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I'm sorry to hear your dog isn't feeling well. It may be difficult to treat at home if he continues to not be able to hold anything down. However, you can try as long as he isn‘t painful, pale, overly lethargic, bloated appearing, excessively panting, ate something toxic or unresponsive (which all require more immediate vet attention).
Wait at least 12 hours before feeding or since last ate something (and at least 8 hrs since last had water), a bit longer if still vomiting. Then try giving some pepcid ac (famotidine- found OTC in any human pharmacy or grocery store) at a dose of 0.25mg per pound of body weight, as long as your dog has been fairly healthy otherwise (no liver/kidney disease or on heart medications). About 1/2 hr to 45 min after giving pepcid, then you can try very very small amounts of a bland food, like baby food (chicken or turkey flavors are good) or boiled chicken. Just about a tsp or so. NO MORE THAN THIS. Even dogs who have lost their appetite will often try this after the pepcid has settled their stomach.
If able to hold down, try again in an hour this same amt. If doing ok, do this for a few hrs, then about 1/2 a meal amount for his next meal time. You can repeat the pepcid in 12 hours as well, if you feel it is needed (while the bland diet helps the most, the pepcid may help speed along the GI's settling).
If doing ok, keep on bland diet for a couple of days, the gradually switch back to normal food. If not able to hold down even the pepcid, he'll need a vet visit sooner than later, as injectable medications will be called for, and further diagnostics may be needed to see if this is more than just a stomach upset. Often antibiotics are needed for the bacteria that has built up in the GI tract. Also, make sure he continues drinking water or even some unflavored pedialyte the entire time so as not to dehydrate, but only very very small amounts offered at a time after fasting, and keep him away from extreme temperatures and indoors while recuperating, except for short leash walks only to do his business.
Here's some more info about Pepcid:
Best of luck, hope your dog is better in no time!