My wife's dog died at age 8 out of nowhere

[m0nchichi]

A few hours ago, my wife's dog died. My father-in-law woke us up because he found her. We went to a wedding yesterday and before we left she seemed fine. She had issues with her joints for the past few weeks and wouldn't eat. One night she vomited and seemed to feel really lethargic. Before all this happened (when she started losing appetite), we brought her to the vet and he did a blood test which came out fine. He gave us something to alleviate her arthritis and to treat a possible infection because of a cut she had on her tail(my wife said maybe her tail got caught up in the fence in the backyard). Months ago she had a benign tumor on her leg the vet removed. They said it didn't spread. Could that have something to do with it? But wouldn't the vet have found something in her blood if the tumor had spread? Yesterday after we got home my wife's brother said she wouldn't eat and come into the house. He had to bring her in. My wife tried to lift her up and she started whining in pain. She started panting heavily but otherwise seemed relaxed. We thought she might be in pain because of her joints so we left her lying in the living room and went to sleep. At 3:40 her Dad found her dead. My wife mentioned that some dogs get tangled up intestines ( I don't know the medical term). Can a dog die from that? I'm sorry if I might confuse you but I can't really think straight and I'm not a native speaker. I haven't slept all night either. Thank in advance!  

[Margot49]

So sorry about the loss of your dog.  There is just no way to tell what she died of.  You would have to have a ne rosy done to try to determine the exact cause.

[m0nchichi]

You mean an autopsy? I wish I was able to do that. I feel so guilty because I had a feeling that it's more than just arthritis. I read about heart worms. Most of the symptoms described correspond with hers. But  shouldn't a blood test reveal any abnormalities?

[Margot49]

Yes, an autopsy.  A simple test would detect Heartworm.  Did your Vet test for that?

[m0nchichi]

I forgot to add that the vomiting started after we gave her the medication the vet prescribed. She seemed more depressed and she also seemed to be more in pain. She had arthritis for a very long time but it never got to the point where she couldn't walk. She basically was just lying around the past weeks because she couldn't really put weight on one leg. But I can't explain to myself why this could have anything to do with her death. Did the medication do something to her? I'd appreciate any vet chiming in.