How many knees does a dog have? The structure of the dog’s skeleton and the most common problems of the musculoskeletal system
When you look at dogs, you get the impression that they are built completely differently than humans. It is often not easy to relate individual parts of the human body to those of a dog. This results in one of the most common mistakes – the statement that a dog has 4 knees: front and rear. This is hardly surprising, because at first glance it may be difficult to determine where they are. What is it really like? How many knees does a dog have? How is its skeleton constructed? What problems with the musculoskeletal system occur most often?
Where are dogs’ elbows and knees?
A dog has not only knees, but also elbows – just like a human. Where to find them? Dogs’ knee joints are located on the hind legs, exactly between the femur and the lower leg bones. This means that dogs have two knees. When looking at the dog from the side, this is the first large joint visible just below the animal’s belly. Another joint that appears to be the knee bending the wrong way is the ankle joint – the same as the human heel. It looks different than in humans, because the dog stands on its toes when walking, and only puts its entire foot on the ground when it sits. Where are the elbows? They are located on the forelimbs and, similarly to the knee, this is the first large joint visible just under the dog’s body – exactly under the chest. This is the place between the humerus and the forearm bones. Another joint that is sometimes mistakenly considered to be the elbow is simply the wrist.
The dog’s skeletal system – how it differs from that of humans
The structure of the skeleton in mammals is based on a similar pattern. Dog limbs look different than human limbs because the individual bones simply have different length proportions. The dog’s skeletal system differs from that of humans mainly in the shape of the bones and their number. How many bones does a dog have? A dog’s skeleton consists of 319 – 321 elements, depending on the length of the tail of a particular individual. This is much more than in humans, who have 206 of them. The largest discrepancy is related to the number of tailbones and teeth. However, in the limbs (not counting the shoulder girdle), the only difference is the number of toes in a dog – in the front paws there are as many of them as in humans, i.e. 5, while in the hind paws there are only 4. Some dogs may still have an additional toe there (so-called dewclaw), or even 2, which often happens, for example, in French Shepherd dogs.
Causes of movement problems in dogs
Dogs, just like humans, may experience mobility problems for a variety of reasons. The most common problems with a dog’s musculoskeletal system depend on its age and breed. Lameness in young animals is usually caused by injuries – dislocations, sprains, fractures or ligament tears, which is related to their high activity. In older dogs, these include degenerative diseases and discopathy. Some breeds are genetically predisposed to hip dysplasia or, less commonly, elbow dysplasia. In small breeds, habitual patella dislocations occur.
Joint dysplasia in dogs
What is joint dysplasia in dogs? Dysplasia generally refers to processes in which abnormalities in the structure of organs and tissues appear. In the case of a joint, its structures develop incorrectly. It most often results from a genetic predisposition, but it is not the only cause. Other factors contributing to joint dysplasia are:
- Inadequate puppy diet with too much calcium or an inappropriate calcium to phosphorus ratio
- Overfeeding leading to excess weight
- Very fast growth of a young dog
- Too strenuous exercise in a growing dog
Therefore, even if the puppy’s parents do not suffer from joint dysplasia, the puppy may develop the disease and vice versa. Reducing the factors that cause dysplasia may prevent it from occurring in a given individual. In the case of hip dysplasia, the abnormal structure of the joint makes the system unstable and predisposes to dislocations. This is painful for the dog and may lead to permanent damage to the structures within the joint. Breeds predisposed to hip dysplasia include large and giant breeds, including: Labradors, Golden Retrievers, Rottweilers, Newfoundlands and German Shepherds. However, Labradors, German Shepherds and Molossians most often suffer from elbow dysplasia.
Be sure to read the article: “How to feed a puppy – the most important rules”.
Arthritis in dogs
This disease occurs in older dogs, over 6 years of age, but usually even later. It is caused by various factors that are often preventable. These are:
- Too strenuous training
- Inadequate nutrition and overweight
- Genetic predispositions
- Past injuries
Osteoarthritis in dogs is initially manifested mainly by reduced physical activity, reluctance to move, changes in the way of moving and intensive licking of paws. Over time, difficulties with getting up, walking up stairs and lameness appear. The sooner you notice the first symptoms, the sooner you can help your pet. It is not worth delaying a visit to the vet. Just because your dog isn’t squealing or limping doesn’t mean he or she isn’t in pain. Arthritis is a chronic and progressive disease, but with early intervention it can be slowed down and significantly improve the dog’s quality of life.
Dyskopatia in a dog
It usually occurs in older dogs with a genetic predisposition or as a result of an injury. It occurs much more often in overweight and obese people, because excessive body weight causes regular overload of the spine. Discopathy results from the degeneration of intervertebral discs, which, as a result of their herniation or bulge, begin to press on the spinal cord. Depending on where the pressure is located, it can cause different symptoms, but all of them are related to pain and problems with movement. Discopathy, unlike joint degeneration, usually occurs suddenly and unexpectedly. It occurs when a weakened disc moves towards the spinal canal. This disease most often occurs in small breeds, such as dachshunds, beagles, French bulldogs or shih tzu, but also in German shepherds, Doberman Pinschers and boxers.
Many joint problems in dogs result from excess body weight. Therefore, a useful skill is the correct assessment of the figure. I encourage you to read the article “Is my dog or cat fat? – BCS figure assessment”.