Q: Can worms build up a resistance against deworming products?
A: Worms can definitely develop resistance to the drugs and changing the type of deworming medication you use from time to time will help prevent this from happening. There is no standard in small animals for when you should change the drug but I would recommend changing the dewormer every six months to prevent resistance from developing.
The best deworming tablets are those that you can pick up from your veterinarian or veterinary nurse. These drugs are scientific, studies have been carried out on them and they are very efficient.
Dr Jevan Christie, veterinarian