Hind leg paralysis (degenerative osteoarthritis) is a condition that involves the gradual deterioration of cartilage, the formation of new bone growths (commonly called spurs), and the thickening of membranes surrounding joints. It occurs in older rats and is more common in males. Usually the rat will lose the ability to sit on his bum, and will walk by dragging his rear. Degenerative osteoarthritis can affect any joint in the body but it’s most visible in the spine, hips, knees, and toes. As the cartilage deteriorates, it flakes away causing the joints to rub against one another. When the spurs develop and the membranes thicken, the spaces in the joints narrow and compress causing inflammation, pain, and stiffness. When osteoarthritis occurs in the spine, the spinal cord is damaged and mobility in the legs and feet may be lost, as well as bladder and bowel control.
Aging and genetics are the main factors that contribute to hind leg paralysis but obesity can increase the severity and bring it about at an earlier age. Frequent strain on the joints, infection, or injury will also speed up the progression of the condition.
Osteoarthritis is a progressive condition and only the symptoms can be treated. When symptoms first begin to appear, apply topical DMSO gel (dimethyl sulfoxide) and provide a Glucosamine-Chondroitin supplement. Use only human/pet approved DMSO and if you notice redness, itchiness, or inflammation of the skin, discontinue use. Ibuprofen can also be given to reduce inflammation. A B vitamin complex seems to delay the symptoms in some rats and a dose of 1-5 mcg of B12 in the complex daily is recommended. If the above treatments no longer relieve pain and inflammation, talk to your vet about prednisone, antibiotics, and a probiotic (prednisone weakens the immune system so it should be used in conjunction with antibiotics and a probiotic).
It’s recommended that you put the rat into a one-level cage with cloth bedding so they can’t fall and injure themselves. Lower the water bottle, food dish, and hammocks to prevent further strain to joints and ensure that they’re able to eat and drink. When your rat is no longer able to hold food in his hands, consider feeding him baby or pureed foods. Gentle massages and range of motion exercises should be done at least daily to prevent stiffness and help with circulation. You should also groom your rat at least on a daily basis. Use a damp cloth to wipe down the entire body, especially the belly and anal area. Remove earwax with an ear-bud by cleaning the outside of the ear (never attempt to insert the ear-bud into the ear canal!). With lots of care your old rats, although paralysed, can enjoy a good quality of life.