Hello, my name is***** and I have over 20 years of experience as a veterinarian. I am very sorry to hear that your girl Ellie is drooling excessively today and vomiting.
Drooling can be a sign of nausea but it can also be a sign of oral pain due to an infected tooth or a foreign body caught between her teeth, on the roof of her mouth or in the back of her throat. Sometimes it is a sign of an oral tumor. If she is an older girl nausea due to organ failure is possible.
Finally drooling and vomiting can also be a response to eating a bitter bug or plant piece. If it comes along with facial swelling or hives it could be related to an allergic reaction.
I do recommend rinsing out her mouth with cool water several times.
I know that may have you looked in her mouth but sometimes it takes a very close look under sedation to find the problem. If she will let you examine the inside her mouth again closely for swelling, reddened areas or any sign or trauma or a foreign body.
You can give her acid reducers to try and settle her stomach in case this is related to nausea. Either:
1) Pepcid-ac (famotidine) at a dose of one 10mg tablet per 20 to 40 pounds of body weight every 12 hours.
2) Prilosec (omeprazole) at a dose of one 10mg tablet per 20 to 40 pounds of body weight every 24 hours.
These will reduce stomach acid and should help settle her stomach. These are quite safe and can be used for several days if necessary.
A couple hours after one of the acid reducers is given you can offer small amounts of water to drink or ice cubes to lick.
If that goes well then tomorrow start a bland diet of 1/3 boiled, lean hamburger (or boiled, white, skinless chicken) and 2/3 plain, boiled, white rice. Give small meals several times a day. Feed the bland diet for several days, then start mixing in her regular diet and slowly convert her back over a period of 5 to 7 days.
If she attempting to vomit but unable to do so, her belly looks at all distended or she won't lay down and settle or she is pawing at her mouth or unable to drink water normally then I recommend she see a veterinarian immediately as this can also be a sign of bloat, a rare occurrence but life threatening if allowed to progress, or something stuck in her mouth.
If her drooling and nausea continues in spite of using an acid reducer and a bland diet then she should see a veterinarian for an examination, some blood tests to look for underlying metabolic disease, possibly sedation to look closely in her mouth and take dental radiographs.
Please let me know if you have any further questions.