Medical Corner: Tumor Removal and Baytril

In the September/October 1996 issue of Rat & Mouse Gazette, the question was asked "has anyone ever had their female rat remove her own tumor?" The following was the only answer I could give at the time:

"I certainly can't speak for everyone, but I have never heard of this happening. I have seen cases where the tumor was irritating the rat so much that the rat chewed at the tumor making it bleed, but I have not seen them remove one.

If you had a rat who had a lump disappear overnight, leaving a gaping hole in the skin, chances are pretty good that it was actually an abscess that opened up and drained, making it appear that the rat had removed what you had thought was a tumor."

For the most part, I would still answer this question the same way, but recently, I had something very strange happen in this area that I thought I would share.

Buddy, one of the babies from the Hawthorne rescue of May 1995, had an abscess on his side directly behind his shoulder. He was about a year old when this happened. I put him on antibiotics and waited for it to pop, or for a scab to form so I could easily open it up and clean it out. It didn't take long, and I removed the cottage cheese-like old pus, cleaned the gaping hole, and continued with the antibiotics. He healed in no time at all.

Several months later, another abscess appeared in the same spot. Again, I put him on antibiotics and waited. I checked on him one day and found that it had already opened and drained on its own. I cleaned out the gaping hole and continued with the antibiotics.

It was several months later when I noticed an abscess forming in the same spot once more, and again, I went through the same waiting game. When the scab finally formed, I began to try to gently squeeze out the old pus. It was different than I had experienced previously - it was encapsulated, but I could clearly see white beneath the membrane that was surrounding it. The hole was about 3/4 of an inch in diameter, was not bleeding, and my squeezing didn't seem to bother Buddy in any way, so I continued. I slowly worked it out. It came out in one entire piece, a little over an inch in diameter. At that point, I could see that it probably wasn't an abscess at all and decided to cut it open. It was extremely difficult to cut and was clearly a fibrous tumor.

Underneath this tumor there was a series of three more small growths held together by a thin membrane. The bottom one seemed to be attached. Although the one that I removed had no blood supply, I feared that the bottom one in this series might, since it was connected, and I did not want to cut it without having the proper equipment available to handle the situation if something should go wrong. Buddy still seemed to be absolutely oblivious to anything that was going on, so I decided to wait until the morning and take him in to see my vet. I put him in my bedroom so I could watch him, in a cage by himself with white paper towels as bedding.

In the morning, the growths had dried up quite a bit and while standing there looking at him, he began to chew them off. He had them gone in no time, with no blood at all (I couldn't believe what I was seeing!). I continued with the antibiotics and he healed up completely. So, I guess with certain types of tumors, it is possible for a rat to remove one, but I wouldn't recommend waiting long enough to see if it does. It is possible that the second growth I thought was an abscess actually was a tumor as well, since I didn't actually see it.

I personally do a lot of home treatment since I have so many rats, but I've been blessed with a terrific vet who has helped me learn how to handle many situations. This, however, was an unintentional mistake on my part which I do not intend to repeat. I definitely recommend getting your rat to the vet as soon as possible to have a tumor removed or to have an abscess drained, if you're not capable of draining an abscess yourself. I do not recommend that anyone try to remove a tumor at home.

An RMCA member recently wrote us the following note. "A small correction - on the Drug Usage Chart on page 19 of the May/June 1997 issue, under Enrofloxacin, it should say that Baytril shouldn't be used on young (under eight month old) rats - it damages their bone growth plates."

Although the Drug Usage Chart was published for the benefit of Gazette readers, its intended use was for the information to reach inexperienced vets through our readers. The drugs and the dosages listed are the ones that we have actually had success with which we highly recommend. It was not intended to provide complete information on the side effects and toxicity of each drug, as that information can easily be obtained by any vet. Also, for the most part, the drugs listed on the chart are only available with a prescription from a vet.

The information available in regards to this member's concern is based on studies in dogs. It is true that Baytril is not recommended for use in dogs during the rapid growth phase (between the ages of 2 and 8 months). High, prolonged dosages of Baytril in these young dogs has induced abnormal carriage of the carpal joint (wrist) and weakness in the hindquarters. This can lead to permanent lameness, but in most cases, improvement has been seen after stopping treatment.

Unfortunately, with no real data regarding Baytril in rats (other than it is safe), we must assume that rats could have the same problem. However, the key words concerning this matter are RAPID GROWTH PHASE. The rapid growth phase of a rat is much shorter than that of a dog. Therefore, use of Baytril in a rat over the age of three months should never be cause for concern.