Whether your kitty's a spring chicken or waiting on her Furball Association of Retired Cats card, rear leg weakness is not normal. It's not necessarily a sign of impending doom, but it does need checked out. An annoying large list of potential culprits can cause back leg problems.
Kitties unfortunate enough to suffer from hip dysplasia will often display rear leg weakness, lethargy and tenderness. They'll also have difficulty standing up, especially after a nice, long nap. The hip joint developed abnormally, and it eventually degenerates. The disease is often genetic and more common in certain breeds, such as Himalayans, Maine coons and Persians.
Some felines, especially those in the older crowd, have to deal with arthritis, a painful condition that targets a cat's joints and worsens over time. Arthritis can develop in any joint, so while it's not specific to your kitty's rear quarters, it can certainly affect them initially. Symptoms often mimic hip dysplasia. Your feline will often lay around more, may limp, refuse to climb stairs, won't jump as high or as often and may even have difficulty ducking into her litter box.
Kidney failure brings with it a host of nasty symptoms, including the possibility for rear leg weakness. Other symptoms include frequent urination, weak stream when urinating, lethargy, lack of appetite and a poor-looking coat. In the latter stages, your kitty's breath will smell like ammonia. Once affected, your kitty's potassium levels often drop, which cause her back leg weakness. Kidney failure itself can also cause weakness.
Diabetes is no fun to deal with, whether you're a human or a cat. The most common symptoms of feline diabetes include increased appetite, thirst, urination and weight. But back leg weakness can also rear its ugly head. The nerves that go to the legs become damaged if your kitty's diabetes is uncontrolled, so she'll feel pain and sometimes even numbness in that area. Getting her diabetes under control usually takes care of the problem.
In what's probably one of the scariest of the potential causes of your kitty's hind end weakness, a blood clot can exit your cat's heart and create a whole slew of problems by blocking the main arteries to her hind legs. When that happens, your cat will likely constantly cry out in pain. She can immediately go from having a noticeable limp to dragging her back legs because of paralysis that accompanies the blocked arteries. Her back feet will feel cold and may even have a blue tint to them.
Other Causes and Advice
It'd be nice if a bit of back leg pain could be attributed to one short list of problems, but that's not the case. Other potential causes include problems with your kitty's spinal cord, trauma -- especially if something fell on her back end or a child sat on her -- bone abnormalities and neurological disorders. Never make an assumption and never blow off your feline's pain. Rear leg weakness is not something you want to wait out. Call up your vet and schedule an appointment. If your kitty's back feet feel cold or she's dragging her legs, take her to your vet or local animal hospital immediately.
- Cornell University College of Veterinary Medicine: Hip Dysplasia
- American Society for the Prevention of Cruelty to Animals: Arthritis
- PetPlace.com: Hypokalemia (Low Blood Potassium)
- What's Wrong with My Cat Or Kitten?: EPUB Version; Dr. John Rossi
- PetMD: Pain from the Nervous System in Cats
- WebMD: Aortic Thromboembolism in Cats
- Ablestock.com/AbleStock.com/Getty Images