Feline Diarhea

I'm new; glad I found you guys. Not new to felines.

I'm working hard to contain and control a seemingly contagious situation of
diarhea in my kittens. One seven week old kitten is in quarantine with a
bad case of it. His two siblings were not infected.
One litter of five younger kittens are showing signs. Two more litters,
one six weeks old; one five weeks old, haven't been infected so far.

I've treated the seriously infected kitten with albon, strongid and
immodium AD. The immodium seems to be the most effective medication.
There has been slight overall improvement in that the diarhea isn't as
watery. Discontinued albon after 3 days; have two additional days of
strongid planned. Immodium for the duration is planned.

The strongid amount is 1/2CC once daily/six days total.

The same has been given to the litter of five, with exception to not using
immodium. Their diarhea is not water; is more like runny stool.

All are eating and active; no signs of respiratory illness or any other
conditions.

Kittens are caged in large clean wire cages, up to five per cage, open air
with a protective roof and full protection from weather. Climate is 68-70
lows and 90 daytime highs. No exposure to rainfall or cold.

Any additional advice?

Thanks for input. I look forward to hearing from you.
Gail