If your pup is lactose intolerant, he may show the following symptoms following the consumption of dairy: Bloating Gas Vomiting Constipation General malaise Loss of appetite If any of the above present themselves, it's best to skip the dairy. A lactose intolerant dog lacks the enzymes required to properly digest dairy products. This is in no way abnormal — in fact, most dogs are lactose intolerant. Speak to your vet if you have questions about dairy products and how they may impact a lactose intolerant pup.