Vomiting and diarrhea are symptoms of many diseases and conditions, and require veterinary consultation if persistent.  Digestive disorders are common in dogs, evidenced by the frequency of email questions received on this topic by the BFCA health committee.  Fortunately, most episodes of digestive upset resolve quickly.

The digestive tract (GI tract, or gastrointestinal tract) moves food from the esophagus to the rectum, taking 8-10 hours for a meal to pass.  The organs along this route serve to break the food down into nutrients that the body’s cells can utilize:  proteins, fats, and glucose (sugar).  The organs of digestion include the stomach, small intestine, large intestine (colon), pancreas, liver, and gallbladder.  Any dysfunction of these organs can cause vomiting and/or diarrhea, which can lead to dehydration and loss of electrolytes (sodium, potassium, chloride).

Dogs that are nauseated prior to vomiting may exhibit these signs:  hypersalivation, anxiety, and repeated swallowing.  The consistency of the vomit or loose stool must be documented.  Vomit may include undigested or partially digested food, or a yellow color denoting the presence of bile that indicates the stomach is empty.  Diarrhea that is watery or bloody needs veterinary intervention, as does blood in the vomit that may look like coffee grounds.  A dehydrated dog will appear lethargic and listless, and may have difficulty walking due to weakness.

Dogs that exhibit frequent or persistent vomiting or diarrhea require veterinary intervention to determine the cause and treatment, plus prevention of dehydration.  Potential causes of GI upset include:

1. Autoimmune diseases such as Crohn’s disease, colitis, irritable bowel disease or syndrome (IBD or IBS), pancreatitis, cirrhosis of the liver, or hepatitis
   http://bichonhealth.org/HealthInfo/DefAutoimmune.asp
2. Congenital megaesophagus (abnormal dilatation of the esophagus causing regurgitation of meals shortly after eating)
3. Gastritis (stomach inflammation or infection)
4. Gastric ulcers, which can be caused by the bacteria H. Pylori
5. Acid reflux (GERD)
6. Acute pancreatitis
7. Liver diseases
8. Gallbladder stones or infection
9. Diabetes
10. Kidney diseases
11. Electrolyte abnormalities
12. Constipation, Bowel obstruction
13. Food allergies
14. Sudden change in diet
15. Toxin ingestion or exposure to chemicals
16. Eating foreign objects
17. Viral or bacterial infections
18. Parasites
19. Cancer
20. Neurological disorders that cause dizziness
21. Recent antibiotic treatment that may have reduced intestinal flora

A responsible dog owner will strive to prevent digestive upset by:

1. Feeding your dog a consistent healthy diet that is appropriate for its age.
2. Avoiding any abrupt changes in food or water sources.
3. Avoiding foods and treats high in fat, which can lead to pancreatitis.
4. Avoiding foods and treats high in glucose, which can lead to diabetes.
5. Obtaining routine stool checks for parasites yearly.
6. Limiting your dog’s access to small objects, string, and chew toys that can break into small pieces that can be swallowed and obstruct the GI tract.
7. Preventing your dog from scavenging in trashcans or compost piles.
8. Preventing your dog from exposure to toxic substances by avoiding: (link to Anne’s safety article)
   1. Dog foods that contain corn, multiple grains, or preservatives.
   2. Poisons such as antifreeze, moth balls, D-con for mice, drugs
   3. Laundry items such as bleach, detergent, and fabric softener
   4. Household cleaners
   5. Grapes, raisons, and chocolate (grapes/raisons can cause acute kidney failure)
   6. Xylitol, an artificial sweetener found in gum, candy, toothpaste, and some baked goods
   7. Cocoa mulch used in gardens
   8. Chemicals found in lawn fertilizers, weed killers, household insecticides, and snow treated by road crews
   9. Excrement from wild animals or other pets, i.e. keep your dog away from bird feeders
   10. Some plants
   11. Potting soil

Treatment is aimed first at resolving the symptoms to prevent dehydration and electrolyte imbalance, then finding the cause with blood tests, fecal exams, and xrays. Vomiting is a coordinated effort of the GI tract and brain to expel the contents of the stomach.  Diarrhea indicates the GI tract is irritable and overactive in its attempts to empty the intestines and colon.  Your veterinarian may prescribe medications that:

1. Reduce stomach acid production (Tagamet, Pepcid)
2. Work on the brain to reduce nausea (Compazine, Thorazine)
3. Slow down the motility of the GI tract (Reglan, Tylon, Immodium)
4. Reduce inflammation for chronic diseases such as colitis, IBD (steroids)

Diet changes on a temporary basis that allow the GI tract to rest may be helpful for treating vomiting and/or diarrhea.  Try a bland, easily digestible, low-fat diet such as hamburger (pour off the fat) or boiled chicken with rice or a canned food prescribed by your veterinarian. Also, canned pumpkin is well known for soothing the GI tract.  Small, frequent meals may be helpful as well on a temporary basis.  If you feed your dog once per day and vomiting occurs around 12 hours later, you may need to feed twice per day, or give healthy treats the opposite time of the day. 

Probiotics (beneficial bacteria) must be considered in treating dogs with digestive disorders. The natural flora of bacteria in the intestinal tract must be balanced for the dog to maintain a healthy immune response to allergens, toxins, and infections.  If the balance of the good bacterial flora in the gut is restored, the irritability of the GI tract will be reduced.  Probiotics (sometimes called Acidophilus) include lactobacillus, bifidobacteria and enterococcus. Giving probiotics can improve digestion, synthesize vitamins, inhibit the growth of bacteria that cause disease, and produce immune stimulating factors and anti-inflammatory properties. Probiotics can be purchased in health food stores and are contained in yogurt, some dry dog foods, and some dog supplements.  Some breeders give their dogs daily doses of probiotics or yogurt, especially during treatment with antibiotics that kill invading bacteria as well as beneficial bacteria.

Research for this article includes:
 The Merck Veterinary Manual
The 5 Minute Veterinary Consult by Larry Tilley& Francis Smith
Textbook of Medical Physiology by Arthur Guyton & John E. Hall
The Dog Owner’s Home Veterinary Handbook by James Griffen & Liisa Carlson
http://www.petshealth.com/dr_library/digestdistdogs.html
ttp://www.animalhealthcare.com/handouts/dogs/Diarrhea.htm
http://www.marvistavet.com/html/the_pet_web_library.html