2007-05-04 15:42:41 · 3 answers · asked by kiis0 x3 2 in Science & Mathematics ➔ Zoology
Most come from leterally "animal factories" that produce animals for research. I am sure there are still some unethical sources out there yet but they are being done away with as they are found. Hopefully nobody's pet is being used.
2007-05-04 15:50:15 · answer #1 · answered by ttpawpaw 7 · 0⤊ 0⤋
They are raised for that specific purpose by laboratories and companies which specialize in such animals. They are raised under carefully controlled conditions, often on specialized diets, and are guaranteed free of disease and parasites. There are also strains offered with specific genetic characteristics. They are very expensive. A specially raised laboratory rat can cost a researcher $150.00 or more.
2007-05-05 01:39:50 · answer #2 · answered by PaulCyp 7 · 1⤊ 0⤋
Generally, they are carefully bred so that they're as alike as possible and as comfortable and easy to handle as possible. If you're looking to find out what something does in a living animal system, testing animals that are too different makes it harder to isolate the particular thing you're testing for.
2007-05-04 23:25:10 · answer #3 · answered by John R 7 · 0⤊ 0⤋