You should never give your pets drugs unless advised by a vet. Even if most medicines prescribed to your pet are (almost) the same as those prescribed to humans, they are usually under different names and have different dose rates!
Once in their system, pets' bodies do not react the same way as humans do with drugs.
Here is a very short list of prescribed drugs that pets should avoid:
- The laxative phenolphthalein
- Iron supplements
- Vitamin D supplements
- Nebuliser medications prescribed for asthma
- Drugs used to control "fits" e.g. phenytoin (toxic in cats)
All of the above have been documented to cause serious illness and are potentially fatal. Never give medicine to your pet without consulting your vet first!