Seizures are a common disease problem in gerbils, with 20-40% of gerbils affected. It is an inherited trait, with members of some family lines at an almost 100% risk of developing these seizures. Seizures usually start at 2 months of age and may become more severe until the animal reaches 6 months of age. At that time, some gerbils may outgrow the tendency to have these seizures.
The seizures are usually short in length, lasting a few minutes, and may be mild or severe. In the mild form, the gerbil may simply freeze and be nonresponsive. In others, the muscles will twitch. In some gerbils, the seizures are grand mal. The seizures are often brought on by stress such as handling or unfamiliar environments. Some hypothesize that this behavior may actually be an evolutionary survival mechanism to deter predators.
Generally no treatment is needed, and after the seizure is over, the gerbil appears normal. However, if the gerbil sustains a grand mal seizure for several minutes, brain damage may occur. It has been suggested that gerbils which are frequently handled during their first three weeks of life may be less likely to develop seizures, however, this has not been proven. Since this appears to be an inherited condition, gerbils who have had seizures should not be bred.