Anyone who has or is thinking about getting a gerbil should read this! These are only a few, but there are much more!
Symptoms: Gerbil cannot close mouth properly, and/or cannot eat.
Causes: Chewed on a hard material like the side of the stone fireplace (that happens all the time!) or cement, or does not have an acceptable material to wear teeth down on.
Treatment: A broken or lost tooth is very difficult or even fatal to a gerbil. Overgrown teeth can be easily clipped by a vet or you, but deep cuts caused by the tooth sinking into the bottom of the lip should be treated.
Symptoms: Red or bleeding nose and/or bald spot above nose
Causes: Allergy to bedding or something in cage or chewing on wire bars of the cage frequently.
Treatment: wash everything in cage and switch bedding to another, more reliable brand. Bald nose problem: Move gerbil and his cages mate(s) to a non-wire bar cage, or if you cannot afford another one yet, give your gerbil things that will not make him bored enough to chew on the bars.
Symptoms: head tilt, loss of balance, or bleeding around ear area.
Cause: Inner ear infection, or simply a scratch from the gerbils nails while he was grooming.
Treatment: Inner ear infections need to be consulted by a vet immediatly, but a scratch on the ear involves a little cleaning with some neosporin and a cutting of all the gerbils' nails, to avoid them being too sharp.
Symptoms: Sometimes lethargy, diarrhea, and orangish-red staining from urine all around the rear end.
Treatment: Wet tail is a disease of hamsters, caused by an organism similar to Lawsonia intracelluraris. It basically causes diarrhea in the hamster.
You can treat it using hamster antibiotics, because it is rare to a gerbil for this disease. I know some gerbils can get it, so this is why I am saying this one too.