Acute Diarrhea

Pet Tales
by Barry B. Burtis

Acute diarrhea

Any animal can suffer from acute or sudden onset diarrhea. It is one of the most common problems in any veterinary practice. If the intestinal tract is somehow injured or diseased,  diarrhea is a most consistent outcome. Puppies and kittens, as the case with other young animals, are frequently affected by this disorder.

The illness is characterized by the sudden occurrence of the passage of unusually frequent, watery or fluid-like feces. Mild acute diarrhea with or without vomiting can be caused by a variety of dietary, parasitic or toxic factors. There are also bacterial and viral infections and other diseases that can be very serious, possibly life-threatening, causes of the problem

It is not uncommon for a pup or kitten arriving in its new home to be affected by an upset of this kind. In most cases this young little animal will have moved from life with mother and some siblings into quite a different kind of place. If purchased from a pet store it will have already lived in at least one and perhaps more new environments before settling in with new owners. This means there will likely have been some significant changes in foods and feeding. The food, itself, may be a new one. Changes in diet can always cause changes in the nature of the stool and possibly increase frequency of stool passage. Remember, already a young animal is adjusting to a solid instead of a milk or liquid  diet so more change can mean more complications. In addition there will different water sources for the pet. We all know the trouble this can cause for anyone. The new little pet will likely be eating at different times than it has previously and there will certainly be changes in activity and playtime routines. Fortunately, diarrhea that can result from these causes is usually not serious. Often, just time to adjust and reducing the volume of food ingested for a short time will lead to prompt recovery.

Sometimes it is not a new food that an animal eats that causes diarrhea, but other things a pet may ingest. There are many indigestible, foreign materials that pets occasionally chew on or swallow. With dogs, bones commonly initiate digestive upsets. Bone is not able to be affected by digestive processes, therefore it can irritate lining tissues of the stomach and/or bowel, it may block or obstruct or even perforate the bowel. Over the years I have been in practice, there are many other items that I have seen cause problems when they are ingested. Coins, marbles, ear rings, fridge magnets, Christmas decorations, beer bottle caps, peach pits, corn cobs, needles, roast cords, rubber balls and pop cans would all be included on the list of such items.  Cats are more likely to eat plant material, sponges, needles and/or thread, ribbons or string. Surgery is often necessary to resolve problems of this kind.

Spoiled food, garbage or other waste, decaying materials that for some reason dogs occasionally find appealing to eat, also may lead to bacterial infections that result in diarrhea. 


Parasite infections will often be a predisposing factor in acute diarrhea. Intestinal parasites, often referred to as worm infections, are also more likely to occur in young animals. Coccidiosis is an in infection with a protozoan parasite that can cause acute, profuse, watery diarrhea, often with blood. Again, young animals are more likely to be infected.

In older animals, there are a number of metabolic diseases - liver disease, kidney disease, pancreatic disease and Addison's disease - that may cause acute or chronic diarrhea.

Finally, there are a number of infectious diseases where diarrhea is a common symptom. Viral diseases that fall into this classification include parvovirus, (canine parvovirus and feline panleukopenia) coronavirus, rotavirus and canine distemper virus. Infectious bacterial causes would include Salmonella, Campylobacter, Clostridium or E. coli organisms.

Treatment for acute diarrhea will depend on the specific cause and how severely the patient is being affected. Next time I will write about one of the most serious causes of acute diarrhea in puppies - canine parvovirus.