Stabilization of Sacroiliac Luxation in 40 Cats Using Screws Inserted in Lag Fashion

Objective: To (1) identify prognostic indicators for stability after stabilization of sacroiliac luxation with screws inserted in lag fashion and (2) report dorsoventral dimensions of the sacrum in cats. Study Design: Multicenter retrospective study. Sample Population: Cats (n=40) with sacroiliac luxation. Methods: Case records and radiographs of cats presented at the Queen's Veterinary School Hospital Cambridge and the Royal Veterinary College Hatfield for screw fixation of sacroiliac luxation were reviewed. Dorsoventral dimensions of 15 feline cadaveric sacral bodies were measured to identify the appropriate implant size for use in fixation with screws inserted in lag fashion. Results: Of 40 cats, 13 had left, 14 right, and 13 bilateral sacroiliac luxations. Of 48 screws analyzed, 42 (87.5%) were placed within the sacral body or exited ventrally and 6 (12.5%) were considered malpositioned. Screw purchase within the sacrum was statistically different between unstable and stable repairs (P=.001). Using confidence intervals for screw length within the sacrum and effect on stability, the lowest screw depth that contained 95% of the screws that did not loosen was ∼60% of the sacral width. Mean dorsoventral sacral dimension at its narrowest point was 5.9±1.14 mm. There was no significant difference in the incidence of implant loosening between those luxations that were 100% reduced and those that were <100% reduced (P=.7837). Conclusions: Screw purchase within the feline sacrum of at least 60% of the sacral width significantly reduces the risk of loosening. Clinical Relevance: Screw placement to a depth of 60% of the width of the feline sacrum is recommended.     

Evaluation of Closed Reduction and Screw Fixation in Lag Fashion of Sacroiliac Fracture‐Luxations

Objective— To evaluate outcome by radiographic assessment after closed reduction and percutaneous screw fixation in lag fashion of sacroiliac fracture‐luxations in dogs. Study Design— Retrospective study. Animals— Dogs (n=24) with sacroiliac fracture‐luxations. Methods— Medical records (1999–2006) and radiographs of 24 dogs (29 fracture‐luxations) that had stabilization of sacroiliac fracture‐luxation by fluoroscopic‐guided closed reduction and percutaneous screw fixation in lag fashion were reviewed. Signalment, body weight, number, and location of all concurrent injuries and implants used for repair were recorded. Radiographs were used to evaluate the accuracy of screw placement in the sacral body, screw depth/sacral width ratio, reduction of the sacroiliac joint, pelvic canal diameter, and hemipelvic canal width. Radiographic re‐examination (range, 4 to >8 weeks postoperatively) was available for evaluation. Results— Mean screw depth/sacral width ratio on immediate postoperative and re‐examination radiographs was 64% and 61%, respectively. Mean percentage reduction of the sacroiliac joint on immediate postoperative and re‐examination radiographs were 91% and 87%, respectively. Pelvic canal diameter ratio demonstrated successful restoration of the pelvic canal. Hemipelvic canal width ratio documented successful closed reduction repair independent of concurrent pelvic injuries. Conclusion— Successful repair of sacroiliac fracture‐luxations, determined by radiographic assessment, can be achieved by fluoroscopic‐guided closed reduction and percutaneous screw fixation in lag fashion. Clinical Relevance— Fluoroscopic‐guided closed reduction and percutaneous screw fixation in lag fashion of sacroiliac fracture‐luxations is a minimally invasive technique that restores and maintains pelvic canal dimensions and should be considered as an alternative to open reduction or nonsurgical management of sacroiliac fracture‐luxations.     

The Surgical Anatomy of the Canine Sacrum for Lag Screw Fixation of the Sacroiliac Joint

One hundred canine sacral bone specimens were examined to identify surgical landmarks that may improve screw placement in sacroiliac repair. A lateral view of the sacral wing was studied, as this structure is most easily identified in the dorsal approach used for sacroiliac repair. The height and length of each sacral wing were measured. Four other features of the canine sacrum were identified and measured in comparison with the sacral wing height and length. The cranial overlap of the sacral wing over the intervertebral space of L₇-S₁ was found to have a mean of 14% of the length of the sacral wing. The ventral overlap of the sacral wing over the pelvic canal was found to be 21% of the height of the sacral wing. The ventral limit of the spinal canal (dorsal limit of the sacral body) was 45% of the sacral wing height. The first pelvic foramen was located at a mean distance of 64% of the sacral wing length and 20% of the sacral wing height. Using these four features, a composite view of the sacral wing is described to illustrate the area of the sacral body where screw placement is optimal.     

A Lateral Approach for Screw Repair in Lag Fashion of Spiral Third Metacarpal and Metatarsal Medial Condylar Fractures in Horses

Objective— To describe a lateral approach for screw fixation in lag fashion of simple spiral medial condylar fractures of the third metacarpus/metatarsus (MC3/MT3).
Study Design— Case series.
Animals— Thoroughbred racehorses (n=9).
Methods— Nondisplaced medial MC3/MT3 condylar fractures (3 thoracic, 6 pelvic limbs), with mean length 126 mm (range, 91–151 mm) were repaired by internal fixation, under general anesthesia, using multiple 4.5 mm cortical screws inserted in lag fashion from the lateral aspect of the limb, using radiographic or fluoroscopic guidance. Horses were recovered from anesthesia in half-limb casts; 7 unassisted and 2 using a rope-recovery system. Horses had 2 months box rest, 1 month in-hand walking, and follow-up radiographic examination at 3 months.
Results— Horses recovered uneventfully from anesthesia. Five horses raced; 1 returned to training, was persistently lame, and was retired to stud; 2 were retired directly to stud; and 1 horse was lost to follow-up.
Conclusions— MC3/MT3 medial condylar fractures were successfully repaired by screws inserted n lag fashion form the lateral aspect.
Clinical Relevance— Use of a lateral approach to medial condylar MC3/MT3 fractures allows screw insertion perpendicular to the fracture plane without interference with palmar/plantar soft tissue structures or from the splint bones. Although repair was performed under general anesthesia, the technique should be adaptable to application in standing horses.     

Lag Screw Fixation of a Sagittal Fracture of the Third Carpal Bone in a Horse

A sagittal fracture of the third carpal bone of a Standardbred racehorse was repaired with lag screw fixation. Healing of the fracture was uncomplicated, and the horse made a successful return to racing. It was concluded that selected sagittal fractures of the third carpal bone may be treated successfully with lag screw fixation. Criteria for selection of cases include fragment size and orientation of the fracture plane.     

Use of Computed Tomography in Standing Position to Identify Guidelines for Screw Insertion in the Distal Phalanx of Horses: An Ex Vivo Study

Objectives— To compare the precision of radiography and computed tomography (CT) preoperatively in the standing position for identification of guidelines for screw insertion in the distal phalanx, and to identify whether standing CT might improve operative time compared with preoperative radiographic planning.
Study Design— Experimental ex vivo study.
Animals— Cadaveric equine thoracic limb pairs (n=10).
Methods— Insertion of a 4.5 mm cortex screw in lag fashion into an intact distal phalanx was evaluated in 2 groups (n=10) of cadaveric equine thoracic limbs. In 1 group, the site, direction, and length of the implant were determined by radiography, and in the other group, by CT. Accuracy of screw placement was verified by specimen dissection. Outcomes were (1) absence of penetration of the articular surface, the solar surface, or the semilunar canal (2) appropriate length and direction of the screw. Surgical time was also measured.
Results— No screw penetrated the articular surface, the solar surface, or the semilunar canal in either group. CT was more accurate to identify guidelines for screw insertion (U=23.50, P =.049). With CT, surgical time (mean, 7.7 minutes) was significantly shorter (U=0.000, P =.000) than with radiography (mean, 12.7 minutes).
Conclusion— Standing CT can be used to accurately determine anatomic landmarks for screw insertion in lag fashion in sagittal fractures of the distal phalanx.
Clinical Relevance— This study has a clear clinical relevance for improved internal fixation of sagittal fractures of the distal phalanx.     

Arthrodesis of the Proximal Interphalangeal Joint in the Horse: A Cyclic Biomechanical Comparison of Two and Three Parallel Cortical Screws Inserted in Lag Fashion

Objective— To compare the biomechanical cyclic fatigue properties of 2 and 3 parallel transarticular 5.5 mm cortical screws used in arthrodesis of the proximal interphalangeal (PIP) joint.
Study Design— Randomized block design, for horse, fixation method (2 versus three 5.5 mm cortical screws), side (right, left) and end (front, hind) in cadaveric equine limbs.
Sample Population— Cadaveric adult equine fore- and hindlimbs (n=5 pairs each).
Methods— Two parallel 5.5 mm cortical screws were inserted in lag fashion, transarticularly through the PIP joint in 1 limb of a pair, and in the contralateral limb, three 5.5 mm cortical screws were inserted in similar fashion. Constructs were then tested in 3-point bending in a dorsal-to-palmar (plantar) direction using a materials testing machine using a cyclic load of −500 to −3500 N at a rate of 6 Hz.
Results— There was no significant difference in displacement at failure, force at failure or number of cycles between limbs. Forelimb constructs tended to fail at a greater mean displacement than hindlimb constructs but this difference was not significant ( P =.06). There was no statistical difference in any tested biomechanical variable between left- and right-sided limbs.
Conclusions— There was no significant difference in the number of cycles to failure for the 2 methods tested.
Clinical Relevance— Two 5.5 mm cortical screws inserted in parallel for PIP joint arthrodesis is surgically simpler, results in comparable biomechanical performance in the current model and should perform as well as three 5.5 mm screws under cyclic fatigue conditions.     

Nephroblastoma in a Cat: The Effects of Nephrectomy and Occlusion of the Caudal Vena Cava

Abstract— A nephroblastoma of the right kidney was observed in a young male cat. The affected kidney and a portion of the vena cava was surgically removed. After failure to establish a patent caval-portal shunt, it was found that the vertebral vein system functioned as a bypass for caval blood flow. Metastatic tumor which became apparent in the lungs and peritoneum five and eight months after ablation of the primary tumor was removed by excision biopsy.
Résumé—Un néphoroblastome du rein droit a é t é observé chez un jeune chat mâle. Le rein malade et une partie de la vena cava ont é t é enlevé chirurgicalement. Après un échec pour établir une anastomose caval-portal pérméable, on a trouvé que le système veineux vertébral fonctionnait comme un court-circuit pour le sang de la veine cave. Une tumeur métastatique apparue dans les poumons et le péritoine 5 et 8 mois après l'ablation de la tumeur a é t é enlevée par une biopsie d'exérèse.
Zusammenfassung— Ein Nephroblastom der rechten Niere wurde bei einem jungen Kater fest-gestellt. Die befallene Niere und ein Teil der Vena cava wurden chirurgisch entfernt. AIs es nicht gelungen war, eine offene Cava-Porta-Verbindung herzustellen, wurde festgestellt, dass das vertebrale Venensystem als Umgehung des Cavawegs diente. Metastatische Tumoren, die in den Lungen und im Peritoneum fünf und acht Monate nach der Entfernung des primären Tumors auftraten, wurden durch Excisionbiopsie entfernt.     

Sperm‐TALP: An Alternative Extender for Retrieving and Diluting Epididymal Sperm in the Domestic Cat

Effects of sperm‐TALP (TALP) on the quality of fresh‐extended and frozen‐thawed epididymal cat sperm were evaluated. The epididymides suspended in Tris–glucose–citrate solution (Tris), a conventional medium, and TALP were cut into small pieces to recover epididymal sperm. In experiment 1, the sperm pellets remained after centrifugation were re‐suspended (1 : 2, v/v) in Tris and TALP. The sperm quality in all four groups, that is, sperm retrieved with Tris (I and II) or TALP (III and IV) and diluted with Tris (I and III) or TALP (II and IV) was assessed. The sperm motility at the 0‐h incubation in TALP–TALP was superior to that of the rest (p < 0.001 to p = 0.04). At the 2‐h incubation, the motility in Tris/TALP–TALP was greater than that in Tris/TALP–Tris (p ≤ 0.001). In experiment 2, after centrifugation, the sperm pellets were added with freezing extenders and frozen. The thawed sperm previously retrieved from the epididymides with Tris and TALP were allotted so as not to further diluted (Tris/TALP–O) and to further diluted (1 : 1, v/v) with Tris (Tris/TALP–Tris) and TALP (Tris/TALP–TALP) and were evaluated the quality. At both incubation times, the motility of frozen‐thawed sperm recovered with TALP (TALP–O/Tris/TALP) was comparable with or significantly higher than that in the Tris groups (Tris–O/Tris/TALP; p = 0.003 to p > 0.05). The motility and viability of thawed sperm in Tris–Tris were significantly decreased during the 2‐h incubation (p = 0.007 for the motility and p = 0.01 for the viability). In both experiments, neither type of diluent (Tris vs TALP) nor incubation time (0 vs 2 h) significantly affected the sperm membrane integrity under hypo‐osmotic condition (p > 0.05). According to beneficial effects on the quality of fresh‐extended and frozen‐thawed sperm demonstrated, sperm‐TALP could be used as an alternative medium for recovering sperm from the epididymides and for diluting epididymal sperm in the domestic cat.     

Complications of Elective Ovariohysterectomies in the Dog and Cat at a Teaching Institution: Clinical Review of 853 Cases

DURING 1975–1978, 853 dogs and cats were presented to the New York State College of Veterinary Medicine (NYSCVM) at Cornell University for elective ovariohysterectomy (OVH). These cases did not include any surgery performed for pathologic reasons (such as pyometra or uterine injury). All the procedures were performed by fourth-year veterinary students under the direct supervision of attending interns or residents.     

Tick communities at the expanding wildlife/cattle interface in the Eastern Cape Province, South Africa: implications for Corridor disease

Corridor disease, transmitted by the brown ear tick (Rhipicephalus appendiculatus), is one of Africa's most pathogenic tick-borne diseases for cattle. With a focus on this species, we investigated the community parameters (richness, diversity and abundance) of ticks in the Eastern Cape, South Africa, and how this may be linked to the increasing wildlife/cattle interface in the region. There were significantly more ticks of a greater diversity and richness at sites positioned at the wildlife/cattle interface ('treatment sites') compared to sites where wildlife was absent (controls). Significantly, R. appendiculatus was only found at the treatment sites. Therefore, it is believed that the wildlife/cattle interface may be playing a crucial role in increasing the occurrence, abundance and distribution of R. appendiculatus in the Eastern Cape. The implications of a Corridor disease outbreak in the region are discussed.     

解读农业行业标准--无公害食品肉牛饲养兽药使用准则

本文通过对农业行业标准"无公害食品肉牛饲养兽药使用准则"进行解析,介绍了标准的内容和特点,并对有关问题进行了探讨,提出了实施无公害食品标准的建议.     

Pharmacology of the fluoroquinolones: a perspective for the use in domestic animals

The fluoroquinolones are a class of compounds that comprise a large and expanding group of synthetic antimicrobial agents. Structurally, all fluoroquinolones contain a fluorine molecule at the 6-position of the basic quinolone nucleus. Despite the basic similarity in the core structure of these molecules, their physicochemical properties, pharmacokinetic characteristics and microbial activities can vary markedly across compounds. The first of the fluoroquinolones approved for use in animals, enrofloxacin, was approved in the late 1980s. Since then, five other fluoroquinolones have been marketed for use in animals in the United States, with others currently under investigation. This review focuses on the use of fluoroquinolones within veterinary medicine, providing an overview of the structure-activity relationship of the various members of the group, the clinical uses of fluoroquinolones in veterinary medicine, their pharmacokinetics and potential interspecies differences, an overview of the current understanding of the pharmacokinetic/pharmacodynamic relationships associated with fluoroquinolones, a summary of toxicities that have been associated with this class of compounds, their use in both in human and veterinary species, mechanisms associated with the development of microbial resistance to the fluoroquinolones, and a discussion of fluoroquinolone dose optimization. Although the review contains a large body of basic research information, it is intended that the contents of this review have relevance to both the research scientist and the veterinary medical practitioner.