Dear Doctor

Letters to Tufts Veterinarians


Owner worries over aging dog’s protein requirements

Q We have a 12-year-old mixed breed — malamute, husky, akita, chow, and Irish terrier. He is in good health for his age, but I am concerned about the level of protein in a senior dog’s food. We have always been very careful not to feed him a senior diet that contains more than 21% protein, as we’ve been told that too much protein makes a dog’s kidneys work harder and can be the cause of kidney disease. But I’ve now read about research that dispels that information. I’ve also seen articles that indicate if the protein comes from meat and not grain, it won’t have a detrimental effect on the kidneys. What’s your position?

Linda Eaves

Fenton, Michigan

Dear Ms. Eaves,

AIt’s important to look at this from a number of angles so you get our full take. First, it is not true that a lot of protein in a dog’s diet will cause kidney disease. Even if a dog develops kidney disease, protein restriction is not recommended in the early stages. Only in the later stages of disease should a dog’s protein intake be restricted (unless he has a specific type of kidney disease called protein-losing nephropathy).

Indeed, some research suggests that restricting protein in the diet of a healthy dog may be detrimental to his health. It’s not surprising. It is already known that geriatric dogs have slightly higher protein requirements than younger adults. Dietary protein restriction in a healthy dog can contribute to muscle loss, a common problem in older dogs. But that doesn’t mean you should automatically put your older dog on a high-protein senior diet.

In fact, you couldn’t even if you tried. There’s no such thing as a true “senior diet,” as we said back in our October issue. The levels of protein and other nutrients in dog food labeled as “senior” foods are all over the map, since “senior” is a marketing term rather than a legal one. Indeed, when Dana Hutchinson, DVM, DACVN, and Tufts veterinary nutritionist Lisa Freeman, DVM, PhD, DACVN, analyzed the nutrient values of 37 over-the-counter diets marketed for senior dogs, they found that protein concentrations varied by almost three-fold (and sodium values by more than 10-fold).

So what do you do? Well, the good news is that if you choose your food wisely, you don’t have to worry about feeding your dog a diet that is a certain percent protein — or about any of the other ingredients, either. The protein percentages found on packages of dog food aren’t terribly instructive, anyway. They don’t give exact amounts of protein, only minimums. The actual protein content could be significantly higher. In addition, while the protein value of dry dog foods may hover around 20 percent, in canned food they can range well under 5 percent. But the canned food doesn’t actually have less protein. It simply has a lot more water, which dilutes the protein per a certain weight of the food. Serving for serving of food that actually goes into your dog’s bowl, the protein values are quite similar.

As for whether your dog gets his protein from meat or grain, it’s a non-issue. The amino acids that make up protein are the same in both animal- and plant-based foods. Once they make their way through a dog’s digestive system, the kidneys (and the rest of the body’s tissues) treat them all the same. The important issues are that the individual amino acids are in the right levels and proportions and that their quality is excellent. But this can’t be determined from the percentages listed on the package (under “guaranteed analysis”) or even from the ingredients list.

Your best bet for making sure your 12-year-old dog gets the best quality food possible is the same for a younger adult dog: look for a statement on the package (often squished up on the side of the bag) that says the food provides complete and balanced nutrition for “maintenance” of adult dogs. Ideally, the statement will also say the food is one that has undergone AAFCO feeding trials, that is, feeding trials up to the standards of the Association of American Feed Control Officials. Foods that have been “formulated” according to AAFCO standards will suffice, but they haven’t been put through testing in real dogs to make sure the dogs stay healthy on them.

For more information on choosing the right food for your senior dog — or a dog of any age — see the website of the World Small Animal Veterinary Association (WSAVA) at:

Howling, but not at the moon

Q Every morning I take my dog to the exact same field for the first walk of his day. He is allowed to go around there off leash. Most days he stays pretty close by my side, perhaps quietly running several feet away at points to sniff something interesting or do “his business” but then coming back and more or less following the same trail I do. But once in a while he runs this way and that, howling like crazy with his tail somewhat stiff. He seems agitated but not altogether unhappy — it actually almost seems like some kind of bravado — and although he appears to be taking a stand, he is willing enough to come back to let me put him on leash when it is time to return home. What could the intermittent howling be about? I certainly am not able to discern anything different on the mornings he gets worked up.

Noel Malvern

Eastchester, New York

Dear Mr. Malvern,

AYour dog’s need to howl is a throwback to his wolf ancestors of the distant past. Wolves communicate with each other through howling — the howl covers different pitches in one vocalization, which helps carry sound over longer distances — and this deeply ingrained behavior has been passed down.

That said, why dogs have retained the ability to howl has not been entirely nailed down. With wolves, it’s about saying “I’m over here” to let other members of the pack know their precise location should they become separated. Wolves also howl to defend their territory. Dogs, on the other hand, seem to howl for any number of unrelated reasons.

Some do it in response to high-pitched sounds, say, the wail of a siren or certain musical instruments; perhaps your dog gets going if he can hear an ambulance or police car in the distance. For other dogs, howling is a manifestation of separation anxiety, although that clearly cannot be the case when it comes to your own dog — your neighbors would be letting you know if it were. For still other dogs, howling can be a sign that they’re hurt. Then, too, some dogs appear to howl just to get their owners’ attention.

As long as your own dog’s howling once in a while is just an observation on your part rather than something you’re worried about or something that annoys other people (the sound does carry), don’t be concerned. Not every last canine behavior needs to be understood.

Dogs whose howling does prove annoying or intrusive, by contrast, need to learn to redirect their instinct. Separation anxiety, as we’ve discussed in these pages, can be quelled with a multi-pronged approach that will also cause the anxious howling to cease. And dogs who howl as an attention-seeking behavior need to be ignored — not hushed by giving in. That only teaches them that howling does the trick. It’s also a good idea to reward a dog with a tendency to howl annoyingly by engaging with him when he is being quiet. That teaches that quiet behavior rather than excessive vocalizing is what will elicit the desired outcome. n


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