WRITTEN BYJamie Case, DVM Veterinarian Dr. Jamie Case graduated from the University of Missouri College of Veterinary Medicine in 2017, after receiving a Bachelor of Science…,All puppies will experience vomiting or diarrhea at some point—and most of the time, it doesn’t mean there’s anything seriously wrong. However, it’s not a good idea to dismiss vomiting or diarrhea in your puppy, especially if you see blood or mucus or if it’s happening often. Learn more about the causes of vomiting and diarrhea in puppies and when you should see your veterinarian to make sure there are no serious underlying causes. Causes of Vomiting and Diarrhea in Puppies There are many reasons your puppy might be vomiting or have diarrhea, from harmless to serious medical conditions. Some conditions might cause blood in the vomit or diarrhea as well. In many cases, it’s impossible to tell what’s causing the upset just by looking at the vomit or diarrhea. The best way to figure out what’s going on is by going to the vet to make sure it’s not serious. Many times, multiple underlying causes will be identified. Here’s a list of the most common causes of vomiting and diarrhea in puppies. Viruses There are several viruses that can cause signs of an upset stomach in puppies. These include the common canine parvovirus, as well as other viruses like canine coronavirus, canine distemper virus, and canine herpesvirus. Viral infections tend to be more severe in young puppies. You can protect your puppy against many of the most common viruses with vaccinations. Typically, puppies require multiple vaccinations spread out over the first several months of life to be fully vaccinated, so work with your veterinarian to determine the most appropriate vaccination schedule for your puppy. Bacteria A healthy puppy’s digestive tract normally contains many strains of bacteria that cause no health issues. However, if certain strains of bacteria multiply too quickly or overgrow, or if your puppy picks up a bacterial infection, it can cause gastrointestinal upset. Bacteria that commonly overgrow include E. coli and Clostridial bacteria, which are both normally present in the GI tract. Stress, a sudden change in diet, a viral infection, or intestinal parasites can all cause these bacteria to overgrow. Bacterial infections that may cause vomiting and diarrhea include: Salmonella Campylobacter Yersinia enterocolitica These bacteria are zoonotic, meaning they can be transmitted to people, so it’s very important to wash your hands after handling a puppy that is experiencing vomiting and diarrhea. Intestinal Parasites Intestinal parasites are another common infectious cause of vomiting and diarrhea in puppies. Even if you don’t see worms in the vomit or diarrhea, and even if your puppy has been dewormed, puppies are highly susceptible to intestinal parasites. The Companion Animal Parasite Council recommends that puppies be tested for intestinal parasites at least four times in their first year of life. Worms that may cause vomiting and diarrhea in puppies include hookworms, roundworms, whipworms, and tapeworms. There are also microscopic intestinal parasites that can lead to gastrointestinal upset, including giardia and coccidia. Stress No matter how playful your puppy seems most of the time, it’s good to remember that puppyhood is a stressful time of life, and stress can cause vomiting and diarrhea. Stress can also affect immune system function and may make puppies more susceptible to viruses, bacteria, and intestinal parasites. Stress can come from leaving their mom and siblings, moving to a new home, being exposed to new situations, and learning the rules that are expected of them. Swallowing Things Puppies are curious and constantly exploring their environment. As a result, they often eat things they’re not supposed to, which can result in either vomiting or diarrhea. Many things puppies eat that cause upset are small enough to pass through the digestive system, irritating the sensitive lining of the stomach and intestines. This can include small toys, mulch, sand, rocks, sticks, paper, food wrappers, or really anything a puppy can get access to and is curious about. This can even include chew treats that were not completely chewed before swallowing. Larger objects are potentially more dangerous because they can get stuck in the gastrointestinal tract and cause an obstruction. Depending on where it’s stuck and whether it’s causing a complete obstruction (nothing can move past the object) or partial obstruction (some things are able to move past the object), this may be a medical emergency. Some larger objects that puppies commonly eat include toys, socks, underwear, blankets, bedding, and bones. Long, stringy objects like fabric, carpet, strings, and ribbons also pose a risk for causing what is known as a linear foreign body. A linear foreign body occurs when one end of a long, linear object gets stuck in the gastrointestinal tract (often where the stomach empties into the small intestine). This can cause the intestines to bunch up on themselves and results in serious, potentially life-threatening infections. Eating Something Toxic Toxins are also common causes of vomiting and diarrhea. Ingesting a toxin may cause a serious medical emergency, so if you suspect your puppy ate something toxic, it’s important that they be evaluated by a veterinarian as soon as possible. Common toxins include human pain medications (ibuprofen, Tylenol, Aleve), household cleaning agents (bleach, carpet fresheners and shampoos, dryer sheets, fabric softeners, and tablets used for toilet cleaning), chocolate, xylitol, grapes, rat poisons, and household plants. It is particularly important to make sure that none of your plants are toxic to puppies. Sudden Changes in Diet Sudden changes in food, introducing too many new treats, or letting your puppy eat human food can cause inflammation in their gastrointestinal tract and may lead to signs of an upset stomach. New foods can also alter the bacteria in their gastrointestinal tract. It is best to gradually transition puppies to new foods over the course of a week (sometimes even more slowly if you have a puppy with a sensitive digestive system). Pancreatitis Treats and human foods that are high in fat pose a risk of causing pancreatitis, which can cause a lot of pain and discomfort in addition to vomiting, diarrhea, and decreased appetite. Chronic Disease Chronic diseases are a less common cause of vomiting and diarrhea in puppies, but if a puppy is having issues with recurrent vomiting and diarrhea or is not responding well to treatment, their veterinarian may start to look for evidence of food intolerances or allergies. If an allergy or intolerance is discovered, your vet may recommend a special diet. Depending on your puppy’s other symptoms, your vet may also test for underlying liver or kidney disease, which can both contribute to vomiting and diarrhea. Other Potential Causes of Vomiting and Diarrhea in Puppies Hernias in puppies can lead to vomiting and diarrhea. A hernia occurs when a portion of the gastrointestinal tract becomes pinched off. Puppies can be born with hernias or they may develop after an injury. Intussusceptions, which occur when a section of the intestines bunches up, can lead to obstruction of the gastrointestinal tract and cause vomiting and diarrhea in puppies.
