Have you ever wondered how your senior dog feels? Does he experience the same aches and pains that we do as we age? In terms of health and care, could he even have a serious age-related condition brewing that hasn’t yet surfaced with noticeable symptoms?

To better understand how our aging dogs’ bodies react to the process, and how we can better help them to grow old gracefully, let’s take a look at how dogs age.

“The aging process in dogs is similar to people, it just happens faster,” says Mark Stickney, DVM, clinical assistant professor of small animal general (elective) surgery at Texas A&M College of Veterinary Medicine. “As the body ages, old cells die and the ability to generate new cells decreases. At the same time, free radicals are generated through normal cell metabolism, but the enzyme systems that manage those free radicals and keep them from damaging the cells are not working as effectively.”

What does that all mean?

“The result is fewer healthy cells that do not live as long or function as well, resulting in signs of aging,” Stickney says.

Aging and Size

Aging in dogs varies significantly by size, with large-breed dogs aging at a faster rate than smaller breeds.

“In general, a dog age 7 or older is considered a senior, but no two dogs are alike,” says Babette Gladstein, VMD, founder of Animal Acupuncture in New York City and a pioneer in prolotherapy, a non-invasive orthopedic treatment. “A small dog weighing less than 20 pounds might not show signs of aging until he’s 12 years old, whereas a 50-pound dog will show signs at about 10.”

Adds Stickney, “Giant breed dogs, which weigh 90 pounds or more when full- rown, are considered seniors at age five.”

As with humans, aging affects just about every part of a dog’s physiology, including the physical and the emotional. Here are some of the most common age-related changes.

Energy and nutrition

Senior dogs have slower metabolisms and are less active, so they need less caloric energy than their younger counterparts.

“Feeding an older dog the same daily caloric intake as a younger, more active dog will cause his body to store the excess calories as fat. This can lead to arthritis and other joint diseases; it may play a role in respiratory disease, diabetes, and kidney disease; and it can result in a shorter lifespan,” Stickney says.

Movement and exercise

Arthritis is a common disorder affecting the joints of older dogs. Larger breeds typically suffer from more severe arthritis than smaller dogs, because they carry more weight in proportion to the size of their joints.

“Since arthritis causes pain, there is some debate as to whether senior dogs are less active because they’re more tired, or whether they fatigue more quickly because it hurts when they move,” Stickney says.

Gladstein suggests avoiding the stress and side effects of drugs and surgery by exploring natural treatments for arthritis and other joint diseases whenever possible.

“Just like older people, senior dogs can have underlying health issues that make them more susceptible to complications from surgery and the effects of prescription medications. Older dogs can benefit from treatments such as acupuncture and prolotherapy,” she says.

Vision

The most common eye condition in older dogs is nuclear sclerosis, a normal age-related change where the fibers in the lens of the eye lose some of their moisture, making them appear cloudy. Fortunately, this does not generally impact the dog’s vision.

Nuclear sclerosis is often confused with cataracts, a serious condition that occurs when the lens of the eye becomes opaque. If left untreated, cataracts will result in blindness. Cataracts can occur at any age, with smaller breeds such as Poodles, Shih Tzus, and Bichon Frises most commonly affected. However, as dogs enter their senior years, incidences of cataracts become more likely in all breeds.

Hearing

Dogs develop hearing loss as a normal part of the aging process. It may be difficult to tell whether your dog has partial hearing loss, however, because dogs have a greater wavelength of sounds that they can hear in the first place.

“Dogs tend to lose the ability to hear higher pitched noises first,” Stickney says. “They might still be able to hear adults, but they can no longer hear a young child. This can pose a problem, because the senior dog can’t hear the child creeping up from behind and could bite out of fear.”

Other medical issues

Instances of all medical issues, regardless of the dog’s size or breed, increase with age.

“For example, all senior dogs are susceptible to chronic kidney disease as the kidney ages and tissues dies,” Stickney says. “Unfortunately, by the time the owner notices the symptoms, the dog is often in kidney failure, meaning that 75 percent of the kidney is no longer functioning. We can medically manage the condition for a few months to a couple of years, but eventually the dog will die from it.”

Because breaking down protein makes the kidneys work harder, Gladstein advises feeding senior dogs a lower-protein diet to avoid stressing the kidneys.

Heart problems and cancer are also typical age-related canine diseases. Scottish Terriers are predisposed to transitional cell carcinoma, a tumor of the urinary bladder. Small breed dogs are more prone to endocardiosis, a condition that results in fluid backing up into the lungs, causing coughing and exercise intolerance.

“Because there are about 150 breeds of dogs, it is difficult to discuss every disease prevalent among every breed,” Stickney says. “Suffice it to say that as soon as you have a dog that meets a certain breed criteria, the same genes that have made that dog look the way he does also predispose him to certain problems. Your veterinarian can advise you as to your particular dog’s genetic predispositions.”

Adds Gladstein, “Just as with people [and physicians], senior dogs should receive more frequent veterinary check-ups -– at least every six-to-nine months. This will enable your veterinarian to identify age-related diseases in their earlier stages, increasing the treatment options and improving the likelihood of a positive prognosis.”

About the Author: Diana Laverdure is an award-winning dog healthcare writer. Her 2011 book, The Canine Thyroid Epidemic: Answers You Need for Your Dog (with W. Jean Dodds, DVM), was named Best Care/Health Book of 2011 by the Dog Writers Association of America and received the 2011 Eukanuba Canine Health Award. She has just finished her second book, Nutrigenomics: Foods that Heal Your Dog (also with Dodds), which will be released later in 2013. She lives with her rescued Shepherd mix, Chase.

Read more by Diana Laverdure:

• How to Care for Your Dog’s Paws
• Puppy Adoption: 6 Steps for Doing It Right
• Can Aromatherapy Help Dogs?
• Spot — and Prevent — Hip Dysplasia in Dogs