10 year period. Two anesthesia-related events were significantly associated with development of AP: regurgitation and administration of hydromorphone at induction. Administration of anticholinergics was not associated with AP. Procedures associated with increased odds of aspiration pneumonia included laparotomy, upper airway surgery, neurosurgery, thoracotomy and endoscopy. Orthopedic surgery, ophthalmologic surgery, dental procedures, MRI, CT, bronchoscopy, cystoscopy, tracheoscopy and neutering were not associated with development of AP. Three patient factors were associated with the development of AP: megaesophagus, and a history of pre-existing respiratory or neurologic disease. Sixty-nine% of dogs with two or more of the above independent predictive variables developed AP.Conclusion and clinical relevanceMost anesthetic agents and procedures were not associated with the development of AP. We need to devise and evaluate strategies to protect at risk patients.     

Standing low‐field MRI of the equine proximal metacarpal/metatarsal region is considered useful for diagnosing primary bone pathology and makes a positive contribution to case management: A prospective survey study

High‐field MRI of the proximal metacarpal/metatarsal region has been associated with great diagnostic potential and clinical reports of standing low‐field MRI of the forelimb suggest the same. To better understand diagnostic outcomes with standing low‐field MRI of the proximal suspensory region, a prospective survey study was conducted and users of a widely available system questioned on their experience, operating procedures, and interpretation of standing low‐field MRI findings. Response data included scores on a modified Likert scale from which weighted ratings were calculated for statistical analyses. Depending on the question, responses were obtained from 17 to 29 of the 38 invited facilities. Users indicated that standing low‐field MRI was most frequently performed in the face of equivocal diagnostic findings; compared to Sports horses, general purpose riding horses were thought less likely to have detectable abnormalities and standing low‐field MRI was rated most useful for the detection of primary bone pathology in the proximal metacarpal region. Standing low‐field MRI signal change involving both the suspensory ligament and adjacent bone concurrently was rated most relevant and abnormalities solely affecting the muscle/adipose tissue bundles least relevant for diagnosing suspensory ligament injury. Transverse scans and in decreasing order T1‐weighted gradient echo, short‐tau inversion recovery FSE, T2*‐weighted gradient echo, and T2‐weighted FSE sequences were most frequently acquired and judged most useful by the majority of users experienced in imaging of the target area. This survey supports the relevant impact of standing low‐field MRI on clinical case management, particularly in the context of imaging the proximal metacarpal region.