Quote Originally Posted by Bogertophis View Post
I think it's likely due to inbreeding, and there's multiple breeds, they aren't all the same. The original pet hamsters were Syrians, and yes, ALL the captive-bred
Syrian hamsters came from a single pair of them that were originally-captured from the wild...so it's inevitable for genetic problems to become established.
But I still suspect it's an over-statement to say "they all are predisposed to forming tumors" any more than all other aging mammals are. The only hamsters
that I worked with were Russian dwarfs...I really like them because they're more social (with each other).
I looked into it and here's what I found;

According to PetMD: An abnormal growth of cells in a tissue or organ is referred to as a tumor, of which there are two types: benign and malignant. Benign tumors, which do not spread, are much more common in hamsters. Malignant tumors (or cancers), meanwhile, may develop in one location such as the hormone-producing glands or digestive system organs and spread into other body parts. Only four percent of hamsters suffer from maligma.

Causes: Both genetic and environmental factors are thought to play a part in the abnormal multiplication of cells, which leads to tumor formation.


I also did see on another forums page that hamsters are prone to tumors (or cancers).