For a range of medical reasons, dogs may need to have a digit, an entire limb or the lower part of a limb amputated. This article looks at the effects of removing a limb or toe in dogs and how best to care for them in the longer term post-amputation.

What are the post-amputation side effects in dogs?

Shift in weight bearing

Digit or limb amputation affects the dog’s balance. To support their body weight, the dog must redistribute their weight to the remaining limbs or digits on the paw. To do this, dogs missing a limb, will reposition their feet relative to the centre of mass to support their weight and maintain their balance.

Alterations in the way dogs redistribute their weight requires them to recruit different muscles in the remaining limbs and trunk to maintain balance.

Change in gait

While limb and digit amputation impairs balance, it also affects locomotor function as evidenced by changes in dogs’ gait.

In three-legged dogs, the duration of the stance phase of the gait increases while the ground forces in quadrupeds and triped dogs are similar. When walking the ground forces in dogs missing a limb are distributed across only three legs and for an increased period of time. This effect is magnified as the dog’s speed increases.

Depending on the amputation site, the dog changes their gait to compensate for the need to redistribute the ground forces.

In dogs with an amputated pelvic limb, compensation mechanisms in the remaining limbs and vertebrae are employed to maintain balance and trunk support for core stability. These mechanisms include altering the vertebral kinematics so the dog bends laterally to place the remaining pelvic limb closer to the ipsilateral thoracic limb (front leg on the same side of the dog’s body). By doing this, the dog adopts a laterally deviated gait in which the thoracolumbar vertebrae is not parallel with forward movement. Such a gait effects vertebral joint motion and involves recruitment of muscles of the back and trunk.

In dogs with an affected front leg, the braking forces usually provided by both forelimbs are transferred to the contralateral forelimb (forelimb on the opposite side of the body) and the ipsilateral hind limb. In dogs with lameness in a front leg, through limb or digit amputation, chronic injury in the hind limbs is typically observed due to the hind limbs performing both braking and propulsion roles.

Change in joint range of motion (ROM)

Alterations in weight bearing and gait affect the joint range of motion in dogs with amputated limbs and digits.

When a pelvic limb has been amputated, the thoracic limbs are more vertical in movement and more retracted when compared with quadraped dogs. The remaining pelvic limb has decreased protraction and increased retraction. This enables the dog to produce the power to shift weight to the thoracic limb. Weight shifting to the thoracic limb in movement requires the pelvis to be tilted which requires a change in hip and lumbosacral joint motion.

The altered pelvis position and torque action caudally-cranially has the following impacts on joint range of motion:

• Increased angulation in the thorocolumbar vertebrae during the stance phase of the gait. This increases flexion in the cervical and thoracic vertebrae especially when trotting.

• Increased lumbar vertebrae extension and flexion as the remaining pelvic limb needs to remain in a position under the trunk to maintain stability and aid propulsion.

• Increased ROM in the tarsal joint. This increases the load on Calcaneal tendon and gastrocnemius muscle on the remaining pelvic limb to absorb increased body weight.

In dogs with a front leg amputated, the carpus joint shows an increased range of motion. It is hyperextended during the stance phase because of the additional weight bearing requirements. The carpal joint, along with the elbow and shoulder to a lesser extent, undergoes significant strain and stress particularly when the dog’s speed increases.

Digit amputation results in a shift in weight bearing. Depending on the digit removed it may affect the range of motion of the tarsal or carpal joint. When digit removal results in the dog limping, similar changes in gait and joint motion to that of dogs with amputated limbs will be observed.

In summary, the effects of a digit or leg amputation in dogs are:

• Shifts in weight bearing

• Changes in gait

• Changes in joint range of motion

Compensating for a loss of a limb or digit leads to increased impact and potential wear on the joints. Many dogs with an amputated limb often show signs of osteoarthritis and joint dysfunction. It is also presumed that cartilage degradation progresses faster in these dogs because of the increased loading of the joints.

Dogs with an amputation also abnormally load the muscles in the remaining limbs, back and torso. Abnormal loading leads to muscle strains, spasms and injury.

In short, without appropriate maintenance, the musculoskeletal structure of dogs with an amputated limb or digit is prone to wear and chronic injury.

How to care for a dog after a leg or toe amputation?

The focus of rehabilitation and maintenance treatments will vary depending on the amputation site but generally will focus on the following body areas:

• Digital amputation – muscles and joints of the affected limb. Depending on the extent of lameness, treatments may also focus on other body areas that bear the load from compensatory weight shifting and changes in gait.

• Limb amputation – muscles and joints of the remaining three legs.

• Partial limb amputation – muscles in proximal limb segments and the muscles and joints of the remaining three legs.

In all amputation cases, rehabilitation and maintenance protocols will treat the muscles and joints of the spinal system which are affected in all cases of lameness.

Rehabilitation and maintenance treatments plans also need to consider the musculoskeletal condition and fitness of a dog before the amputation. When dogs have limbs or digits removed because of illness such as osteosarcoma they are typically older dogs with pre-existing musculoskeletal abnormalities.

A treatment plan would typically include the following goals and strategies:

• Relieve muscle tension in compensatory muscles through massage (including trigger point therapy), stretching, joint mobilisations and passive range of motion techniques.

• Lubricate affected joints through massage, joint mobilisations and range of motion techniques.

• Strengthen supporting muscles using exercise therapy.

• Maintain healthy circulation in affected limbs using massage therapy.

Following post-surgery rehabilitation, quarterly maintenance treatments should be sufficient to address post-amputation side effects on the dog’s movement and musculoskeletal system.

Dogs with an amputated leg or digit can live very full and active lives with the appropriate maintenance. How do you manage the effects of your dog’s amputation? Leave me a comment here or on the Full Stride Facebook great to share your experiences for “dog parents” considering amputation.

For information about Full Stride’s Canine Myofunctional Therapy treatments click here.

Until next time, enjoy your dogs.

Source:

Goldner, B, Fuchs, A, Nolte, I, & Schilling 2015 “Kinematic adaptations in tripedal locomotion in dogs” The Veterinary Journal 2015

Hogy, S.M, Worley, D. R. Jarvis, S.LK, Hill, A.E, Reiser, R. F and Haussler, K.K 2013 “Kinematic and kinetic analysis of dogs during trotting after amputation of a pelvic limb” American Journal of Veterinary Research, 74: 1164 – 1171

Kaufman, K.L and Mann, F. A. 2013. “Short- and long-term outcomes after digit amputation in dogs: 33 cases (1999–2011)” Journal of the American Veterinary Medical Association, May 1, 2013, Vol. 242, No. 9 , Pages 1249-1254

Jarvis, S.L, Worley, D.R, Hogy, S.M, Hill, A,E. Haussler, K.K, Reiser R, F. 2013 “Kinematic and kinetic analysis of dogs during trotting after amputation of a thoracic limb” American Journal of Veterinary Research, 74:1155 – 1163