It’s always hard to watch our dogs age – even when they’re healthy. Many dogs, however, and their owners will face the same diagnosis as they age – osteoarthritis.
Sometimes we write it off to our beloved canines simply slowing down as they get older, but it’s a mistake to do that, says Darryl Millis, D.V.M., a diplomate of the American College of Veterinary Surgeons and the American College of Veterinary Sports Medicine and Rehabilitation and a professor of orthopedic surgery at the University of Tennessee College of Veterinary Medicine in Knoxville. “That’s a red flag to me,” he says. Most canine osteoarthritis is diagnosed as the result of a regular veterinary checkup when the owner makes an “off-the-cuff” comment. Millis says that when the condition is diagnosed, its severity determined, and treatment started, most owners’ response is: “Wow! I didn’t realize how affected my dog was.”
About one in five adult dogs is affected by arthritis, according to an estimate by Hill’s Pet Nutrition, which makes a prescription dog food specifically for dogs with the disease. Millis says, however, that not all those dogs will be diagnosed.
Most often treatment is based on medication to relieve pain and an anti-inflammatory to reduce swelling around the affected joints, caused by the deterioration of the cartilage that cushions the ends of bones in the joint.
There is no cure for arthritis, Millis says. It’s a long-term chronic condition that requires management on the part of the dog’s veterinarian and its owner. “Arthritis is a lifelong condition. If we can slow it down, hopefully that patient will be more comfortable and perform better,” he says.
“The only thing that’s been shown to slow down arthritis is weight loss,” Millis says. Non-steroidal anti-inflammatory drugs – known as “NSAIDs” – don’t slow down the disease. However, he adds, “There is some evidence in people that the rate of cartilage loss is slowed down with some supplements.” We’ve all heard stories of how chondroitin, glucosamine and omega-3 fatty acids have helped our friends or our friends’ dogs with their joint issues.
In addition to medication, aquatic therapy “is very effective,” Millis says, explaining that he saw a patient just the day prior to this interview. Based on the dog’s X-rays, he believed the dog needed a hip replacement. “But the dog moved very well.” It turned out the owner had been taking the dog swimming for 30 to 40 minutes every two weeks for three or four years. Canine rehabilitation facilities have special tanks with underwater treadmills designed for aquatic therapy.
According to Millis, owners can only do two things to give their dogs a better chance at reducing arthritis: keep their dogs at a lean body weight from the time they’re puppies, and identify and treat any dysplasia or cruciate ligament ruptures as quickly as possible.”
An unknown percentage of dogs, however, will not find relief in drugs or will, but not for the rest of their lives.
For those dogs, some options exist that don’t involve major surgery.
Sound Waves Soothe Joints
It sounds kind of out there, but sound waves actually can alleviate the pain and inflammation associated with osteoarthritis. Officially called “extracorporeal shock wave therapy,” it “doesn’t cure the arthritis certainly and it may not improve the range of motion, but it does make them more comfortable,” Millis says.
He and his colleagues have done two studies on the treatment. “It seems to be a little better for elbow arthritis,” than it is for the disease in the hip, he says.
In the initial study, they used it on dogs whose owners were contemplating euthanasia because their dogs’ pain had become unmanageable. “The owners came back and said the dogs were doing things they hadn’t done in quite a while.” In the second study, 80 to 85 percent of the dogs showed improvement of about 4 to 5 percent of vertical weight-bearing force. This refers to the amount of force that a dog places on the foot while walking or trotting. The improvement with shock wave therapy is similar to what is usually achieved with an NSAID, and most of these dogs are already on NSAIDs and other treatments.
Millis says ESWT is best used on moderate to severe cases of OA, and the dog usually has two treatments two to three weeks apart. Each treatment will generally cost between $150 and $500, depending on the locale and treatment protocol. It requires a special machine that not all veterinarians have, but which most can access through colleagues who treat horses. ESWT has been used on horses with tendon and ligament injuries for more than a decade, and in dogs maybe five to 10 years, Millis says.
Normally, owners will go the medication route first, then when that ceases to alleviate the pain or if it never does, they’ll consider ESWT. “Most of the time, it’s for the patient who’s exhausted the easy stuff.
“I just treated a dog yesterday. You concentrate the sound wave to a particular tissue depth, directed at the edges of the joint. Theories have bounded back and forth” about how it actually controls pain. It seems to alter the nerve input to the spinal cord. It may inhibit the stimulatory nerves or stimulate the inhibitory nerves. But it also has other mechanisms, such as increasing growth factors and blood supply.”
Relief from the treatment generally lasts six to 12 months, he says, and the worse the arthritis is, the more often treatments seem to be needed.
Although ESWT is “not that widely used,” a general practice veterinarian can easily administer it, Millis says. When a practitioner purchases a machine, the manufacturer sends a representative to the practice to teach the veterinarian how to use it.
Stem Cells Inject Relief
Stem cell therapy for OA comes with a much higher price tag: $2,000 to $3,000. “Most the time, yearly injections seem to keep things under control,” Millis says.
This treatment, like ESWT, is usually tried after less expensive protocols no longer relieve the dog’s pain. “I’m not sure that’s the best way to do it, but that’s the progression for many owners,” he says. “Most of the time, the easier stuff does work for a while. Then they look for other alternatives. Quite honestly, biological treatments would probably work better earlier in the course of the disease.”
At the University of Tennessee, Millis likes to do the procedure using fluoroscopy – a kind of X-ray – to make sure the cells are going into the joint. “I want to make sure we’re injecting in the right spot.”
Although some companies provide an in-office system for extracting stem cells from a dog’s fat, Millis prefers to use stem cells cultured from the dog’s bone marrow. He says when the injection is created from fat,stem cells, white blood cells, red blood cells and part of the blood serum are all in the injection. “The problem is the number of stem cells is variable. There are a lot of unknowns about that.” With an injection made of cultured stem cells, it’s only stem cells. “The advantage is that you know you’re getting all stem cells.”He admits he has no science to back up his preference, however. His teaching hospital offers the procedure with both cultured stem cells and those made from fat using a company called VetStem.
Stem cell therapy for OA has been commercially available for several years, Millis says. He’s also used it successfully in partial Achilles tendon ruptures in dogs, though he says it takes “a while” for them to heal.
No one is yet quite sure how the stem cells work on OA, though stem cells can become any kind of cell: bone, muscle, cartilage, etc. “We’ve harvested synovial fluid [from arthritic dogs] and injected stems cells. It may alter the balance between the breakdown of and building of cartilage. With the stem cells and other biologic treatments, it puts it more in favor of anabolic – or cartilage building.”
However, some of the results he and his colleagues have seen are “a little bit different. We have some dogs that actually have more inflammation after the injection.”
Some newer research done using animal models has led some to return to thinking that the stem cells may be able to “latch onto the denuded bone and turn into cartilage.
“There are a lot of unknowns at the moment,” he says, “but a lot of hope. Not much data.”
For dogs that see improvement from the treatment, it may be a 5 or 6 percent improvement in vertical force. So, a dog might go from 60 to 65 in terms of weight-bearing force on the limb. With NSAIDs, most dogs go up 3.5 to 5 percent, he says, but some up to 8. “Keep in mind, these dogs are on other things already. Even though they’re not normal, they do seem to have some improvement on average. No treatment for arthritis is 100-percent effective.”
If you’re considering stem cell therapy for a dog with OA, Millis says if it were his dog, he’d go the cultured stem cell route. It takes longer to culture the stem cells, but it’s worth the wait in his opinion. Although a lot veterinary teaching hospitals are using stem cells to treat OA, Millis says a general-practice veterinarian is perfectly capable of doing it using fat-derived cells, as would any veterinary orthopedist. However, if you want to use the cultured stem cells, “that’s a little more limited,” he says.
So, the bottom line is to keep your dog lean, take care of any injuries, and, with a little luck, he’ll never need any of these treatments.