Heart Rate Changes Before, During, and After Treadmill Walking Exercise in Normal Dogs.

In dogs, changes in heart rate (HR) can reflect conditioning, fear, anticipation, and pain; however, these are not routinely assessed in veterinary rehabilitation patients. Knowing the expected HR changes during rehabilitation exercises can guide protocols and can optimize post-operative therapy. The primary objectives of the study were to assess HR in dogs undergoing treadmill exercise (TE) during the walk and to compare the three collection techniques of HR, namely, auscultation, a HR monitor (HR MONITOR), and a Holter monitor (HOLTER). We hypothesized that the HR would increase by 20% during TE, that HR taken after TE would not be the same as the HR during TE, and that all methods of measurement would have good agreement. HR was recorded in all methods simultaneously, in eight adult healthy large breed dogs during rest (REST), immediately before TE (PRE), during TE (WALK), and 15 and 60 s after TE (POST-15, POST-60). Statistical analyses included Spearman and Pearson correlations, Bland-Altman analyses, and a repeated measures ANOVA with Sidak's post-hoc test (significant at value of p < 0.05). Increased HR was reflected in TE during WALK, and elevations in HR during WALK were not reflected in POST timepoints. Auscultation was also not possible during WALK. Significant moderate-to-strong correlations existed among all monitoring options at each of the timepoints (rho range = 0.5-0.9, p < 0.05). There were no correlations between peak HR and age or weight. The main limitation of this study is that only healthy and large breed dogs were used. Both monitors captured the increase in HR during exercise and could guide TE regimens to minimize patient risk of injury and to maximize training effectiveness.

Evaluation of Thermographic Imaging in Canine Hindlimb Muscles After 6 Min of Walking-A Pilot Study.

Objective: To evaluate changes in superficial temperature of hindlimb muscles before and after a 6-min walk in healthy dogs. Methods: Two infrared thermographic images were captured of the proximal and distal hindlimbs of 11 healthy dogs before and after a 6-min walk. Orthopedic exam and objective gait analysis confirmed the healthy status of study subjects. Superficial temperatures of the gastrocnemius, biceps femoris, and gracilis were assessed. Analysis of images was performed using 2 different methods of region of interest (ROI) selection. ROI were selected first using one point (single pixel) in the muscle and then separately by selecting a line (LN) corresponding to many points of each muscle belly from which an average was taken. P < 0.05 was considered significant. Results: There was no significant change in temperature using point ROI before and after 6 min of walking of the gastrocnemius, gracilis, and biceps femoris muscles (p = 0.273, p = 0.349, p = 0.351, respectively). Using linear ROI, both biceps femoris and gracilis muscles exhibited significant increases in temperature (p < 0.0001, p = 0.032, respectively). There was no significant increase in temperature of gastrocnemius muscle for both point and linear ROI selection (p = 0.273, p = 0.448, respectively). The right biceps femoris temperatures were higher compared to left biceps femoris using the linear ROI before and after walks (p < 0.0001). The overall (left and right limbs pooled) standard deviation of point selected values were greater than LN selected values of the biceps femoris (1.35 and 1.11) and gastrocnemius (1.51 and 1.23). In contrast, standard deviation for the gracilis measurements were decreased using point selection vs. LN selection (1.09 and 1.3). Conclusions: The biceps femoris and gracilis muscles demonstrated significant increases in surface temperature after 6 min of walking using the linear method of ROI. Measurement of numerous points along the entire length of the biceps femoris and gastrocnemius muscles may provide a more accurate assessment of the increased vascularity within the tissues resulting from work compared to single point selection. Clinical Significance: Prior activity and ROI selection method should be considered when interpreting thermography results.

The Effects of Varying Concentrations of Dietary Protein and Fat on Blood Gas, Hematologic Serum Chemistry, and Body Temperature Before and After Exercise in Labrador Retrievers.

Optimal dietary protocols for the athletic canine are often defined by requirements for endurance athletes that do not always translate into optimal dietary interventions for all canine athletes. Prior research studying detection dogs suggests that dietary fat sources can influence olfaction; however, as fat is added to the diet the protein calories can be diminished potentially resulting in decreased red blood cell counts or albumin status. Optimal macronutrient profile for detection dogs may be different considering the unique work they engage in. To study a calorically low protein: high fat (18:57% ME), high protein: high fat (27:57% ME), and high protein: low fat (27:32% ME) approach to feeding, 17 dogs were provided various diets in a 3 × 3 cross over design. Dogs were exercised on a treadmill and blood was taken pre-exercise, immediately post-exercise, 10- and 20-min post-exercise to assess complete blood count, serum chemistry, blood gases, and cortisol; as well as rectal and core body temperature. Exercise induced a decrease in serum phosphorus, potassium, and increases in non-esterified fatty acids and cortisol typical of moderate exercise bouts. A complete and balanced high protein: high-fat diet (27:57% ME) induced decreases in serum cortisol and alkaline phosphatase. Corn oil top dressed low protein: high-fat diet (18:57% ME) induced a slightly better thermal recovery than a complete and balanced high protein: high fat diet and a high protein: low fat (27%:32% ME) diet suggesting some mild advantages when using the low protein: high fat diet that warrant further investigation regarding optimal protein and fat calories and thermal recovery.

The effects of exercise and diet on olfactory capability in detection dogs.

A previous work suggests that dietary fat may influence canine olfaction. The present study evaluated whether olfactory performance could be influenced by forms of dietary fat and exercise. Seventeen certified detection dogs were fed three different diets (high fat, low fat or high polyunsaturated fat) for 12 weeks. After 12 weeks, olfactory testing was performed using a scent wheel in an olfaction laboratory using three explosive materials. The dogs completed eight to twelve scent trials before and after a 30 min treadmill exercise on five consecutive days. A mixed-effect logistic regression model was used to examine how diet, pre- or post-exercise, trial number, odourant, mass of target and target position influenced the probability of dogs alerting on the target odour. There were no significant changes in the dog's ability to find a target odour at threshold amounts. Dogs were 1·42 (1·08, 1·87; 95 % CI) times as likely to find a target on the high polyunsaturated fat diet relative to the high-fat diet (P = 0·009). The low-fat diet was not significantly different from either the high-fat diet or the high polyunsaturated fat diet (P = 0·12). Dogs were 1·49 (1·26, 1·76; 95 % CI) times as likely to find a target prior to exercise relative to after exercise (P < 0·001). Dogs on the high PUFA diet utilising maize oil showed mild improvement in olfaction. The exact reasons are unknown; however, the higher relative amount of linoleic acid in the diet may play a role in olfactory sensation which warrants further examination of optimal diets for detection dogs.

Telemetric measurement of body core temperature in exercising unconditioned Labrador retrievers.

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°C at pre-exercise to 40.4 ± 0.6°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.

Hematologic, serum biochemical, and cortisol changes associated with anticipation of exercise and short duration high-intensity exercise in sled dogs.

BACKGROUND: Many studies have demonstrated changes in clinicopathologic variables in response to exercise in athletic dogs. These changes have been attributed to the duration and intensity of exercise. However, inconsistencies in the timing of collection of resting blood samples can be a confounding variable when interpreting results. OBJECTIVES: The objectives of this study were to determine whether hematologic and biochemical data in sled dogs are influenced by (1) anticipation of an exercise event or (2) short-duration high-intensity exercise. METHODS: Blood samples were collected into EDTA tubes and tubes without anticoagulant from sled dogs at rest, immediately before a 3-mile run (preexercise), and immediately after the run (postexercise). A CBC, biochemical profile (including electrolytes, glucose, proteins, creatinine, urea, enzymes, cholesterol, and total bilirubin), and serum cortisol concentration were measured using standard methods on automated analyzers. RESULTS: Significant increases in sodium, chloride, albumin, calcium, and cortisol concentration were observed in preexercise samples when compared with resting samples. Hyperglycemia and a further rise in serum cortisol concentration occurred immediately postexercise. CONCLUSIONS: The results of this study indicate that anticipation of exercise affects several biochemical analytes, emphasizing the importance of appropriate timing of baseline blood samples. The pronounced hyperglycemia immediately after short-duration exercise may be a breed- or exercise-dependent phenomenon.

Recent developments in canine locomotor analysis: a review.

Subjective evaluation of canine gait has been used for many years. However, our ability to perceive minute details during the gait cycle can be difficult and in some respects impossible even for the most talented gait specialist. The evolution of computer technology in computer assisted gait analysis over the past 20 years has improved the ability to quantitatively define temporospatial gait characteristics. These technological advances and new developments in methodological approaches have assisted researchers and clinicians in gaining a better understanding of canine locomotion. The use of kinematic and kinetic analysis has been validated as a useful tool in veterinary medicine. This paper is an overview of the kinematic and kinetic analytical techniques of the last decade.

Bioelastic membranes for topical application of a thromboxane synthetase inhibitor for protection of skin from pressure injury: a preliminary study.

A previous study showed that topical exposure to bioelastic-thromboxane synthetase inhibitor-matrix resulted in local tissue concentrations of thromboxane synthetase inhibitor sufficient for thromboxane synthetase inhibition. The objective of this research was to use an animal model to determine if a dressing having controlled release of thromboxane synthetase inhibitor (dazmegrel) could be used to prevent tissue breakdown over pressure points, i.e., lesion at the assistive device-skin interface. The animal model studies utilized the greyhound, a dog that has thin skin, angular conformation, limited body fat and is predisposed to pressure ulcers similar to those occurring in humans. The model uses a short-limb walking cast on one pelvic limb with the severity of the dermal pressure lesions induced over the medial malleolus controlled by the amount of padding in the cast and length of time the cast is in place. The bioelastic matrix loaded with dazmegrel provided protection from shearing and pressure skin injury over the medial malleolus, as evidenced by a decrease in epidermal abrasion/ulceration as measured with planimetry. Histopathologic evaluation of the skin over the medial malleolus indicated a protective function of the bioelastic matrix as measured as lower numbers of neutrophils, lymphocytes, and decreased collagen density compared to such numbers when no bioelastic matrix was present. These studies provided evidence that bioelastic-thromboxane sythetase inhibitor- matrix helps in preventing or reducing the severity of pressure lesions, e.g., assistive device-skin interface wounds.

Effects of bandage configuration on paw pad pressure in dogs: a preliminary study.

Seven bandage configurations were placed on the right forepaw of six English pointer dogs to evaluate the effects that configurations have on reducing pad pressure. The "clam shell" configuration resulted in less pressure being applied to all palmar pad surfaces. For the major weight-bearing pad, a basic paw bandage with an intermediate compressible foam sponge that had a hole under the major weight-bearing pad, combined with a metal splint paw cup under the sponge, resulted in a significantly lower pressure recording than for other bandage configurations. Digital pads 3 and 5 had the greatest pressure in a basic bandage configuration. Based on pressures on these pads, a basic paw bandage with an intermediate compressible foam sponge under the major weight-bearing pad, with or without a metal splint paw cup under the sponge, helped elevate the digits to relieve pressure on them. Placing a foam sponge pad, with or without a splint paw cup under the palmar paw surface, also provided less pressure on these pads.