Like people, most dogs and cats are not lactose-intolerant. Obviously, if your pet is, he or she will not be able to digest any dairy products and may end up vomiting and/or having diarrhea after drinking milk or eating any other dairy product like cheese, ice cream, yogurt, etc. Pets that can digest dairy products have an important advantage because these products happen to be excellent for stomach problems- they produce mucous. This is what lines all of our stomachs- pets and people alike, and protects the stomach wall from the stomach acid that aids in digestion.
Stress and many medications can decrease the amount of protective stomach mucous and predispose all of us, including our pets, to developing a stomach ulcer. This is an actual abrasion of the inside of the stomach wall and at the very least, will cause some pain and possible bleeding. At the very most, it can be life-threatening.
Cats that do not drink enough water can be given diluted milk (preferably skim) to drink. It is a tasty treat and will help hydrate your pet (most cats never drink enough water).
During hot summer months, ice cream or frozen yogurt is a great way to cool off your pet instantly. Watch out for brain freeze! Our pets really enjoy this treat and eat it up fast. Because it is so cold, the frozen treat cools our pets faster from the inside out. If your pet is lactose-intolerant, put some chicken or beef broth into an ice cube tray and once frozen, give that as a tasty treat to cool your pet off.