My gerbil is puffy furred, discharge from eyes and/or nose, and otherwise is sneezy, clicky and miserable. It may improve briefly when I take it out for playtime.

Possible allergy or allergies to things in it's environment. It can be difficult to find and may be multiple allergens.

Bedding (even carefresh), food/feed, treatstuff, even the silicone sealant used in tanks have been reported as allergens. Another serious allergy difficult to track, is ammonia sensitivity. IF the tank isn't cleaned every few days to a week (depending on the bedding) the ammonia fumes from their urine causes them to react... if you have animals this sensitive, it can be difficult to discern what's going on, what's causing it and dealing with it. If you have animals this sensitive don't breed them as such an allergy isn't a good one to perpetuate.

IF you suspect this, start by putting the animals on cheap white shredded paper towels. You want the undyed unprinted bargain stuff (no reinforcing fibers). Remove everything from the tank or cage except the waterbottle. Bedding is the most common allergy, so this will usually fix things. It will take TWO WEEKS of being on paper towels to show improvement if it's a bedding allergy, and allow the animals to recover.

In order of most allergic to least, (some beddings in this list are not recommended for gerbils ever, but are in the list)

Cedar, pine/chlorophyll pine, aspen, carefresh, carefresh ultra, corncob, paper towels

Cedar has too many aromatic oils and usually cause severe respiratory problems in gerbils and other small animals, it should NEVER be used (many packages say 'safe' or have a picture of a small rodent on them).

Pine or the green 'chlorophyll' pine, can also have problems, even if it's well aired. Reports of HUMANS having allergies to this bedding. Chlorophyll pine can be expensive, and mostly if it gets wet it can shed the green onto a light colored animal (have seen a white syrian hamster dyed lime green after a water bottle leak into a freshly changed tank). Don't use.

Aspen has few aromatic/volatile oils, and is more expensive but available for wood shavings. Some gerbils can have problems with aspen though.

Carefresh is a greyish flaky stuff. Fairly good absorption. Can be dusty. Reports of pups having respiratory problems on it. Mite contaminated batch shipped to pet stores in one major city reported (vet confirmed, everyone had a few weeks of infestation, traced to all stores supplied by one wholesaler, or all three store chains in town).

Carefresh Ultra is said to be less dusty. More expensive, harder to find.

Corncob is sold in the bird section. It has fair absorption and smell control. No reports of pup problems on it. Can be a little expensive. Recommended for least reports of allergies in humans and animals, and for those in close quarters with their pets (bedroom keeping or apartments). If you have an ammonia sensitive animal, two inches of corncob changed weekly should take care of that problem. IF you can train the animals in that tank to do a potty corner, then clean that every day and that will also help.

If the animals don't seem to improve by moving to paper towels, examine the feed for excess dust. Pick out any raisins, pumpkin seed, sunflower seeds, flax, safflower. Take the feed outside and upwind, pour a few feet from one container to another, allowing the breeze to take the dust away. If you have human allergies in the house, this may alleviate those. A feed store custom mix is more prone to causing human allergies. Freeze your feed for at least 7 days at 0F... in case of mite or bug contamination (weevils, bran bugs, the small miller moths) ... this will kill anything in the food. Also, if you are worried about your food staying 'fresh' you can bag it in baggies, freeze, and take out one baggie at a time. Leave the bag sealed, and out for 24 hours, and you won't have to worry about any moisture condensation ruining the food.

A noticeable change should happen in a few days. IF this isn't happening...the animals remain puffed furred, but improve if taken out for short periods....IF the animals are being kept in a tank...switch them to a cage or a Jumbo Kritter Keeper (10 gallon/38L size) to get them away from the silicone sealant in the tank. One case of a pair of sisters having a silicone allergy have been reported.

If your animals have bedding or silicone allergies, it's suggested that you don't breed them, as the tendency for the allergy may be perpetuated. Allergies are not a good thing to breed into the gerbil gene pool.

Puffiness and bloating has also been reported for animals very sensitive to the AMMONIA in their urine. In this case put them on corncob bedding, which is about the most absorbant there is, and remove their nest every three days and give them a new one. IF you have animals with this extreme sensitivity to ammonia, do not breed them.