Hello, I'm Dr. Deb.
I recently came online and see that your question about Harley hasn't been answered. I'm so sorry that you've had to wait for a response under the circumstances, but if you still need assistance, I'd like to help if I can.
First, let me extend my most heartfelt condolences to you and your family. I'm quite certain that you're all still in shock over her sudden loss in this way.
While sudden death
in dogs this age isn't common, it can happen. Actually, sudden death can be seen in just about any aged dog, unfortunately.
Of course, without an autopsy, we can't know for sure but in most cases of sudden death which are seen in a dog this young, the reasons are going to be either a
1. heart attack or fatal arrhythmias or conduction issues
2. pulmonary thromboembolism which is basically a clot to the lungs
aneurysm (rupture of a vessel wall).
4. possible clot or embolism to the brain
5. Ingestion of certain human medications, toxins or poisons although gastrointestinal signs are usually seen prior to collapse
I know in these situations that the tendency is to feel or think that we missed some signs that our pet was ill; that if we had only intervened sooner, that there could have been something to prevent the horrible outcome. But, this isn't true for the vast majority of sudden death cases. It's the sad truth that nothing could have been done to prevent this from happening.
I hope this helps to provide possible explanations for what happened to her but I know it doesn't come close to easing the pain that you feel.
Again, my sincerest condolences to you and your family and my apologies once again for the delayed reply. Deb