system
Given the following post, respond as if you're commenting on Reddit:
human
Why were rabbits chosen as the animal model for early HCG pregnancy tests?

Mice were used before.
gpt
The rabbit test was faster. The mouse test, called the Aschheim–Zondek or A-Z test, used immature mice and involved injecting them with urine multiple times a day for several days. This was because the small mice would die if subjected to too much urine at once. The test took 4-5 days to get results. The rabbit test, on the other hand, got results in 1-2 days and was easier to administer. Both tests were eventually superseded by a test involving toads that was faster (5-12 hours) and non-fatal for the toad.