It really depends on the medication and whether it is likely to change. If the cat's illness involves regular checks and potential dose/drug changes then you might be better just getting it from the vet. If it's definitely long-term meds, check the prices online and ask your vet a) what they charge for a written prescription and b) how many repeat prescriptions they will be likely to provide. Remember to check delivery charges too.
Yes definitely worth pricing it up. We got insulin from Animed direct.co.uk which our vet recommended, the other one she recommended was petdrugsonline.co.uk. I got syringes from viovet. Is worth asking your vet.
It really depends on what you have been prescribed often cats with HCM are prescribed human meds’ and those can actually been cheapest from the human pharmacy with a private veterinary prescription. If you list the drugs you have been prescribed I might be able to give you an idea.
Frusemide will need to be a licensed product such as Libeo so your vets or online pharmacy, frusemide products are very cheap so you may not make a massive saving on line. There is no licensed atenolol or clopidogrel have no veterinary license product so a private prescription at the human pharmacy is likely to be the cheapest way we find we can buy from Boots cheaper than our wholesaler can supply.