Metronidazole dosing for tapeworm/giardia

I have been struggling with my mother cat, four babies, and two teenage cats having serious diarrhea, for about three weeks. I think it was introduced when I brought one of the teenage cats back from an adoption place. It took a while to spread. Since I live with them in an apartment and use newspaper as litter, I can see the outcome up close.  I saw that that adopted cat had tapeworm, from a little soft triangular worm at her butt. And clear things in her throw up. But I didn't think to separate her from the others, because my previous experience with tapeworm is that it was easily cleared up with one pill, and no easy way to separate them. Not so easy now.

Within one week, all the cats had diarrhea. The babies were six weeks old, getting weaned. Originally their poop had been normal. A week later, it was not just diarrhea with jelly-like parts, but the older cats were throwing up regularly after eating, and beginning to get thin. I put Advocate on them, which kills a lot of internal worms, but that had no obvious effect. I took the teenagers (who were more serious) to the vet, and she said Advocate doesn't kill tapeworm. She gave me tapeworm pills for all the cats, and that stopped the jelly part of the poop, but not the other effects.

So I began to think of giardia, which I had had experience with before, but as I remember didn't quite look the same.  It was a little hard to find Flagyl a local pharmacies -- it used to be common, and available here without perscription. The pills come in 250 mg, and you have to chop them up to cat-size doses, less than 1/4 size for the small cats. but it is really hard to get them to swallow it. One dose, I expected that to fix it (it did once before), but it gave only a little improvement .... my simple minded expectation, I saw on this website that 5-10 days treatment is advised.

But how to get it down their throats! I just happened to have brought some big cans of fish in tomato sauce, which people in Taiwan eat as a side dish with rice. My cats love it, especially the sauce. I suddenly thought that the tomato sauce might cover up the flavor of the bitter Flagyl. I mixed a powdered 250 mg pill with the sauce first, and about 2/3 of the fish in the 425 cc can. I mashed the fish somewhat. The cats were hungry, I intentionally hadn't fed them for half a day. They all lit into the fish mix except for the one teenage cat who was the original source, and who is half wild cat and always resistant to getting medicated. I felt sad that forcing medicine down her throat in early attempts to control the diarrhea probably made her more resistant.

If this feeding succeeds in bringing the cure, I'll give an update on the website. Probably they have a combination of parasites, who knows what. The mother cat and one of the teenagers used to be kept outside on my farm, though now they are in my apartment.

You might try ordering some S. boulardii WITHOUT the MOS from Amazon and adding it to their food.  (The MOS that is in most of the human preparations tastes bitter and most cats will not eat it, but the plain S. boulardii can be mixed with food.)  That seems to clear up a lot of things ferals have that cause that distinctive foul odor and/or loose stools.  Its a probiotic derived from yeast, will not harm them, and you can use it in addition to the metronidazole.