Medical Corner: Care of Older Paralyzed Rats

Kaleigh Hessel
From the September/October 2000 Rat & Mouse Gazette

The scope of this article is not to discuss the various causes of paralysis in rats, but to discuss what I have learned about caring for older rats with limited or no mobility. I will primarily be discussing the gradual deterioration of mobility in the hind legs that occurs in older rats.


If you look at a young, healthy rat, you will notice that he walks on the front part of his feet with his tail held off the ground. It looks a bit as if he is walking on his tiptoes. One of the first things you will see when a rat starts to lose mobility and flexibility is more of a tendency to walk flat-footed. As time goes on you will also notice that the rat is more likely to drag his tail on the ground. Usually, you will not even notice this flat-foot walking, as it does not affect the overall gait of the rat. Your furry friend can still keep up with his cagemates in the running and climbing departments.

The age at which you first notice this will depend on the rat. In my rats, I've noticed it as early as 20 months of age. How the weakness/paralysis progresses is likewise variable. I have noticed the weakness in virtually every rat I've had that lived over age two, but only two boys have progressed to complete paralysis. I'm sure it is possible for a female rat to also progress to complete paralysis, but it has not happened in my females. To be honest, I've not heard of anyone with a female rat who became completely paralyzed from spinal degeneration.

As the weakness progresses, you will notice an increased difficulty in your rat in moving his back legs. His toes will tend to stay a little curved and he may have difficulty standing on his back legs without support. He can usually continue to sit back on his haunches to eat and groom, but may tumble once in a while. When he walks, he must make a deliberate effort to bring each back foot forward. You may also see some muscle wasting over the back flanks as this condition progresses. Increased calorie intake may help prevent some of the muscle loss. I have started supplementing Tessa and Mochy, my two girls currenly over the age of two, with Nutrical and other higher calorie foods. I am not seeing as much muscle loss as I have in the past, despite the fact that they both have somewhat limited mobility.

One of the most important things to consider at this point is safety. Most likely, your rat does not realize he is weaker than he used to be. Cage climbing will definitely provide a danger of falls in or out of the cage. Tessa, who is almost three and has considerable weakness in her back legs, continues to try to climb the cage any time she is out of it. She has fallen once when I turned my back for a minute; fortunately, she hadn't gotten very far, and was uninjured. I have a three foot tall cage, if she had fallen from closer to the top, she could have been seriously injured or killed. You also have to watch inside cage climbing if you have a multi-level cage.

One other precaution is cage flooring. Most of us know that we must cover wire shelves that are 1" x 1/2", but some people may be less likely to cover the 1/2" x 1/2" wire. When a rat starts to have weakness in his back legs, it is much easier for his feet to get caught in the wire. I have 1/2" x 1/2" wire on my shelves and second floor that is covered by plastic needlepoint canvas. Despite this, Tessa recently managed to catch the back of her foot in the wire in a place where the canvas was chewed. Make sure that if you don't keep your cage floor covered that you do so as your rats age. Make sure the covering is in good condition and replace it when it gets chewed.


When my boys were losing mobility in their back legs I tried Ibuprofen with one and steroids with the other. Neither seems to make a bit of difference. They certainly did not reverse the problem and I can't even say I saw a slowing in the progression. With Tessa and Mochy, I have started using Glucosamine-Chrondroitin. I am still playing with the dosage, but I am somewhat optimistic. It seems that both girls are not losing function as quickly as they were before. Right now, they are getting about 40mg/kg once a day. With this treatment, you want to start in the early stages of the deterioration to help prevent the loss of function. If you wait until your rat is barely moving it won't do much good.


If you rat becomes completely paralyzed he is at increased risk for pneumonia, bladder infection, skin breakdown, and injury from cagemates.

Pneumonia becomes an increasing possibility with immobility. The pooling of secretions in the lungs provides a great medium for bacterial growth, and, of course, our furry friends have enough respiratory problems as it is. Some rats will move around quite a bit after suffering paralysis of their hind legs. They just drag themselves around with their front legs like nothing is wrong. Some will be relatively immobile right from the beginning, and most will become sedentary at some time after losing the use of their back legs. My rat, Lancelot, became paralyzed at age two years and seven months. He lived to be three years old. Initially, he would move himself around over small distances, but as time wore on he was more likely to stay in one place. You can help your rat by taking him out frequently and placing him in different positions. Moving his joints around with gentle range of motion exercises will help keep his joints flexible and prevent contractures of muscles into abnormal positions.

The first rat I had that developed complete paralysis was Merlin, Lancelot's brother. He was just over two when he bacame completely paralyzed. Within two to three weeks of becoming paralyzed Merlin developed a severe bladder infection. Rats with paralysis from spinal degeneration are at risk for bladder infection because in some cases of paralysis, depending on the nerve involvement, the bladder does not fully empty. The urine that is left in the bladder promotes bacterial growth. It is questionable whether anything can be done to prevent this. Certainly, checking for a persistently enlarged bladder would be helpful. Preventative antibiotics may also be helpful. When Lancelot became paralyzed I started him on a maintenance dose of Trimethoprim Sulfate once a day. He stayed on this medication the rest of his life. Lastly, just knowing this is a possibility will help you catch any infection early. Be on the lookout for foul smelling or bloody urine. Sadly, Merlin did not survive his bladder infection. Despite aggressive antibiotic therapy, we could not clear up the infection.

Skin breakdown is also a big consideration. A paralyzed rat cannot as easily move himself out of his own urine and feces. Continual exposure to the urine, along with the pressures of being in one place, can lead to pressure ulcers, otherwise known in human lingo as bedsores. The most important thing to do is wash the rat off several times a day with gentle soap and water. Lancelot actually seemed to like this, but I found that it was not enough, since I was gone during the day for more than eight to nine hours. When I arrived home, Lancelot's skin would be red and irritated. I found that Desitin cream worked very well to prevent skin damage during the day. I would wash off the Desitin in the morning and at night and reapply. Don't forget to put a little Desitin on the feet; they are typically also in contact with urine during the day. I also found that a piece of fuzzy acrylic fleece directly under Lancelot would wick the urine away from his skin and into the litter below. Of course, you have to change the fleece daily (at least). The fleece also helped protect bony joints from undue pressure.

At some point, you are going to have to consider moving your paralyzed rat into a cage by himself. I really put this off as long as I could. I felt that the poor guy had enough going against him; I didn't want him to be lonely as well. Unfortunately, one day I came home and found red drainage in one of Lancelot's eyes. He was also keeping it closed. I don't really think there was a fight between the rats - it is more likely that the boys were playing and Lancelot got in the way. Since he can't easily move out of the way, one of them probably stepped on his eye and scratched the cornea. The vet confirmed that it was a corneal abrasion and I treated it with antibiotic ointment. It turned out to be a pretty severe injury and he lost the eye. At the point of injury, I moved Lancelot into a cage by himself, but still felt bad about it. I made sure I got him out daily on the couch with his friends. He really seemed to enjoy those times.


Think adaptive! Try to think of all the things a rat would normally do and come up with ways to make it easier for them. Feeding time, for instance, can be very frustrating. While most of these rats maintain their ability to hold things with their front paws, they can no longer sit back to eat them. Also, getting into the bowl can be a challenge since they can only lift themselves with their front legs. I would recommend a bowl with a very narrow lip. In some cases, you will have to put the food directly in front of the rat on a towel or a rag. Some rats, as they get older, may have some difficulty with their front feet as well. If a rat cannot hold his own food you will need to move to a soft diet, and possibly hold his food for him. Make sure the rat can get to the water bottle without moving.

Believe it or not, rats get wax in the ears - a lot of wax! A paralyzed rat cannot perform many grooming functions. I've always watched my rats scratch inside their ears, but never really realized they were actually removing wax. Obviously, a paralyzed rat cannot get his back feet up to his ears. You will need to gently clean his ears with a Q-tip about once a week. Rear toenails will need to be trimmed frequently. They are not getting any friction to help keep them worn down. Be careful not to cut them too short.


Obviously, this is something everyone will have to decide for himself. For me it was not an issue. Lancelot was not in pain and ate like a hog up until the day he died. He was a big-time kisser and really enjoyed snuggling. He was a champion bruxer! I never questioned my decision to care for him in his weakened condition. Lancelot died quietly in his sleep one day at the age of three years and two weeks. Merlin was a different story. He was miserable with his bladder infection, and after lots of painful trips to the vet and some pretty aggressive antibiotic treatment, I made the decision, along with my vet, to put him to sleep. I can't say that will happen with my girls who are showing signs of degeneration, but as long as they seem to enjoy being here, I will do everything I can to meet their needs.