why would abrother and sister die with days of each other

Question
We had a brother and sister french lop eared rabbits aged 8 wks old they both fitted and died on last fri and the male today.
Both had visited 2 different vets for 2 different toilet problems.
What could have been the cause?

Answer
Did they have diarrhea?  Baby bunnies who have a sudden change in diet will sometimes get diarrhea and it frequently is fatal.

Or, they could have had a parasite called coccidia which caused issues and can kill them.

Those are the most likely causes.

If you get more rabbits, be sure to get whatever food they have been eating and slowly transition them to what you plan to feed them, make sure they have plenty of hay, and don't start veggies until they are at least 3 months old.

I am sorry for your loss and that the vets couldn't determine the issue.

Kim