410 Canine Sports Medicine and Rehabilitation
with external skeletal fixation (Souza et al.,
2012). Dogs treated with PRP had significantly
greater healing scores based upon radiography.
This prospective, randomized study provides
good evidence of the benefit of PRP use on bone
healing. One characteristic of the study, how‑
ever, that was unclear is whether all the dogs
studied were of the same age. This is relevant
because the author (SF) recently completed a
prospective, randomized clinical trial assessing
the effects of PRP on bone healing in 60 dogs
treated by tibial plateau leveling osteotomy
(Franklin et al., 2017b). The PRP had a high
platelet concentration, neutral leukocyte con‑
centration, no erythrocytes, and was activated
with calcium chloride and thrombin to form a
gel that was placed in the osteotomy at the
time of surgery (Figure 16.4). Bone healing was
assessed using radiography, ultrasonography,
and MRI. With basic statistical testing, it
appeared that PRP provided a small, but sta‑
tistically significant, benefit. However, multi‑
variate analysis demonstrated that the small
differences in healing scores were attributable
to variations in individual dog age rather than
to use of PRP. Accordingly, there is limited and
variable evidence regarding benefit of PRP on
long bone healing in dogs.
Osteoarthritis (intra‐articular injections)
In 2013, three studies were published providing
initial data regarding efficacy of different PRP
preparations in treating naturally occurring
disease in dogs. The author (SF) performed a
blinded, prospective, randomized study com‑
paring the efficacy of intra‐articular use of a
leuko‐reduced PRP with the use of hyaluronan
and corticosteroid for treatment of elbow osteo‑
arthritis (OA) in 10 dogs (Franklin & Cook,
2013). Significant improvements were identi‑
fied in both treatment groups based on client
and veterinarian assessments using subjective
outcomes measures. Some improvements were
greater in the PRP treatment group but the
study did not include force plate data, so only
limited conclusions can be drawn.
Fahie and colleagues (2013) performed a pro‑
spective, randomized, controlled study compar‑
ing the efficacy of filtered platelet therapy with
saline injection for treatment of OA in 20 dogs.
This product is not technically a PRP because
it suspends the cellular components in saline
rather than plasma. However, it is considered
similar to PRP in concept and probable mecha‑
nism of action. The solution contains a mild
increase in platelet concentration and is leuko‑
cyte‐rich with a hematocrit of approximately
22%. The study included objective force plate
data for half the dogs in addition to using vali‑
dated subjective outcome measures for all dogs.
The results demonstrated significant improve‑
ments in objective and subjective outcomes over
a 12‐week follow‐up period with intra‐articular
use of the product. Interestingly, the nine dogs
in the control group were injected at study end
and showed significant improvement based
upon force plate data after receiving treatment.
Yet another group published results from a
prospective, randomized study assessing the
effects of three PRP injections after intra‐articu‑
lar stabilization for treatment of cranial cruciate
ligament (CCL) rupture in 10 dogs (Silva et al.,
2013). Peak vertical force and vertical impulse
measured using a force plate improved from
preoperative to day 90 post surgery for the six
dogs treated with PRP; no such improvement
was noted for the four dogs in the control group.
Likewise, force plate data indicated significantly
greater weight bearing with the affected limb for
dogs treated by PRP compared with the affected
limb of control dogs at day 90 post surgery.
More recently, three in vivo studies in research
dogs have been performed. One study induced
OA in the stifle of 12 dogs by partial CCL tran‑
section and complete medial meniscal release
(Cook et al., 2015). Dogs were randomized to
receive five injections of either saline or a leuko‐
reduced PRP. Comfortable range of motion
was better maintained in the treatment group.
Based upon objective, kinetic pressure mat
data, weight bearing was significantly better
(by about 10%) at weeks 5, 12, and 18 following
treatment with PRP in comparison to the saline
sham‐treated group. Blinded histological scoring
of the CCL was significantly better in the treat‑
ment group. A follow‐up investigation compared
the efficacy of the same PRP with oral carpro‑
fen or arthroscopic saline lavage for managing
experimentally induced injury of the CCL in
dogs (Bozynski et al., 2016). Both arthroscopic
lavage‐ and PRP‐treated dogs had less lame‑
ness, pain, and stifle effusion and greater subjec‑
tive function than dogs treated with carprofen.
Dogs receiving PRP demonstrated the greatest
benefit. PRP was also associated with the lowest