Monty's behavior mystified his owner, Karen Mitchell. The 7-year-old dog -- a mix of pit bull, boxer, and pointer -- was long housebroken and rarely had indoor accidents.
So when Monty began urinating in odd places, Mitchell, 43, at first attributed the dog's behavior to the stress of big life changes. Mitchell and her husband had recently welcomed a new baby daughter and had moved into a new house in Alameda, Calif.
But when the urinating didn't stop, a worried Mitchell finally took Monty to the veterinarian after he wet himself during sleep. "He actually slept in his pee," she says. "He wasn't acting out by peeing in the corner because he's mad that we moved. This was definitely a sickness."
Monty's vet delivered a prompt diagnosis: diabetes.
Pet Health: Pay Attention to Your Pet’s Symptoms
What our sick pets can't say in words, they'll demonstrate through physical symptoms and behavior changes.
"Dogs and cats can't tell us when something hurts or doesn't feel good. But the owners that see them every day will realize when they're not just being their regular selves," says Mark Stickney, DVM, director of general surgery services at Texas A&M University College of Veterinary Medicine and Biomedical Sciences. "Any change in your pet's behavior from what it normally does is a reason to see your veterinarian."
Pay special attention to cat health, says Julie Meadows, DVM, assistant professor for clinical medicine in community practice at the University of California-Davis Veterinary Medical Teaching Hospital. Cats are less likely to show owners that they're sick, and owners may be less attentive to them because they are more independent.
To help you know what to look for, WebMD asked several experts to provide six "red flags" that should prompt a call or visit to the veterinarian about your pet's health. And as always, if you are concerned about anything at all, reach out to your vet.