Lower centrifugation speed and time are positively associated with platelet concentration in a canine autologous conditioned plasma system.

OBJECTIVE: To evaluate the effect of variable centrifugation protocols on the cellular composition of the final product of a canine autologous conditioned plasma double-syringe system. ANIMALS: 30 client-owned healthy adult medium- to large-breed (17- to 45-kg) dogs. METHODS: 35 mL of anticoagulated whole blood from each subject was aliquoted into 3 samples: a baseline and 2 double syringes. The syringes were processed for platelet-rich plasma (PRP). Each double syringe was randomly assigned to 1 of 5 groups, which varied in centrifugation settings between 580 and 1,304 X g and 5 and 10 minutes. CBC analysis was performed on each of the samples to determine cellular composition. A mixed-effect linear model was fit to the data. RESULTS: 60 PRP samples and 30 whole blood samples were analyzed. Manufacturer settings generated a platelet fold change > 1 but did not increase concentration to the extent expected. When comparing speed alone, increased centrifugation force was associated with lower platelet fold change. When comparing time alone, increased centrifugation time was also associated with lower platelet fold change and lower leukocyte concentration. CLINICAL RELEVANCE: Autologous conditioned plasma double syringes require a low volume of initial whole blood, making them preferable for canine PRP in clinical settings. This study aimed to evaluate the effect of the centrifugation protocol on the final product cellular composition in dogs and add to the available data on protocols to maximize platelet yield in PRP. Due to inherent individual variability, this study emphasized the importance of evaluating biological samples prior to administration to predict and improve patient outcomes.

Ground reaction forces, temporospatial parameters, range of motion, and limb characteristics were analyzed for small and medium size sound dogs with the use of pressure sensitive walkway.

OBJECTIVE: To study ground reaction forces (GRF) and temporospatial parameters for small and medium size dogs using a pressure sensitive walkway (PSW). We hypothesized that, at a given speed, small dogs would have shorter stance time than medium dogs and that dog height (DH) would influence GRF. ANIMALS: 30 healthy, sound dogs were divided into 2 groups, small < 15 kg and medium dog group weighing 15 to 25 kg. PROCEDURES: GRFs were measured for both groups at walk and trot using PSW. Muscle mass and joint angles were measured. Data were analyzed using SAS version 9.4. Two groups were compared using 2-sample t test, Wilcoxon rank sum test, and Fisher exact test. RESULTS: GRFs were successfully measured in both dog groups for walk and trot. Medium dogs had larger limb girth, more peak pressure, max force, increased stance, swing time, and larger stride length compared with small dogs. Stance time increased as DH increased at walk and trot (r = 0.854, P < .001; r = 0.876, P < .001). Stance time increased as BW (body weight) increased at walk and trot (r = 0.887, P < .001; r = 0.858 P < .001). Inconclusive data was obtained for stride acceleration and velocity. The handler side did not influence results (P > .05). Range of motion (ROM) did not differ among groups. CLINICAL RELEVANCE: Results suggested that PSW is a reliable device for small and medium dogs. At walk and at a trot, GRF are smaller in small dogs compared with medium dogs, suggesting that normal reference data for PSW need to take BW and DH into account.

Assessing the Relationship Between Emotional States of Dogs and Their Human Handlers, Using Simultaneous Behavioral and Cardiac Measures.

Negative stress due to human handling has been reported for a number of domestic animals, including dogs. Many companion dogs display significant stress during routine care in the veterinary clinic, risking injury to staff and potentially compromising the quality of care that these dogs receive. On the other hand, positive interactions with humans can have a beneficial effect on dogs, particularly in stressful situations such as animal shelters. Research has shown that dogs can detect human emotions through visual, auditory, and chemical channels, and that dogs will exhibit emotional contagion, particularly with familiar humans. This study investigated relationships between emotional states of dogs and unfamiliar human handlers, using simultaneous measures of cardiac activity and behavior, during two sessions of three consecutive routine handling sets. Measures of cardiac activity included mean heart rate (HRmean), and two measures of heart rate variability (HRV): the root mean square of successive differences between normal heartbeats (RMSSD); and the high frequency absolute power component of HRV, log transformed (HFlog). We also assessed human handlers' emotional state during handling sessions following an intervention designed to reduce stress, compared with sessions conducted on a different day and following a control activity. Polar H10 cardiac sensors were used to simultaneously record cardiac activity for both canine and human participants, and behavioral data were collected via digital video. The strongest influence on the dogs' stress levels in our study was found to be increasing familiarity with the setting and the handler; HRmean and SI decreased, and HRV (as RMSSD) increased, significantly from the first to the third handling set. Canine HRV (as HFlog) was also highest in set 3, although the difference was not statistically significant. There were no strong patterns found in the human cardiac data across handling set, session, or by pre-handling activity. We did not find consistent support for emotional contagion between the dogs and their handlers in this study, perhaps due to the brief time that the dogs spent with the handlers. Recommendations for application to dog handling, and limitations of our methods, are described.