Most experts recommend buying a gerbil from a reputable breeder rather than from a pet shop, since the animals are usually healthier and tamer. Choosing a healthy, happy gerbil is important, and you should avoid any animal that looks, sounds, or acts unhealthy or strange. Since gerbils are happiest when they have companions, it is recommended that you buy at least two.
As a general rule of thumb, when you are choosing household pets like gerbils, you should obtain them from a reputable gerbil breeder rather than the local pet shop. The gerbil cages at many pet stores are often overcrowded, and many of the animals may not be healthy. Breeders, on the other hand, typically take care of their animals a little better, and they also usually spend more time handling them. This is not always a hard and fast rule, however, since some pet stores take excellent care of their animals, while some breeders may not.
Before you purchase a new gerbil, you should make sure that it's healthy. It should not have any sores, scratches, or bite marks, nor should it have any missing patches of hair. Its fur should be clean and shiny as well. It is also usually a good idea to look closely at the fur under the skin to check for mites or other ectoparasites.
Like many other domesticated rodents, such as rats, gerbils are prone to contracting respiratory infections. Before buying a gerbil, you should listen closely to the sounds of its breathing. Never purchase gerbils that are wheezing or having trouble breathing. Red mucus around the nose is another telltale sign of a respiratory infection.
Also, pay close attention to how a gerbil acts before you purchase it. It should not bite when it is handled, nor should it act uninterested. Healthy, well-adjusted gerbils will usually be active and interested in their environments. As long as they are not awakened out of a deep slumber, they will usually sniff and attempt to run around when picked up. Gerbils that act lethargic, even after being nudged gently, should be avoided.
By nature, gerbils are very social creatures, which is why you should buy at least two. It is important to watch how a gerbil interacts with other gerbils in the enclosure. They will often play with one another and huddle together while they sleep. Generally, a lone gerbil that keeps to itself is most likely ill, injured, or maladjusted.