Doses anyone know what would cause sudden lameness in one leg? Our boxer is 8 and had TPLO done on the opposite leg 2 years ago. A few days ago his fixed leg was sore and he was put on meloxicam. Then suddenly his right leg went lame with a fever of 104. Tons of tests done by the vet and nothing really out of the ordinary. He is home now and is on prednisone and gabapentin as she thinks it may be neurological and immune related arthritis. He is not using his right leg at all....I hate seeing him like this but don’t understand the reason he’s so lame. Our vet is even stumped... we are waiting for Lyme tests to come back as well.