Do you all use the deworming medications as preventive measures or only if you suspect your flock has worms?
As a caveat, I live in an area where I have hot, dry summers and rocky soil. So I am fortunate to raise chickens in a not very worm-friendly environment.
But, I have been raising chickens for 7 years and I have never wormed them. It has not been my experience that chickens with access to the outdoors will inevitably acquire heavy worm burdens and suffer. As I raise chickens for both eggs and meat, I often check out the intestines when I butcher. I have yet to see a roundworm or evidence of intestinal damage. Last year, I did have a minor tapeworm issue, but the problem resolved itself without wormers as the seasons changed. After doing extensive research, I found there is evidence that chickens are able to rid themselves of at least certain types of tapeworms on their own.
The one thing I pay most attention to, is what I observe in my birds. Are the active? Are they a good weight and not losing/gaining weight? What is their egg production like in terms of quality and quantity? What do their droppings look like? Do I have unexplained deaths or failure to thrive? When we butcher, I pay close attention to what they liver, heart and digestive track look like. As long as my flock remains in good health, I do not plan on routine deworming for a several reasons:
--It's a hassle. A minor drawback, but a drawback nonetheless.
--There are no almost no approved deworming medications for chickens. Virtually everything people use to treat chickens is an off-label use of mediation developed for other livestock. My sense is that it is probably safe, but I would not be comfortable giving or selling people eggs where the chickens have been treated with a mediation that does not have a tested, government approved egg-withdrawal time. As least without informing them first of the issue.
--Speaking of egg-withdrawal. Most off-label users throw away eggs for two weeks after administering the dewormer. As you have to repeat the medication 10 to 14 days again after the first dose, you will end up throwing away a month's worth of eggs every time you deworm.
--Resistance to dewormers is a huge and growing problem in the livestock industry. The more everyone uses dewormers, the faster worms are going to develop tolerance to dewormers. In the time I have been following this forum, I have already heard of tapeworms developing resistance to Valbazen.
--Finally, deworming, may have limited utility unless it is combined with a comprehensive strategy for reducing worm load in your environment. The day after you have finished your treatment protocol, your birds can become almost instantly re-infected if they are continuing to peck at the same ground and eat the same insects.
