did my cat died because of rat poison?

a week ago, my kitten who was about 8 months old had diarhea (diarrhea), flu and very high fever. The vet said it was due to cat enteritis as his white blood cell count was low. The vet gave some antibiotics and now the kitten seems fine. The vet also warned us that it is highly infectious, and sure enough a few days later another of my cat showed the same symptoms and again, after treatment at the vet he got better. The thing is, after a few days, three other cats were having very rapid breathing and was drooling, and when brought to the vet, they were immediately put on the drip. There were fluid in their lungs and the vet also gave some injections to eliminate the fluid. But three of them died within hours (one of them even had jaundice). At first, we all thought it was also enteritis, but the vet had another suspicion. she asked if any of our neighbors hate cats as they could have been poisoned. I checked around my house today and saw these small little pellets in green,and orange colors (they look like small plastic beads). Could this be rat poison? because if the cats did die of enteritis, how come they don't show signs like diarhea (diarrhea) and vomitting like the other cats that survived? and I know that small kittens can easily succumb to enteritis but the ones that died are nearly adults and they were vaccinated before. Does anybody know what's happening?

[Thomas Dock, CVJ, Vet. Technician]

Hello there...I am very sorry to hear about your cats.   It must have been a terrible shock for you.

It's going to be very hard for us to answer that question...first, since you are in a different country, the pellets you are describing might be unknown to our doctors.  Did you have a necropsy (animal autopsy) done on any of the cats?

If there are still pellets around your house,  you might take them to your veterinarian as they will be more familiar with products sold in your area.