At some time or another, whether you have one new pup or a whole litter in your household, you will be greeted with puppy diarrhea.  Diarrhea is a symptom - not a disease.  It is the passage of loose, unformed stools. In most cases, there is an increased number of bowel movements.

Once food enters the small intestine is takes about 8 hours to get into the colon.  The colon serves as a storage center where approximately 80% of the water is resorbed into the pup’s body.  The colon accumulates the waste and normally evacuates a well-formed stool.  Transit time in the intestinal tract can be sped up for a variety of reasons.  When food passes rapidly through the bowel, it arrives at the rectum in a liquid form.  This results in large, loosely-formed bowel movements.  This condition, which is due to hypermotility of the bowel, accounts for 90% of the diarrheas in dogs.

As mentioned earlier, diarrhea is just a symptom.  To identify the exact cause, you need to examine characteristics of the stools.  The following list helps rule-in or out different disease processes:

Color
Yellow; greenish stool: bowel hypermotility
Black, tarry stool: bleeding in the upper intestinal tract
Bloody stool: bleeding in the lower intestinal tract
Pasty, light-colored stool: lack of bile
Grey, rancid-smelling stools: inadequate digestion

Consistency       
Watery: extreme hypermotility and bowel wall irritation
Foamy: bacterial infection
Greasy: malabsorption of food

Odor                 
“Sour-milk” smell: hypermotility and malabsorption
Putrid: intestinal infection

Frequency         
Small; several in an hour: colitis (inflammation of the large bowel)
Large; 3-4 times a day: malabsorption or small bowel disease


After having examined the nature of the diarrhea and understanding more about how and where the bowel abnormality is located - it is time to add some causes for the bowel upset.

Most cases of diarrhea are due to an irritation of the bowel lining from ingested substances or infectious agents, causing hypermotility.  For example, any sudden change in the pup’s diet will cause diarrhea.  When bringing a new pup home, always ask the breeder what he or she was feeding the dog.  It is best to continue feeding that brand as long as you feel it is providing the proper nutrition for a growing pup.  If not or if you prefer a different brand, the two products MUST be mixed together for at least 7 -10 days to avoid diarrhea.  Start with a mixture of 25% new food and 75% previously-fed food.  Over the course of the next few days, gradually increase the new food content while decreasing the previously-fed food.  Mixing the two foods gives the pup’s body time to produce the needed enzymes to digest the new food ingredients.

Drinking of unfamiliar water may cause a pup to have diarrhea.  The water may contain a different mineral content that of the home water supply, heavy metals (lead), protozoal organisms (simple, one-celled organisms), or bacteria (E. coli, Leptospirosis).  Dogs can become ill when drinking water from a contaminated stream or pond.  It is best to carry water with you from home when traveling.

Pups will occasionally experience diarrhea when they become excited or emotionally stressed.  The hormonal effects of the pup’s “upset” will cause the bowel hypermotility resulting in loose stools.

Dietary indiscretions can cause diarrhea in pups.  If the pup is left unattended, it may eat things it shouldn’t.  Some things pups will get into include:  decaying animal parts, garbage, sticks, grass, insects, small rocks, rug or blanket material, clothing, or children’s toys.  More serious consequences are encountered if the pup gets into toxic substances such as:  gasoline, kerosene, cleaning fluids, refrigerants, antifreeze, insecticides, flea collars, bleaches (especially toilet bowel cleaners), some ornamental plants, lime, paint, caulks, rat poisoning, or fireworks containing phosphorus.  Many of these substances are also irritating to the stomach and cause vomiting.

Some dogs become allergic to certain foods or feed ingredients.  Some animals are unable to tolerate milk, eggs, corn or corn by-products, rice, wheat, soybean, chicken, beef, or chemical preservatives.  The subsequent diarrhea is due to malabsorption of the food due to an inflamed bowel wall.  Food allergies are often very difficult to manage.  The dog’s immune system can not tolerate certain allergens (a substance that causes a hypersensitivity).  The allergen irritates the bowel wall and causes diarrhea.  These dogs also display intense itching and subsequent hair loss.  Several dog food companies make high quality diets that contain very different sources of protein and carbohydrates than available in regular commercial foods.  These special hypo-allergenic diets include combinations of fish, venison, duck, and potato.  Many times dogs suffering from food allergies must have a change of diet every 6 months.  Even though they do well on a diet in the beginning - allergic dogs often develop a sensitivity to the new food once they have been eating it for awhile.  Sometimes the only answer is having the owners prepare a well-balance homecooked diet for the animal.

Intestinal parasites can cause diarrhea in pups.  Roundworms, hookworms, and whipworms are commonly found in stool samples of pups with diarrhea.  These “worms” can be treated with prescription medication from your veterinarian.  Remember to treat the bitch too if you have the litter of pups at home. Another important concept is that of cleaning the environment where the pup or pups are housed.  Parasite eggs contaminate any location where the dog has passed stool.  Whipworm eggs are very difficult to destroy.  It is best to remove the pup from any enclosed “play yard” where whipworms may have been deposited and establish a new pen for the dog after proper medication has been administered.  Next, the area previously infected with the whipworms will need to be treated with a lime preparation and not used for dog housing for 1-2 years.

Certain infectious agents can cause diarrhea in pups.  Canine parvovirus, canine corona virus, canine distemper, canine infectious hepatitis, Salmonella, Leptospirosis, E. coli, coccidia, giardia, and Histoplasma to name a few.  Laboratory testing needs to be done to properly identify these specific diseases.  Your veterinarian will need to recommend the course of treatment.

Most cases of uncomplicated diarrhea may be treated at home.  At the first sign of the pup having diarrhea, try to think over the events that led up to this episode and usually the cause of the illness can be identified.  So the first step is to find and eliminate the underlying cause.  Overeating of a rich food?  Long weekend being boarded away from home?  Eating a decayed bird on the beach?  Next, withhold all food for 24 hours.  Now this step can not be done if the pup or puppies are under 8 weeks of age because the pup(s) will become hypoglycemic (low blood sugar).  A young pup under 8 weeks should have food withheld for no more than 12 hours.  While withholding food, offer very small amounts of ice water.  Place a few ice cubes in an empty water bowl, adding only ¼ to ½ cup of water over the ice cubes at a time.  Administer Kaopectate (same weight doses as used for humans - read the label first!) by mouth four times a day for 3 days.  As the pup begins to respond (less diarrhea production), start him off on a bland diet of boiled chicken or hamburg meat (discard the fat), cooked rice, cottage cheese, cooked macaroni, and soft boiled eggs.  At first, this diet should be offered in only very small amounts 5-6 times a day.  As the food is tolerated and  the stools begin to firm, the meals can increase in size and decrease in frequency.  Continue the bland diet until the stools are of normal consistency.  Then slowly introduce the regular dog food.  Mix 25% of the regular food with 75% of the bland diet for 2-3 days.  Then gradually increase the regular food and decrease the bland diet over the next 7-10 days.  If at any time the diarrhea returns, add more of the bland diet to the mixture and allow the stools to firm again.

It is also a good idea to add yogurt with active culture to the pup’s bland diet.  If an animal has had severe or prolonged diarrhea, the healthy bacteria needed for proper digestion have usually been lost into the watery, loose stools.  Therefore, adding  a tablespoon of yogurt to the food twice daily will help firm up the stools.

If for any reason the pup does not respond to the bland diet therapy or the overall condition of the animal worsens, the dog should be examined by a veterinarian.