Plenty of dogs like milk and cheese and would happily grab a taste if you offered, but dairy products don’t go down well for all dogs. Many dogs are lactose intolerant.
Lactose intolerance means your dog can’t digest dairy products. Specifically, they can’t digest lactose, which is the sugar in milk. If a dog (or person!) with lactose intolerance eats dairy, they’ll likely experience symptoms like bloating, stomach pain, diarrhoea, nausea, or vomiting.
Below, learn the symptoms and causes of lactose intolerance and get expert guidance on when to consult a veterinarian. You’ll also find tips for managing lactose intolerance in dogs and a few suggestions for lactose-free alternatives.
5 Symptoms of Lactose Intolerance in Dogs
Lactose intolerance in dogs can cause five main symptoms, according to Dr Ari Aycock-Williams, DVM, DACLA. These symptoms include:
- Diarrhoea: The most common sign of lactose intolerance is diarrhoea, which usually occurs within 12 hours of consuming dairy.
- Vomiting: Lactose intolerance can also lead to vomiting after dairy consumption. Your dog may also drool a lot or lick surfaces if they feel nauseous.
- Lack of appetite: Dogs who feel nauseous due to an upset stomach may also lose interest in eating.
- Bloating: More gas in the stomach and intestines can cause your dog to look and feel bloated. You may or may not notice this physical change. Gas can cause physical discomfort, so your dog may be less interested in exercise or playtime.
- Flatulence: It’s natural for dogs to fart, and gas isn’t usually a concern unless it’s excessive. If you notice your dog farting more than usual, this could be a sign of lactose intolerance—especially if they have other symptoms.
Lactose intolerance vs. dairy allergy
It’s important to make sure you don’t confuse lactose intolerance with a dairy allergy, Dr Aycock-Williams says. These two conditions cause different reactions, though they may involve some of the same symptoms.
Allergies involve an immune system response to a specific protein in dairy products. The immune system’s usual role is to protect a dog from disease and injury. But in the case of a dairy allergy, they overreact and treat the protein as an invading threat. An allergic reaction can range from mild to life-threatening.
This differs from a food intolerance, which involves a dog’s digestive system having trouble processing a particular food, such as dairy. This can be uncomfortable but not dangerous.
So, a dairy allergy can cause your dog an upset stomach and may lead to other symptoms, such as skin irritation, sneezing, or difficulty breathing, according to Dr Wendy Hauser, DVM, founder of Peak Veterinary Consulting and Special Advisor to ASPCA® Pet Health Insurance. Dr Hauser recommends contacting a vet if these symptoms don’t go away within a day or two.
What Causes Lactose Intolerance In Dogs?
“A deficiency of the enzyme lactase causes lactose intolerance in dogs. Lactase is necessary for breaking down lactose, the sugar in dairy products,” says Dr Jaclyn M. Coble, DVM, CCRP, CVA, the CEO and Founder of Sea Legs Integrative Veterinary Health. “When dogs don’t produce enough lactase, they can’t properly digest lactose, resulting in unwanted symptoms.”
Undigested lactose travels to a dog’s colon, where gut bacteria begin to break it down. This produces excess gas, which can lead to digestive distress that can be a symptom of lactose intolerance.
According to Dr Coble, lactose intolerance is common for dogs of any breed, age, sex, or size. Often, puppies lose their ability to digest lactose as they mature and stop relying on their mother’s milk. This usually happens after puppies reach 4 weeks of age.
However, some pups have lactose intolerance. Lactose-free milk or milk replacements are available for puppies without access to their mother’s milk, either due to intolerance or because they are orphaned.
How Do Vets Diagnose Lactose Intolerance?
Dr Aycock-Williams says an elimination trial can help diagnose lactose intolerance in dogs.
To do an elimination trial (with your vet’s guidance), you’d avoid giving your dog any food, treats, or table scraps that contain cheese, milk, or any dairy product.
Your vet will probably also perform a physical examination and ask questions to learn more about your dog’s symptoms. They can offer more guidance on removing dairy from your dog’s diet and monitoring their symptoms to check how your dog reacts to the dietary changes.
If you’re worried about the cost of multiple exams or ongoing treatment, pet insurance can be an excellent option. Plans may cover checkups, exams, medications, and more.
How To Manage Lactose Intolerance In Dogs
Lactose intolerance doesn’t usually require medication or further treatment.
“You can easily manage your dog’s lactose intolerance by removing all dairy products from your dog’s diet and avoiding them in the future,” Dr Hauser says.
If your dog develops diarrhoea or has increased gas after eating dairy products, these symptoms should quickly resolve if your dog doesn’t consume any additional dairy products. That said, Dr Hauser recommends seeking veterinary care if your dog seems in distress and has significant pain, or if vomiting or diarrhoea persists for more than a day.
Are There Lactose-Free Alternatives For Dogs?
Yoghurt contains probiotics that can boost your dog’s gut health. These are live bacteria that help to balance the community of bacteria living in your dog’s gut. Some bacteria are harmful, but others can help reduce gas or help dogs poop more consistently over time.
Dr Hauser suggests asking your veterinarian about lactose-free alternatives for your dog if you like to give them yoghurt for its probiotic benefits.
Some supplements also provide probiotics. You can also try these products:
- Purina Pro Plan FortiFlora Canine Probiotic Supplement
- Zesty Paws Probiotic Bites
- YuMOVE Probiotic and Prebiotic Supplements
Although lactose intolerance in dogs is common, it’s manageable, and your dog can still lead a happy and healthy life—even if they have to go dairy-free!
