Your dog used to hear the bowl from across the house. Now half the meal is still there. You may hear that older dogs simply need less food, but a change in appetite is not something to explain away without looking at the whole dog. Painful teeth, illness, changes in smell or mobility and many other factors can affect eating. A vet can help find out which applies.
Blue Cross recommends watching older dogs for changes and keeping veterinary care current. The practical first step is to describe exactly what has changed, rather than saying "fussy lately." That record helps your vet decide how promptly the dog needs assessment and what to check.
Measure the next few meals
Note how much food you offer and how much remains. If another pet has access, feed separately so you know who actually ate it. Check the food's freshness and whether the recipe or packaging changed. Record whether your dog still wants treats, chews on one side, drops food, approaches the bowl and walks away, or seems unable to bend down comfortably. Note water intake, stool, vomiting, weight, energy and any new medicine.
A dog who eats a treat is not necessarily healthy. Some dogs will accept a tasty bite despite illness, while their normal meal remains untouched. Equally, a dog whose appetite changes after a new food may still have a separate medical issue. Bring the packaging and your timeline to the vet.
Do not build a new diet before the examination
It is tempting to keep changing the meal until the dog finally eats something. That can make the picture harder to understand and may upset the stomach. Do not replace a prescribed diet, add supplements or withhold food to "reset" appetite without the vet's direction. If there is a dental problem, softer food might seem to help, but the painful tooth still needs care. Ask the vet what to offer while waiting for the appointment, especially for a dog with diabetes or another condition that depends on regular meals.
Set the bowl where the dog can reach it without slipping or climbing stairs. A mobility problem can make a dog look uninterested when getting to the food is the hard part. You can adjust access now, but still have the change assessed.
When to call promptly
Ask your vet how urgently to act if your dog has stopped eating or is eating much less, especially if they are weak, vomiting, having diarrhea, losing weight, drinking differently or seem in pain. The urgency depends on the dog, other symptoms and medical history. Do not wait out an arbitrary number of days from a website. Seek urgent veterinary care for collapse, severe weakness or other emergency signs.
Even a gradual decline deserves a check. Your vet may examine the mouth and body, discuss medication and diet, and advise testing based on the findings. Once you know the cause, the feeding plan can be tailored rather than guessed.
Common mistakes
"It's just age" can delay care. Free-feeding without measuring makes it hard to tell whether intake changed. Offering a long sequence of rich treats may keep the dog interested but can obscure the pattern or upset digestion. And putting the bowl on a slippery floor may make an older dog reluctant to stand there.
Today, measure one meal, note what remains and call the vet with the timeline. The goal is not to persuade the dog to finish the bowl at any cost. It is to understand why eating changed.
Sources: Blue Cross, "Caring for older dogs": https://www.bluecross.org.uk/advice/dog/caring-for-older-dogs.