The Dag defect is one of the primary morphological defects in sperm correlating with reduced fertility. This defect is found in the spermatozoa of many livestock species. The aim of the study was to assess the morphometry of the heads of normal sperm and sperm with the Dag defect in the semen of Duroc breeding boars. Sperm morphology was examined in ten ejaculates each from 12 Duroc boars. In total, 3,600 morphologically normal sperm and 838 sperm with the Dag defect were evaluated. The area, perimeter, length and width of the sperm head were measured and these basic morphometric parameters were used to calculate four additional shape indices characterising the sperm head, i.e. ellipticity, elongation, roughness and regularity. Sperm with this defect had markedly smaller heads, 0.32 μm shorter and 0.19 μm narrower than the heads of sperm with normal morphological structure. The heads of sperm with the Dag defect also had a 1.1μm smaller perimeter and a 2.5 μm² smaller surface area than the heads of morphologically normal sperm. The Dag defect is found in boar sperm irrespective of the age of the individual. It affects the morphology of the sperm head.

OBJECTIVE To assess the effect of horseshoes with and without traction adaptations on the gait kinetics of nonlame horses during a trot on a concrete runway. ANIMALS 5 nonlame adult light-breed horses. PROCEDURES Kinetic data were obtained for each horse when it was trotted across a force platform within a concrete runway unshod (control) and shod with standard horseshoes; standard horseshoes with high profile–low surface area calks, with low profile–high surface area calks, and coated with a thin layer of tungsten carbide (TLTC); and plastic-steel composite (PSC) horseshoes. Kinetic data were obtained for the control treatment first, then for each of the 5 shoe types, which were applied to each horse in a random order. Kinetic variables were compared among the 6 treatments. RESULTS Body weight distribution did not differ among the 6 treatments. Compared with the control, the greatest increase in forelimb peak vertical force was observed when horses were shod with PSC shoes. In the hind limbs, the greatest increase in peak braking force was observed when horses were shod with PSC shoes, followed by the TLTC and low profile–high surface area calked shoes. The PSC shoes yielded the greatest coefficient of friction in both the forelimbs and hind limbs. Stance time was longest when horses were shod with standard shoes. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that PSC and TLTC shoes provided the best hoof protection and traction and might be good options for horses that spend a large amount of time traversing paved surfaces.

OBJECTIVE To compare left ventricle (LV) volume and function variables obtained by use of 1-D, 2-D, and real-time 3-D echocardiography versus ECG-gated multidetector row CT (MDCT) angiography, which was considered the criterion-referenced standard. ANIMALS 6 healthy, purpose-bred dogs. PROCEDURES Dogs were anesthetized and administered a constant rate infusion of esmolol, and 1-D, 2-D, and 3-D echocardiography and ECG-gated, contrast-enhanced MDCT were performed. End-diastolic volume (EDV), end-systolic volume (ESV), stroke volume, and ejection fraction (EF) were calculated by use of the Teichholz method for 1-D echocardiography, single-plane and biplane modified Simpson method of disks (MOD) and area-length method for 2-D echocardiography, and real-time biplane echocardiography (RTBPE) and real-time 3-D echocardiography (RT3DE) for 3-D echocardiography. Volumes were indexed to body surface area and body weight. Median values, correlations, and limits of agreement were compared between echocardiographic modalities and MDCT. RESULTS EDV and ESV measured by use of RTBPE and RT3DE had the strongest correlations with results for MDCT. Values obtained for EDV, ESV, stroke volume, and EF did not differ significantly between echocardiographic methods and MDCT. Use of RT3DE and RTBPE slightly underestimated EDV, ESV, and EF, compared with values for MDCT, as determined with Bland-Altman analysis. CONCLUSIONS AND CLINICAL RELEVANCE Values for EDV and ESV obtained by use of 3-D echocardiography, including RTBPE and RT3DE, had the highest correlation with slight underestimation, compared with values obtained by use of MDCT. This was similar to results for 3-D echocardiography in human medicine.

OBJECTIVE To evaluate effects of anatomic location, histologic processing, and sample size on shrinkage of excised canine skin samples. SAMPLE Skin samples from 15 canine cadavers. PROCEDURES Elliptical samples of the skin, underlying subcutaneous fat, and muscle fascia were collected from the head, hind limb, and lumbar region of each cadaver. Two samples (10 mm and 30 mm) were collected at each anatomic location of each cadaver (one from the left side and the other from the right side). Measurements of length, width, depth, and surface area were collected prior to excision (P1) and after fixation in neutral-buffered 10% formalin for 24 to 48 hours (P2). Length and width were also measured after histologic processing (P3). RESULTS Length and width decreased significantly at all anatomic locations and for both sample sizes at each processing stage. Hind limb samples had the greatest decrease in length, compared with results for samples obtained from other locations, across all processing stages for both sample sizes. The 30-mm samples had a greater percentage change in length and width between P1 and P2 than did the 10-mm samples. Histologic processing (P2 to P3) had a greater effect on the percentage shrinkage of 10-mm samples. For all locations and both sample sizes, percentage change between P1 and P3 ranged from 24.0% to 37.7% for length and 18.0% to 22.8% for width. CONCLUSIONS AND CLINICAL RELEVANCE Histologic processing, anatomic location, and sample size affected the degree of shrinkage of a canine skin sample from excision to histologic assessment.

OBJECTIVE To use CT-derived measurements to create a ferret-specific formula for body surface area (BSA) to improve chemotherapeutic dosing. ANIMALS 25 adult ferrets (19 live and 6 cadavers). PROCEDURES Live subjects were weighed, and body measurements were obtained by each of 3 observers while ferrets were awake and anesthetized. Computed tomography was performed, and a 3-D surface model was constructed with open-source imaging software, from which BSA was estimated. The CT-derived values were compared with BSA calculated on the basis of the traditional tape method for 6 cadavers. To further validate CT analysis software, 11 geometric shapes were scanned and their CT-derived values compared with those calculated directly via geometric formulas. Agreement between methods of surface area estimation was assessed with linear regression. Ferret-specific formulas for BSA were determined with nonlinear regression models. RESULTS Repeatability among the 3 observers was good for all measurements, but some measurements differed significantly between awake and anesthetized ferrets. Excellent agreement was found between measured versus CT-derived surface area of shapes, traditional tape– versus CT-derived BSA of ferret cadavers, and CT-derived BSA of cadavers with and without monitoring equipment. All surface area formulas performed relatively similarly. CONCLUSIONS AND CLINICAL RELEVANCE CT-derived BSA measurements of ferrets obtained via open-source imaging software were reliable. On the basis of study results, the recommended formula for BSA in ferrets would be 9.94 × (body weight)2/3; however, this represented a relatively minor difference from the feline-derived formula currently used by most practitioners and would result in little practical change in drug doses.

Objective: To optimize the use of CT-guided modeling for the calculation of body surface area (BSA) in domestic rabbits (Oryctolagus cuniculus). Animals: 12 domestic rabbits. Procedures: Adult rabbits (body weight, 1 to > 4 kg) that were client-owned animals undergoing CT for disease diagnosis or deceased laboratory animals donated from other research projects were scanned with a CT scanner. Images were transferred to a radiation therapy planning software program. Image slices were captured as contiguous slices at 100 kVp and 100 mA and processed to 0.1-cm-thick sections. The length of each contoured slice was summed to calculate a final BSA measurement. Nonlinear regression analysis was then used to derive an equation for the calculation of BSA in rabbits. Results: The constant calculated by use of this method was 9.9 (range, 9.59 to 10). The R2 for the goodness of fit was 0.9332. The equation that best described BSA as a function of body weight for domestic rabbits with this method was as follows: BSA = (9.9 × [body weight {in grams}]2/3)/10,000. Conclusions and Clinical Relevance: The BSA calculated via the CT-guided method yielded results similar to those obtained with equations for other similarly sized mammals and verified the use of such equations for rabbits. Additionally, this technique can be used for species that lack equations for the accurate calculation of BSA.

Objective-To use an amplified ELISA technique to document the presence and quantify the concentration of the house dust mite allergen, Der f 1, in skin and coat dust samples collected from dogs. Animals-29 pet dogs of various breeds. Procedure-Dogs were weighed, and body surface area in square meters was determined. Skin and coat dust samples were obtained by vacuuming dogs. Collected dust was analyzed by use of standard and amplified ELISA techniques. Results-By use of the standard ELISA technique, Der f 1 was detected in skin and coat dust samples from 6 of 29 (21%) dogs. Mean concentration of Der f 1 in the 6 samples with positive assay results was 16.16 ng/mL (range, 5.61 to 31.24 ng/mL). Samples with negative assay results were retested for dust mite allergen by use of an amplified ELISA technique; an additional 14 dogs had positive assay results. Mean concentration of allergen was 0.36 ng/mL (range, 0.19 to 2.20 ng/mL). Combining both techniques, 20 of 29 (69%) dogs had positive assay results for Der f 1. Conclusions and Clinical Relevance-Results of our study indicate that house dust mite allergens are present on the skin and in the coat of dogs, and this source of allergen may act as a reservoir for allergen exposure in hypersensitive dogs. Use of an amplified ELISA technique to determine environmental concentrations of house dust mite allergens in homes and on dogs will help to identify the relationship between immunologic findings and environmental exposures in dogs with atopic dermatitis.

Tooth surface and interradicular area (furcation) measurements were taken of 20 first mandibular molar teeth obtained randomly from canine cadavers. The lingual furcation entrance had a mean width of 1.2 +/- 0.3 mm. The buccal furcation entrance had a mean width of 1.3 +/- 0.4 mm. There was no significant difference between mean furcation entrance measurements. The horizontal attachment area between the cementoenamel junction and the coronal roof of the lingual furcation was 1.1 +/- 0.4 mm. The horizontal attachment area between the cementoenamel junction and the coronal roof of the buccal furcation (0.5 +/- 0.3 mm) was significantly different from the lingual horizontal attachment area. Distal root length and mesial root length were 16.0 +/- 1.5 mm and 16.1 +/- 1.6 mm, respectively. The mean coefficient of variation for variables measured was 14.0%. Tooth size did not have a significant effect on furcation entrance measurement. All teeth had a concavity coronal to the furcation area, which extended apically for a mean distance of 65.6% of the distal root length and 83.8% of the mesial root length. Furcation anatomy of the first mandibular molar is complex and may be a contributing factor in periodontal disease involving the interradicular area.

OBJECTIVE To develop and assess a novel ex vivo corneal culture technique involving an agarose-based dome scaffold (ABDS) for use as a model of in vivo corneal wound healing in dogs and rabbits. SAMPLE Corneas from clinically normal dogs (paired corneas from 8 dogs and 8 single corneas) and rabbits (21 single corneas). PROCEDURES 8 single dog corneas (DCs), 1 DC from each pair, and 10 rabbit corneas (RCs) were wounded with an excimer laser; 1 DC from each pair and 11 RCs remained unwounded. Corneas were cultured for 21 days on ABDSs (8 pairs of DCs and all RCs) or on flat-topped scaffolds (8 single DCs). The surface area of corneal fluorescein retention was measured every 6 (DCs) or 12 (RCs) hours until full corneal epithelialization was detected. Changes in corneal clarity were evaluated at 0, 7, 14, and 21 days. RESULTS Median time to full epithelialization for wounded dog and rabbit corneas was 48 and 60 hours, respectively; among wounded DCs, time to full epithelization did not differ by scaffold type. After 21 days of culture on ABDSs, all DCs and RCs that epithelialized developed a circular, diffuse, cloud-like pattern of optical haze, whereas DCs cultured on flat-topped scaffolds developed a focal, crater-like region of optical haze. All corneas on the ABDSs maintained convex curvature throughout the study. CONCLUSIONS AND CLINICAL RELEVANCE Wounded ex vivo DCs and RCs cultured on ABDSs reliably epithelialized, formed optical haze (consistent with in vivo wound healing), and maintained convex curvature. This culture technique may be adaptable to other species.

OBJECTIVE To determine whether exercise on alternative terrain affects the development of the digital cushion and bony structures of the bovine foot. ANIMALS 20 weaned bull calves. PROCEDURES Two-month-old calves were randomly allocated to an exercise or control group. For 4 months, the control group was maintained in grass paddocks, and the exercise group was maintained in a 0.8-km lane with a mixed terrain of dirt, stones (0.32- to 0.95-cm pea gravel and 5-cm crusher run), and grass. Water and food for the exercise group were located at opposite ends of the lane; calves were fed twice daily, which ensured they walked 3.2 km/d. Pedometers were applied to all calves to measure distance traveled. All calves were slaughtered at 6 months of age. The right forefeet and hind feet were harvested for MRI and CT evaluation. RESULTS Control calves walked a mean of 1.1 km daily, whereas the exercised calves walked a mean of 3.2 km daily. Mean digital cushion volume and surface area were 25,335 mm3 and 15,647 mm2, respectively, for the exercised calves and 17,026 mm3 and 12,745 mm2, respectively, for the control calves. When weight was controlled, mean digital cushion volume and surface area for the exercise group were increased by 37.10% and 18.25%, respectively, from those for the control group. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that exercise on alternative terrain increased the volume and surface area of the digital cushion of the feet of dairy calves, which should make them less susceptible to lameness.