Hemorragic Gastroenteritis

Joey had Hemorragic Gastroenteritis after being scared by fireworks.
Hemorragic Gastroenteritis is an acute disorder in dogs that causes vomiting and bloody diarrhea. Some may even vomit blood. This is a very serious condition and can be fatal in a very short amount of time if not treated.
The exact cause of Hemorragic Gastroenteritis is unknown, but there are several things that can bring it on such as stomach or intestinal ulcers, trauma, gastrointestinal tumors or obstruction, foreign bodies, infectious disease such as parvovirus, and coagulation disorders. Stress from thunderstorms, fireworks, and even being put in a boarding kennel can cause this as well. One of the more common causes is rapid food changes which is why it's always important to switch your dogs food gradually over a 10-14 day period.
There isn't any breed that's "immune" from Gastroenteritis, however it does seem to happen in small breeds more often than large breeds.
Dogs will begin vomiting or having loose bloody stools, and will dehydrate rapidly. Typically IV fluids along with anitibiotics are needed or the dog may not survive. In dogs who are not extremely dehydrated from vomiting or the diarrhea, fluids injected under the skin and antibiotics along with a bland diet may be all that is needed.
Do not attempt to treat this at home, the dog needs to see a veterinarian.
My personal Hemorragic Gastroenteritis experience:
Joey is a 6/7 year old Miniature Schnauzer. I've only had him for a few months. His previous owner had cancer and could no longer care for him so he brought him to where I work and asked us to find a home for him. After a couple weeks there and no potential homes, I decided to take him home.
Joey is a very emotional dog- any loud sound sends him right into my lap trembling in fear. On July 3, 2008 my neighborhood sounded like a war zone with all the fireworks and Joey was a total wreck.
At 9 pm, I gave him a sedative to hopefully take the edge off. This worked for a little while, but then he woke up and began vomiting. He vomited several times through the night. He was still drinking well but wasn't interested in food.
The following morning, he didn't want his morning treats and everytime he'd drink water, he'd vomit it right back up. Then he went out to potty, and he had bloody diarrhea. I knew right then that this was serious and wasn't going to stop without medical treatment.
Since it was July 4, my usual vet was closed so I had to take him to the emergency clinic. As I was in the room waiting for the doctor, Joey vomited more water up, and there were spots of blood in it.
The vet did bloodwork and thankfully Joey wasn't that bad off yet and didn't require IV fluids. They gave him an injection to stop the nausia, injection of fluids under the skin and an injection of antibiotics. He was to have no food/water for 12 hours to give his stomach a break (the injection of fluids would get him through that time), and then was started on a few oral medications along with a bland diet.
As of this writing (July 6), Joey is doing much better. He is still on the medications and the bland diet, and has not vomited since at the Emergency Vet Clinic.