 Another risk to rat owners is Rat @-@ bite fever . This is a rare disease among domesticated rats and is most often found in rats from large chain pet stores who breed their stock of rats in masses ( usually with the intention of being snake food rather than pets ) or from breeders who fail to take good care of their rats . This disease is fairly unnoticeable in the rat , but is characterized by the swelling of the site of the bite or scratch where it was contracted , a fever , vomiting and body aches . It is contracted by being bitten or scratched by an infected rat . 
