This article is from the Winter 1999 AFRMA Rat & Mouse Tales news-magazine.

By Carmen Jane Booth, D.V.M.

Emily Shabaz, Madison, WI
Q I had seven female rats. Two of them died of respiratory disease. Now I have one that has had it for almost maybe two months. She kinda walks on her side and makes that weird choppy sound when she breathes (she’s an albino rat). She eats, drinks, plays, and grooms herself nicely. I’m just wondering what I should do!

Kaly Hessel, Carrolton, TX
Q I have a Siamese rat which I obtained from a pet store (I couldn’t resist, she kissed my hand). I named her Lili. I was not not sure of her age, but she was so small I thought she was too young to be pregnant. About 3 days after I got her she started sneezing and having a little pink drainage from her nose. She was treated with trimethoprim sulfate for about 3 weeks. The symptoms disappeared after about 1 week. During the course of her treatment it became very obvious that she was pregnant, and she had nine cute little babies after she’d been with me for 2½weeks. Everything went fine, Lili never had any other symptoms nor did the babies. I found good homes for all the babies and kept one and named her Raven. After all the babies were weaned and had gone to their homes (approx. 6 weeks after delivery), I moved Lili and Raven into a large cage with three other females. It went well with every one getting along just swimmingly. About 2 hours after I moved her into the new cage, Lili developed a head tilt to the left. There were no other symptoms with it, and her balance was good. No circling. I moved her to a cage by herself and started her on Baytril 1.4 mg (approx.) twice a day. On Monday we went to the vet who added trimethoprim .1 cc BID. Lili has now been on antibiotics for a little over 2 weeks with no change. No other symptoms have surfaced and she continues to eat and gain weight. We’ve been back to the vet once and she is reluctant to change anything thinking the antibiotics just need a little more time to work or it’s not an antibiotic sensitive problem. I have had two other Siamese rats from the same pet store (maybe same breeder?). One was a male who got pneumonia and died within hours at 3 months of age. The other was a sweet sweet female who had a head tilt with severe balance problems who, after many different antibiotics, had to be euthanized due to intractable seizures. I have a bad feeling that Lili’s problem may be other than infectious, and wondered if anyone there had any other ideas or suggestions. I’ll try almost anything. Thanks so much in advance.

A A head-tilt (torticollis) in any animal can be caused by a number of different medical abnormalities. A primary brain lesion, such as a tumor or other neurologic problem is less likely in domestic rats. The most common cause is from damage to the inner ear from bacterial infections, where there is sufficient inflammation and disruption to the balance center (semicircular canals) that reside in that location. The history is suggestive that there may be respiratory concerns. What happens is that the signals from the balance center are altered by the damage, and the animal’s brain gets erroneous data concerning its position in space, and tilts its head to try and orientate itself to the erroneous positional data. If the damage is severe enough, than the head-tilt may be permanent or progress to rolling. I have seen this in rodents and rabbits, and have cultured a variety of different organisms from the inner ear at necropsy. If the rat is an older rat (1.5 + years), than a primary tumor would be higher on the list of differential diagnoses. Your veterinarian’s suggestion to give the antibiotics more time is a good one. The inner ear is a difficult area to treat, and it often takes longer for any positive results to be seen with antibiotic therapy.

Mickey Maeckelbergh, Belgium
Q My young Hairless rat has a head tilt (his head is hanging to one side). My vet has given me Baytril for this, she thinks it is a middle ear infection. His one eye is bigger than the other one. For the rest of him, he looks healthy, he plays with the Dumbo and the Dumbo Hairless, and his appetite is good. Do you know what I can do to make him better?

A In this situation, the cause of the head tilt (torticollis) has not been determined. The most likely cause is a middle ear infection which can sometimes be confirmed by radiographs. In the event that the radiographs are negative and the torticollis does not resolve with antibiotics, then other causes of torticollis should be considered. In this age of animal, the probability of tumor is small.A primary problem in the brain is possible, but very uncommon.

The most likely cause of torticollis in this animal is probably from a middle ear infection. If the infection is resolved with antibiotics and the damage to the balance centers in the ears is minimal, than the animal may recover and regain normal head position. In some cases even with resolution of the infection, the damage is permanent and the animal has torticollis for the remainder of its life. If confirmation by radiographs is desired, than I would suggest that the rat not be anesthetized if possible. Special techniques were used when I was in veterinary school for radiographs in rodents.

Fleur Wiorkowski, Commerce, TX
Q I recently had to euthanize one of my mice, Jacob, because he became suddenly very sick. I went to visit my parents for the weekend, leaving all my rodents and other companion animals with adequate food and water, of course, and when I came home, he had developed a definite lilt to his head, in other words, he constantly kept it tilted to one side. By the next day, it was so severe that he couldn’t lift his head off the corn cob bedding in his cage. When I got home from work later that day, he was only alive in the abstract sense, not moving around at all. It became clear to me that he would not recover, so I had him euthanized. I am new to rodent care, and I was wondering if his symptoms were part of a disease process or if he was just elderly (I got him from a pet store, so I have no idea how old he was). His cage mates seem to be fine as far as I can tell. I was just curious as to what this disease was so I can head it off, if possible, if any of my other rodents acquire it.

A In mice, the most frequent cause of a head tilt (torticollis) is damage to the semicircular canals in the inner ear that send information to the brain regarding spatial relationship (body position). The most common cause of injury is as a result of bacterial infection in the middle or inner ear canal. In this case, because of the sudden onset and severe nature of the symptoms, a tumor in the brain, or a stroke is more likely. A stroke is basically where there is disruption of blood to part of the brain where the brain tissue is injured or dies. Although the exact age of this mouse in unknown, I suspect that he was probably over 1.5–2 years old.

I found out something interesting regarding older mice during my extracurricular studies with one of the top rodent pathologists who studies aging rodents. Depending upon the strain, most mice are deaf at about a year, and many develop problems with their incisors (the long upper and lower front teeth) as they age. The underlying cause of these lesions (problems) is unknown, and there is no treatment. This is just another one of the common findings in older mice.

Cocoa Satin rat with “wry neck”.

Back to top