Diagnosing OA in Companion Animals

B. Duncan X. Lascelles, BVSc, PhD, DACVS: You mentioned, Bryan, that the aging patient and the signs are missed. But I think there’s a lot of discussion, at the moment, about this idea that the diagnosis of osteoarthritis is delayed in the veterinary population. If I can bring it back to you, Mark, let’s focus on those younger patients who come into your practice. Why is the diagnosis delayed? What are the main blocks to making that diagnosis and to having those conversations? You mentioned some of them in terms of time, but are there other aspects?

Mark Epstein, DVM, DABVP, CVPP: The main obstacle for the owners is simply a lack of education. They come inwith a preconceived notion.

B. Duncan X. Lascelles, BVSc, PhD, DACVS: So, how do we educate owners? What’s the best format or way of doing this?

Mark Epstein, DVM, DABVP, CVPP: In the exam room, when they are puppies, clearly there’s going to be some predisposition. The old Ortolani sign that we were taught is real, and if you get that subluxating little pop, you’ve got a little bit of a window here—up to about 14 weeks—to do the JPS (juvenile pubic symphysiodesis). And that can save that dog a lifetime of misery. Sometimes we go right past that and we just omit it. But if it’s an at-risk breed, and we all know what those are—we’ll take the Labradors, and maybe a quintessential one, and a common breed—the education about OA needs to start right there, right then.

We have to affirm here that in dogs, unlike humans where the condition is more wear-and-tear over time—unless there’s been trauma to a joint—it is mostly confirmational and developmental; they’ve had it for most of their lives. A dog is at risk for it because of a predisposition, because of trauma, because of weight, obesity—any of these factors. We need to get our meat hooks into them at that point and not just when the owners are bringing in a debilitated and progressively disabled dog, because that is really what is happening to them.

Bryan T. Torres, DVM, PhD, DACVS-SA, DACVSMR: I think there’s a misconception with owners and, sometimes, with veterinarians. We’re so well trained. We go through school and we look at x-rays of joints that are osteoarthritic, and we see these chronic degenerative changes and we say that’s the osteoarthritic joint. But this starts well before we see those changes.

B. Duncan X. Lascelles, BVSc, PhD, DACVS: When does osteoarthritis start?

Bryan T. Torres, DVM, PhD, DACVS-SA, DACVSMR: Probably well before we even see or feel the Ortolani; that has been going on for a while. For the dog who comes in with elbow incongruity, that has been going on for a while. Those changes have probably already started. Those changes within the cartilage, or some damage to the cartilage, don’t show up on x-rays. What we’re seeing in our radiographs are signs of a more chronic process that’s going on for a while. And so, the ability to potentially make some changes to these patients, earlier on, can potentially have huge benefits later on in life.

B. Duncan X. Lascelles, BVSc, PhD, DACVS: You’re really saying that osteoarthritis is present as soon as we make a diagnosis of developmental disease in dogs?

Bryan T. Torres, DVM, PhD, DACVS-SA, DACVSMR: Absolutely, yes. If those joints aren’t congruent, if we’ve got hip dysplasia and you’re feeling Ortolani, if you have noticeable elbow congruity, those changes within the cartilage, it’s there. This has started, and it will continue to progress as they get older, regardless of what we do. The question is, what can we do now? What can we do early to slow that progression or make some changes, so that when they’re 6, 7, 8, 9, 10 years old, we have made a positive impact, which we started addressing when they were younger? And that’s the real question: how can we effectively make those changes?

B. Duncan X. Lascelles, BVSc, PhD, DACVS: Osteoarthritis is a young dog disease?

Bryan T. Torres, DVM, PhD, DACVS-SA, DACVSMR: Absolutely.

B. Duncan T. Lascelles, BVSc, PhD, DACVS: Given that it is a young dog disease, but they’re in otherwise relatively good health—let me bring in Margaret and Sheilah here—can we prevent the disease? Can we alter the progression of the disease, per se? Because, intuitively, it makes sense that if we control to the progression of disease, we would make pain control easier.

Sheilah Robertson, BVMS, PhD, DACVAA, DACAW: I think with these discussions, it doesn’t matter at what stage, but I agree with Mark and Bryan. These are almost like the first puppy visit discussions, when you bring your dog or your cat in, because it’s such a huge disease that’s going to impact most dogs and cats at some point in their life, earlier or later. And I think that’s when it really needs to be discussed—those contributing factors that can, not easily, be dealt with, such as obesity. Obesity, I think we always thought of as, for example, the overweight dog with extra strain on their joints because they’re overweight. But I think we now have this whole shift where we’re understanding that obesity, itself, is an inflammatory disease and causes chronic, systemic inflammation. So, we have all these inflammatory mediators, like IL-6 (interleukin 6), which maybe has an effect on the joint, not just the extra weight on the joint.

We can talk about weight control, and we probably can’t overemphasize that enough. We can talk about correct diets, but do we know that we should start dogs on high EPA (eicosapentaenoic acid) diets very early? Do we wait until we have clinical signs of the disease? The other thing is, the whole world is becoming more sedentary; that’s affecting the pet. So, again, talking about consistent exercise—the owners have heard it before and they know it’s real. What we have to do is engage them into doing it. We know how we could help the pet, but it’s the actual “doing it” part where there is, maybe, the disconnect.

B. Duncan X. Lascelles, BVSc, PhD, DACVS: There are some dramatic data in terms of caloric intake over a lifetime in dogs.

Margaret Gruen, DVM, MVPH, PhD, DACVB: Yes.

B. Duncan X. Lascelles, BVSc, PhD, DACVS: Having a dramatic protective effect on the development of disease.

Margaret Gruen, DVM, MVPH, PhD, DACVB: Yes. Weight management is probably one of the top things you can do, especially from an early age, because it is much more difficult to get that weight off later once they’re already overweight and have pain. Then, asking them to ramp up exercise becomes more difficult and the caloric restriction is hard for owners to do.

I also wanted to mention cats and the early diagnosis in cats. I think that there’s several things that go on with why we miss the diagnosis in cats. One is that cats simply aren’t coming to the veterinarian as often as they should and that there’s difficulty in examining cats in the veterinary room. They don’t move around as well, and they’re less likely to jump up or jump down. We can’t see them do these functional and performance assessments. It’s difficult to interpret their orthopedic exams, so we need good education on how to interpret them.

But, then, we don’t even have that many options for people to give out. If we do find pain, what are we going to do about it? And so, I think people are hesitant to look when we don’t have that many options. Weight management is a big one. How do we feed these cats? Feeding them right out of a bowl may not be the best way to get them enough exercise and engagement. How do you get a cat to exercise? Well, maybe feeding it by hand or tossing food, or that sort of thing, may be the way that you do it. We’re not typically walking them on leashes. So, I think that there’s a lot of work to be done in education and recognition for cats, too.