Originally Posted by casportpony
Studies show that ivermectin is not an effective poultry wormer unless high doses are given. There are also many posts here on BYC with necropsy pictures from people who thought it was an effective wormer......
Wazine, Safeguard, Valbazen are not FDA approved for laying hens, they aren't banned for use, so all can be used as long as one waits until the drugs clear.
I agree that Ivermectin results are mixed depending upon the study and source you read. Ivermectin efficacy depends upon the parasite type. It is effective on some, while not as effective or ineffective on others. In red roost mite, for example, treatment must be at toxicity level for even a short term benefit.
But as you can see below from the Merck's manual, it is deemed effective on a number of parasites.
Note red roost mites would have to be treated at point of toxicity for short benefit while other types are successfully treated at acceptable doses)
For internal parasites, I find
"and ivermectin 1% at 10 mg/mL in water were effective in removing A galli, H gallinarum, and Capillariain chickens (Round worms, cecal, and capillary)"
The problem with Ivermectin has been over use and appropriate use (correct application and applied correct number of times). Any wormer's effectiveness will vary with both application type and overuse. It is best to rotate wormers and insecticides to avoid resistance build up to the particular medicine. And that can be the reason behind such mixed reports on many of the meds. It may depend on the local resistance of the parasites.
Unfortunately, the government has made rotation of meds difficult as only Hygromycin B is currently approved for worming, and Permethrin (or variations) for dusting or spray, of the types commonly used in back yard situations. (There is a longer list for external parasites which typically are used by poultry industry rather than the back yarder, but Hygromycin is the only currently approved poultry wormer for hens laying eggs for human consumption).
Only FDA approved drugs are allowed for use. That's not banned, that is approved only. Many drug manufacturers have let their FDA approval lapse because it takes time and money to keep up with the certification process and the poultry industry does not find it profitable to do so. It keeps industry sanitation with cages, rotation and culling. Sevin is such example of a drug that used to be approved for poultry but which the drug manufacturer itself no longer sought to keep FDA approved. Sevin is still sold for garden plants, but is no longer approved for poulty.
It is important to understand that, legally, the FDA only allows drugs that have been approved, which means Wazine, Fenbedazole, and even Ivermectin are not approved for hens laying eggs for human consumption and therefore technically should never be used for that purpose.
On the other hand, the government expects and requires all animals to be treated and cared for humanely and medically if necessary. What that means is that you may have to treat an animal under vet supervision but lose your organic status for that animal and ability to sell food products from that animal ever again, even with appropriate pull times.
This is targeted at commercial and certified organic growers. Many of us sell through a Farm Direct to Consumer provision that allows us to sell eggs without government licensing or inspection. So essentially there is no oversight. With no oversight, then technically you can do what you want as there is no "egg police." What it could mean (this being spoken from my experience as an ex-paralegal) is that if someone ate your eggs and got sick and sued you, and it came out that you used non FDA approved products on your birds, you could have a greater legal battle on your hands. It is a bit of "no man's land" with a lot of "don't ask, don't tell."
My customers don't care (including the vets at my daughter's vet clinic) as long as I practice appropriate pull dates as supported by authoritative research and documentation. They simply want eggs from happy, healthy hens, farm fresh.
A number of people do care, and my daughter who is now an organic farmer with her husband, must follow strict guidelines to keep their eggs appropriately certified which essentially means herbal wormers only, culling any sick animal.
My understanding as I have had to wade through these legal "technical' questions for myself.
edited for grammar typos
Edited by Lady of McCamley - 11/8/15 at 1:38pm