It is so nice of you to rescue these kittens. I think this grumbling and runny stool could be due to parasites (worms), food issues, or from inadequate bacterial populations in the intestinal tract.
Have you had a fecal test done at your vet? They should check for the usual parasites and for Giardia. Dewormers that you get at pet stores often don't work or may not work against the particular parasites your kitten has. So I would talk to your veterinarian about a proper dewormer such as Profender or Drontal, even if the fecal tests are negative.
What food are you feeding them? The problem could be due to the type of food or brand. You may need to try a different brand. Make sure it is a high quality kitten food.
I would also talk to your veterinarian about a probiotic such as Fortiflora. That helps with the normal bacteria in a cat's intestinal system and can really help a lot in kittens.
It is hard for me to address the breathing problem without seeing the kitten myself. If it continues, you may ask your vet to do an xray of the chest to see if there is anything abnormal they can see.
I hope this helps. Write back with updates or any other questions. My recommendation is to keep the kitties indoors even after neutering. So many bad things can happen to them outside. They will have less medical problems which saves you money in the long run.
Judy Karnia, DVM
Scottsdale Cat Clinic
I am about to worm them again today, I use front line spot on wormer from my vets.
I feed them a small amount of wet food 3 times a day, (I was told that it was best to give kittens little food ofter) Its supermarket brand but the women I got them off said that she tryed them on kitten food first and they had diarrhea and were sick so she gave them adult food and they were fine. They also have access to dry biscuits and water all day.
I am going to the vets again in a few weeks and I will talk to them about your suggestions.
I want to keep them inside too but everyone tells me its unfair and cats should have some freedom so I'm not sure.
Frontline treats fleas but does not kill intestinal parasites.
Cats this young should be eating kitten food. You probably need to use a different brand. Usually diets found at the pet store are higher in quality than supermarket brands and therefore may be better digested.
You can create an indoor environment that is interesting for them. If they are used to being indoors they won't miss the outdoors. They will also have each other to play with. Going outdoors exposes them to disease, parasites, and trauma. There is also the stress of having to maintain a territory and fight off other cats.
Sorry I meant to say we use Profender not front-line, they are both spot on's so I wrote the wrong one.
I do want them to stay indoors, I have taken them out in the snow on harnesses and my male doesn't seem to keen anyway, but that may have just been the snow!
Thank you for your help, I will look into better food brands.