My cat is limping and has a swollen knee. Is it broken or sprained?

Oh no, poor Belis! It is certainly possible that her leg is broken, but it could also be sprained or infected from an animal bite if she's allowed outside. She has to see a vet for this, so I would bring her into one right away. Given that it's really swollen and she's been walking around with a limp limb for three to four days, medical attention is required now. Please bring her into an ER vet or find a vet on call to see her now.

The chance that there is a blood clot contributing to these clinical signs is very unlikely. Typically, when something like this happens, your cat would be in absolutely uncontrollable pain, screaming and crying like nothing you have every heard. You might also notice that the feet and limbs are noticeable cold. This doesn't sound like the case. In all likelihood, Autumn simply sprained or strained something and is now experiencing some discomfort as a result. One other cause of shifting or sporadic lameness in the limbs are tick borne diseases such as Lyme disease. While these are far more common in dogs, they can definitely occur in cats as well. Depending on your geographic region, the type of tick borne diseases that are most common will vary considerably. Hope this makes sense. Get Autumn into the vet for some examination if the symptoms don't subside in the next day or so. Just don't try and give any over the counter pain medication at home as there are none that are safe for cats.

Poor Tom! Without seeing him I cannot say for sure what he has injured. He could have simply sprained a muscle or broke a toenail. Unfortunately, he could have also broken a bone. I would strongly recommend to have your vet take a look at him. Your vet will be able to localize the pain and take x-rays if needed. They will be able to get him started on pain meds and the proper treatment plan to help him feel better. I hope this helps!

If the lameness has persisted for 3 weeks and you notice that there is a difference in the shape of the shoulder area and leg position, I fear that the injury could be more serious than a sprain. Muscle injuries normally recover in 4-5 days of rest and antinflammatories. I would recommend to have him reassessed, there is a medication that can be given at home prior to the visit to help with the stress, I would ask your vet. Hope this helps !

It's possible there is a sprain or a break if the limp is persisting. It would be best to bring Morgana to your vet for an X-ray and an exam to check for sprains, breaks, or even an infection hidden under the skin that could be causing discomfort.

Restrict Spaghetti's activity as much as you can. No excessive running, jumping or rough play. If the lameness does not begin to resolve in the next 24-48 hours, have her seen by your vet. Go sooner if you notice any swelling or if the lameness worsens.

Poor Jango! I would wait another 24 hours. Keep him confined to a small room to keep down his movement, and force him to rest. Have a litter box, food, and water in the room. If you can find a crate large enough to hold all of that equipment plus him, I would put him in it. No running, jumping, or playing. Don't let him outside if he's normally allowed outside. Should he still be limping after 24 hours, then I would take him into the vet for a lameness exam and possibly x-rays. Please do NOT give him any human pain medications, as many are toxic to cats and are fatal if given.