Good Morning, Stabalon, and thank you for your question. I am sorry to hear that your puppies may have a serious disease.
I believe that you are probably talking about Leishmaniasis, which is caused by a protozoal parasite (Leishmania) which is spread by sandfly bites. This disease is more common in foreign countries and rare in the US, but has been seen on occasion. I have not seen a case of this disease in my area in the midwest.
Here is some information on this disease which will be helpful for you:
This disease can affect multiple body systems, so the symptoms and prognosis can vary depending on what is affected. From my research, it is difficult to treat, there are no specific medications, but if it is treated early and long term dogs may do okay. It can relapse weeks, months or even years later however, so they rarely completely cure of this disease.
it can cause liver and kidney disease, and this can certainly have a poor prognosis and eventually be fatal. But again this would depend on the exact progression in each dog.
I hope this provides some extra information for you and again, I'm sorry to hear about this in your dogs.