First may I say that I am so very sorry for your loss.
I know you are searching for an answer, as to why Cyrus died. As the others have already suggested,
It could have been heart problems or liver problems...or a multitude of health issues.
However, the fact that you are saying his test results were fine, would lead me to think that it was his heart that was causing the problem.
As you may know, Boxers are notoriously known to be prone to heart problems.
One of the conditions is called Cardiomyopathy. Some boxers will show no symptoms at all, and live to a ripe old age... (like Cyrus )...before any symptoms start. The sudden, temorary weakness and collapse could have been due to his heart skipping beats, or temporarily stopping. Heart problems would also explain the ascites that the others have mentioned.
I love boxers...they are such fun...(see my photos )
I am sure you and Cyrus had 9 wonderfully fun years, and 9 years is a good life for a boxer.... You took good care of him.
Please accept my heartfelt sympathy...
God Bless his Beautiful Spirit and Soul...
Connie
I want to add my sorrow for your loss. I know all too well what you have gone through, since I lost Capt Jack a month ago. I know there several
reasons you poor dog Cyrus passed on, but it was not for the lack of your
love for him. I know you would like to know what took him from you, but
sometimes dogs get sick with something and there is little you can do.
9 years is not uncommon for larger breeds to develop some type of
health problems. Regardless, I sure he had a wonderful life with you.
Remember the good times you had with Cyrus, because I know he loved
you. I am still low in grief over the loss of Jack and doubt I will get over
losing him for long time, if ever. I consider dogs and cats part of family.
Take care,
Mark
I agree with Ginger's feelings on ascites. There are quite a few causes of this buildup of fluid in the abdominal cavity and most of them are very serious or life threatening. The fluid can come from the lymph system, it can come from the leakage of blood vessels into the abdominal cavity, it can come from an abdominal mass. Right-sided heart failure is another potential cause.
Without a necropsy there will be no way to tell for sure what the cause of death actually was. Please accept my most sincere sympathies on your loss. At least you were able to be with him at the end, although that is small comfort when a beloved pet dies suddenly and unexpectedly.
Ghilly
Oh goodness, I am so sorry. Your poor boy. You were with him at the end to comfort him, but it is so sad.
Test results or not -there was something seriously wrong. The vet didn't run enough tests. That's my opinion, because that swollen belly was caused by something.
The cause could have been many things, but it sounds as if he had "ascites" when fluid builds up in the abdomen....that could have been caused by Spleen or liver cancer...heart failure....etc. I don't really know for sure.
I am so sorry your Cyrus died