PROGRESSIVE SYRINGOHYDROMYELIA AND DEGENERATIVE AXONOPATHY IN A BOBCAT (LYNX RUFUS) FOLLOWING SURGICAL CORRECTION OF A CHIARI-LIKE MALFORMATION.

A 3-yr-old male captive bobcat (Lynx rufus) presented with chronic ataxia and right-sided head tilt. Magnetic resonance imaging (MRI) revealed cerebellar crowding and compression consistent with Chiari-like malformation. The clinical signs did not improve after surgical occipital craniectomy, and 2 mo postoperatively a second MRI showed hydromyelia and continued cerebellar compression. The bobcat was euthanized, and necropsy showed chronic focal cerebellar herniation and chronic multifocal atlanto-occipital joint osteophyte proliferation. Histology confirmed the presence of a thick fibrous membrane along the caudal aspect of the cerebellar vermis, suggestive of postoperative adhesions, and axonal degeneration of the cervical spinal cord, even in sections without a central canal lesion. These lesions appear to have been complications associated with surgical correction of the Chiari-like malformation.

Use of a novel morphometric method and body fat index system for estimation of body composition in overweight and obese dogs.

OBJECTIVE: To develop morphometric equations for prediction of body composition and create a body fat index (BFI) to estimate body fat percentage in overweight and obese dogs. DESIGN: Prospective evaluation study. ANIMALS: 83 overweight or obese dogs ≥ 1 year of age. PROCEDURES: Body condition score (BCS) was assessed on a 5-point scale, morphometric measurements were made, and visual and palpation-based assessments and dual-energy x-ray absorptiometry (DEXA) were performed. Equations for predicting lean body mass, fat mass, and body fat as a percentage of total body weight (ie, body fat percentage) on the basis of morphometric measurements were generated with best-fit statistical models. Visual and palpation-based descriptors were used to develop a BFI. Predicted values for body composition components were compared with DEXA-measured values. RESULTS: For the study population, the developed morphometric equations accounted for 98% of the variation in lean body mass and fat mass and 82% of the variation in body fat percentage. The proportion of dogs with predicted values within 10% of the DEXA values was 66 of 83 (80%) for lean body mass, 56 of 83 (68%) for fat mass, and 56 of 83 (67%) for body fat percentage. The BFI accurately predicted body fat percentage in 25 of 47 (53%) dogs, whereas the value predicted with BCS was accurate in 6 of 47 (13%) dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Morphometric measurements and the BFI appeared to be more accurate than the 5-point BCS method for estimation of body fat percentage in overweight and obese dogs. Further research is needed to assess the applicability of these findings to other populations of dogs.

Use of a morphometric method and body fat index system for estimation of body composition in overweight and obese cats.

OBJECTIVE: To develop morphometric equations for prediction of body composition and create a body fat index (BFI) system to estimate body fat percentage in overweight and obese cats. DESIGN: Prospective evaluation study. ANIMALS: 76 overweight or obese cats ≥ 1 year of age. PROCEDURES: Body condition score (BCS) was determined with a 5-point scale, morphometric measurements were made, and dual-energy x-ray absorptiometry (DEXA) was performed. Visual and palpation-based evaluation of various body regions was conducted, and results were used for development of the BFI system. Best-fit multiple regression models were used to develop equations for predicting lean body mass and fat mass from morphometric measurements. Predicted values for body composition components were compared with DEXA results. RESULTS: For the study population, prediction equations accounted for 85% of the variation in lean body mass and 98% of the variation in fat mass. Values derived from morphometric equations for fat mass and lean mass were within 10% of DEXA values for 55 of 76 (72%) and 66 of 76 (87%) cats, respectively. Body fat as a percentage of total body weight (ie, body fat percentage) predicted with the BCS and BFI was within 10% of the DEXA value for 5 of 39 (13%) and 22 of 39 (56%) cats, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: The BFI system and morphometric equations were considered accurate for estimation of body composition components in overweight and obese cats of the study population and appeared to be more useful than BCS for evaluation of these patients. Further research is needed to validate the use of these methods in other feline populations.

Magnetic resonance imaging of the canine abdomen: effect of pulse sequence on diagnostic quality.

Motion artifact is an important limiting factor for abdominal magnetic resonance imaging (MRI) in veterinary patients. The purpose of this study was to determine the effects of pulse sequence on abdominal MRI diagnostic quality in dogs. Ten normal dogs were each scanned using 16 MRI pulse sequences. Sequences included breath-holding sequences, respiratory navigation sequences, and traditional spin-echo sequences. Four observers independently scored diagnostic quality for each sequence based on the appearance of specific organs, overall diagnostic quality, and degree of artifactual interference. Signal-to-noise ratio and contrast-to-noise ratio were also calculated for each sequence. The sequence with the highest overall mean diagnostic quality score was the dorsal T2 turbo spin echo (TSE) with fat saturation and breath-holding. The sequence with the lowest mean diagnostic quality score was the dorsal T2 fast spin echo. The sequence with the highest signal-to-noise ratio for all evaluated organs was the sagittal T1 spin echo. Signal-to-noise and contrast-to-noise ratios did not correlate with subjective assessment of overall diagnostic quality for the majority of the sequences evaluated (P < 0.05). The three sequences considered to have the highest diagnostic quality for the cranial abdomen were the dorsal T2 TSE with fat saturation and breath-hold, transverse T1 turbo fast low-angle shot gradient echo with breath-hold, and dorsal T2 half-Fourier acquisition single shot TSE with respiratory navigation. These sequences had short acquisition times, yielded studies of similar diagnostic quality, provided complementary information, and are therefore recommended for routine canine abdominal MRI protocols.

Septic pericarditis, aortic endarteritis, and osteomyelitis in a dog.

A 7-year-old, female spayed rottweiler was referred with a history of an acute onset of collapse attributable to cardiac tamponade. Thoracic radiographs revealed an enlarged cardiac silhouette compatible with pericardial effusion, sternal osteomyelitis, and an unusual mineralized lesion determined later to be within the aortic wall. The pericardial effusion was a septic exudate secondary to infection with Staphylococcus species and hemorrhage into the pericardium through a mineralized aortic lesion. The case demonstrates the importance of complete evaluation of thoracic radiographs in a patient with cardiac disease and the potential value of cytopathological evaluation of pericardial fluid.