Front Matter

Chapter 16 Biological Therapies in Canine Sports Medicine 407

they are convenient and require less time and
hands‐on work (Figure 16.3). In addition, these
commercially available point‐of‐care systems
might facilitate maintenance of sterility and
could potentially produce a more consistent
PRP product, although this has not been
demonstrated.

Commercially available PRP preparation

systems

Most PRP systems were designed and manu‑

factured for preparing PRP from human blood.

However, the cellular elements in human blood

differ from those in canine blood in character‑

istics such as size, density, and sedimentation

rate. Hence, characteristics of PRP acquired

using a given system with human blood are not

necessarily representative of the PRP that is

acquired using the same system with canine

blood. Therefore, it is important that data from

dogs are considered. Fortunately, there are now

several studies characterizing PRPs made with

canine blood (Thoesen et  al., 2006; Stief et  al.,

2011; Carr et al., 2015; Franklin et al., 2015; Frye

et al., 2016). Of these, one author (SF) completed

a 15‐dog cross‐over study assessing the charac‑

teristics of PRP made with five different PRP

systems (Franklin et  al., 2015). The degree of

platelet concentration varied from platelet

reduction in one system to an average increase

of five‐fold over baseline with another system.

Similarly, three systems produced a PRP with

negligible hematocrit while the PRP from two

systems consistently had a notable hematocrit.

Lastly, some systems produced leukocyte‐rich

PRP while other produced a leuko‐reduced PRP.

Growth factor concentrations (TGF‐β1,

PDGF‐BB) were also quantified in these PRPs.

As with human PRPs, there were moderate

correlations between the platelet concentration

and the anabolic growth factor concentrations

(Sundman et  al., 2011). However, the greatest

variable influencing growth factor concentra‑

tion was intentional activation of the PRP. This

became apparent as one of the PRP systems

included a calcium chloride activator that was

used during the PRP preparation. Although the

platelet concentration in this PRP was moderate,

it had significantly higher TGF‐β1 and PDGF‐

BB concentrations than all other PRPs. Further

investigation with one of the other PRP prepa‑

rations confirmed that platelets in such a PRP

preparation are not activated during the PRP

preparation process. Like platelets in human

and equine PRPs, these platelets were capable

of activation, and growth factor release was

dramatically increased once the PRP was mixed

with either calcium chloride or thrombin, with

thrombin producing the most robust activation

Figure 16.2 Platelet pellet after a second centrifugation
in a double‐spin platelet‐rich plasma preparation
protocol.

Figure 16.3 Platelet‐rich plasma (PRP) preparation
machine that can provide automated separation of the
blood into separate fractions including platelet‐poor
plasma, PRP, and the red blood cell pellet.