Computed tomographic evaluation of the distal limb in the standing sedated horse: Technique, imaging diagnoses, feasibility, and artifacts.

In several veterinary institutions, adjustments of CT machines have been made that allow for imaging of the standing horse. The risk of general anesthesia is eliminated and the shorter scan completion time reduces cost to clients. The objective of this retrospective, analytical study was to evaluate the technique, imaging diagnoses, feasibility, and image artifacts of multi-slice helical CT of horses' distal limbs acquired under standing sedation. The CT images of 250 horses of various breeds, aged 3-23 years, that underwent standing distal limb CT were evaluated. Three observers assessed the CT images for artifacts and inter-observer agreement was calculated. Eighty-six percent (95% confidence interval (CI), 81-90) of the scans were carried out on the forelimbs, while 14% (95% CI, 10-19) were of the hindlimbs. A total of 65% (95% CI, 59-71) of horses that underwent standing sedated CT had single imaging diagnoses. Seventy-one percent (95% CI, 65-77) of the cases had unilateral lesions, 27% (95% CI, 22-33) had bilateral lesions and 2% (95% CI, 1-4) had no diagnosed lesions. The average CT acquisition time was 17.5 minutes (range = 15-20). The average number of acquisitions per horse was 1.7 (median = 1; range = 1-4). There was good to excellent agreement between all three observers for the presence of motion artifact in the metacarpo/metatarsophalangeal joints, identification of marked beam hardening artifact, mild solar/ skin dirt, and photon starvation artifact (kappa 0.61-0.80). No complications were encountered. Standing examination of the distal limb achieved diagnostic image quality that was obtained with minimal acquisition attempts and in a timely manner.

Unilateral, Rostral Maxillary Sinusitis Resulting from Displacement and Retention of an Alveolar Plug in a 4-Year-Old Horse.

Sinusitis is a common occurrence in horses and often develops secondary to dental disease. Extraction of cheek teeth in horses is associated with variable degrees of complications and although postoperative displacement and retention of alveolar plugs has been identified as one such potential complication, few cases of resulting sinusitis have been reported. This manuscript describes a four-year-old Thoroughbred mare that was presented for chronic unilateral left-sided mucopurulent nasal discharge after extraction of the left maxillary second molar tooth two months earlier. Radiographic and computed tomographic (CT) examinations revealed a well circumscribed, soft tissue opacity in the left rostral sinus compartment. Intraoral examination revealed feed impacted in the alveolus of the extracted tooth and an oral sinus fistula. Upper airway endoscopy showed thick, purulent material at the nasomaxillary aperture. Sinoscopy showed unexpectedly clean frontal, dorsal conchal and caudal maxillary sinuses. The alveolar dental plug associated with previous exodontia became apparent within the sinus and was removed through the sinoscopy portal. Repeat endoscopies confirmed progressive clearance of the sinusitis during hospitalization. Unilateral nasal discharge returned three months later. An abscess within the sinus had formed. Complete resolution of the sinusitis was achieved after lancing the abscess and further sinus lavage. Sinoscopy through a frontal sinus trephination portal proved useful in diagnosis and treatment. Detailed evaluation of structures allowed for rapid establishment of adequate drainage and communication between all sinus compartments without osteoplastic surgery.

Radiographic and CT features of zygomatic arch pneumatization in a Thoroughbred with a recurrent progressive ethmoid hematoma.

A 7-year-old Thoroughbred gelding presented with a history of mild unilateral right-sided epistaxis and facial swelling over the right caudal maxillary sinus and zygomatic arch. Eleven months previously a progressive ethmoid hematoma had been surgically removed from the right caudal maxillary and conchofrontal sinus. Computed tomography identified a large expansile soft-tissue attenuating mass in the right caudal maxillary sinus, with protrusion into the conchofrontal sinus, that extended into the zygomatic arch. Lytic expansion and thinning of the cortex with pneumatization of the zygomatic arch was present. The mass was surgically excised after a biopsy had confirmed the recurring progressive ethmoid hematoma.

Micro-anatomy of the ear of the southern white rhinoceros (Ceratotherium simum simum).

The white rhinoceros is the largest of the five extant rhinoceros species. The population is declining rapidly because of intense poaching. However, normal anatomical descriptions in this species are lacking. The purpose of this study is to describe the osseous anatomy of the middle and inner ear of the southern white rhinoceros using micro-focus X-ray computed tomography imaging. Four temporal bones obtained from two 1-day old southern white rhinoceros preserved in 10% formalin were scanned. Tri-dimensional reconstructions were obtained and volumes of the middle ear ossicles and inner ear structures were calculated. Excellent high spatial resolution 3D images were obtained for all samples and virtual models of the auditory ossicles and bony labyrinth were generated. Visualization of the tympanic membrane, middle ear and inner ear structures was possible in all samples. Whereas the stapes and incus had a shape similar to their human or equine counterparts, the malleus showed a unique appearance with a long rostral branch projecting latero-distally to the manubrium. The cochlea described 2 turns rostro-laterally around its axis, with a medial direction of rotation. However, identification of the soft tissue structures of the middle ear was sometimes difficult and visualization of the small structures of the membranous labyrinth was not possible using this formalin fixation and alternative techniques should be investigated. Further investigations are needed in order to provide a complete virtual model including both soft and bone tissues of this difficultly accessible region.

Ex Vivo Assessment of an Ultrasound-Guided Injection Technique of the Lumbosacral Disc in the Horse.

OBJECTIVES: The aim of this study was to describe an ultrasound-guided injection technique of the lumbosacral disc in horses through the cranial vertebral notch of the sacrum and to evaluate both accuracy and potential complications of the technique on equine cadavers. MATERIALS AND METHODS: Twenty-four injections of the lumbosacral area were performed on 12 equine cadavers shortly after euthanasia under ultrasound guidance with the horse in recumbency using two different dyes (one colour for each side). The lumbosacral area was dissected in each horse and the accuracy of the technique, as well as its potential complications, was evaluated detecting the dyes and the structures that have been coloured. RESULTS: The lumbosacral area was correctly reached in only 11/24 injections. However, this technique allowed a lumbosacral peridiscal injection in 7/12 horses. The main difficulty was reaching the ventral opening of the L6-S1 intervertebral foramen that is partially hidden by the iliac wing on ultrasound. Puncture of the vertebral canal has been observed in 11/24 cases. The L6 spinal nerve roots emerging through the intervertebral foramen could potentially be damaged when inserting the needle. CLINICAL SIGNIFICANCE: The described ultrasound-guided technique allows peridiscal injection in the lumbosacral space in less than 60% of cases with potential sciatic nerve damage. Further investigations are warranted before using this technique in clinical practice in horses suffering from lumbosacral lesions.

A bilateral sinus cyst treated via a bilateral frontonasal bone flap in a standing horse.

Bilateral paranasal sinus diseases are rarely reported in horses. Treatment using a bilateral frontonasal bone flap on a standing, regular-sized adult horse has not been described previously. A 13-year-old Thoroughbred gelding was evaluated for bilateral mucopurulent nasal discharge. Radiographic, endoscopic and computed tomographic examinations revealed bilateral sinus pathological changes consistent with an ethmoid haematoma involving the maxillary and frontal sinuses. A bilateral frontonasal bone flap was created under standing sedation and local anaesthesia. A tracheotomy was performed initially to ensure a patent airway during the procedure. Additional analgesia had to be given to transect the dorsal part of the nasal septum while elevating the flap. The sinus masses were removed and communications with the nasal cavities created uneventfully. Small sequestra were removed transendoscopically from the left caudal maxillary sinus 4 weeks after the initial procedure. The horse made a complete recovery with an excellent cosmetic outcome. Histopathology revealed the mass to be a sinus cyst. We concluded that a bilateral sinus bone flap can be used in adult regular-sized horses to access the left and right paranasal sinuses simultaneously. Regional nerve blocks should be performed in order to increase analgesia. A temporary tracheotomy prevents any airway obstruction during the procedure. The post-operative cosmesis is excellent.

Surgical removal of a gastric trichophytobezoar in a foal.

This report describes a rare case of gastric impaction caused by a trichophytobezoar in a foal. This case highlights the difficulty in diagnosing this condition and reports surgical removal via a gastrotomy after failure of medical treatment.

Ablation chirurgicale d'un trichophytobézoar gastrique chez un poulain. Ce rapport décrit un rare cas d'obstruction gastrique causé par un trichophytobézoar chez un poulain. Ce cas souligne la difficulté à diagnostiquer cette affection et fait rapport sur l'ablation chirurgicale lors d'une gastrotomie après l'échec du traitement médical.(Traduit par Isabelle Vallières).

Complications and risk factors of castration with primary wound closure: Retrospective study in 159 horses.

Castration with primary wound closure reportedly has lower complication rates and shorter recovery periods compared to castration with second intention healing. However, little is known about risk factors associated with complications using primary wound closure. Medical records of 159 horses castrated and having primary wound closure were reviewed. Main short-term complications were: scrotal hematoma in 12 horses (7.6%), signs of colic in 6 horses (3.8%), fever in 4 horses (2.5%), and peri-incisional edema in 3 horses (1.9%). As for long-term complications, 24 out of 105 (23%) horses sustained some form of edema. One horse was euthanized because of a suspected inguinal abscess. Among tested parameters, horses aged 3 to 6 years old and French trotters appeared to be more at risk of developing complications. Intraoperative ligation of the cremaster muscle and use of electrocautery prevented complications. Overall, client satisfaction was excellent (98%).

Complications et facteurs de risque de la castration avec fermeture des plaies par première intention : étude rétrospective chez 159 chevaux. La castration avec fermeture des plaies par première intention a un taux de complications plus faible et une période de convalescence plus courte que la castration avec cicatrisation par seconde intention. Cependant, on en sait peu sur les facteurs de risque associés aux complications en utilisant la technique de fermeture des plaies par première intention. Les dossiers médicaux de 159 chevaux castrés de cette façon ont été examinés. Les complications à court terme sont les suivantes: hématome scrotal chez 12 chevaux (7,6 %), signes de coliques chez 6 chevaux (3,8 %), fièvre chez 4 chevaux (2,5 %) et de l'œdème péri-incisionel chez 3 chevaux (1,9 %). En ce qui concerne les complications à long terme, 24 sur 105 (23 %) chevaux ont présenté un certain degré d'œdème. Un cheval a été euthanasié à cause d'un probable abcès inguinal. Parmi les paramètres testés, les chevaux âgés de 3 à 6 ans et les Trotteurs Français semblent être plus à risque de développer des complications. En outre, la ligature peropératoire du muscle crémaster et l'utilisation du bistouri électrique semblent prévenir les complications. Dans l'ensemble, la satisfaction des clients était excellente (98 %).(Traduit par les auteurs).

Laparoscopic Evaluation of Umbilical Disorders in Calves.

OBJECTIVE: To describe a laparoscopic technique for evaluating umbilical disorders in calves, including feasibility, visualization of umbilical structures, and related complications. STUDY DESIGN: Prospective clinical study. ANIMALS: Male calves (15 Holstein, 2 Montbeliard) with umbilical disorders (n=17). METHODS: Calves <2 months old with obvious umbilical disease were assessed by clinical examination and ultrasonography of the umbilical structures. Laparoscopic evaluation was performed in dorsal recumbency under subarachnoid lumbosacral anesthesia and sedation. An open insertion technique with short 60 mm cannulas was used after creating 2 portals 10 cm cranial to the umbilicus (one 5 cm left of midline for the laparoscope and one 5 cm right of midline as an instrument portal). After laparoscopy, abnormal tissues were resected by laparotomy during the same anesthetic period. RESULTS: Laparoscopic evaluation of umbilical structures was performed quickly (mean surgery time 7.1 ± 2.5 minutes). Umbilical structures could be completely visualized in all calves without intraoperative complications. In addition to abnormalities previously detected on ultrasound, laparoscopy enabled detection of adhesions 7 calves that were not suspected on ultrasound, as well as focal enlargements of the umbilical arteries and urachus close to the bladder in 5 calves. Laparoscopy failed to detect abnormalities observed with ultrasound or laparotomy in 4 calves, including small hernias and omphalitis. CONCLUSION: Laparoscopic evaluation of umbilical structures was performed safely and quickly in young calves and allowed complete evaluation of intra-abdominal umbilical structures and may, therefore, be a useful adjunct to physical examination and ultrasound to fully assess the abdomen in calves.

A case of facial deformity due to bilateral developmental maxillary cheek teeth displacement in an adult horse.

A 7-year-old mare presented with facial deformities associated with oral discomfort and weight loss was found to have bilateral, palatal, developmental displacements of the maxillary 08s, with secondary diastema. Following repulsion of both displaced teeth, the horse regained weight and resumed training. Bony deformities remained visible 9 mo after discharge.