Is It OK To Give A Puppy De-worming Medicine For Longer Period Of Time Than It Is Recommended? What Would Happen If A Puppy Continues Taking The Medicine? Would The Worms Develop Some Kind Of Defence Mechanism And Defeat The Effect Of Medicine?

What type of parasite are you trying to treat and what with and how is it being given? Is it under veterinarian supervision? Usually the first dose kills the adults though sometimes might take more if severe and then another dose is given to kill the 'eggs' but it can depend on situation. Or are you asking about a parasite that is treated with antibiotics as that is a little different and they would be on a course for a period of time? Different parasites require different treatments (so different time frames and instructions ect.) so if you are using the wrong one for a particular parasite you wouldn't be treating it but maybe just preventing the one you are treating for. OTC meds aren't generally effective, work on mainly one type of the many parasites and have an alarming tendency to cause illness/death when when used on label. All dewormers can be dangerous though those have a very high incidence for very little effect and are different from the ones the vet might use and no dewormer should be used on your own without a vet or a great deal of experience (meaning under supervision of the vet). So, what are the details in this case specifically? If you and your vet are trying something that doesn't seem to be effective their may be some alternatives or something if you are having a hard time clearing up a case with the more common methods. .
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