With dogs having four limbs, it is a common ideology with many people that dogs have four knees? Some, on the other hand, will openly admit that they are utterly confused. They have no idea if dogs have four knees or two knees or none at all. Our article today attempts to answer this question in the best way we can. The first thing you need to note is that your dog is more like you than you think. That is, they are very similar to you in morphology and physiology. In case you have forgotten your biology, those refer to your outward body, and the internal working of it respectively.
The first thing we will discuss is the anatomy of a dog, especially their joint anatomy. That is, how their joints work. As you know, knees are joints.
Dogs vary in their anatomy according to their various breeds. In fact, when compared to other animals dogs have the most varied anatomy across breeds. However, there are certain physical characteristics that all dogs share irrespective of their breed from the big great Irish wolfhound to the teeny Chihuahua. And that’s the nature of their feet!
Dogs have really tight, small feet, and they walk on their toes. Of the four limbs, the two rear ones are quite sturdy and rigid while the pair in front a bit looser. They are also more flexible being attached to the torso by only a single muscle. Unlike humans, dogs lack a collarbone which gives their shoulder bones a disconnected form. However, this is not such a bad thing as it is this feature that allows the dog to have ample room to run or leap with giant strides.
Now, let’s quickly take a look at a dog’s bones and joints
Joint Anatomy of Dogs
Joints are formed when two bones meet and are held in place by a supporting tissue. When a joint is formed, it might be able to give restricted or full range movements depending on the joint and where they are located. Some very moveable joints include those at the shoulders and hips. Others that do not move very much can be found around the skull. You sure wouldn’t want the joints in your skull or that of your dog moving around a lot.
Remember that we said that you and your dog are more alike than you think? Well, here’s one thing you both have in common. It might interest you to know that while all the limbs of a dog are called legs, they are not all the same. We have already described a difference in their anatomy above. But to bring it further home, the pair of legs a dog has in front are very similar to your own hands, while the rear ones are similar to your legs.
This already helps us narrow down something; that dogs certainly do not have four knees. If they have any number of knees at all, it is going to be two. Why? Because, as we have described, the rear limbs are more like the legs of the dog than the ones in front. Great! Now, let’s forge ahead and check out the bones and joints found in a dog and see if a knee is mentioned.
Carpal Joint: This is the joint formed at the wrist. It is formed from the joining of the radius and ulna with some other carpal bones (seven small ones in total). These carpals also give rise to five other metacarpal bones and these bones (called phalanges) create a connection to the feet. Structurally, this joint-bones system work together to keep the dog from falling and also help in his movements.
Elbow Joints: Very similar to your own elbows, they are formed in the forelimbs of the dog (which closely resemble your own hands). They are formed when the proximal end of the radius and ulna of the forelimb join together with the distal end of the humerus. The proximal end is science jargon for the nearest end of the bone, while the distal end refers to the farthest end.
Stifle Joint: This is also known as the knee of the dog and is a really complex joint. This joint does a lot of work by way of movement which includes; rotation, sliding, and gliding. And it does this by flexing and extending. The stifle joint is by far the largest knee in a dog’s body and with how complex it is, it isn’t difficult to tell how disastrous it can be to have an injury to that part of the dog’s anatomy.
Hock Joint: This joint is characterized by it’s odd, “out-of-shape” shape. It is similar to the human ankle and connects the dog’s shin bones with its paws. There are ligaments inside and outside the hock joints which help to hold this joint in place.
Hip Joint: It forms by the fitting of the proximal end of the femur to the acetabulum (the hollow socket formed in the pelvis). So, like you, dogs have two hips where their legs fit into their pelvis.
Did you see where the knees were mentioned? Like we said, the fact that a dog has four limbs doesn’t mean that they have four knees. So, to answer your question: dogs do have knees? Yes, they have two beautiful ones just like their dog parents as well! But just before we go…
Something you should know about the Dog’s Knees
There’s something known as a luxated patella. The patella is also known as the kneecap; the protective bone that covers the knee joint. When you look at your dog’s hind limbs, you should normally see two ridges forming a groove (somewhat deep). The patella should normally slide up and down in there but when the patella is luxated, you find that those ridges aren’t so prominent anymore and the groove is also not as deep as it used to be.
As hurtful as this may sound, it does reverse itself once the muscles around the quadriceps are relaxed. The pain usually comes as a result of the “kissing” of the kneecap with the bony femur.
Small breeds (especially Miniature and Toy poodles) usually run the risk of luxating their patella more than other breeds, although not all of them, just a small population of them.
Although, this condition reverses itself, bear in mind that if not corrected in time, it could eventually lead to lameness. Symptoms of a luxated patella include the backward extension of the affected limb with the dog being unable to flex the leg back into position.