Welcome back, Beth! I sure do understand how hard it is to wrap your heads around everything that’s happened, especially while you continue to grieve the loss of your dear boy.

I need you to know that I am not a vet, so my thoughts are just based on my own reading and experiences here on the forum. But in answer to your questions, I do think there’s been some thought that there may be a genetic component to Cushing’s. But an actual mechanism has never actually been identified, and I think the notion mainly derives from the observation that certain breeds may have a higher incidence than others. But as far as your situation, I don’t know that there’s any reason to fear that Luigi actually has any significantly higher risk, just because he is Mario’s brother. My guess is that any genetic component is a lot more complicated than that.

Also, to my knowledge, there’s no known link to any particular diet or toy. So I don’t believe there’s anything that you personally did — or didn’t do — to cause Mario’s disease. Nor will you be putting Luigi at risk. We have had a few members who have had more than one dog who was diagnosed with Cushing’s, even though the dogs were not related. But I don’t believe this is because of anything the dogs were eating or doing. But rather, once an owner has had one dog with Cushing’s, they are much more observant of any symptoms that might develop in another dog. Just as is the case with you and Luigi, they’re much more tuned into monitoring appearance and behavior. Therefore, they may be more likely than other owners to notice that something’s even amiss.

So in summary, I highly doubt that Luigi is at any significantly greater risk. But in the event that he does develop any suspicious symptoms, the one plus is that now you’re ever so much more highly informed as to how to treat the disease. And you’d always have all of us to support you in any way that you might need us.

Marianne