Your dog's knee joint is primarily composed of three bones (the femur, the tibia and the patella) connected by several bands of tissue called ligaments. Two of these ligaments, the anterior cruciate ligament and the caudal cruciate ligament, hold the knee together and enable it to bend correctly. The anterior cruciate ligament is located near the front of your dog's knee, and the caudal cruciate ligament is located towards the back of the knee joint. A cranial cruciate ligament rupture is when the tissue of either of these two ligaments gets torn.

Your dog will limp and appear in pain. In some cases, the knee will be swollen.

A rupture may happen if your dog takes a misstep and twists the leg. In older dogs, especially large dogs, the ligaments weaken and may become stretched or torn under minimal stress such as jumping off a bed or couch. Overweight dogs are also more prone to ruptures.

There are two tests that your vet will generally perform to look for a cranial cruciate ligament rupture. The first test is called a cranial drawer. Your vet will grasp your dog's femur bone with one hand to hold the femur steady, and use the other hand to manipulate the tibia. If the tibia moves abnormally forward, it means that a cruciate ligament is ruptured. The second test is called the tibial thrust test. For this test, your vet will stabilize the femur with one hand, flex your dog's ankle and push the tibia. Again, if the tibia moves abnormally forward it means that a cruciate ligament is ruptured. It may be necessary to sedate your dog to perform these tests. Frightened dogs may tense their muscles which will alter the test results. Finally, your vet will also likely take x-rays to assess the knee joint.

It is sometimes possible to treat these ruptures by putting your dog on non-steroidal anti-inflammatory medications, giving your dog joint supplementation and, if your dog is overweight, putting your dog on a weight-loss diet. Your dog will also have to remain inactive for several weeks. However, in many cases, surgery is the only effective option. Surgery generally carries a good prognosis.

Obviously it is not possible to prevent all circumstances which may lead to a cranial cruciate ligament rupture. However, keeping your dog at a healthy weight is one way to help safeguard against a cranial cruciate ligament rupture.

No, you cannot get a cranial cruciate ligament rupture from your dog.