Antihelmintics:

• These are group of drugs used to kill or expel the parasite worms or helminths
• These drugs are widely used in veterinary medicine both prophylactically and to treat chronic and acute infections.

Ideal properties of Antihelmintics:

• It should have broad spectrum of activity i.e. it should be effective against all internal parasites including nematodes, cestodes, trematodes
• It should have a wide margin of safety
• It should have selective toxicity i.e. toxic to parasites but not to host
• It should have good efficacy against both mature and immature stages of helminths.
• It should not interfere the physiological function, development or growth of host
• It should have minimal withholding period
• It should be easy to administer to a large number of animals in herd or flock
• It should be economical
• It should be compatible with food or other compounds

Depending on their primary action, they are broadly classified as antinematodal, anticestodal and antitrematodal drugs.