Gerbils and Your Health

The news hasn’t been friendly for rodent-lovers in the past few weeks. First, we heard about antibiotic-resistant salmonella outbreaks caused by pet hamsters. Now, an unusual case involving donated organs implicates a hamster as a carrier of LCMV (Lymphocytic choriomeningitis). What is going on? Is keeping a pocket pet really dangerous to your health? Should you take Mr. Fluffy back to the pet store in order to keep your family safe?

Put the cage back on the shelf for now. A careful assessment of the facts behind each case and the likely risks indicate that the hamster, rat, gerbil or mouse sharing your home is no more dangerous today than he or she was yesterday.

Salmonella

Let's begin with the salmonella outbreaks reported in 2004. The first two reported cases involved children in South Carolina and Minnesota who became ill after handling (and even kissing) animals which were obviously ill or which died shortly after purchase. Salmonella symptoms in rodents are similar to those in humans, with diarrhea the most obvious sign.

Aided by computerized records of outbreaks, the Centers for Disease Control (CDC) were able to link these cases with a shipment of 780 hamsters received in Minnesota from an Iowa distributor. Within a month, 60% of these animals died and the rest were euthanized. Further study by the CDC found two important factors in the contamination:

• Animals shared carriers, cages, and food bins that were not sanitized sufficiently to prevent disease transmission.
• Breeders and/or distributors of these animals used antibiotics routinely in the animals' food and water, leading to antibiotic-resistant salmonella strains.

Reducing Risk of Salmonella

The salmonella story points out several important lessons that can help us enjoy our furry friends safely. They include:

• Do not ignore symptoms of illness, especially diarrhea, in any pet. Take sick animals to a vet promptly.
• Wash hands thoroughly after handling animals and their bedding, just as you would after using the bathroom or changing diapers.
• Purchase your animals only from reliable sources.

Reliable Sources for Pets

This last point deserves some additional consideration. Remember the CDC's story mentioned a shipment of 780 hamsters. Animals that are bred or wholesaled in such quantities must be considered complete unknowns. You can be certain that there was no one to notice if one of those 780 animals displayed symptoms even as obvious as diarrhea. Mass-produced animals will change hands many times, be exposed to many other animals, and be housed in conditions which are industrial at best, filthy at worst.

On the other hand, reliable sources such as hobby breeders and animal rescue organizations can provide you with pets who have been carefully watched and frequently handled. A local pet store that deals directly with a breeder (and not a distributor, where animals are congregated) can also be a good source, but ask questions and do not be put off with vague answers.

Small-scale breeders and rescue organizations emphasize cleanliness and daily attention, and know each animal as an individual. In the past, we considered this important mainly in terms of a pet's behavior and socialization. These new stories demonstrate that choosing your pet carefully can be a matter of your health, as well.

LCMV

LCMV made the news recently and sensationally as the cause of death among three recipients of donated organs. The infection that killed them was traced back to a single donor who apparently contracted the disease from her pet hamster, although she had no symptoms of the disease herself.

LCMV is not a new disease. It has long been present among the common wild house mouse. About 5% of wild mice in the US are probably infected with LCMV, which they carry with no symptoms. People can experience LCMV as a brief, flu-like illness which can progress to more serious meningitis, with attendant risks of neurological damage. LCMV is also dangerous to fetuses, particularly during the first two trimesters. The three organ recipients who died were also victims of their depressed immune systems. (Among otherwise healthy persons, LCMV has less than a 1% mortality rate.)

Contact with the droppings, urine, or saliva of wild mice is the most common way for people to become infected with LCMV. Hamsters and other pocket pets are not natural reservoirs for this disease. Pets infected with LCMV most likely were infected through contact with wild rodents.

Reducing Risk of LCMV

Your most likely risk of LCMV comes when you are cleaning the garage and come upon a mouse nest. To clean such an area safely, follow the recommendations of the CDC, which include spraying the area with a bleach solution, avoiding breathing in dust, and wearing gloves.

As a pocket-pet owner, you should keep yourself and your pet safe.

• Insure your pet does not come into contact with wild rodents: keep food stored in mouse-proof containers, keep pets indoors.
• Purchase your pets from reputable sources where they would not have come into contact with wild rodents.