When a cat’s diet needs to be changed, it’s almost always best to do so gradually. Veterinarians commonly recommend mixing a small amount of new food in with the old and then gradually increasing the ratio in favor of the new food. The process can take as few as three days when a cat digs in to a new diet and has no adverse effects to it up to several weeks for finicky individuals or those with sensitive gastrointestinal tracts.
Sometimes a dietary change cannot be made slowly, however. A situation here in my home state reminded me of this recently. A wildfire burning in the Colorado Springs area forced the evacuation of almost 40,000 people and an untold number of pets. Several temporary animal shelters in the area put out calls for donations to help feed the animals under their care. The cats residing there are fortunate to be safe, but many are probably having to eat foods they have little experience with. I’m sure shelter personnel are doing their best to keep them well fed under very difficult circumstances.
If you ever find yourself in a position where you are forced to suddenly offer your cat a new food, following a few tips can help you encourage her to keep eating and minimize the chances that she will have an adverse reaction to a sudden dietary change.
First of all, if more than one food is available, pick the variety that is most similar to what your cat has been eating. If she is used to kibble, stick with kibble. The same goes for canned. If you know what the primary ingredients are in your cat’s old food, try to find a new variety that includes as many of them as possible. Cats that are used to eating a fish-based diet are more likely to accept another fishy food in comparison to one based on beef.
The first time you offer a new food to your cat, put just a small amount in front of her. It can be difficult to determine if a cat is nibbling when the bowl is filled to the brim. Check to see whether she has eaten anything in about 30 minutes. If she has, offer another small meal a few hours later. As long as everything is going smoothly (e.g., she continues to eat and does not develop vomiting or diarrhea), gradually transition to your normal feeding schedule over the next couple of days.
If the cat shows no interest in the new food, pick up her initial meal after 30 minutes, and do not offer anything else to eat (including treats) for a few hours before trying again. Hunger has a way of overcoming a reluctance to try a new food. Continue offering a small meal, giving the cat a reasonable amount of time to eat, and then removing the food if she refuses every 4 hours or so for 12-24 hours. If the cat still refuses to eat, try a different formulation following the same timetable.
If you cannot get your cat to start eating within 36-48 hours despite trying at least three types of food, call your veterinarian. Cats that do not take in adequate calories are at risk of hepatic lipidosis, a serious form of liver disease.
Dr. Jennifer Coates