The drugs cause desired short-term disruptions in the brain, but they also cause undesirable long-term changes to the brain and other vital organs in the body, leading to drug addiction. Common drug addictions include: 1  Marijuana. 2  Heroin. 3  Cocaine/crack. 4  Synthetic drugs such as bath salts and spice.
1 Penicillin G, common vet prescriptions known as CrystacillinÂ® or Flo-CillinÂ®, is an antibiotic used to treat and prevent bacterial infections in dogs and cats. 2  This is a natural penicillin and is cultured from the bacteria Penicillium chrysogenum.
Our understanding of animals helps us both understand why penicillin is dangerous to guinea pigs, and why we would not test penicillin on them to assess human safety. The reasons why guinea pigs differ in their reactions from most other mammalian species are very specific.