Rehabilitation is a fast growing area of veterinary and complementary medicine, and its role is rapidly being recognized as essential in the recovery of canine musculoskeletal and neurological injuries.

So why is it that many canine injuries are often treated with little thought to rehabilitation and return to function? Animals are just given pain relief and recommended to lead walk for two weeks? Of course, in some mild lameness cases, where a specific diagnosis is not confirmed but suspected this plan of action can be successful. However in the majority of canine lameness cases, whether a pet or a working dog, they can benefit from the inclusion of a specific and appropriate rehabilitation programme within the veterinary treatment plan.

Just as with human athletes, if rehabilitation is inadequate the animal is:

 Prone to reinjury

 Incapable of performing at pre-injury standard

 Predisposed to injuring another part of the body

Effect of injury upon muscle: Rapid muscle atrophy occurs due to a cellular response to pain, inflammation and immobility. Persistent pain will cause muscle weakness due to decreased neural input. Joint effusion may lead to reflex inhibition of surrounding muscles.

Definition of rehabilitation:

 The restoration of normal form and function after illness or injury

 The restoration of the ill or injured patient to optimal functional level in all areas of activity

Millis, Levine and Taylor (2004) define veterinary physical rehabilitation as the use of noninvasive techniques, excluding veterinary chiropractic therapy, for the rehabilitation of injuries in nonhuman animals.

For the successful rehabilitation of the canine patient a team approach is recommended, with the veterinarian, physiotherapist or physical therapist, veterinary nurses (if hospital based), owner and other individuals such as a hydrotherapist.

Rehabilitation Principles

In order to develop a successful rehabilitation plan it must be...

 Individual specific

 Appropriate

 Achievable

 Functional

 Measurable

Specific

To the individual patient, specific for the pathology and for the individual's functional impairments, using correct exercise technique with precise progression.

Appropriate

To the condition/pathology and the stage of healing. Appropriate for the level of previous function - if it is a geriatric pet then it will not require the high level neuromotor skills of a search or agility dog.

Achievable

For the owner/handler AND the dog and start as early as possible.

Functional

Must include functional retraining so the dog is able to return to full function. Include functional skills, tasks and activities of daily life. From basic transfers to stairs/ramps/toileting to high level - poles/slalom/jumping/pulling.

Measurable

Needs to include outcome measures that are repeatable and validated, i.e., goniometry range of motion (ROM), weight transfer using scales, pressure mats and video analysis.

Components of Rehabilitation

 Muscle conditioning

 Flexibility

 Proprioception

 Functional exercises

 Sport skills

 Correction of abnormal biomechanics

 Maintenance of cardiovascular fitness

Canine Forelimb Lameness & Biomechanics

The canine forelimb is a crucial weightbearing structure, taking approximately 60% of the dog's weight. The forelimb is used as a 'strut' (Carrier, Deban, Fischbein 2008) but is also actively involved in propulsion in the dog (Williams, Wilson, Daynes, Peckham, Payne 2008). The forelimb is an intricate structure with complex muscular and soft tissue structures both within the thoracic limb and extrinsic attachments to the thorax. When diagnosing and rehabilitating canine forelimb lameness often the extrinsic structures are overlooked, and to achieve successful functional rehabilitation a holistic approach is important. Williams et al. (2008) has demonstrated that the extrinsic muscles pectoralis profundus and latissimus dorsi muscles in the greyhound contributed significantly to thoracic limb muscle mass and they are adapted to produce large amounts of work. Biceps brachii and triceps brachii not only generate high forces but also play a role in stiffening the limb joints during stance and dynamic stability. The long head of triceps is stronger than all other muscles in the greyhound, and its specialized role in force production is thought to be crucial in stabilizing the elbow and shoulder joints during stance.

The forelimb of the dog is not only designed to withstand and generate large forces, but also provide mobility and dynamic stability. The shoulder joint alone is able to flex, extend, rotate, abduct and adduct. There are 24 intrinsic muscles and 8 extrinsic forelimb muscles (Evans, deLahunta 2004). This is important to keep in mind when diagnosing and assessing canine forelimb lameness, the muscles may either be the primary site of damage or dysfunctional secondary to a joint, ligament, nerve or skeletal injury.

For example, a biceps tendinopathy may result in brachiocephalicus, triceps, pectoral and latissimus dorsi shortening and dysfunction, and if only the biceps brachii muscle is treated the dog will not achieve a symmetrical and functional gait pattern and full range of motion (ROM) until these secondary issues are addressed. This is also the case with other orthopaedic conditions - muscle strains, ligament injury and joint dysfunction such as elbow dysplasia or osteoarthritis. In the case of neurological injury, if there is reduced dynamic stability or control around a joint due to neurological injury, atrophy and weakness there are similar secondary adaptations that must be identified in the extrinsic musculature in order to restore normal movement and function.

This paper does not have the scope to discuss diagnosis of forelimb lameness, or the numerous pathologies prevalent in the canine forelimb so instead will move directly onto the rehabilitation of the canine forelimb.

Rehabilitation

After a veterinary diagnosis has been reached, functional impairments must be identified to establish a specific rehabilitation protocol for the individual patient. On gait analysis and functional movement assessment, abnormal movement patterns or the inability to perform are noted, such as, the inability to transfer from sternal recumbency to standing, or transfer body weight onto the affected limb. Trunk control is also noted and neuromuscular control around the affected limb. Then the range of motion and the tissue (ligament, joint, muscle, tendon) integrity (provocation tests) needs to be established. Neurological or proprioceptive deficits must be identified and muscular imbalance, atrophy or hypertrophy noted. A full palpatory assessment is then carried out to assess pain response and tissue 'feel' and irritability.

Following an in-depth physiotherapy assessment, a specific, achievable, functional and measurable rehabilitation programme may start to be established whilst working with the owner's goals and ability to implement the programme at home. Owner compliance is crucial for a successful rehabilitation programme as the reality is - they have to do a lot of the work and management when the dog is at home. The owner also may have to commit extra time and travel as part of the rehabilitation programme such as transporting the animal to hydrotherapy and physiotherapy sessions, walking the dog separate to other dogs in the household to enable appropriate exercise, time one on one with the dog doing exercises and training. The owner must be on board and understand the commitment required for the entire period of the rehabilitation.

The rehabilitation programme needs to be tailored to the type of injury (acute or chronic, post-surgical, neurological or musculoskeletal), the breed and temperament, previous and potential level of function (family pet? agility dog? police dog?) and the expectations of the owner. Treatment and rehabilitation also needs to be specific to the stages of healing to maximize effectiveness.

Home Environment

Home environment modification is part of the rehabilitation plan, and is vital element often overlooked. The success of the rehabilitation programme may hinge on effective management of the animal at home. Where does the dog spend most of its day? Out in the backyard where it can jump on and off walls and a deck or steps unsupervised? Or inside on polished wood floors or tiles? Is the dog able to transfer in and out of its bed safely? Does it run to the front door, slipping and sliding around corners when the doorbell rings or to chase the cat? Does it jump on and off furniture numerous times a day? Modification of the home environment depends on the individual dog, pathology and home situation but it is essential to glean as much information as possible from the owner. In some cases it is beneficial to organize a home visit to truly assess the home environment.

Home Exercise Programme

Home exercise programme (HEP) should be tailored to the dog's needs and impairments, it should be specific, progressive and achievable for the owner and the dog. At each physiotherapy session, the HEP should be progressed in response to the dog's improvement in order to challenge and improve strength, ROM, proprioception and dynamic control.

Musculoskeletal Rehabilitation

Stages of Healing (Edge-Hughes, Nicholson 2007)

Early Stage 1 - Haemorrhagic Phase: 24-48 Hours

 Cellular changes and swelling occur as erythrocytes and neutrophils infiltrate the area.

 Goals: RICE principles (rest, ice, compression, and elevation) minimize bleeding, control swelling, prevent stress and tension, control inflammation and pain for the first 24 hours. 24–48 hours pain free movement should be initiated.

Late Stage 1 - Substrate Phase: Day 3–5

 Monocytes and macrophages break down dead cells and collagen, vascular permeability is increased, granulation tissue begins to form.

 Goals: assist removal of traumatic inflammatory exudates to promote healing. Physiotherapy modalities such as pulsed ultrasound, pulsed electromagnetic field therapy (PEMF), low grade mobilisations.

Stage 2 - Regeneration Phase: Day 5–21 (Up to 15 Weeks)

 Formation of new collagen fibres, they are small and weak in a disorganized arrangement so vital to encourage alignment of fibres and increase tensile strength with appropriate stimulus. At 2 weeks post injury, collagen synthesis is at its greatest (Sharma, Maffulli 2005) so important to incorporate a small degree of stress to promote collagen alignment.

 Increase ROM, increase flexibility and minimize adhesions, balance and weight shift exercise to encourage weight bearing and proprioception, active muscle contractions - walking, obstacles.

 Strengthening as the animal becomes less painful, eccentric strength training and mechanical loading.

 Enhance circulation to allow delivery of oxygen and nutrients and remove inflammation.

 Tissue regeneration and metabolism encourage collagen synthesis and tissue metabolism.

 Restoring proprioception (coordination and body awareness) and neuromotor control to avoid re-injury and secondary dysfunction. Sensory facilitation, proprioceptive techniques, balance work and coordination retraining.

Stage 3 - Remodeling Phase: 6 Weeks–1 Year

 Consolidation stage - repaired tissue changes from cellular to fibrous, fibroblast activity high and fibres become aligned in direction of stress.

 Maturation stage - changes from fibrous to scar tissue, decreased vascularity and metabolism reduces.

 Goals: increase muscular strength, maintain tissue flexibility, promote joint mobility and continue the improvement of proprioception and neuromotor control.

 Aim is a gradual return to function and in the athletic canine a graduated return to sport.

Principles of Muscle Conditioning

1. Specific Adaptation to Imposed Demand

 Should be sports specific to ensure optimal neural patterning and correct timing. The type of muscle contraction in speed and intensity will cause specific training effects. High intensity (recruitment of fast twitch muscle fibres) vs low intensity (recruitment of slow oxidative fibres).

2. Overload

 To gain an increase in strength, power or endurance.

 Overload by increasing speed, resistance, number of repetitions, frequency or duration of sessions, decreasing recovery time.

 High repetition, low resistance then progress to low repetition, higher resistance programme.

Components of Muscle Conditioning

 Muscle strength (ability to exert force), muscle power (rate of doing work), muscle endurance (ability to sustain contraction or perform repeated contractions), motor re-education (local vs global muscles and their role in joint stability).

Proprioception

 Body awareness - nerve impulses from joints, muscles, tendons that provide information about joint position, motion, vibration and pressure.

 Nerve endings and pathways damaged with injury and impair segmental transmission of nerve impulses, resulting in impaired balance, decreased coordination, diminished joint position sense, altered reflexes when performing movements.

 Proprioceptive retraining is not stressful on healing tissue and facilitate effectiveness of strength and endurance exercises. Weight bearing provides proprioceptive input.

Cardiovascular Fitness

 Maintenance of cardiovascular fitness is essential.

Progression of Rehabilitation

We can manipulate different parameters to progress the rehabilitation programme:

 Type of activity

 Duration of activity

 Frequency of activity/rest

 Intensity of activity

 Complexity of activity

Monitoring of Rehabilitation Programme

Monitoring of the rehabilitation programme throughout its duration is essential. Not only to enable appropriate progression but to ensure that the injury is responding adequately. As described above, the stages of healing are variable, dependent on the severity of injury so a general prescription of 2 week progressive intervals is not effective. As is often the case during rehabilitation, sometimes there is a set back and the animal may need to be taken back to the previous level for a period.

Signs monitored throughout the rehabilitation programme are pain, tenderness, ROM, swelling, heat, and ability to perform exercises /functional activities.

Return to Sport/Activity

How do we determine this?

 Pain free full ROM

 No persistent swelling

 Adequate strength and endurance

 Good flexibility

 Good proprioception

 Adequate fitness

 Adequate skills

 No persistent biomechanical abnormality

Prevention is always better than cure, and is especially important in the sporting or working dog.

References

1.  Brukner P, Khan K. Clinical Sports Medicine. 2nd ed. Australia: McGraw Hill; 2001.

2.  Carrier DR, Deban SM, Fischbein T. Locomotor function of forelimb protractor and retractor muscles of dogs: evidence of strut-like behavior at the shoulder. The Journal of Experimental Biology. 2008;211:150–162.

3.  Edge-Hughes L, Nicholson H. Canine treatment and rehabilitation. In: McGowan CM, Stubbs N, Goff L, eds. Animal Physiotherapy: Assessment, Treatment and Rehabilitation of Animals. Oxford: Blackwell Publishing; 2007.

4.  Evans HE, deLahunta A. Guide to Dissection of the Dog. 6th ed. USA: Saunders; 2004.

5.  Millis DL, Levine D, Taylor RA. Canine Rehabilitation and Physical Therapy. USA: Saunders; 2004.

6.  Sharma P, Maffulli N. Tendon injury and tendinopathy: healing and repair. Journal of Bone and Joint Surgery. 2005;87(1):187–202.

7.  Williams SB, Wilson AM, Daynes J, Peckham K, Payne RC. Functional anatomy and muscle moment arms of the thoracic limb of an elite sprinting athlete: the racing greyhound (canis familiaris). Journal of Anatomy. 2008;213(4):373–382.