Feeding & Nutrition

A reader wrote in last month to ask whether the bone broth she had started pouring over her twelve-year-old terrier's dinner was doing anything, or whether she was simply spending money on warm water. It is a fair question and the honest answer sits in between. Warm water with flavour in it is not nothing. It is also not the joint supplement, immune booster or gut healer the label implied, and in her dog's case the more interesting question was why a dog who ate happily for eleven years suddenly needed persuading.

Toppers are the fastest-growing shelf in the pet aisle, and the growth is not really about nutrition. It is about the guilt of putting down brown pellets twice a day and the pleasure of watching an animal fall on its dinner. Broths, gravies, freeze-dried crumbles, goat's milk pouches, sprinkle-on powders, spoonable pâtés sold as boosters. A few are genuinely useful. Several will quietly unbalance a carefully formulated diet or hide a problem that belongs in a consulting room.

Take the useful part first, because it is real. Moisture is the strongest argument, particularly for cats, who evolved to take most of their water from prey and are poor at making up the shortfall at a bowl. Anything that puts more water in with the food is doing something worthwhile, and a splash of plain warm water achieves most of it for free. Palatability is the second argument, and it matters most in the animals who need calories most: a cat recovering from illness, a dog nauseated by medication, an elderly animal whose sense of smell has faded. Warming food to body temperature releases aroma, and aroma drives appetite in both species. Often the topper is really a delivery system for warmth and smell.

Now the arithmetic that keeps everything else honest. A complete diet is balanced as fed, which means every nutrient sits in proportion to the calories. Pile something on top and you dilute that balance. The working rule most vets use is that everything outside the complete diet, treats and toppers together, should stay under about ten percent of daily calories. Beyond that you are shifting the nutrient profile, and in a growing puppy or an animal on a therapeutic diet for kidney or heart disease, that shift is not academic.

The second half of the rule is the one everybody skips: those calories come out of the main meal, they do not go on top of it. A generous spoonful of a rich topper on a small dog's dinner can be a significant slice of the day's energy. Weight gain in pets is almost never a dramatic event. It is a spoonful a day for two years.

Then there is what is actually in the bottle, which brings us to onions and garlic. Both belong to the allium family, both damage red blood cells in dogs and cats through oxidative injury, and cats are more sensitive than dogs. Onion and garlic powder are more potent by weight than the fresh vegetable, and they sit in almost every stock cube, gravy granule and carton of supermarket broth, which is why you cannot share the stock from your own kitchen. The risk from a single lick is small, but this is a food people intend to give daily, and repeated exposure is how haemolytic problems build. Garlic sold as a pet supplement deserves the same scepticism.

Salt is the other reason to keep human stock away from the bowl. Commercial broths are seasoned for human palates, which means sodium levels that are irrelevant to a healthy young dog and genuinely counterproductive for a dog on a low-sodium cardiac diet. An owner doing everything right with a prescribed diet can undo it with a daily pour of stock. Products sold specifically for pets are usually far lower in sodium and allium free, but read the ingredients rather than the front of the bottle.

If you make your own, keep it dull: bones or meat and water, no onion, no garlic, no salt, no stock cube for depth. Simmer it, cool it, skim the fat off the top and strain out every fragment of bone, since cooked bones splinter and should never reach the bowl. Fat matters in a dog with a history of pancreatitis, because a fatty broth is a fatty meal by another name. Freeze it in ice cube trays and the portions look after the ten percent rule for you.

As for the claims, the collagen and glucosamine story is thin. Protein is digested to amino acids before it is absorbed; it does not travel intact to a sore hip. There may be effects worth studying, and the research in companion animals is limited enough that anyone speaking with confidence in either direction is overreaching. Judge a broth on moisture, smell and whether your animal eats better with it, which are the things it verifiably does.

Check the label for the wording about intermittent or supplemental feeding. It means the product has not been shown to be complete on its own, which is fine for a topper and a problem only when the topper quietly becomes half the meal.

Which returns us to the reader's terrier. The pattern worth watching is the escalation. You add a topper, the dog eats. Two weeks later he waits for the topper. You upgrade. He waits again. Animals learn quickly that holding out produces something better, and a fussy eater can be manufactured in a fortnight by an anxious owner with a well-stocked cupboard. That is the harmless version.

The version that concerns me is the animal who genuinely needs the topper to eat at all, because appetite loss is a clinical sign. Dental pain, kidney disease, nausea, an overactive thyroid in an older cat, early heart failure in a dog, gastrointestinal disease and pain of almost any kind all show up first as a pet who has gone off food. A topper makes that sign disappear while the cause carries on. If you have needed one every day for a fortnight to get food eaten, particularly in an older animal or one that is also losing weight, book the appointment. Take the bottle with you. Half the time it is a tooth.