A 12-year-old Thoroughbred mare was evaluated for routine dental floating and vaccinations. During inspection of the mouth, a mass was noticed within the buccal soft tissues adjacent to the left maxillary arcade, situated at a rostrodorsal to caudoventral oblique angle at the level of the third and fourth premolar teeth. The mass measured 9 × 3.5 cm and was firm and freely mobile under the skin of the left cheek. The horse was sedated and a MacPherson mouth speculum was placed. Sharp enamel points were present along the buccal surface of the left maxillary arcade, and
An 11-year-old male sexually intact mixed-breed dog was referred to the University of Illinois Veterinary Teaching Hospital for evaluation of a right-sided perineal swelling and a perianal mass. The dog was evaluated 1 week earlier by the referring veterinarian for straining and inability to defecate. On physical examination, there was a 1-cm-diameter firm nodule 3 cm ventral to the anus and a 5 × 4-cm mass in the right perineal region that had a palpable fluid wave. Rectal palpation revealed a fluid-filled mass compressing the rectum and an irregular, enlarged, nonpainful prostate. All other physical examination findings were unremarkable.
Objective—To determine the accuracy of 3-D and 2-D ultrasonography for quantification of tumor volume in dogs with transitional cell carcinoma (TCC) of the urinary bladder.
Animals—10 dogs with biopsy-confirmed TCC.
Procedures—The urinary bladder of each dog was distended with saline (0.9% NaCl) solution (5.0 mL/kg), and masses were measured via 3-D and 2-D ultrasonography. Masses were also measured via 3-D ultrasonography after bladders were distended with 2.5 and 1.0 mL of saline solution/kg. Subsequently, the bladder was deflated and distended with CO2 (5.0 mL/kg); CT was performed after IV contrast medium administration. Tumor volumes were calculated via 3-D ultrasonography, 2-D ultrasonography, and CT (reference method) and compared via ANOVA, Deming regression, and Bland-Altman plots. Repeated-measures ANOVA was used to assess effects of bladder distension on 3-D tumor volume measurements. Repeatability of measurements was estimated via the coefficient of variation for each method.
Results—Repeatability was considered good for all 3 methods. There was no significant difference in tumor volume measurements obtained via 3-D ultrasonography at different degrees of urinary bladder distension. Results of Deming regression and Bland-Altman plots indicated excellent agreement between tumor volume measurement with 3-D ultrasonography and CT, but not between 2-D ultrasonography and CT.
Conclusions and Clinical Relevance—Tumor volume in dogs with TCC of the urinary bladder was accurately measured via 3-D ultrasonography. Use of 3-D ultrasonography can provide a less expensive and more practical method for monitoring response to treatment than CT and was more accurate than 2-D ultrasonography.
Objective—To determine expression of folate receptors (FRs) and folate uptake in multicentric lymphomas in dogs.
Sample—10 dogs with histopathologically confirmed multicentric lymphoma and 20 archival lymph node biopsy specimens from dogs with multicentric lymphoma.
Procedures—Multicentric lymphomas in 10 dogs were prospectively evaluated for FR expression by use of immunohistochemical analysis and for in vivo folate uptake by use of nuclear scintigraphy. Dogs with FR-expressing tumors were eligible for FR-targeted chemotherapy. Twenty archival lymphoma biopsy specimens were also evaluated with immunohistochemical analysis.
Results—FRs were not detected with immunohistochemical analysis in lymph node samples obtained from the 10 dogs or in archival biopsy specimens. However, nuclear scintigraphy revealed uptake of radioactive tracer in 6 of 10 dogs. Five of these 6 dogs were treated with an FR-targeted chemotherapeutic agent; results of treatment were complete remission in 1 dog, stable disease in 2 dogs, and progressive disease in 2 dogs. Treatment-related toxicoses generally were mild.
Conclusions and Clinical Relevance—This study provided strong evidence for folate uptake in a substantial portion of multicentric lymphomas of dogs and indicated the antitumor activity of FR-targeted chemotherapeutics for these cancers. Use of FR-targeted chemotherapeutics may be promising for the treatment of FR-expressing multicentric lymphomas in dogs. Further studies are needed to determine reasons for lack of immunoreactivity to currently identified anti-FR antibodies and to develop improved methods for detecting FRs in lymphomas of dogs.
Objective—To evaluate tendon injuries in horses over a 16-week period by use of ultrasonography and low-field magnetic resonance imaging (MRI).
Sample—Tendons of 8 young adult horses.
Procedures—The percentage of experimentally induced tendon injury was evaluated in cross section at the maximal area of injury by use of ultrasonography and MRI at 3, 4, 6, 8, and 16 weeks after collagenase injection. The MRI signal intensities and histologic characteristics of each tendon were determined at the same time points.
Results—At 4 weeks after collagenase injection, the area of maximal injury assessed on cross section was similar between ultrasonography and MRI. In lesions of > 4 weeks' duration, ultrasonography underestimated the area of maximal cross-sectional injury by approximately 18%, compared with results for MRI. Signal intensity of lesions on T1-weighted images was the most hyperintense of all the sequences, lesions on short tau inversion recovery images were slightly less hyperintense, and T2-weighted images were the most hypointense. Signal intensity of tendon lesions was significantly higher than the signal intensity for the unaltered deep digital flexor tendon. Histologically, there was a decrease in proteoglycan content, an increase in collagen content, and minimal change in fiber alignment during the 16 weeks of the study.
Conclusions and Clinical Relevance—Ultrasonography may underestimate the extent of tendon damage in tendons with long-term injury. Low-field MRI provided a more sensitive technique for evaluation of tendon injury and should be considered in horses with tendinitis of > 4 weeks' duration.