Later on that first day, at dinner time, the same thing happened, but this time the 'second helping' stayed down. However, she looked so woebegone that we took her to the vet hospital. It was a public holiday the following day, and we knew it would be at least 36 hours before we could take her to our own vet.
So at midnight she was admitted.
It was scary. Words like 'bowel obstruction' were mooted.
The next day, she seemed a bit better, so we took her home. But she sort of 'faded' throughout the day, lying flat as a carpet, and we decided to go back. She was re-admitted.
The hospital was wonderful. All sorts of tests and examinations were done, and we had a phone consultation with each vet attending to Penny. (Lots of phone calls at midnight and five a.m sure take the energy out of a worried owner.)
Hoping for the less frightening diagnosis, I concentrated my internet info-search on gastro-enteritis. Bowel blockage was just too alarming to consider. And the other possibilities that were suggested I don't even have the courage to write.
What I gathered, from the plentiful info from the hospital, and from sites on the internet, is that gastro is diagnosed by ruling out all other possibilities.
Greenbriar Animal Hospital's advice reassured us that we hadn't overreacted by going to emergency:
How is your dog acting? If he's running around [after vomiting] and acting just like he always does, good. You have more time to address the problem. But if your dog is acting ill, is lethargic, doesn't want to do the things he usually jumps at (like a walk), or is spending lots of time just lying around or sleeping, you need to get him to the vet now. Even if this means an emergency visit.And...
a dog who has vomited 3-5 times in one day has a lot more urgency to the situation and should be seen now.The Greenbriar Hospital has good advice about how to handle a less urgent case at home.
Bedfordview Vet Hospital compares a canine case of gastroenteritis with cholera in humans, as to its level of severity.
An article on Hub Pages explains the illness and makes the point that if gastroenteritis is caught early, it can be resolved. It gives a chilling explanation of why we should act on this condition quickly:
While the symptoms of this condition may be pretty worrisome for the owner, when caught early, treatment is much easier and effective. Cases left going on for too long may cause complications and also potentially death. The reason behind this is that untreated gastroenteritis will cause major dehydration. With major dehydration the red blood cell count will increase consistently causing the blood to concentrate and thus, become thicker.
An article at VCA Animal Hospitals is great and lays out clearly the things we needed to tell the vets, the treatments that could be expected, and some possible causes. The stand-out reassuring quote for me was:
Most cases of acute gastroenteritis improve rapidly after re-hydration. If the vomiting and diarrhea do not improve significantly within forty-eight hours of treatment, the diagnosis should be re-evaluated.I was very impressed at the way the emergency hospital considered all possibilities throughout Penny's stay.
Pet Health Network has a good overview.