Major diseases dogs and humans have in common

Dogs, just like us, can suffer from allergies, arthritis and joint pain, different types of dementia, all forms of cancer, dental disease, diabetes, gastrointestinal and digestive disorders, and heart, kidney, and liver disease. The list is long (see sidebar, “Numbers of dogs that get major illnesses”), and cats are affected by these illnesses too.

“We share all the big diseases with our animal friends,” says Robin Downing, DVM of Windsor Veterinary Clinic and The Downing Center for Animal Pain Management in Windsor, Colo.

Dr. Downing believes a lot of these illnesses — for people and dogs — stem from obesity. “In terms of health issues, obesity trumps everything,” she explains. “Obesity is the number-one disease in humans and in our dogs and cats.”

According to the Association for Pet Obesity Prevention, an estimated 54 percent of dogs and cats in the United States are overweight or obese — that’s an estimated 93 million overweight or obese dogs and cats. The Centers for Disease Control lists adults age 20 years and older who are overweight at 69 percent of the population.

“Obesity is a shared disease with too many calories in and not enough out,” says Dr. Downing. “We know that obesity leads to diabetes, cancers of all types, and just think about the stress that being overweight puts on our joints and organs.

“We have no excuse for our dogs or cats to be obese. Animals don’t have any control over what they eat. The veterinary profession is frustrated by the number of overweight dogs and cats we are seeing in our practices.”

One of the problems is most pet parents don’t recognize when their dogs are overweight. “We don’t know what is a normal weight for our pets,” she says. “Pet food today is extremely palatable, and most of us don’t practice portion control. In the wild, we don’t see overweight animals. They eat what they need, not to excess. Obesity is an animal welfare issue.”

Pain is the number-one reason people seek medical care for themselves. When it comes to our pets, we often don’t know when they are in pain. “We see the symptoms from the pain, and at that point a disease could progress to where treatment will be more aggressive and more costly,” says Dr. Downing.


Caring for people and dogs with major illnesses are the same. The more advanced the illness, the more aggressive the treatment. For example, cancer treatments include medicines, surgeries, radiation, chemotherapy, and immunotheraphy. A combination of therapies can be used. Eradicating the illness often depends on how advanced it has become.

Canine dementia

When Dr. Downing came out of veterinary school about 20 years ago, no one talked about Canine Cognitive Dysfunction Syndrome. Today, it’s found in about 50 percent of senior dogs. “It’s the canine equivalent of Alzheimer’s or dementia in humans,” she says.

On the one hand, our dogs are living longer healthier lives. It used to be dogs lived to 12 or 13; now some dogs are living to 16 and older. “Now, that our dogs are living longer, we see illnesses like this one,” says Dr. Downing. “It’s more like a form of dementia in humans than actual Alzheimer’s. It’s clearly not the same as Alzheimer’s. It’s just like with us — a lot happens between ages 50 and 75 and 75 and older.”

With Canine Cognitive Dysfunction Syndrome (CDS) dogs become disoriented, may experience separation anxiety at age 11 or older when they’ve never done that before, their sleep patterns may be disrupted — like sleeping all day and being awake at night — and may become aggressive.

CDS is treated with medications and special prescription diet.

“Water on the brain”

Another illness that affects both dogs and humans is hydrocephalus or “water on the brain.” The water is actually cerebrospinal fluid, a clear liquid that surrounds the brain and spinal cord. Treatment for dogs and humans consists of surgery where either the obstruction is removed or a shunt is inserted. If left untreated, the illness can be fatal.

When it comes to treating our dogs and humans, veterinarians and doctors are learning a lot from each other.