I'm sorry you lost one to disease.
This is why I don't mix species. Some may carry a disease without symptoms. Some animals are disease carriers and never get sick from what they carry. What they carry may be normal for that species but mix them with another species that's never been exposed to the disease they carry & that one can get very sick then die.
This is a huge problem for people like me who keep pet rats. There are no vaccines for them as there are for dogs & cats. It's extremely risky to get a group of rats from one source then try to mix them with any rats from another source. You can lose them all to disease very quickly when you do that.

Typhoid Mary is good human analogy for this topic. She was a food server/cook who carried the disease without being sick herself. She shed the disease and infected humans who spread it to others & caused the epidemic that killed so many people.
I just never take the risk, I don't mix my species and I wash my hands in between handling species.
-----
PHRatz