Pet Vet: Aging pets face common woes

November 4, 2013

Aging is a process we all go through in life and so, too, do our companions. Every individual ages uniquely, however there are common changes that occur in virtually all cases. The development of arthritis would be one of those changes commonly occurring with aging.

Carrie is pretty sure her dog Max has arthritis. He is a big boy, about 90 pounds of mixed breed dog that Carrie says looks more bear than dog. He is 9 years old and has real trouble getting up after lying down, especially on smoother surfaces. He seems to get rolling once he starts, but getting outside has become a challenge for him. He has to negotiate three steps to get to his yard and the same three to get back inside the house. Lately Carrie has noticed he has begun to develop sores on the tops of his rear feet and upon further investigation, she noticed he will sometimes drag the tops of his rear feet on the ground when he walks. She is convinced he has arthritis and wants to know what options she might have to help Max.

I must agree with Carrie that Max has arthritis, however I am not sure that is the cause of all that she is seeing with Max. There are different types of arthritis and the type to that I am referring here is called osteoarthritis. Literally meaning inflammation of one or more joints in the body, arthritis causes pain and over time can lead to boney changes in the affected joint or joints that lead to more pain. The reason I am in agreement with Carrie that Max does have arthritis is simply because he is a big older dog and arthritis comes with the territory as these patients age. Actually, aging and arthritis are two peas in a pod. That said, Carrie’s description of Max dragging the tops of his rear feet on the ground when he walks is not usually a sign of arthritis.

When a dog drags the rear feet when walking, we call this loss of conscious proprioception. In essence, this means Max is unable to realize his rear feet are not in the proper position. He simply does not perceive them being out of place because he has deficits in his neurological system. The signal from his feet to his brain telling the brain the position of his feet is partially blocked. The too, the signal from the brain back to the feet telling them to flip into the normal position can also be compromised. There are several possible causes for this problem the most common of which is a condition called lumbosacral instability.

Lumbosacral instability occurs at the point where the vertebral column, the "backbone," joins the pelvis via a fused set of vertebrae called the sacrum. In dogs, especially older big dogs, this joint can become unstable over time leading to arthritis and the secondary changes associated with it. It is these changes resulting from instability that can partially and even completely, in some cases, block nerve communication from the rear limbs to the brain and back. In cases of complete blockage, paralysis occurs. These dogs cannot walk. Max is not there yet.

Max needs to be thoroughly evaluated by his veterinarian, an evaluation I suspect that should include a neurological examination and radiographs of his pelvis and spine along with his rear limbs. If my assumption is correct, Max will have arthritis and lumbosacral instability. The arthritis can be helped with the use of non-steroidal anti-inflammatory medications and possibly supplementation with glucosamine and chondroitin sulfate along with DHA. Lumbosacral instability, however, is something we are unable to repair.

I have had some success, albeit temporary, treating these patients with anabolic steroids. These are the drugs made famous through abuse by athletes in various sports, but they do have medical use. They can allow muscle strengthening, even with decreased nerve input as occurs with lumbosacral instability. With additional muscle strength in the rear limbs, these dogs can improve their gait and get around better. This is very important because without exercise, the muscles of the rear legs will atrophy, worsening the dog’s ability to walk.



McClatchy-Tribune Information Services