I have a miniature schnauzer and they can have problems with their eyes, so my breeder provided me with certificates of eye test of both parents and of my pup eyes as well.

That was the only testing I had done

Yes and No.
Have a ten year old cavy who was not from health tested parents and she has only just recently developed a grade 1 heart murmur and needs no medication. Lost a cavy at the beginning of the year aged 2 and a half who was from health tested parents.My other two cavs were not from health tested parents but have both just had clear heart eye tests.
I still think it’s a good thing for the parents to be health screened but i am fully aware that the available tests only indicate the current health status of the parents. They don’t guarantee that they will produce healthy pups in the litter.Until they develop DNA tests for the hereditary conditions that cavies get/identify carriers health screening is all that can be done at the mo.