Fresh blood in dog diarrhea, also known as hematochezia, is a sign of lower gastrointestinal disease but can have many other, less serious, potential causes. The causes include parvovirus, bacterial infections, intestinal parasites, diet and tumors, veterinarian Bari Spielman says. Diagnosing the cause of the dog’s hematochezia is the first step in deciding on the correct treatment procedure.
Viral infections such as parvovirus can cause hematochezia. Parvovirus generally affects puppies younger than six months that live in a kennel or shelter environment. Parvovirus is deadly if left untreated, but treatable if caught early. Treatment includes supportive care and antibiotics, veterinarian and vice president of the American Society for the Prevention of Cruelty to Animals Veterinary Outreach Lila Miller says.
Bacterial infections that cause hematochezia in dogs include clostridium and salmonella. These bacterial infections respond to antibiotics but can cause problems in humans,says dog breeder Norma Bennett Woolf. Children are more susceptible, and keeping them away from sick dogs protects them.
Types of intestinal parasites that cause hematochezia include roundworms, tapeworms, hookworms and whipworms, according to the Dog Worm Guide. Roundworms are the most common and have the appearance of spaghetti. Tapeworms are made of segments that look like grains of rice when dry. Hookworms feed on the dog’s blood and can cause anemia. Whipworms also suck blood and get their name from their whip-like shape. Anti-parasitic drugs often help with intestinal parasites. Dogs usually pick them up by eating infected soil, feces or animal carcasses.
Any food item that causes inflammation in a dog’s lower bowel can cause hematochezia. Spoiled food, foreign material, a change in diet, a dietary allergy or eating people food all have the potential to inflame the bowel, Spielman says.
Tumors within the rectum, colon or anus often bleed when enlarged and cause hematochezia in dogs, Spielman says. These masses can either be benign or malignant. Diagnosis is through an abdominal ultrasound, and the mass is then biopsied. Surgery may be required to remove the mass.