how can you tell if the medicines will affect the animals, in the same way they affect humans?

Question: how can you tell if the medicines will affect the animals, in the same way they affect humans?
- Keywords:
  animal testing,
  medicine,
  transferable
Asked by princesskuntuckey to Hitesh, Hywel, Mae, Nik, Tiffany on 19 Jun 2012. This question was also asked by janosk1dns.
- Tiffany Taylor answered on 19 Jun 2012:
  
  Good question! And sometimes it’s really difficult to tell. We choose animals which we know have an immune system which works in a similar way. We also know in which ways their bodies differ, so if the drug is having an effect on the body which we know behaves differently to our own, further tests need to be done to check it’s safe for people.
- Hitesh Dave answered on 19 Jun 2012:
  
  good thinking!!..Most of the appropriate species of animals required for testing are similar to humans as far as physiology concerns..they will have similar digestive system, similar tissues but bit smaller in size…All of these tissues works similar like human tissues…also before testing we check the medicine route as well and try to test medicine with the same intended route..I mean if we take pills orally than we give medicine to animal via mouth…

Question: how can you tell if the medicines will affect the animals, in the same way they affect humans?