Chapter 5 Introduction to Canine Rehabilitation 115can greatly affect the healing time during the
recovery and rehabilitation phase. Of addi
tional consideration is pain management and
the use of regenerative medicine and other
concurrent medical treatments that might accel
erate or slow the healing timeframe.
There is a somewhat predictable progression
of the body’s tissues through the healing pro
cess. The time frame for each phase is variable
depending upon the factors discussed above.
The inflammatory phase occurs from day 0 until
approximately day 6 and includes a complex
series of physiological events. Initially, the
chemically mediated vascular responses of
vasodilation and vascular permeability occur,
allowing for white blood cell migration and
platelet aggregation to the site of tissue damage.
This allows for phagocytic processes to clean
cellular debris and fight against foreign patho
gens, and causes fibrin clot formation to reduce
bleeding and repair endothelial cell wall dam
age. Pain responses are associated with tissue
damage from the production of pain‐mediating
substances such as prostaglandins and brady
kinins. Vasoconstriction follows with a resulting
reduction in blood flow. The goal of this phase
of healing is to reduce blood loss, protect against
foreign pathogens, clean debris from damaged
tissue cells, and begin stabilization of the injury
site. The reparative or proliferative phase begins
day 3 to day 5 and lasts until about day 14, with
fibroplasia and granulation tissue formation,
epithelialization, angiogenesis, and contraction
of the wound bed. This phase provides a weak
scaffold upon which the scar tissue forms. The
maturation or remodeling phase occurs anywhere
from weeks to months following the injury and
is dependent upon the type of tissue that is
involved in the injury. In the natural healing
process, without surgical or regenerative
medicine intervention, complete recovery of the
strength of the original tissue rarely occurs
because the repaired tissue, or scar, is less organ
ized than the noninjured tissue. Of note is that
the presence of inflammation, although initially
protective, chronically (or without the ability to
progress healing to the proliferative phase) will
extend healing times, possibly delay or cause
nonunion or nonhealing of tissues, and result
in weak, disorganized scar tissue formation
(National Pressure Ulcer Advisory Panel, 2016;
Physiopedia, 2017a).
Bony injuries heal in a similar fashion;
however, osteoclasts and osteoblasts form a
soft callus in the reparative or proliferative
phase at about 2 weeks from the onset of the
injury. This phase continues for 6 to 12 weeks
during which time the soft callus is replaced by
a hard callus. The maturation or remodeling
phase can last for months during which the
hard callus is remodeled and strengthened as it
is gradually replaced by lamellar bone (Marsell
& Einhorn, 2011; Physiopedia, 2017a).Pain response to injury
Although pain is a subjective sensation defined
as “an unpleasant sensory and emotional expe
rience associated with actual or potential tissue
damage,” pain management is a consideration
in the rehabilitation treatment of the canine
patient with regards to the presence of tissue
damage and/or inflammation. The rehabilita
tion therapist might use rehabilitation modali
ties and manual therapies, in combination with
traditional pharmacological and medical man
agement, to assist in the management of pain
and inflammation. Furthermore, the rehabilita
tion therapist might direct interventions, such
as therapeutic exercise, toward progressively
increasing functional capacity and return of the
patient to full activity as efficiently and safely
as possible, so as to redirect the patient’s per
ception of pain (Prentice, 2013).
Of concern in this return to activity are the
alterations in central and peripheral neuromus
cular processes, which are influenced by the
presence of joint effusion, inflammation, and
pain. As a result of these alterations, normal
muscular contractions and motor control can
be inhibited. Left unattended, these neuro
muscular changes can lead to biomechanical
alterations and subsequent aberrant forces on
the injured and surrounding tissues. To compli
cate matters, these alterations in neuromuscu
lar control are present after pain has resolved
and tissue healing takes place. Long term, these
biomechanical faults can lead to further injury
and contribute to degenerative processes along
the kinetic chain. The rehabilitation therapist
should be aware of the potential for these
changes and be prepared to apply interventions
that can assist in the restoration of normalized
neuromuscular functioning through manual