My cat is limping and can't put weight on her back leg. What's next?

Poor Sophie! It's possible she was injured or bitten and the leg is sprained, has an abscess (infection under the skin) or other issue. It would be best to bring her to a vet ASAP so they can examine the leg and treat/clean it and provide medications as needed. Keeping her resting and placing an Elizabethan (cone) collar on her until you can get to your vet can help keep her from licking at it which can lead to additional irritation and pain.

Since it has only been going on a few hours and she does put some weight on it when jumping I think you could monitor her today. I would try to keep her indoors and confined to small room so she stays quiet and rests the leg as much as possible. If swelling starts, she starts acting lethargic, or the limping doesn't resolve in the next 24 hours I would have her evaluated by a veterinarian so they can assess her for wounds or more serious injuries. Hope she feels better asap !

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.

I am sorry to hear about Luna. If Luna is limping there are many different possible causes, including soft tissue injury (such as a muscle sprain/strain, torn ligament), a fracture (it isn't always obvious when a pet breaks a bone if the fracture is not displaced), a torn or sore toenail, a skin infection of the toenails or bottom of the foot, nerve disorders, or in older pets tumors of the muscle or bone. I would recommend examination by a vet if the issue has been present since Sunday with no improvement. Unfortunately there are no safe pain medications available over the counter for cats, so I would just try to keep her quiet/restrict her activity/keep her indoors until she can be seen.

You didn't mention if it was a hind leg or a front leg. There are different possibilities for injuries based on which leg is injured. She may just sprained the leg but if she is holding the leg completely up and not putting any weight on it then it could be broken and she needs to see a vet. If she is putting weight on it but just limping slightly then just watch her for a few days. If it doesn't resolve then she should see a vet.

I'm glad Panda returned home! Limping is a sign of pain in cats, and if she can't jump onto the sofa, then I suspect she may have an injury to her spine, hips, or back legs. Muscle wastage and weakness in her back legs is serious as well. I would take her into a vet immediately. The vet can do a physical exam, blood tests, a urinalysis, and a lameness exam to determine what is causing her symptoms, and how to treat them. She could have gotten hit by a car while missing, or attacked by another animal. Please take her into the vet now.

Poor Kosho! She could have accidentally injured her limb at night while you were asleep. She could have severely strained a ligament, torn a ligament, broken a bone, or potentially could have an osteosarcoma. An osteosarcoma is a tumor of the bone in cats, the most common bone tumor cats can get. It would cause sudden and severe lameness. Unfortunately, cancer is always a possibility in an old cat. I would take Kosho into the vet today for an exam. The vet can do a physical exam, routine blood tests, a urinalysis, and x-rays to determine what is causing her limp and how best to treat it. She will also need some pain medication as well. Do not give her any human pain medications. Many are toxic to cats and are fatal if given. Please take her into a vet now.