Diarrhea is not a disease, but rather a symptom. It could be caused by parasites, liver or kidney disease, dietary indiscretion,
foreign bodies, cancer, food allergies, digestibility issues, pancreatitis, stress, and on and on.
These conditions can result in diarrhea for one of three reasons:
1) Malabsorption (a form of osmotic diarrhea): The patient's body is not effectively pulling fluid (and nutrients) from the
lumen of the intestine.
2) Secretory problems: The patient's body is putting too much fluid into the lumen of the intestine and it cannot be absorbed
3) Motility: An overactive intestinal tract is moving things too quickly through the gut and there's no time for fluids to
be pulled back into the body.
How often is diarrhea more than the runs?
According to a Cornell study, 16 percent of dogs symptomatic for gastrointestinal disease (vomiting, diarrhea, or both) and
10 percent of cats with gastrointestinal signs test positive for Giardia on an in-clinic ELISA. What's more, the number of patients suffering from digestibility problems or a food allergy is substantial
enough to have supported the creation of dozens of specially formulated sensitive-stomach pet foods.
With all this in mind, Dr. John Stoner, who owns Shippensburg Animal Hospital in Shippensburg, Pa., says there's no doubt
a pet with diarrhea needs to visit a veterinarian. "Diarrhea in cats, for example, could be a sign of inflammatory bowel disease
(IBD)," he says. "Often this illness goes untreated for months or years, and by the time I see the patient, it's emaciated
and acutely ill. Treating patients this sick is much more expensive for the owner and a positive outcome is less likely."
Dr. Howard Gittelman, of Animal Medical of New City in New City, N.Y., cites a University of Minnesota College of Veterinary
Medicine study that found 39 percent of cats with cholangiohepatitis also had IBD. "But patients in general, and cats especially,
may suffer from malnutrition when sick with chronic diarrhea for a long time," Dr. Gittelman says.
"Acute diarrhea, of course, is another matter," he says. "In addition to the zoonosis of some infectious causes, acute diarrhea,
when accompanied with vomiting, can lead to acid-base imbalances and dehydration." While bringing pets into the clinic can
be challenging for clients, the potential health problems their pets face may result in bigger challenges—unless they visit
Bash Halow, CVPM, LVT, owns Halow Consulting in New York City and Wyalusing, Penn.