Blood in stool


Fresh blood in stool

Question: Dear Dr Mike,

The following is the case:

I found there are fresh blood on my British short hair kitten (4 months)'s anus after defecation. I got this male kitten 2 weeks ago and this problem happened quite often (3-4 random days) but not always. I feed him dry food for kitten and sometimes mixed with boiled chicken meat. I took him to a local vet and the vet told me he is very heathly and give me a deworm pill for him. But this happened again and again, I am very worry about that. Could you give me some advice? Thanks!

Regards, Ernest

Answer: Ernest-

Bright red blood in a cat's stool can happen for several reasons. It is not uncommon when bowel movements are hard or dry. If this is the case, identifying the cause for the hard/dry stool, if possible, may resolve the problem.

Several intestinal parasites, including worms, can lead to blood in the stool. This is a fairly unusual complication of coccidiosis but kittens are the most likely patients to have clinical signs associated with coccidiosis, so it might be worth rechecking a stool sample to see if coccidia are present.

Some cats have Campylobacter or clostridial bacterial infections that cause colitis and this can lead to blood in the stools. Cats can have mild to moderate colitis and have normal stools in some cases, except for subtle signs like occasional bright red blood on the stool or around the rectum. Fecal smears can help to identify campylobacter (acid fast staining) and clostridia (show up with normal staining). Culturing the stool may be necessary to identify other possible bacterial infections such as Salmonella or E. coli.

Some kittens evert their rectal mucosa when they strain to have a bowel movement. The mucosal tissue is easily irritated to the point that it will bleed. In some cases the rectal mucosa will remain everted for a few moments or even much longer, after a bowel movement and looks like a pink ring of tissue around the rectal opening. I think of this as an anatomical problem but it is often actually a secondary problem when a cause of straining is present, such as worms, coccidia, giardia, inflammatory bowel disease, etc.

Some kittens with blood in the stool with no apparent cause seem to respond to changes in diet to the highly digestible foods like Hills i/d (tm) or Purina's EN (tm) or to low fat/moderate fiber foods like Hills w/d (tm). It took me a while to build up the courage to try w/d since it doesn't seem like an appropriate diet for a kitten but it has helped several times for us when not much else was working for diarrhea that seemed to be from colitis in kittens. I don't think we have tried it for a kitten with normal stools and blood but I think I would if I couldn't find a cause for the problem.

We do have a fairly large number of cats in our practice whose owners see blood in their stools occasionally and who seem to be unaffected by the problem even over long time spans. I think that this experience is not uncommon among veterinarians and may explain why many vets seem to take a pretty non-aggressive approach to the problem. However, I think that cats often have subtle signs no matter what disease or disorder they have and that it is reasonable to continue to pursue a diagnosis if you wish to. I'd be surprised if your vet wasn't willing to keep working towards a diagnosis if you express a desire to find the cause of the problem.

Good luck with this.

Mike Richards, DVM 2/2/2002

Bloody stool

Question: Dr. Mike,

I have 4 cats and recently noticed, on several occasions, that there has been a bloody stool in the litterbox. It looks like a mucousy secretion mixed with blood. I am not sure which cat it is, although I think I have it narrowed down to one of two. One of these is a kitten who has yet to be neutered (in case that impacts it in any way).

I was able to collect a sample and am going to take it into my vet's office for analysis. He suggested it may be intestinal worms. I am suspicious of one of my kittens, so I assume that would make sense (although he was dewormed).

He also suggested that if it is confirmed that he has worms, all the cats do.

Any ideas what a bloody stool is suggestive of? also, why would all the cats have the intestinal worms - is it spread through fecal contact?

The kitten I suspect was on Griseofulvin (reduced dosage) for 5 weeks to treat his ringworm. Any connection?

Thanks, Jill

Answer: Jill-

Bright red blood in small quantities, sometimes mixed with mucous, is a fairly common finding in cats and sometimes we can't find a cause despite pretty thorough work-ups. However, there are some things to consider about this, especially in your case.

Griseofulvin can cause diarrhea and it can cause liver problems. Since the liver is responsible for making the blood clotting components there is a chance that the problem does relate to the griseofulvin. Last year there was a study done using lufenuron (Program Rx) to treat ringworm. It seems to be less likely to cause side effects and is easier to use. If you need to treat ringworm in the future it might be worthwhile to look into this.

There is some evidence at this time that cats do not develop very good immunity to roundworm infections and that roundworms may be a more common problem in adult cats than veterinarians tend to think. Roundworms are transmitted when roundworm eggs are passed in the stool of an infected cat. The eggs do have to incubate (probably not the right word) for several days before they become infective, though. So the transmission occurs from contact with contaminated soil in most cases. Roundworms can encyst in body tissues and reinfect a cat throughout its lifetime once they are acquired. For this reason, some veterinary infectious disease specialists recommend routinely deworming cats once a year. So it is reasonable to deworm all the cats and this is true even if worms aren't found on fecal examination.

Hookworms are less common and should show up in the fecal examination. Tapeworms don't usually show up in fecal examinations but segments of the worm (actually egg cases) are passed and look like small white worms about 1/2 inch long that later dry up and look like rice granules stuck in the hair. Tapeworms are most commonly acquired by eating fleas that have ingested tapeworm eggs.

There are a number of organisms that are sometimes suspected to cause chronic gastrointestinal disease in cats, including giardia, coccidiosis, cryptosporidiosis, and Clostridium bacteria. Several of these are possible to find on fecal examinations, especially if they are specifically looked for using special fecal floatation or fecal smear stains. Disorders of intestinal motility (megacolon) or capable of causing dehydration (most disorders of cats) can also lead to blood in the stool as dry stools irritate the lining of the digestive tract. All of these things are worth looking for but often it is not possible to find an underlying cause despite a careful search. On the other hand, if the kitten and other cats are acting normal, eating well and seem OK otherwise it is also probably reasonable to do simple things like deworming and then wait to see if other signs of problems occur.

I hope that this is a past problem at this point.

Mike Richards, DVM 12/21/2001

Blood in stool

Q: Dear Dr. Mike, My brother just called in a panic. Our 2 year old persian, Dudley, is experiencing bloody bowel movements. I looked at a sample and found no trace of tapeworms, but there is a fair amount of bloody milky discharge. I am concerned that somehow Dudley, an indoor cat, has contraced a parasite or is experiencing a bowel obstruction. Please advise so I know how large to let my concern grow. Thanks

A: If Dudley continues to have blood in his stool, it would be best to have him checked by your vet. I don't think I'd panic over this situation as long as he seemed to feel OK otherwise. Blood in the stool is common enough in cats that it shouldn't be taken as an automatic sign of serious illness all by itself. If signs of depression, blood loss elsewhere, vomiting, or anything else accompany the onset of blood in the stool then it would be best to have Dudley checked as soon as possible. The major problem that we worry about with this clinical sign is exposure to a warfarin based poison -- these are usually used to kill mice and rats. It is always a good idea to make sure that such exposure is unlikely when unusual bleeding is observed. Most of the time cats who have ingested enough of this toxin to cause bleeding disorders are pretty depressed.

So, if the blood in the stool has continued but Dudley seems OK, schedule a visit at your convenience. If the blood in the stool has continued and he seems depressed, have him seen as soon as possible -- even if you have to go to an emergency veterinary hospital. If it has stopped, it would probably still be a good idea to have him examined -- just in case.

Mike Richards, DVM

Last edited 09/06/07


Michael Richards, D.V.M. co-owns a small animal general veterinary practice in rural tidewater Virginia. Dr. Richards graduated from Iowa State University's College of Veterinary Medicine in 1979, and has been in private practice ever since. Dr. Richards has been the director of the PetCare Forum...