Common Reasons for Canine Diarrhea:

Many things can disrupt this well-balanced canine digestive system, causing dogs to have diarrhea or—less frequently—constipation. Some causes, like eating too much grass, are not serious at all. (Some dogs really enjoy grazing on grass.) Others causes can be life-threatening problems, such as an indigestible object (like a rock) lodged in the stomach, or a disease like cancer.

Source: https://www.purina.com.tr/dogs/health-and-nutrition/symptoms-to-watch-out-for/guide-to-dog-poop

When in doubt, always consult your veterinarian. There are many reasons why a dog may develop loose stools, but most of the time, dog diarrhea is caused by:



→ Dietary indiscretion: Eating too much food, eating garbage, or eating spoiled food. There’s
     actually a name for it in veterinary circles—“garbage toxicosis” or “garbage gut.”
→ Change in diet: It may take a few days for a dog’s digestive system to adapt to digesting new
     proteins. That’s why many dog-food manufacturers recommend that you go slow when you
     switch from one brand of food to another.
→ Food intolerance
→ Allergies
→ Parasites: Most of these will cause illness in puppies or in adults with weak immune systems:
     o Roundworms
     o Hookworms
     o Whipworms
     o Coccidia
     oGiardia
→ Poisonous substances or plants
     o Swallowing an indigestible foreign body, like a toy or socks
→ Infections with common viruses such as:
     oParvovirus
     o Distemper
     oCanine coronavirus
→ Bacterial infections, such as salmonella
→ Illnesses, such as kidney and liver disease, colitis, inflammatory bowel disease, and cancer
→ Antibiotics and other medications
→ Stress or emotional upset