What caused my dog's sudden death, lethargy, vomiting, and not eating?

I'm really sorry to hear this and for the loss of your dog. Unfortunately, what you are describing is not specific to any one disease, so I cannot tell you exactly what happened. In order to tell for sure, I would have to get more information about his case, examine the body and send samples for testing. However, considering how soon he died, this indicates that he either had severe organ damage, or a severely altered blood chemistry. This can happen in cases of certain infections and in cases of poisoning. There are also many other preexisting conditions like cancer, heart/vascular disease and parasitism that could also cause their to be a sudden decline in health. I know that didn't fully answer your question, but I hope that helps you to understand what may have happened. For more information, you may consider asking the veterinarian that gave the treatment, or ask another vet doctor in your area to review the case.

I'm very sorry for the sudden loss of your dog. With his history I would be suspicious of an infection, heart disease, sudden bleeding or a toxin that could cause death. While Lyme disease can be serious his signs aren't specific for a Lyme infection. For a specific answer tissue and/or body fluid samples as well as a post mortem exam like an autopsy would be needed. However even with those we sometimes cannot pinpoint the exact cause of a sudden death.

I'm very sorry you recently lost Keylo! Please accept my condolences for your loss. Without seeing him in person, I can't say what caused him to pass away, but it could be cancer, heart disease, liver disease, or kidney disease to name some causes. I hope this helps, again I'm sorry for your loss.

I'm sorry to hear that you're having this problem! Unfortunately, it's really not possible to know what's causing this without more information, since acting lethargic and not eating are very vague symptoms that could be caused by almost any kind of illness. If any of the dogs have had lab work, x-rays, or other testing done, it would be helpful to know what the results were in order to give some possibilities. For a definitive diagnosis, the best option would be to have an autopsy (called a necropsy in animals) performed on one of the dogs who passed away.

Oh no, I'm so sorry that you suddenly lost Minnie Mae Pearl! How horrible for you, please accept my condolences for your loss. Please keep in mind I can't say for certain what caused her to pass away, but I can offer some guess. It is possible that she had cancer. It's common in senior dogs, and it can be festering for a while before the dog sudden becomes ill. They can't tell us when they are sick and are pretty stoic with pain, so oftentimes when we notice something is wrong, it's very late in the disease. That happened with my own dog last year. He seemed perfectly normal, and then one night he appeared to crashed. I rushed him into the clinic for treatment, and he had an abdomen full of fluid likely from a ruptured splenic tumor. He had shown no other signs of illness before then, and unfortunately I had to let him go, so I completely understand how hard it is to suddenly lose a beloved pet and feel devastated. Her death could have also been caused by liver disease, pancreatitis, or a number of other illnesses. I wish I could say for certain to give you some answers, but I can only offer my guesses and my sincerest condolences for your loss :-(

I'm so sorry to hear about the loss of your dog. There are many different problems that could cause those symptoms, so unfortunately an autopsy (called a necropsy in animals) would be the only way to know for sure. Some possible causes would include some type of toxicity (such as antifreeze or rat poison), an illness such as kidney or liver failure, or some type of cancer. Your vet could do a necropsy or direct you to a pathologist for more advanced testing if you want to try and determine a specific cause of death.

I'm sorry to hear that but these are very general symptoms of organ failure so I couldn't tell you what could have possibly caused that, it could be pretty much anything, from an internal disease to an intoxication.