Hey guys!
Just like to say say that I treat mites and lice with permethrin spray, it's safe affordable, EFFECTIVE, easy to use (if your weather isn't freezing), labeled for use in chickens and requires NO withdrawal time for eggs, and has residual effectiveness. Plus the benefit of working for mosquitoes and other pests as well. Scaly leg mites and depluming mites (which are also microscopic) however are both systemic feeders and will be more properly treated with the Ivermectin. Regarding egg withdrawal, here is one resource I have, hope it's are helpful. Though I already know it realy isn't regarding Ivermectin.
http://www.farad.org/publications/digests/122015EggResidue.pdfAs far as worming goes... the ONLY worms that will ever be seen in droppings are round worms and tape worms. All others will stay in the intestines and ONLY pass microscopic eggs, that you will never see.
That being said, Many wormers won't treat all worms. Unless you KNOW you have a specific issue... treating on routine without confirmation, especially if using the same thing over and over, is simply helping what parasites MIGHT be their build resistance to said drug.
Sorry I didn't use as many smiley faces as possible, I'm still adjusting to this new forum and can barely see what any of them are. Please know I mean this as respectful, friendly, helpful, and informational sharing of my experience. Best wishes to all who read!
I used to just worm my dogs when I saw one come in and scoot their bum. I never wormed chickens in the past 8 years because I didn't know you need to until recently. I don't believe in treating for what I don't have and maybe not treating what I do have.
So I suggest getting a fecal float and making sure to use the right medication... IF you even need to. It cost $25 at my vet which is a bit, but compared to losing out on eggs and the hardship worming places on the birds.. maybe worth it on occasion. I also just bought my own microscope to run samples since I have so many animals! I do flock samples, herd samples, and pack samples... meaning multiple samples from each species combined into a single float (of their own species). It will pay for itself quickly!
Recently saw one of my dogs scooting and have one pullet with muddy bum (which people swear is worms). Decided to vet test for parasites and both came back clean, meaning negative. No need to treat.
Regarding DE as a wormer it is complete hogwash. It is rendered useless when it becomes wet as the intestines are. And also is very soft and ground down when going through the gizzard where harder rocks stay to grind stuff. Studies conducted on cattle (according to wiki article on DE) showed no significant difference in worm load from those treated with DE as wormer. Seeing roundworms after feeding DE doesn't necessarily mean it worked. It could just mean you have a heavy worm load. DE, by the way is approved as an ingredient in animal/chicken feed at a rate of up to 2% as an anti caking agent. Many feeds have it, none tout worming benefits.