Evaluation of Canine Cortical Bone Graft Remodeling

A stable cortical bone fracture model was developed to evaluate the remodeling rate of cortical bone grafts. Samples of cortical bone were harvested with a trephine and press fit into predrilled holes in the femoral diaphyses of four live dogs. The percentages of new bone, unremodeled graft bone, porosity, forming bone surface area, and resorbing bone surface area were determined morphometrically and compared in cortical autografts, cortical allografts sterilized with 84% ethylene oxide (EO), and allografts sterilized with 12% EO. The host-graft interfaces healed without formation of fibrous tissue or cartilage, indicating a stable fracture surface. The amount of new bone formed in cortical autografts and allografts sterilized with 84% EO was significantly greater than the amount of new bone in allografts sterilized with 12% EO. There was no significant difference between the amounts of new bone formed in the allografts sterilized with 84% EO and the cortical autografts. No significant differences were detected in percentages of porosity or bone surface areas.     

Exploratory Celiotomy in 200 Nontraumatized Dogs and Cats

Two hundred dogs and cats undergoing exploratory celiotomy for reasons other than trauma were grouped by disease classification and by body system affected. There were 61 animals in which infection or inflammation predominated, 63 animals with neoplasia, and 76 animals with noninflammatory and non-neoplastic conditions. Body systems affected were digestive, lymphatic, urinary, reproductive, other, and undetermined. Seventy-three percent of the animals survived the hospitalization period; survival rates for animals with infection or inflammation, neoplasia, and other disorders were 69%, 60%, and 86%, respectively. Within the same groups, the exploratory celiotomy provided strictly diagnostic information in 72%, 79%, and 24% of the animals, and surgical treatment was provided to 28%, 21%, and 58% of the animals, respectively. Intraoperative cytologic and histologic diagnoses were consistent in 78% of the animals; the consistency rates for animals with infection or inflammation, neoplasia, and other disorders were 81%, 88%, and 59%, respectively. Complications after surgery were observed in 30% of the animals, with 60% of the complications disease related. Complications were observed in six animals with reproductive disorders (67%), six animals with urinary disease (46%), 35 animals with digestive disease (29%), and three animals with lymphatic disease (13%).     

Comparison of Fine-Needle Aspiration and Surgical-Tissue Biopsy in the Diagnosis of Canine Brain Tumors

OBJECTIVE: To compare the diagnoses obtained using fine-needle aspiration (FNA) and surgical-tissue biopsy of focal cerebral masses with the histologic diagnoses obtained via necropsy. STUDY DESIGN: A prospective case series. SAMPLE POPULATION: Ten client-owned adult dogs of various breeds. All dogs had clinical signs of cerebral disease and had a focal brain mass identified using magnetic resonance imaging; all were eventually euthanatized. METHODS: Immediately after euthanasia, the brains were removed en bloc from the cranial cavity. FNAs were obtained from each mass using a 22-gauge hypodermic needle and a 12-mL syringe. Cytologic preparations were made from each aspirate. A 14-gauge Tru-cut biopsy needle was used to obtain a core tissue sample from each mass. The biopsy specimens were fixed in 10% buffered formalin and submitted for histologic evaluation. The brains were similarly fixed and stained. Six-micrometer-thick transverse sections of the brain were examined microscopically. RESULTS: Neoplasia was confirmed in all dogs histologically in the 6-microm transverse sections. Four meningiomas, 2 astrocytomas, 2 oligodendrogliomas, 1 pituitary adenocarcinoma, and 1 neurofibrosarcoma were identified. FNA correctly identified all of the masses as neoplastic. Cytologic diagnoses correlated with the histologic interpretation in 5 of the masses (50%). Tru-cut biopsy specimens identified all 10 masses as neoplastic; in 9 of the 10 (90%), the diagnosis correlated with the histologic diagnosis. CONCLUSIONS AND CLINICAL RELEVANCE: FNA is a sensitive method that can be used to determine the presence of neoplasia in the brain, but is not as definitive as the Tru-cut biopsy in determining the specific type of cerebral neoplasm.     

Incarceration of the Small Intestine in the Epiploic Foramen Report of 19 Cases (1983–1992)

The medical records of 19 horses referred for colic and subsequently found (18 confirmed, 1 suspected) to have small intestinal incarceration through the epiploic foramen were reviewed. These horses were of various ages and breeds; they had clinical signs of colic for an average duration of 13.5 hours before examination. Seventeen horses had nasogastric reflux, and 15 had palpable small intestinal distention. Three horses were killed during surgery because of severe intestinal damage. Of the remaining 16 horses, 13 required intestinal resection and anastomosis. The length of incarcerated small intestine varied from 8 cm to 17.6 m. The ileum was involved in 12 cases. In one horse, the mesoduodenum was disrupted before surgery, causing intra-abdominal bleeding; incarceration of bowel was not found during surgery. The short-term (1 month) survival rate was 74% (14 of 19 cases), and the long-term survival rate was 63% (12 of 19 cases). The follow-up period was 3 months to 45 months (mean 17.2 ± 7.2 months).     

Complete atrioventricular canal defect in a foal: Clinical and pathological features

Atrioventricular (AV) canal defects comprise a rare category of congenital heart disease associated with abnormal development of the endocardial cushions. These anomalies include a broad spectrum of lesions involving the atrial septum primum, the inlet portion of the ventricular septum, and the atrioventricular valves. In severe cases heart failure may result. The present report describes cardiopulmonary findings in a six-week-old, female Thoroughbred foal with persistent tachypnea and tachycardia since birth. Clinical, echocardiographic, cardiac catheterization, and pathologic findings were compatible with complete AV canal defect with bi-directional shunting, congestive heart failure, and pulmonary hypertension. Gross cardiac pathologic findings included a large atrioventricular septal defect, a common atriovalvular orifice, five atrioventricular leaflets, with two free-floating bridging leaflets. Histopathologic lesions in the lung included hypertrophy of the pulmonary arteriolar walls due to thickening of the tunica media. This represents a well documented case of complete endocardial cushion defect with anomalous development of the atrioventricular valves and resultant pulmonary hypertension and heart failure.     

Behavioral responses following eight anesthetic induction protocols in horses

Objective To compare behavioral characteristics of induction and recovery in horses anesthetized with eight anesthetic drug protocols. Study design Randomized prospective experimental study. Animals Eight horses, 5.5 ± 2.4 years (mean ± SD) of age, and weighing 505 ± 31 kg. Methods After xylazine pre‐medication, each of eight horses was anesthetized on four occasions using one of eight different anesthetic induction protocols which incorporated various combinations of ketamine (KET), propofol (PRO), and thiopental (THIO): THIO 8 mg kg^?1; THIO 6 mg kg^?1 + PRO 0.5 mg kg^?1; THIO 4 mg kg^?1 + PRO 1 mg kg^?1; THIO 2 mg kg^?1 + PRO 1.5 mg kg^?1; KET 2 mg kg^?1; KET 1.5 mg kg^?1 + PRO 0.5 mg kg^?1; KET 1 mg kg^?1 + PRO 1 mg kg^?1; KET 0.5 mg kg^?1 + PRO 1.5 mg kg^?1. Quality of induction and recovery were scored from 1 (poor) to 5 (excellent), and time taken to achieve lateral recumbency, first movement, sternal recumbency, and standing were evaluated. Results Time taken to achieve lateral recumbency after drug administration differed significantly (p < 0.0001) among the various combinations, being shortest in horses receiving THIO‐8 (mean ± SD, 0.5 ± 0.3 minutes) and longest in horses receiving KET‐2 (1.4 ± 0.2 minutes). The best scores for induction quality were associated with KET‐1.5 + PRO‐0.5, and the worst scores for induction quality were associated with KET‐2, although the difference was not significant. Time to first movement varied significantly among drug protocols (p = 0.0133), being shortest in horses receiving KET‐2 (12.7 ± 3.6 minutes) and longest in horses receiving THIO‐8 (29.9 ± 1.5 minutes). Horses receiving THIO‐8 made the greatest number of attempts to attain sternal posture (6.5 ± 4.7) and to stand (1.6 ± 0.8). Horses in the THIO‐8 treatment also received the poorest recovery scores (3.3 ± 1.0 and 3.0 ± 0.7 for sternal and standing postures, respectively). The best recovery scores were associated with combinations comprised mainly of propofol. Conclusions Combining propofol with either ketamine or thiopental modifies behaviors associated with use of the individual drugs. Clinical relevance Quality of early anesthesia recovery in horses may be improved by some combinations of propofol with either thiopental or ketamine.     

Cytologic and Histopathologic Evaluation of Extruded Canine Degenerate Disks

Objective— To describe the cytologic and histopathologic appearance of degenerate disk material in dogs with Hansen type I intervertebral disk disease (IVDD).
Study Design— Case series.
Animals— Dogs (n=45) that had surgical intervention for Hansen type I IVDD (January–November 2007).
Methods— Impression smears and histopathologic sections were prepared from surgically removed degenerate disk material. All slides were evaluated for overall cellularity, quantity and attributes of extracellular matrix, types of cells present, and their cytomorphology. Histopathologic sections were also examined for presence of neovascularization and hemorrhage.
Results— Cytologically, 11 of 45 samples consisted of only extracellular matrix, 30 had evidence of inflammation, and 20 contained dysplastic spindloid cells. Histologically, hyaline cartilage predominated in 35 of 45 samples, fibrocartilage in 4, and spindloid cells in 6; 37 of 45 were inflamed, 37 were hemorrhagic, and 13 had neovascularization.
Conclusions— The cytologic and histopathologic appearance of extruded degenerate disk material in dogs is variable and can include dysplastic spindloid cells.
Clinical Relevance— The variability in cytologic findings and frequent presence of dysplastic spindloid cells suggest that cytology alone may not be a reliable tool to differentiate degenerate canine disk material from a mesenchymal neoplasm.     

Chemonucleolysis with Collagenase A Radiographic and Pathologic Study in Dogs

Collagenase, a proteolytic enzyme, was injected intradiscally in nine clinically normal, middle-aged beagles. Calcium chloride diluent solution (control), 100 ABC units of collagenase, and 250 ABC units of collagenase, were injected in randomly selected intervertebral discs (T13-L1 to L5-L6). On day 11, the discs injected with collagenase were narrowed radiographically, but there was no significant change in myelograms. Grossly and histologically, there was dissolution of the intervertebral discs, mainly nucleus pulposus, and protrusion of nucleus material in the vertebral body through bony end-plates in discs injected with collagenase. Collagenase chemonucleolysis may be an alternative to spinal surgery for intervertebral disc protrusion in dogs.