I have a budgie who was diagnosed with testicular cancer about 18 months ago. He has been having a hormone implant to shrink rather tumor every 6 months appr. His cere eventually turns bright blue again,when it starts to go brown again we go back to the vet. Today i had another budgie xrayed and vet found a mass that looks lounge it could be cancer as well. They gave him the hormone injection this time and will see how he is in 2 weeks and assess him again. It is very common in budgies apparently.
I'm very sorry for the loss of your baby it would have been such a heartbreaking decision to make but you did the right thing not letting him suffer anymore. No doubt i will have to make this rescission one day which I'm dreading.