Objective—To determine magnetic resonance imaging (MRI) vertebral ratio values representing vertebral canal height, vertebral canal shape, and vertebral body shape in Doberman Pinschers with and without disk-associated cervical spondylomyelopathy (DACSM) and clinically normal English Foxhounds. Animals—Doberman Pinschers with (n = 18) and without (20) DACSM and clinically normal English Foxhounds (18). Procedures—All dogs underwent low-field MRI of the cervical vertebral column. From 5 specific measurements made at C3 through C7, 4 linear vertebral ratios were calculated and assessed for correlation: vertebral canal height-to-body height ratio (CBHR), vertebral canal height-to-body length ratio (CBLR), caudal canal height-to-cranial canal height ratio (CCHR), and vertebral body length-to-height ratio (BLHR). The CBHR and CBLR described vertebral canal height, CCHR described vertebral canal shape, and BLHR described vertebral body shape. A midvertebral canal-occupying ratio (mVCOR) for the spinal cord was calculated at C5. Results—Compared with both groups of unaffected dogs, CBHR, CBLR, and BLHR for Doberman Pinschers with DACSM were significantly smaller. The C7 CCHR was significantly larger in DACSM-affected Doberman Pinschers, compared with clinically normal English Foxhounds. Ratios did not differ significantly between unaffected Doberman Pinschers and clinically normal English Foxhounds. Correlation coefficients between CBHR, CBLR, and mVCOR were low and not significant. Conclusions and Clinical Relevance—Doberman Pinschers with DACSM had significantly smaller vertebral canal heights and more square-shaped vertebral bodies, compared with unaffected Doberman Pinschers, combined with a funnel-shaped vertebral canal at C7. Breed-specific differences were not evident. Linear MRI vertebral canal-to-body ratios do not appear to predict relative vertebral canal stenosis.

Objective—To evaluate expression of matrix metalloproteinase (MMP)-2 and -9 and membrane-type 1 MMP (MT1-MMP) in melanocytomas and malignant melanomas of dogs, analyze in vitro production of MMPs by canine melanoma cell lines and primary dermal fibroblasts, and investigate mutual communication between tumor cells and fibroblasts and the influence of collagen on MMP regulation. Sample—35 biopsy specimens from melanocytic tumors and primary dermal fibroblasts of dogs and 3 canine melanoma cell lines (CML-1, CML-10c2, and CML-6M). Procedures—MMP-2, MMP-9, and MT1-MMP were detected in tumor samples by use of unohistochemical analysis. In vitro production was analyzed via reverse transcriptase-PCR assay, immunocytochemical analysis, zymography, and immunoblotting. Results—MMP-9 was overexpressed in malignant melanomas, compared with expression in melanocytomas, whereas no significant differences in MMP-2 and MT1-MMP immunostaining were detected. Stromal cells also often had positive staining results. In vitro, all 3 melanoma cell lines and dermal fibroblasts had evidence of MMP-2 and MT1-MMP, but only melanoma cells had evidence of MMP-9. Coculture of CML-1 or CML-10c2 cells and dermal fibroblasts induced an increase in expression of the active form of MMP-2. Culture of melanoma cells on type I collagen increased the activation state of MT1-MMP. Conclusions and Clinical Relevance—MMP-9 expression was increased in malignant melanomas of dogs. Stromal cells were a source for MMPs. Stromal cells, in combination with matrix components such as type I collagen, can interact with tumor cells to regulate MMP production. Information about MMP production and regulation could help in the development of new treatments.

This project evaluated the use of an ingestible temperature sensor to measure body core temperature (Tc) in exercising dogs. Twenty-five healthy, unconditioned Labrador retrievers participated in an outdoor 3.5-km run, completed in 20 min on a level, 400-m grass track. Core temperature was measured continuously with a telemetric monitoring system before, during, and after the run. Data were successfully collected with no missing data points during the exercise. Core temperature elevated in the dogs from 38.7 +/- 0.3 degrees C at pre-exercise to 40.4 +/- 0.6 degrees C post-exercise. While rectal temperatures are still the standard of measurement, telemetric core temperature monitors may offer an easier and more comfortable means of sampling core temperature with minimal human and mechanical interference with the exercising dog.

Final observations on experimental transmission of chronic wasting disease (CWD) from elk (Cervus elaphus nelsoni) and white-tailed deer (Odocoileus virginianus) to fallow deer (Dama dama) are reported herein. During the 5-year study, 13 fawns were inoculated intracerebrally with CWD-infected brain material from white-tailed deer (n = 7; Group A) or elk (n = 6; Group B), and 3 other fawns were kept as uninoculated controls (Group C). As described previously, 3 CWD-inoculated deer were euthanized at 7.6 mo post-inoculation (MPI). None revealed presence of abnormal prion protein (PrPd) in their tissues. At 24 (Group A) and 26 (Group B) MPI, 2 deer were necropsied. Both animals had a small focal accumulation of PrPd in their midbrains. Between 29 and 37 MPI, 3 other deer (all from Group A) were euthanized. The 5 remaining deer became sick and were euthanized between 51 and 60 MPI (1 from Group A and 4 from Group B). Microscopic lesions of spongiform encephalopathy (SE) were observed in only these 5 animals; however, PrPd was detected in tissues of the central nervous system by immunohistochemistry, Western blot, and by commercial rapid test in all animals that survived beyond 24 MPI. This study demonstrates that intracerebrally inoculated fallow deer not only amplify CWD prions, but also develop lesions of spongiform encephalopathy.

Objective—To evaluate a commercially available modified-live Streptococcus equi subsp equi vaccine for safety and persistence in vaccinated ponies and to detect recombination or reversion events in the vaccine strain. Animals—5 ponies that were 1.5 to 8 years old (group 1) and 4 ponies that were 6 months old (group 2). Procedures—Ponies were vaccinated, with a subsequent booster vaccination 2 to 3 weeks later, and monitored for 50 days. At booster vaccination, an equal amount of a tracycline-resistant wild-type strain of S equi was administered. Recovery of all strains was performed by use of bacteriologic culture and PCR assays. Results—Ponies in group 1 had background antibody titers against S equi antigen before vaccination despite the lack of known exposure to S equi. Ponies in group 2 were immunologically naïve. Increases in anti-S equi antibody titers were detected in both groups. Ponies in group 1 did not have clinical signs of disease caused by S equi. In group 2, all ponies developed abscesses in retropharyngeal lymph nodes; 1 pony developed severe clinical disease and was euthanized. The vaccine strain was recovered from ponies in group 2 for up to 24 days after vaccination. Conclusions and Clinical Significance—Although the vaccine was successful in inducing IgG antibodies against S equi in all ponies, findings suggested that the vaccine may have caused substantial morbidity and some deaths in the young ponies. In young ponies, the vaccine strain persisted in tissues for weeks; however, no evidence of recombination was detected.

Objective--To establish a computed tomography (CT)-angiography protocol and measure the diameters of major arteries in parrots. Animals--13 Hispaniolan Amazon parrots (Amazona ventralis). Procedures--16-slice CT scanning was used to measure the apparent diameter of the ascending aorta, abdominal aorta, pulmonary arteries, and brachiocephalic trunk. Before scanning, all birds underwent ECG and echocardiographic assessment and were considered free of detectable cardiovascular diseases. Each bird was anesthetized, and a precontrast helical CT scan was performed. Peak aortic enhancement was established with a test bolus technique via dynamic axial CT scan over a predetermined single slice. An additional bolus of contrast medium was then injected, and a helical CT-angiography scan was performed immediately afterward. Arterial diameter measurements were obtained by 2 observers via various windows before and after injection, and intra- and interobserver agreement was assessed. Results--Reference limits were determined for arterial diameter measurements before and after contrast medium administration in pulmonary, mediastinal, and manual angiography windows. Ratios of vertebral body diameter to keel length were also calculated. Intraobserver agreement was high (concordance correlation coefficients ≥ 0.95); interobserver agreement was medium to high (intraclass correlation coefficients ≥ 0.65). Conclusions and Clinical Relevance--CT-angiography was safe and is of potential diagnostic value in parrots. We recommend performing the angiography immediately after IV injection of 3 mL of iohexol/kg. Arterial diameter measurements at the described locations were reliable.

Liver function tests help to investigate actual liver function. In dogs, only a few tests are available. We evaluated the formation of monoethylglycinexylidide (MEGX) in clinically healthy dogs to assess the usefulness of this liver function test in dogs. Twenty-five healthy dogs were used in this study. The MEGX test was done according to human protocols. The results of our study showed that dogs synthesize MEGX after the administration of lidocaine. There was no age dependence of this test in dogs and no significant difference between measurements obtained at 15 and 30 min after administration of lidocaine. Female dogs had significantly (P < 0.05) higher concentrations of MEGX 15 min after administration. The reference interval for dogs after 15 min is 34 to 79 μg/L and after 30 min 39 to 89 μg/L. In conclusion, the MEGX test may be an additional liver function test in dogs.

Objective-To evaluate effects of extracorporeal shock wave therapy (ESWT) and polysulfated glycosaminoglycan treatment (PSGAGT) on subchondral bone (SCB), serum biomarkers, and synovial fluid biomarkers in horses with induced osteoarthritis. Animals-24 healthy 2- to 3-year-old horses. Procedures-An osteochondral fragment was created on the distal aspect of the radial carpal bone in 1 middle carpal joint of each horse. Horses were randomly allocated to receive local application of ESWT (days 14 and 28; n = 8), PSGAGT (IM, q 4 d for 28 days; 8), or a sham ESWT probe (placebo; days 14 and 28; 8). Serum biomarkers were measured every 7 days, and synovial fluid biomarkers were measured every 14 days. Bone density was measured by use of computed tomography on days 0 and 70, and microdamage and bone formation variables were compared among groups at the end of the study (day 70). Results-There was no significant effect of ESWT or PSGAGT on any bone variable. Serum osteocalcin concentration was significantly greater in horses that received ESWT, compared with placebo-treated horses, and serum concentration of the C-terminal telopeptide of type I collagen was significantly higher in horses that received ESWT, compared with placebo- and PSGAG-treated horses. Concentrations of the synovial fluid epitope CS846 were significantly higher in joints with osteoarthritis treated with ESWT Conclusions and Clinical Relevance-Treatment of osteoarthritis with ESWT had no effect on SCB but did induce increases in serum biomarkers indicative of bone remodeling. Treatment of osteoarthritis with PSGAG had no effect on SCB or biomarkers.

Objective-To determine variations in cytologic counts of bronchoalveolar lavage (BAL) fluid attributable to month of collection, first and second aliquots, and left and right lung sites in horses with recurrent airway obstruction (RAO). Animals-5 horses with RAO and 5 healthy horses without respiratory tract disease. Procedures-Horses were housed in a stable for 5 months prior to and throughout the study. Bronchoalveolar lavage fluid was collected from the right and left lung of each horse 3 times at monthly intervals (February, March, and April). Each BAL fluid collection was performed by use of 2 incremental instillations of 250 mL of isotonic saline (0.9% NaCl) solution in the same bronchial site. Analysis of BAL fluid included volume of BAL fluid recovered, a CBC, and differential cytologic counts. Results-Volume of BAL fluid recovered and cytologic counts did not differ in horses with RAO across time or between right and left lungs, except for the number of mast cells. Horses with RAO had significantly lower volumes of BAL fluid recovered, significantly lower percentages of macrophages and lymphocytes, and significantly higher percentages of neutrophils than did healthy horses. Despite individual variation, all horses with RAO had > 25% neutrophils throughout the study period. Conclusions and Clinical Relevance-Despite variation among horses, BAL fluid cytologic counts were repeatable over short and long periods and samples can be used for longitudinal studies as a diagnostic tool of pulmonary inflammation in horses with RAO.

Objective—To evaluate changes in the cortical bone of the proximal phalanx of the fore-limbs of Thoroughbreds in response to training. Animals—Twenty-seven 2-year-old Thoroughbreds (20 females, 2 males, and 5 geldings). Procedures—Horses were principally in training for races in a straight line and in a clockwise direction. Lateromedial and dorsopalmar radiographic views of each metacarpophalangeal joint were obtained before the horses started training and 1 year after starting exercise and racing. Width of the dorsal, palmar, lateral, and medial cortex and the width and thickness of the medulla were measured. Ratios (rather than absolute values) were used to remove the effect of differences in bone size among horses. Results—10 horses were lost from the study. Radiographs were obtained for 17 horses 1 year after starting training (9 horses raced in a clockwise direction, and 8 raced in clockwise and counterclockwise directions). There was no difference between the cortical bone in the right and left forelimbs at the start of the study. After training for 1 year, the palmar cortex in the right forelimb was significantly thicker than that in the left forelimb. Conclusions and Clinical Relevance—The strain patterns, biomechanics of rapid exercise, and type of training most probably determined differences in the adaptive responses of the proximal phalanx. The data reported here can be used in the evaluation of weight-bearing distribution along the proximal phalanx and evaluation of the relationship between exercise and bone remodelling of the proximal phalanx.