There are a few occasions throughout a dog's life when you would want to assess the dog's diet and possibly transition the dog's diet to a new food. Those occasions are when they enter or leave a life stage and their nutritional needs change, or when their old food isn't supplying what they need for a particular health condition. Another reason might be if your current dog food is causing an adverse reaction in your dog. Whatever the cause, it's important to talk to your vet before switching your dog's food, and transition to the new diet slowly.
Slowly transition to a new dog food
Unfortunately, it is quite common for some dogs to experience vomiting or diarrhea when switching food, especially if the switch is made abruptly. Switching disrupts the balance of bacteria in a dog's system. Transition to the new dog food slowly, over about 5 days to a week, or even more.
The American Kennel Club says that for most dogs, a good diet transition will look like this:
Day 1: 25% new food and 75% old food
Day 3: 50% new food and 50% old food
Day 5: 75% new food and 25% old food
Day 7: 100% new food
The Clinical Nutrition Service at the Cummings Veterinary Medical Center at Tufts University says an important consideration is the number of calories in the old kibble or wet food compared to the new dog food. For instance, if your dog needs 750 calories a day, and your old food has 500 calories per cup and your new food has 350 calories per cup, your daily transition would take into consideration an amount that allows your cat to get the 500 calories at a minimum. It's ok to estimate. The Clinical Nutrition Service says it's more important to make sure the switchover is gradual than to focus on the exact number of calories for a few days.
Talk to your vet before switching your dog's food
There may be a few reasons why you may feel your dog needs a new diet. If you notice your dog throwing up after eating, it may be a common assumption that they are sensitive to the food, but that isn't necessarily the case. Your dog may have anxiety or fear about eating or may be eating too quickly to chew their kibble. If your veterinarian suspects that a food sensitivity or allergy is happening, they may want to take a more measured approach to transitioning to a new food and try some dietary eliminations first.
If your dog has entered into a new life stage — for instance if they are leaving puppyhood or entering the senior stage of life — your veterinarian will help you ensure that your dog's nutritional needs are being met. Likewise, if your dog's health condition changes, your vet can help you find a food that provides the right nutritional needs for that condition. Whatever the cause of wanting to change to a new dog food, it's important to let your vet know you want to change your dog's diet and get their advice.
What if there are problems?
If your dog does have problems such as vomiting or diarrhea because their food was transitioned too fast, Pet Coach recommends withholding food for 12 to 24 hours. When you resume feeding, offer only a bland diet of boiled chicken and plain cooked white rice or cottage cheese in small amounts of 1 tablespoon of every hour and gradually increase the amount as long as there's no vomiting. You might then slowly transition them back to the prior dog food that you were trying to switch from or another one that you know was well-tolerated. Another option may be to introduce probiotics to help promote intestinal health and recovery. Your veterinarian can give you more help or even medications to help them recover, if the vomiting and diarrhea goes on for more than the next day or two.
Monitor your dog's digestive health by evaluating their poop. Yes, there are charts for looking at the quality of the poop! There's a range of normal, but if your dog's stool is consistently outside of the normal range, it would be a good idea to consult your veterinarian.
- Pet Coach: I changed my dogs food about 3 days ago and she has had diarrhea and has been vomiting since I changed food. What should I do from here?
- The Clinical Nutrition Service at the Cummings Veterinary Medical Center at Tufts University: How do I switch my pet’s food?
- Pro Plan Veterinary Diets: Fecal Scoring Chart
- Hills Pet: Why Dogs Throw Up After Eating