My dog hit his head, then threw up 12 hours later. Should I worry?

Vomiting after an head trauma might be concerning. I recommend to bring her to the vet for a physical and neurological examinations to exclude brain damages (i.e. concussion). Please post again on the forum if you would like to discuss it further. I hope my answer was helpful.

Monitor for any vomiting or trouble walking or a head tilt. If you notice any eye movements jumping back and forth or a head tilt, that is a sign of head trauma. If you notice no signs after 12 -24 hours then you have nothing to worry about

He will probably be OK, however I would closely observe him for the next 24 hrs for signs of unusual behaviors, lethargy, or vomiting. If any of this occurs, Jax needs to be taken to a veterinarian or emergency room right away to assess him for more serious complications.

I am sorry to hear about Chewie. If his energy levels appear normal and he has stopped vomiting you can continue to observe him. We normally recommend nothing orally for 6 to 8 hours (no food or water) after vomiting to give the stomach a rest and then slowly reintroduce water then food http://www.veterinarypartner.com/Content.plx?P=A&S=0&C=0&A=353. If he continues to vomit then a vet exam is needed. Other reasons to seek veterinary care include lethargy/weakness, pale gums, painful or swollen abdomen, or vomiting blood.

Concussions can be tough to diagnose and can be very serious (just like in humans). Here is a link which may help: https://www.petcoach.co/article/concussions-in-dogs-what-you-should-know/ Without knowing the cause for the abnormal behavior, it's difficult to know how to treat him or if home care is even possible (just like humans, sometimes a doctor's care is absolutely needed). At home you want to make sure he is protected from harm such as falling down the stairs. You should make sure he is eating and drinking (you may need to bring him the bowls and hand feed him). There may only be so much you can do and there may be treatment he needs to avoid further complications. To be safe, I recommend to have your pup examined.

Poor little Reggie. Since he's acting normally, I'd keep an eye on him for now. If you notice him getting dizzy again, has blood coming from his nose or ears, confusion, disorientation, difficulty walking, or abnormal eye movements, have him seen by a vet immediately. Otherwise, he should be ok.

I think you should just keep a close eye on him for the next 24-48 hours. If he shows no signs of illness then I wouldn’t be worried. If he starts acting abnormal at all then you should get him to a vet for an exam.