African Rats - The Deadly Illness

Mary Ann Isaksen
From the July/August 1998 Rat & Mouse Gazette


In the past several months, many peopleís African Giant Pouched rats have been getting sick. No matter what treatment is administered, it seems once these majestic animals get whatever terrible virus or bacterial infection this is, there is nothing that can be done to save the ratís life.

When it first started happening, we thought there might be some connection to heredity, and I spent much time trying to see where the connection might be. Now, after seeing it run through my own African rat population, I am quite sure it has nothing to do with heredity, and is definitely some sort of illness that they just canít seem to fight off.

I lost my beautiful one year old, Tanzania, on March 5, then my sweet, talkative, cuddly 4-1/2 year old male, Monster, on March 8. I thought it was going to stop there, but it wasnít long at all before Lyric and Gomez began showing the same symptoms. I immediately started antibiotic treatment along with fluid therapy, but nothing helped; their symptoms just kept on progressing.

On March 23, I made it home from work just in time for my incredible 3-1/2 year old girl, Lyric, to take her last precious breaths in my arms. I decided I had to do whatever I could for Gomez, no matter what the consequences, since I still had one healthy African rat left and I had to know if there was anything else that might stop this thing in its tracks.

When I awoke the following morning (March 24), I found Gomez with his teeth clasped around the bars of the cage. He was almost totally unresponsive and had blood around his mouth. I decided I couldnít allow this poor rat to suffer any longer and made the heartwrenching decision to euthanize him.

Morticia is still fine several months later, showing absolutely no signs of this illness, and I pray that she will continue to be spared even though she doesnít care for being handled.


The most visible symptoms with this illness are lethargy and shaking. The rat closes his/her eyes and very rarely opens them again, if at all. If they do open their eyes, itís only a tiny bit. Their eyes almost seem to be sunken into their head. They seem to quiet down and only vocalize when they are touched, making me believe that they are in some pain, the degree of which I couldnít begin to guess.

The shaking is very obvious when you stand the rat on its feet. It appears that all coordination is lost and they have a difficult time staying upright. Also, while holding them like a baby, you may notice their feet trembling.

All of my rats had a good appetite until a few days prior to their death. They also tried to eat and drink when hand fed/watered, but couldnít on the day before their death. They would bite at the syringe when it was put in their mouth, but were not able to swallow. Water would run out of their mouth and down the side of their chin. I didnít continue to try to feed them when this began for fear that they would gag and choke on food.

Their stools were completely normal until a few days before their death. I examined the stools looking for parasites, but saw nothing. A few days prior to their death they began having loose stools, although they were not runny and could not be considered diarrhea. I attributed this to me feeding them soft foods, but I suppose it could have also had something to do with the progression of the illness.

At no time did I notice a difference in urine output, although Tanzy did seem to drink for long periods of time during the phase of her illness when she was still active. She drank slowly, but for long periods of time, although she did not drink nearly as frequently. Because Monster, Lyric, and Gomez lived in the Office/Rat room (Tanzy lived in my bedroom), I was not able to observe the frequency of their drinking. However, I did notice that the illness did seem to progress faster in the older rats.


Photo by Mary Ann Isaksen

It is obvious that this illness is passed from one African to another through the air. Tanzy was the first to become ill and she lived in a completely separate room from the others, but three out of four of the others also became ill and died.

The real question is: where did this illness come from and what is it? Unless someone has a vet they can turn to and can afford serological testing, tissue testing, etc., we will probably never know what it is. My veterinary source for that kind of testing on an illegal animal was lost to me when I moved from California to Massachusetts. Regarding where it came from, we may never have the answer to that, either, without knowing what it actually is.

This illness has not only appeared in my African population here in Massachusetts - it has emerged in several different areas of California. So far, the only connection we can make is that all of the homes in which African rats lived, who became ill and died, also had domestic rats as pets. However, at this time there are still homes housing both African rats and domestic rats in which this illness has not appeared. Also, I have had African rats for 3-1/2 years living in the same room with domestic rats with no problems until now. Therefore, making any real connection with all of this is essentially impossible.


Where do we go from here? At this point, I donít have the slightest clue. What Iím hoping from writing this article is that somebody will recognize something and at least get an idea about what has been happening. I am much too close to this one to sit back and make an objective observation. Anyone have any ideas?