I’m so sorry for your loss. I lost my beloved Pecan (Cockapoo) on early morning of March 20. She was healthy and happy until Wednesday 6:30pm and passed away at 4am on Thursday an hour after we rushed her to the hospital. It was so sudden that the vet thought it was stroke but I suspect she had the same condition as your Dog. I feel so guilty for not being able to save her. She was my confidant, my companion, my therapist and my best friend. She was with me 24/7 for 9 years. I never left her alone for over 3hrs. How can a perfect dog who was so warm, happy and kind go so fast. I see and feel her everywhere. Thinking about her sweet face and innocent eyes aches my heart. Is it normal to feel this guilty? I haven’t stopped crying. Hang in there my friend. Life is so unfair but I’m sure our dogs want us to be healthy and happy again. I just hope I didn’t let her down.