Comparison of radiographic scoring systems for assessment of bone healing after tibial plateau leveling osteotomy in dogs.

Introduction: Accurate radiographic assessment of bone healing is vital in determining both clinical treatment and for assessing interventions aimed at the promotion of bone healing. Several scoring systems have been used to evaluate osteotomy changes following tibial plateau leveling osteotomy (TPLO). The goal of this study was to compare the ability of five radiographic scoring systems to identify changes in bone healing following TPLO over time (Aim I), and to evaluate the influence of limb positioning on TPLO osteotomy scoring (Aim II). Materials and methods: Phase I-A randomized, blinded, prospective study was conducted using similarly positioned postoperative TPLO radiographs from seven dogs taken immediately postoperatively, 6-weeks, and 8-weeks postoperatively. Ten reviewers assessed the radiographs, and five different scoring systems were tested for each set including three previously published ones, a Visual Analog Score (VAS), and a subjective 11-point scale. For each system, responses for 6-week postoperative were compared to 8-week postoperative. Scores were judged as correct (=showing an increase in score), incorrect (=decrease in score), or unchanged (=same score). Phase II-An international group of 39 reviewers was asked to score radiographs from three dogs, taken in different positions, using the VAS grading system. Scores were averaged and comparisons were made for each set. Results: Phase I-The VAS system identified the greatest number of sets correctly (76%), with the least unchanged scores (15%), and 9% incorrect scores. Phase II-All three patients had an increase in the average difference between VAS-scores for differently positioned radiographs compared to similarly positioned radiographs. The magnitude of change between different positions far exceeded the magnitude of comparison of the similarly positioned radiographs from the 6- and 8-week time point. Discussion/Conclusion: The VAS system appears to be the most appropriate of the tested systems to identify small changes in bone healing. In addition, the positioning of postoperative TPLO radiographs makes a substantial difference in the healing score that is assigned. Care must be undertaken when performing postoperative radiographs in both the clinical and research setting to ensure accurate assessment of bone healing.

A biomechanical investigation of the static stabilisers of the glenohumeral joint in the dog.

The aim was to determine the relative contribution of the glenohumeral ligaments/joint capsule complex and the limited joint volume/adhesion-cohesion (UV/AC) mechanisms to the static stability of the canine glenohumeral joint (GHJ). The GHJ of 32 complete cadaver specimens were manipulated to determine the presence of gross laxity (> 2mm translation) at joint angles of 150 degrees, 135 degrees and 90 degrees. Following the removal of the peri-articular muscles, laxity was measured by applying a 15N force to the scapula in a variety of directions whilst the humerus was fixed to a jig. This was repeated for the abovementioned angles in intact joints and after venting and flushing to eliminate the UV/AC mechanisms. Results of clinical palpation and biomechanical studies were compared. Manipulation revealed a marked variation between joints although there was a tendency for progressive laxity as the joint was flexed. This finding was supported by the biomechanical study that also demonstrated no significant difference between intact and vented joints except in a cranio-caudal direction at 135 degrees and 90 degrees, and in a medial/lateral direction at 135 degrees. Static stabilisers permitted a wide range of motion. Individual clinical palpations did not correlate well with biomechanical findings. Manipulation was difficult to perform and is unlikely to be a reliable method for determining subtle joint laxity. The static stabilisers do not appear to play a significant role in providing joint constraint during normal range of motion (except extension). Diagnoses of pathological laxity attributable to the static stabilisers should be made with caution and surgical treatments should take cognizance of the above-mentioned biomechanical features.

Congenital narrowing of the intrapharyngeal opening in a dog with concurrent oesophageal hiatal hernia.

A one-year-old, male, smooth-haired standard dachshund was presented with a history of chronic hypersalivation, dysphagia, puffing of the cheeks on expiration, and inspiratory stridor. Oral examination revealed a moderately thickened tongue radix and that the normal intrapharyngeal opening was obliterated. A 7 mm long, midline palatal slit was the only communication between the naso- and oropharynx. The soft palate was fused to the caudal pharyngeal wall. A concurrent hiatal hernia was diagnosed on thoracic radiographs. The soft palate abnormality was surgically corrected and the hiatal hernia was managed medically. On follow-up evaluations, the clinical signs had markedly improved, and the hiatal hernia was no longer visible on survey thoracic radiographs.

The prevalence of subclinical gastroduodenal ulceration in Dachshunds with intervertebral disc prolapse.

Endoscopy was used to determine the prevalence of subclinical gastroduodenal ulceration in 30 Dachshunds undergoing decompressive surgery for acute intervertebral disc prolapse. The endoscopy was performed on the day of admission and on the 3rd or 4th day after surgery. Three regions of the stomach (cardia, corpus and pylorus) and the proximal duodenum were visually inspected and biopsy samples were taken for histopathology. The combination of visual and microscopic changes were then used to determine the prevalence of subclinical gastroduodenal ulceration in this population. An overall prevalence of 76% was calculated from these findings. Ulcerogenic medication administered prior to admission did not appear to influence the prevalence. This result identifies a need for veterinarians to be aware of this potentially severe complication and warrants the use of prophylactic anti-ulcer medication in spinal surgery patients.

Cervical teratoma in a dog.

A young adult boxer dog was examined for a painless swelling in the left cranial cervical area that was refractory to antibiotic therapy. Ultrasound examination revealed a hypoechoic mass abutting the rostrolateral aspect of the left mandibular salivary gland. The cystic mass was excised and was found to extend through the capsule of the salivary gland and appeared to be confluent with the glandular tissue at this point. Histopathological examination of the excised tissue demonstrated tissue from all 3 germinal layers. There was no indication of malignancy and the mass was diagnosed as a benign cervical teratoma. Hypotheses regarding the origin of teratomas in general are discussed and the origin of the teratoma in this case is suggested.

Effects of general anesthesia and surgery on renal function in healthy dogs.

OBJECTIVES: To evaluate renal function in healthy dogs undergoing general anesthesia and ovariohysterectomy without concurrent IV administration of fluids. ANIMALS: 35 healthy client-owned dogs. PROCEDURE: Dogs were medicated with promazine hydrochloride (0.05 mg/kg of body weight, SC) approximately 45 minutes before induction of anesthesia with thiopental sodium (10 to 15 mg/kg, IV). Anesthesia was maintained with 2% halothane in oxygen. Ovariohysterectomies were performed by senior veterinary students under the direct supervision of a veterinary surgeon. Renal function was assessed (serum urea and creatinine concentrations, fractional clearance of sodium, urine alkaline phosphatase [ALP] and gamma-glutamyltransferase [GGT] activities, urine specific gravity, and enumeration of renal tubular epithelial cells in urine sediment) prior to and 24 and 48 hours after surgery. RESULTS: Duration of general anesthesia ranged from 80 to 310 minutes. Urine specific gravity and ALP activity and serum urea and creatinine concentrations did not change over time. Fractional clearance of sodium decreased 24 and 48 hours after surgery, whereas urine GGT activity and the ratio of urine GGT activity to urine creatinine concentration increased 24 hours after surgery, compared with presurgery values. Renal tubular epithelial cells increased in number in urine sediment from 11 of 35 (31.4%) dogs and 5 of 35 (14.3%) dogs 24 and 48 hours after surgery, respectively. However, this increase was not clinically relevant. CONCLUSIONS AND CLINICAL RELEVANCE: Intravenous administration of fluids to healthy dogs undergoing general anesthesia and elective surgery may not be necessary for maintenance of renal homeostasis.

Caudal cervical disc protrusion in a Bengal tiger (Panthera tigris tigris).

A young adult male white Bengal tiger (Panthera tigris tigris) presented with hindlimb ataxia. Cervical and lumbar myelography revealed a compressive lesion of the cord at C(6-7). Corticosteroid therapy and confinement failed to provide lasting remission of signs. A modified, inverted cone ventral slot decompression was used to remove the fibrous material causing cord compression at C(6-7). Temporary Horner's syndrome and laryngeal paresis developed postsurgically because of excessive tissue retraction. The animal recovered normal ambulatory function 6 wk after surgery.

Double aortic arch and persistent left vena cava in a white lion cub (Panthera leo).

A 4-mo-old female white lion (Panthera leo) cub was presented with a 2-wk history of persistent postprandial regurgitation, mild dyspnea, and poor weight gain. The cub was weak and thin but otherwise alert. Survey and contrast radiography revealed a large dilated esophagus cranial to the heart base, with an esophageal filling defect present at the level of the fourth thoracic vertebra. A vascular ring anomaly was tentatively diagnosed. Exploratory thoracotomy revealed a double aortic arch and a persistent left vena cava. The left aortic arch was ligated and divided, and recovery was uneventful. A single episode of regurgitation occurred within the first postoperative month, and the cub gained 5.5 kg in weight during the same time period. Neither double aortic arch nor persistent left vena cava has been reported in a nondomestic felid.

Chlamydia-induced septic polyarthritis in a dog.

A systemic disease associated with pyrexia, lymphadenopathy, and arthropathy of several joints of the appendicular skeleton in a dog is described. Chlamydia-like organisms were detected on light-microscopic examination of a smear made from joint fluid aspirated from one of the affected joints. A group-specific lipopolysaccharide antigen shared by all Chlamydia spp. was demonstrated by direct fluorescent antibody staining of joint fluid, which also proved positive for chlamydia by means of the relevant polymerase chain reaction test. An indirect fluorescent antibody test on serum was also positive, although the complement fixation test was negative. Attempts to grow the organism from joint aspirates in the yolk sac of embryonating hens' eggs and on appropriate tissue cultures, however, failed. Chlamydia spp. are considered to have played an aetiological role in this case, making it the first substantiated case of naturally-occurring arthropathy in a dog due to chlamydiosis. The origin of the infection could not be traced.

Thyroidal radioisotope uptake in euthyroid cats: a comparison between 131I and 99mTcO4.

Two thyroidal evaluation systems in euthyroid cats (n = 12) were compared. A single, confirmed hyperthyroid cat was included for interest. Firstly, thyroidal uptake of an intravenous bolus of approximately 111 MBq (3 mCi) 99MTcO4 was estimated by using a scintillation camera and calculating the ratio of thyroid to salivary activities at 20 min and 4 h. Thyroid to salivary activity ratios were 1:1 at 20 min and 2:1 at 4 h. Two discrete areas of salivary uptake were identified, namely a parotid/mandibular complex and a more rostral buccal/sublingual complex. These results were compared to radioiodine uptake of an oral dose of approximately 0.925 MBq (25 microCi) 131I using a standard thyroid uptake system, measured at 1, 2, 4, 6, 8, 10, 12, 24 and 48 h after administration. Mean radioiodine thyroidal uptake started at 33% at 1 h, stabilised at 21% between 4 and 24 h, and dropped to 18% at 48 h. There was a significant correlation between the early thyroid:salivary ratio of the parotid/mandibular complex and the radioiodine uptake at 12 h.

Dermoid sinus in a crossbred Rhodesian ridgeback dog involving the second cervical vertebra.

A 4-year-old neutered Rhodesian ridgeback/dalmatian crossbred bitch was presented with a cervical, dorsal midline cutaneous swelling after 2 unsuccessful attempts at surgical resection of a dermoid sinus. Radiographs of the cervical spine indicated a C2 transosseous communication with the vertebral canal. Ultrasonographic evaluation demonstrated 2 interlinking cavities terminating close to C2. Complete resection of the sinus tract necessitated a partial dorsal laminectomy. Histology confirmed the diagnosis. This case is compared to similar cases in the literature.

Black grain eumycetoma (Madurella mycetomatis) in the abdominal cavity of a dog.

A uterine stump granuloma was surgically removed from a sterilized bitch. Histopathology and fungal culture revealed Madurella mycetomatis eumycetoma. Infection may have occurred through a cesarean wound dehiscence. Long-term fluconazole therapy was instituted but failed to arrest and eliminate the infection.