Osteoarthritis, Cognition and Animal Healthcare

As I've talked about in previous posts, I'm taking a zoology class this semester on the biology and psychology of human and animal relationships with Patricia McConnell. I'm really enjoying the class so far because it has me thinking more critically about the way humans think about and treat other animals.

Case in point, I read the article Polar Bear Mercedes' Health Failing mostly because it is about a polar bear (as I've proclaimed before, they are my absolute favorite animals and have been since I was a child). I was having a gushy "oh poor polar bear" sort of moment. BUT reading the article made me think a lot about veterinary science and the way that humans take care of the health problems of other animals.

The article is about a specific polar bear in the Highland Wildlife Park in the United Kingdom that has been diagnosed with osteoarthritis. Currently the bear is being treated with painkillers for the condition, which is a degenerative disorder of the joints. Joints are places in the body where bones meet. They are held together with cartilage, tendons and muscles that enable the joint to bend. When an individual has osteoarthritis the cartilage starts to break down, causing the bones to rub directly together. This can cause pain, swelling and stiffness that drastically limits movement as the disease progresses.

At the Bronx Zoo.
Source: Wikipedia Commons

There is no known cure for osteoarthritis (which it should be noted affects many different species, and is very common in humans) but the symptoms can be controlled with painkillers. The condition typically effects older individuals. In the case of the polar bear, the patient is 30 years old which makes her a very old lady as far as polar bears go. Because there is no cure for the condition it is possible that the polar bear will be put down when her condition progresses enough to reduce her quality of life.

I can't help but wonder how we define quality of life for a polar bear. Even though she is suffering from a condition that also effects humans, we can't necessarily define the polar bear's suffering or quality of life the way we would our own. How do veterinarians or zoologists decide when enough is enough for a polar bear? She can't tell us when she's tired of living with the disease. Quite frankly assisted suicide isn't legal in humans, so what is it that makes euthanasia in animals alright? I support trying to limit the pain and suffering of animals that have been brought under human care, but what needs to be considered before deciding that it is time for them to die?

In humans a joint that no longer functions due to damage from osteoarthritis could be replaced with an artificial one made of plastic, metal or cement. That type of invasive surgery wouldn't be done on other species. Not only are these procedures extremely expensive, they require strenuous physical therapy and rehabilitation to come back from. This is a case where the condition might be the same across species, but the way it is treated is different. Really all they could do to alleviate the bear's symptoms is treat it with painkillers (which is what they are doing.)

A human joint with osteoarthritis.
Source: NIH-NIAMS photo gallery

It is interesting to consider how the polar bear would deal with the disease in the wild. They certainly wouldn't have pain killers at their disposal. In this case the polar bear wouldn't even have made it to old age (and have developed this disease) if it weren't for human interference. It was rescued after being shot in the wild and brought to a zoo, and later moved to the wildlife park.

These aren't easy questions. Animal behaviorists are still searching for answers about how much other species are self-aware. The fact is we don't know how much the polar bear thinks, or what it thinks - about its life or its condition. Even though I don't have answers, I appreciate my zoology class for getting me to think like this about how humans manage other animal's health.

If you are interested in animal cognition there is an entire journal dedicated to scientific research being done in the field called (shockingly) Animal Cognition where you can learn more about studies of what and how animals think.