If your dog vomits, your first action must be to make sure your Maltipoo did not ingest any poison or dangerous non-food object. If you do suspect that your Maltipoo swallowed something that he or she should not have, bring him or her to the closest animal hospital...it is important to remember the saying of "Better safe that sorry" if your dog may have been accidentally poisoned.
If that is not a possibility, most likely your dog is allergic to a food ingredient that he or she ate. Make a list of everything your Maltipoo may have eaten in the past 48 hours. To give the body a chance to rest and to allow the trigger to be cleansed from the body, a very bland home cooked diet
is usually recommended.
You should begin by feeding your Maltipoo just a simple protein such as boiled lamb and a simple carb such as sweet potato or white rice. This should be served with zero additions...no seasoning, no flavoring, no butter, etc. Allow 2 weeks to pass before you add a 2nd ingredient, such baby carrots. Every 2 weeks, if your Maltipoo tolerates the food, add 1 more ingredient. As you add new foods, you will be able to determine which one is causing the problem. If your dog handles all basic foods well, this lends to the conclusion that it was an allergen common with processed foods.
While you are waiting for your dog to recover, be sure to offer them a lot of water (Fresh water should always be available even with perfectly healthy Maltipoos) and a soft, warm place to rest., as their stomach will need to calm down. Within 72 hours, your Maltipoo should be feeling much better. If not, bring him or her to the veterinarian ASAP, as dehydration can quickly occur if your dog continues to vomit and/or have diarrhea.