Maybe Down a Leg, But Don’t Count Them Out
by Colleen Lum, LVT, CCRVN, CCFT
At some point in time, nearly all of us have observed a dog with only 3 legs, maybe even only 2 legs. Dogs and cats “do well” with adapting to these changes in their anatomy as a tripod, but over time the toll of having to compensate and use their body in a way that was not intended will cause many health issues a lot sooner than if they had all four limbs. From a preventative standpoint, rehabilitation can help with slowing down these compensatory issues and provide a better quality of life for our tripod patients as they age.
What changes do we see?
For starters, normal weight distribution for dogs when standing is typically 30 percent on each front limb and 20 percent on each hind limb. The natural increase in weight on the front end of the body comes from the weight of the head. In the case of our tripod patients, a couple different factors may come in to play regarding how they prefer to distribute their weight:
-Absence of forelimb vs hind limb
-Established joint disease in remaining limbs
Typically with the absence of a front limb, the dog has to place a higher percentage of body weight on the remaining front limb (likely more than 50%!). This can cause
-Loss of range of motion and early progression of joint disease (osteoarthritis) in all limb joints (worst in remaining forelimb)
-Muscle atrophy of the remaining forelimb musculature from disuse of certain muscle groups
-Compensatory muscle tension in the chest, shoulders, neck and hamstrings of the hind limbs
-Increased “twisting” of the upper spinal column caused by necessary changes in remaining forelimb placement
The same can be said in the case of the hind limb tripod, causing
-Loss of range of motion and early progression of joint disease (osteoarthritis) in all limb joints (worst in remaining hind limb)
-Increased strain placed on the front half of the spine, shoulders and neck from force generated from front limbs
-Outward rotation of the remaining hind limb causing increased tension in the inner thigh musculature
So what preventative measures can we take to help?
Thankfully there are a few options depending on the patient’s needs and their family’s goals. Options such as prosthetic devices, carts/wheelchairs or targeted rehabilitation therapy either separate or in conjunction can help provide better quality of life for our beloved tripods.
Prosthetic devices can be useful with patients who still have a portion of their limb to attach a device. In the case of a front limb prosthesis, the elbow joint is usually required in order for the “limb” to be attached firmly. As for our hind limb patients, we need a little more of the limb present due to the angled anatomy. Typically having a little limb below the hock or ankle joint is needed for a prosthesis. If a patient is a candidate, we can fit them and work with the family to re-train proper use of the device and limb. It does require patience and not all tripods are a good candidate for such a device but if successful, it can help take some of the burden off of the rest of their body by at least having four limbs part-time. It is not advisaed to leave a pet unattended in their prosthetic device.
Carts or wheelchairs may be a better option for our older tripod patients who have a significant amount of osteoarthritis and muscle tension. This is also true if they are not likely to acclimate to a prosthesis or if they are not a candidate for a device. They are usually the fastest way to provide support and a quick return to mobility if that is the main priority. That does not necessarily mean that they do not require some tutoring on how to utilize a cart appropriately. Most patients need some adjustments to their carts along the way as they start to acclimate to it as well as learning how to maneuver efficiently and safely. Carts are not meant for the dog to be in for long periods of time nor are they always a good fit for indoor use depending on the size of the pet and the design of the house.
Last, but certainly not least, is physical rehabilitation. This can be pursued in conjunction with prosthetic and cart patients alike. The primary goals of physical rehabilitation for the three-legged (or fewer) patient are to
-Decrease compensatory pain along the spine and remaining limb joints and musculature
-Strengthen core and limb musculature
-Provide additional support if needed for off balanced limb (i.e. single forelimb vs single hind limb)
We typically start with exercises used to improve stabilization and gradually increase the difficulty in order to provide a good foundation on which to build limb strength and range of motion. One of the biggest challenges is encouraging the patient to learn how to slow down and engage musculature correctly instead of using momentum to get through their movements. Massage and regular VSMT (veterinary spinal manipulation therapy aka chiropractic) are recommended to help keep the spinal motion units moving properly and to maintain a lower level of compensatory muscle tension associated with chronic altered gait patterns.
A Final Note
In reality, we are only able to work within the parameters that the patient’s anatomy will allow. However it is a better outcome for our tripods than if no preventative care is pursued to help stave off early mobility issues. There is a special place in all of our hearts for our tripod patients. They teach us that even though they are different, and may be observed as disadvantaged, they continue to live their lives with the same exuberance as any dog with all four limbs.