Here are some potential reasons why your guinea pig's leg might not be working:
* Injury: A fall, a fight, or even a misstep can cause a fracture, sprain, or dislocation.
* Infection: An abscess or other infection can cause swelling and pain, leading to difficulty moving.
* Arthritis: Older guinea pigs are more prone to arthritis, which can cause stiffness and pain in the joints.
* Other medical conditions: Some conditions, such as neurological disorders or even tumors, can affect limb function.
It's important to note that a limping guinea pig could be suffering from something serious. Please don't delay getting your guinea pig to the vet. They can examine the leg, determine the cause of the problem, and recommend the best course of treatment.