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QUESTION: My 10 year old Westie has blood in his stool last 3-4 month.  His stool is normal consistency, the blood is bright red, always at the end.  We took him to the vet, did the blood test and x-rays.  X-ray was normal, blood test WBC came elevated at 17,000.  The doctor thought he had an infection, and prescribed him antibiotics,  retested him after antibiotics, the WBC came down to normal level, but the blood in his stool still present.  He seems to be as playful and happy as always, but it looks like there is more blood in his stool.  I'm worried, should I take him to another vet?  Could it be cancer?


What is your dog eating? What seems complicated can sometimes be so simple. Most of the time, in both dogs and cats, bloody stool is the result of their diet.

When they eat grocery store brand foods, or even so-called premium foods, if the food irritates their colon or the rectal area (very common) then the result is blood in the stool. The food passes through the colon and irritates the delicate tissues until they bleed. The reason there is no blood leaking out of the rectum in between is because it's only when the food crosses that area that the vessels rupture, resulting in the blood on the stool.

When we have had owners change to a higher quality food, such as Science Diet, the blood stool goes away in about two days. I had the same thing happen to my 5 cats about 30 yrs ago before I switched them ALL to Science Diet. I have never had a cat OR dog have bloody stool again.

Other problems it could are hemorrhoids,polyps, tumors or infection in the anal glands that is breaking through into the colon.

Chances are pretty good it's the food. Tell me what he is eating and I can tell you whether or not that's a common cause of this.

Have you changed his food as well? Since this is only a 4 month issue, sometimes the change alone is the cause, but it should have stopped by now if that was it unless, as I said, the food is irritating his colon and rectal tissues.

---------- FOLLOW-UP ----------

QUESTION: Jana, thank you so much for your detailed answer.  The food we are giving him is "Kirkland Chicken and Rice Premium" from Costco, I will definitely try Science, and see if it helps.  The vet also suspected anal sacs infection, he thought that antibiotics will help.  No, we did not change his food, the vet kind of mention it, but did not give us any recommendation on what to try.
Thanks again, we appreciate your help very much.

seven day transition chart
seven day transition c  
Hi Tom,
I'm going to give you the short sweet version of true dog food 101.

99% of all dog food companies source their foods from giant palettes that are brought from China frozen and set out on docks in the shipping yards every morning.
Companies like Purina, Blue, WalMart, Costco (Kirkland brand) (and you name-it-if-it-came-from-the-grocery-store or Pet Smart (think Nutro))get together and bid on these frozen bundles of chicken, beef, dogs, whatever is in those palettes. They often buy jointly to keep costs down.

This food, by the ton, is then shipped to their manufacturing plants and processed into Old Roy etc. Since the ingredients can change weekly (called open formulation) so can the quality/consistency of the food batches. This is why so many dogs can eat the same food and then suddenly get diarrhea or worse from it.

Hills, on the other hand, and maybe one or two more companies, only use fixed-formulation when making their foods. This means the same ingredients, same everything batch after batch.

However, Hills goes one step further. They never have and never will buy food from overseas. ALL of their foods are grown here in the USA- the chicken, beef, grains, vegetables- everything is grown from US farmers. Their food is cored frozen at the gates and tested before the trucks are allowed in to deliver it. That means they take a sample of any frozen meats and test them before allowing the trucks in to drop off.

That's what creates quality, highly consistent and nutritious food, batch after batch.
Maybe some smaller companies do this as well but I don't know of any.

Hills was started by veterinarians and is still a veterinarian run research facility. They don't just "make" pet food. They create and test their formulas on real animals that are extremely well cared for at their facilities. They KNOW if their senior diets work because they feed them to senior dogs and cats.

Hills is the first company to have created "wellness" formulas that help fight and prevent diseases. They were were among the first to study and test foods to help combat hip and joint problems in giant and large breed dogs. They are the ones that found the correlation between too much calcium (which breeders always gave thinking it was needed) and phosphorous.

Dogs that eat this formula do much better and have less hip dysplasia then dogs eating Purina or other foods.

At any rate, because of this 50 yr history of veterinary research that is Hills they make top quality food with precision formulations that provide optimal nutrition for your pets.

Most vets don't get much training on nutrition in vet school. Most, if anything that they learn they learn after school on their own. Hills dedicates itself to providing information to vets and vet techs to help them educate their clients on the benefits of nutrition for their pets. They have a motto at Hills that says "what most vets feed their own pets." The reason for that is it's true.

So I do hope that helps. Because he is ten, I recommend a senior formula for him. I put my cats on the Ideal Balance Mature formula and they LOVE IT! They were on the Longevity senior before that but they went wild over this.

Here is the canine version:

Please let me know how he does in a few weeks. I'm including a seven day feeding chart to switch him over slowly so he won't get any stomach upsets or diarrhea.  

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Jana Connell RVT, CVT


PLEASE READ BEFORE SUBMITTING TO ME: I am NOT a vet and do NOT diagnose diseases. That is only for a licensed Veterinarian to do. I will give you suggestions and steer you toward calling your vet for help. You can call the vet's office and talk to the technician there or the vet at times. Don't be afraid to call them! If you have a serious issue with your pet please post it to one of the veterinarians in here- I will tell you the same thing in my answer. IF your pet is injured or in an emergency situation, CALL YOUR VET- Do not wait and post in here. Just call the vet's office and get them in to see the vet right away. Critical treatment time is lost if you seek answers here when you should have your precious pet at the vets!! Don't sit at home waiting for an answer when your pet is critically ill or injured!! I can answer most questions about small animal and wildlife care as well as small animal nutrition. I can also answer questions about all phases of dental care for small animals. I DO NOT answer questions about birds (unless it is wildlife or songbirds) or HAMSTERS/GERBILS/CHINS/GUINEA PIGS/REPTILES/FROGS/RABBITS/PET BIRDS OF ANY KIND so please submit these questions to the appropriate sections. I, as well as other experts in here, do NOT do homework questions- that is for YOU to do! Please respect these rules for all of us. Thanks!


I have over 42 years experience in the field of veterinary medicine. I specialized in small animals and did wildlife rehab for over 25 years, mostly raptors, squirrels and opossums. I am a Small Animal Nutritional Consultant with 6 certificates from Hills Pet Foods, CNM and Purina. I also specialized in Small Animal Dentistry which is a field I truly love. I also Teach Veterinary Technology to working technicians who are studying to take their California Tests to become Licensed Technicians. They have to take both the VTNE (Veterinary Technician National Exam) and the California boards.

Audubon,World Wildlife Federation, American Society of Veterinary Dental Technicians.


Licensed with California and Oregon, RVT and CVT. Certified Veterinary Dental Technician Have over 1500 logged hours of Continuing Education Credits(that means I keep up to date!).

Awards and Honors
Nominated for Expert of the Month for the last 5 years.

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