I think he's around 9? I have always given everyone DE in their food, and no one else has any symptoms of anything, very suspicious....What would you give him for internal parasites that the DE wouldn't take care of? Thanks for your response, by the way....I do love him.
9 is VERY old for a chicken, goodness! What a testament to your good care that he's still around at such a ripe old age!
I have been told by a few breeders who seem to be very "in the know" on all current medications/treatments/supplements, and the current theory behind DE being FED to birds is that it is harmful to the digestive tract. You probably already know that DE, upon magnification, has very sharp edges; the thought behind it used to be that these sharp edges cut into any parasite's body (i.e., worms) and would kill it. However, recent findings (I cannot quote research papers, as this is not something I personally researched - it was information gleaned from another breed board) seem to indicate that DE can damage a digestive tract in the same way that it kills parasites; by making tiny knicks along the soft tissue. This would eventually cause scar tissue to develop & build up along the intestinal walls. Again, I'm not an expert, and I don't know this to be true, beyond what I have read.
I do believe DE is effective in keeping a flock that is already free of parasites externally (mites, lice) clean, but it is definitely not a treatment for an infestation.
With a bird that old, I don't know how much I would try, personally. The normal "protocol" for treating worms, assuming he has them (but it doesn't seem like he would) would be Wazine first, followed by something stronger and more "across the board" in nature to eliminate any internal parasites. Again, though, I am just not sure that is a good course of action with a bird this old. And, my guess, by your postings, is that you're opposed to chemical use?