Q: My kitten cries and often has a bloody anus after eliminating. I got him at 5 weeks old and he is now 12 weeks. He’s been to the vet three times for checkups and shots. They gave him two different de-wormers even though there were no signs of parasites. We believe it may be the food he is eating. He is an ordinary orange tabby shorthair cat. Is food the reason for his pain?
A: Thanks for getting in touch, and I am sorry to hear of this kitty’s problem. Although we cannot diagnose him from afar, there are a number of potential causes of blood in the feces of cats.
To clarify an important point, the presence of bright red blood in the feces (called hematochezia) suggests bleeding in the gastrointestinal (GI) tract that occurs near its end (i.e., the colon, rectum, and anus), as in this case. The blood is not digested and appears pretty much like blood that is found in the blood vessels.
This is to be distinguished from melena, which refers to fecal blood that has a dark brown or black tarry appearance. Melena suggests that GI bleeding is occurring higher up in the GI tract (i.e., in the intestines or the stomach), as the dark appearance of the fecal blood in this case is due to the fact that the blood is partially digested as it passes through the upper GI tract.
For this discussion, I will assume that you are referring to hematochezia, with bright red blood in the stool, that your kitten doesn’t have diarrhea, and he is otherwise apparently healthy.
The possibility of intestinal parasites such as roundworms/hookworms or Giardia is something to consider, although cats harboring these parasites often have diarrhea. These infections are usually diagnosed via fecal analysis, although in some cases cats suspected of having these infections will be treated empirically with appropriate antiparasitic drugs. Importantly, treatment success should be verified by follow up fecal analysis, and some cats require repeated treatments to effectively address GI parasites.
Constipation can also cause hematochezia, and this can be suspected if the feces are eliminated in small amounts and/or if the stool looks excessively dry.
Rectal polyps, which are usually benign tissue growths within the rectum, can also cause hematochezia. These are usually diagnosed via physical (rectal) examination, specialized radiography (X-rays), and/or colonoscopy.
Inflammation and/or infection of the anal sacs (two small pouches found around the anus) can cause hematochezia, and this condition is usually diagnosed via physical examination by a veterinarian.
Perianal fistulas, which are abnormal, tunnel-like formations that can form in the skin and deeper tissues around the anus due to chronic inflammation, can cause hematochezia in cats. These are more common in dogs than in cats and are usually diagnosed via careful veterinary examination.
Atresia ani is a relatively rare feline congenital condition in which the end of the GI tract (i.e., the rectum and anus) forms abnormally during development, resulting in either a complete or partial lack of communication between the end of the GI tract and the outside world. This condition is usually diagnosed via physical examination and specialized radiographic studies, and definitive treatment often requires surgery.
Finally, a relatively rare cause of hematochezia in cats is inherited abnormalities of the coagulation system or the administration of drugs that inhibit the coagulation system.
Importantly, there are certainly other potential causes of hematochezia in cats, including food allergies, inflammatory bowel disease, viral, bacterial, or fungal infections, GI lymphoma, and pancreatitis, but these are usually associated with some combination of diarrhea and generalized systemic illness, and are not commonly associated with overt pain upon defecation.
Please discuss these options carefully with your veterinary team, and send us an update when you can.
