Intra- and Inter-individual Variability of Platelet-rich Plasma Volume and Cellular Composition, and Associated Clinical Outcomes in Dogs Treated for Elbow Dysplasia

Platelet-rich plasma (PRP) is a biological product commonly used in veterinary orthopaedics. There is a lack of descriptive information of the final product used in clinical studies.The objectives were to describe and analyze the intra-individual variability of the quantity and cellular composition of the autologous conditioned plasma (ACP) obtained at various time points in each patient in a group of dogs suffering from elbow dysplasia, and to describe the outcome from an owner's perception.Dogs diagnosed with elbow dysplasia treated with three ACP injections 1 week apart were included. A complete blood count on whole blood and ACP was documented in at least two infiltrations. Volume of ACP and degree of platelet increased concentration factor, leukocyte and red blood cell decreased reduction factor were evaluated at each time point. Intra-individual variability of ACP characteristics, mean ACP volume collected and injected, and number of injected platelets were analyzed. Canine brief pain inventory (CBPI) scores were recorded.In this study 23 dogs were included. No difference was observed in intra-individual ACP volume collected, leukocyte reduction factor and red blood cell reduction factor, or number of platelets injected at various time points, while a significant difference was observed in intra-individual platelets concentration factor. The CBPI scores decreased between pre- and post-injection scores in the majority of the patients.Regarding ACP, platelets concentration factor is variable in the same patient at various time points while the volume collected and the purity are stable.