It is very common for puppies — up to about six months old — to get hiccups. They are growing quickly, which can be a cause.
It is less common for adult dogs to get hiccups but it definitely happens. Dogs who eat too fast or gulp water can get hiccups, but hiccups can also be a sign of stress or occur when the dog eats something that “doesn’t agree with” him.
So, what do you do?
Saying “BOO!” does not work. I’ve tried it. I don’t think that getting the dog to breathe into a paper bag works either, though I have not tried that.
Giving the dog a drink or a small treat might work. Try some water with a teaspoonful of apple cider vinegar mixed in; it is supposed to work for our hiccups too. Or try waiting a few minutes. The hiccups don’t usually last for long.
If your dog has hiccups that do last for longer than a half-hour or so, or your dog gets hiccups frequently, talk to your vet about it. Sometimes — rarely — hiccups can be a sign of something more serious.
The Thinking Dog 
Our dog got the hicups a lot as well. We had to go to a slow eat bowl and this seemed to work well. We also changed to using a low grain feed option for its dinner and this also helped. As our puppy grew up the hiccups also disappeared. I now know that younger dogs are more prone to hicups. I also like Mels reply above as its a great tip to help out a hicuping dog.
LikeLike
My 7-year-old miniature schnauzer gets hiccups occasionally, unrelated to anything I can ascertain. Because hiccups are spasms of the diaphragm, I push gently but firmly on her upper abdomen, timed when a hiccup starts. After a few pushes, the hiccups disappear. Hope this helps some other animal.
LikeLike