Quarantine is a process by which you try to eliminate or minimize the
risk of introduction of specific viruses, bacteria, or parasites into
an existing colony of animals. In the case of our rodents, quarantine
is used before new animals are introduced or when animals have been
away for breeding or showing. When done properly, the virus,
bacteria, or parasite should remain with the quarantined/infected
animals and not be spread into the resident colony of rodents. When a
problem is found in the animals being quarantined, you can treat the
specific problem rather than place the other resident animals at risk.

When bringing in new animals or after a show, it is best to
quarantine animals for a minimum of two weeks before reintroducing
them to your other animals. This means you keep them in a separate
building that doesn't have the same air flow from your other animals
(e.g., garage, shed, friends' house, etc.). If you don't have the
facilities to keep them in a separate area, then it is best to keep
them in a room at opposite ends of the house from where your other
rodents are located. It is important to remember that some disease
causing viruses and bacteria are transmitted in the air and by you
(clothing, equipment). In either case, they should be cared for after
the other animals. Specifically, this includes feeding, watering,
cleaning cages, playing with them, etc. You will want to have
separate watering containers, cleaning buckets, bedding, and cleaning
disinfectants for the animals in quarantine. It is also a good idea
to get in the habit of changing your clothes and showering after you
care for the quarantined animals and before you take care of your
existing colony when returning from a show or other event where you
handled or were in contact with other rats.

If during the two-week quarantine period you notice signs of
respiratory (i.e., sneezing, rattling/wheezing, eye/nose discharge)
or other symptoms (i.e. lethargy, lack of appetite/water consumption,
swellings, death, etc.), then you should immediately consult with
your veterinarian as to the specific treatment indicated...