Correlation of Clinical, Radiographic, and Surgical Localization of Intervertebral Disc Extrusion in Small-Breed Dogs: A Prospective Study of 50 Cases

Objective —To compare prospectively clinical, radiographic, and surgical findings of intervertebral disc extrusion (IDE) localization in small-breed dogs and to determine the best means of lesion localization for the purpose of hemilaminectomy. Study Design —Clinical, radiographic, and surgical findings of small-breed dogs with thoracolumbar IDE were prospectively compared for agreement on lesion localization. Sample Population—50 small-breed dogs with IDE treated at the three participating veterinary hospitals were included in the study if no other confounding diseases were identified and if the owner gave permission for diagnostic tests and surgery. Methods —Clinical and surgical findings were recorded by the surgeon assigned to the case. Radiographic studies were evaluated independently by two radiologists blinded as to the clinical and surgical findings. values and 95% confidence intervals were calculated for agreement on lesion localization by clinical, radiographic, and surgical means and for agreement between radiologists. Results —K values for agreement of lesion localization were as follows: clinical versus surgical, 0.595; radiologist A versus radiologist B, 0.81; radiologist A versus surgical findings, 0.60; radiologist B versus surgical findings, 0.71. Both radiologists' interpretation of IDE localization agreed with surgical localization in 60% of cases. Conclusions —Clinical lateralization of IDE was found to be the least reliable factor of those studied for determining on which side the hemilaminectomy should be performed. Results of this study differ from those of previous studies examining the reliability of myelography to localize the site of IDE accurately. The results of this study further suggest that surgery may not be an absolute standard for determination of the localization of IDE in small-breed dogs. Clinical Relevance —Intervertebral disc extrusion in small-breed dogs frequently results in bilateral distribution of extruded material. Computed tomography or magnetic resonance imaging may be necessary to delineate completely the distribution of extruded disc material in IDE.     

THE DIAGNOSIS AND EPIDEMIOLOGY OF AN INFERTILITY DISEASE IN THE FEMALE KOALA

A radiographic technique, incorporating pneumoperitoneum, was developed to aid in identification of cyst-like structures in the reproductive tract of female koalas. These lesions, including pyometra and fluid-filled cysts associated with the upper reproductive tract, were viewed as radiopacities with clearly demarcated margins lateral to the caudal lumbar vertebrae. This technique provided a means of assessing with a high degree of reliability the incidence and distribution of this condition in various populations of koalas throughout eastern and southern Australia. A radiographic survey of 237 adult female koalas revealed a 43% (101/237) incidence of this condition, which is closely correlated with the lack of reproductive success observed in some populations of koalas in the wild. Although the etiology of this condition is little understood at present, the isolation of Chlamydia psittaci from the reproductive tracts of affected koalas, both male and female, is recorded.     

Risk Factors for Incisional Complications after Exploratory Celiotomy in Horses: Do Skin Staples Increase the Risk?

Objective: To assess risk factors for celiotomy incisional infection in horses, especially the use of staples for skin closure. Study Design: Case series. Animals: Horses (n=356) that had 1 exploratory celiotomy for colic and survived >2 weeks after surgery between March 1, 2004 and December 31, 2007. Methods: Incisions were classified as “normal” (no complication, only edema, serous drainage lasting <24 hours) or as “surgical site infection (SSI)” (persistent serosanguinous drainage or purulent drainage with or without positive bacterial culture). All possible risk factors, including method of skin closure (monofilament sutures or staples), were statistically analyzed using univariate and multivariate logistic regression. Results: Of 356 horses, 303 (85%) had normal wound healing and 53 (15%) developed a SSI (purulent: 48 [14%]; persistent serosanguinous: 5 [1%]). Bacterial cultures were positive in 33 of 40 cases. Factors significantly associated with SSI in the multivariate analysis were: use of staples for skin closure (odds ratio [OR] 3.85, P<.001) and surgical site closure by a 1st or 2nd year resident (OR 2.20, P=.016). Lavage of the linea alba with sterile saline solution after closure was a protective factor (OR 0.38, P=.004). Conclusion: Use of staples for skin closure and less experienced surgeons closing the abdomen are risk factors for incisional infection. Incisional lavage after linea alba closure was a protective factor. Clinical Relevance: Despite their ease and speed of application, skin staples can lead to an increase in celiotomy wound complications in horses.     

Replacement of the Medial Collateral Ligament with Polypropylene Mesh or a Polyester Suture in Dogs

The medial collateral ligament of one stifle in 20 adult dogs was excised and replaced with polypropylene mesh or a polyester suture. After 26 weeks, the fibrous tissue-prosthesis composites were evaluated clinically, morphologically, and biomechanically. Clinical lameness was not significantly different after 10 days. The polypropylene mesh reconstructions consistently had more fibrous tissue and greater collagenous ingrowth than the polyester suture reconstructions. There were four complications related to fixation of the polypropylene mesh prosthesis and one to the polyester suture. The polypropylene mesh reconstructions had greater stability and were biomechanically more similar to the natural ligaments than the polyester suture reconstructions. Although the results with polypropylene mesh were favorable, more challenging biomechanical testing and alternative anchoring techniques are required before polypropylene mesh can be recommended as a collateral ligament replacement in dogs.     

The effect of forced exercise on development of heart, lung and diaphragm muscle in weanling horses

Eleven weanling Quarter Horses were separated into two treatment groups, EX = exercise (n=5) and NEX = non-exercise (n=5). At 150 days-of-age, EX horses were started on a 120-day exercise conditioning program. Horses were exercised over a sandy track using a mechanical walker at 3 m/second for from 3.4 to 34.0 minutes/day, 5 days per week; they travelled in opposite directions on alternate days. Horses were weighed and measured for height at the withers at the beginning and end of the study. Homes were euthanized at approximately 270 days-of-age. Rump fat thickness was measured, and heart, lung and diaphragm muscles were removed, dried to constant weight and expressed as percent of body weight or in ratio to height at the withers.     

Effect of Experience on Adrenocortical and Thyroid Responses of Arabian Horses to Gymkhana Games

Gymkhana is an equestrian event consisting of speed pattern racing and timed games for riders on horses. The aim of the study was to evaluate the effects of gymkhana competition on total cortisol and total and free iodothyronine changes in 23 Arabian purebred horses, by taking into account the effects of previous sport experience on gymkhana riding events. Compared with pre-competition values, an increase of total cortisol concentration has been observed in experienced horses at 30 minutes (P < .001) after exercise and in inexperienced horses both at 5 minutes (P < .05) and at 30 minutes (P < .01) after exercise. Compared with pre-competition values, an increase of total triiodothyronine (T₃) concentration has been observed in experienced horses at 5 minutes (P < .05) after exercise. Data obtained showed that gymkhana riding events induced differential adrenocortical and thyroid responsiveness according to previous experience of sport horses. Hence, cortisol and iodothyronine patterns may provide additional information for the monitoring of gymkhana riding performance.     

RADIOGRAPHIC AND PATHOLOGIC FEATURES OF OSTEOPETROSIS IN TWO PERUVIAN PASO FOALS

The radiographic and pathologic findings of two Peruvian Paso foals with osteopetrosis are described. Both foals, one male and one female, presented with respiratory difficulty, brachygnathia and failure to rise after birth. Both foals were mildly anemic, hypogammaglobulinemic and had elevations in serum alkaline phosphatase. Increased medullary bone opacity was noted on radiographs of the extremities, spine and skull in both foals. A lack of normal cortical:medullary bone distinction was evident radiographically. The medullary primary spongiosa appeared to run in parallel columns away from the physes of all long bones and the vertebrae. This created a distinctive hour glass appearance to the osteopetrotic bones. One foal developed a bacterial pneumonia. Both foals were euthanized due to failure to thrive. Histopathology and electron microscopy documented these foals to have normal osteoclastic numbers but lack normal ruffled borders, lack of a clear zone and normal lysosomal numbers indicative of cellular dysfunction. These clinical, radiographic and pathologic findings are similar to the juvenile, lethal autosomal recessive form of osteopetrosis described in humans. Osteopetrosis has not been previously described in a female foal.