Vomiting in Dogs
Vomiting is common in dogs. All vomiting is the result of activating the vomiting center in the brain. The vomiting center is well developed in dogs, so dogs vomit more readily than most other animals. As a dog perceives a need to vomit, he becomes anxious and may seek attention and reassurance. He then begins to salivate and swallow repeatedly.
Vomiting begins with a simultaneous contraction of the muscles of the stomach and abdominal wall. There is an abrupt increase in intra-abdominal pressure. The lower esophagus relaxes, allowing the stomach contents to travel up the esophagus and out the mouth. The dog extends his neck and makes harsh gagging sounds. This sequence should be distinguished from the passive act of regurgitation.
Causes of Vomiting
The most common cause of vomiting is eating indigestible substances, such as grass, that irritate the lining of the stomach. Another cause of vomiting is overeating-dogs who eat more than their daily amount of food, perhaps because they have gotten into the dog food bag. Also, puppies who gobble their food and exercise immediately after are likely to vomit. This after-meal vomiting is frequently caused by feeding a group of puppies from a common food pan. Since they are all competing for food, each one eats as much as he possibly can. Separating puppies, or feeding them frequent small meals, eliminates the problem of gorging.
Dogs may vomit when they are upset, excited, or suffering from a phobia (for example, during a thunderstorm). Phobic dogs also drool, whine, paw, and tremble.
Vomiting occurs with most acute infectious diseases. It also occurs with many chronic diseases, including kidney and liver failure, Cushing's syndrome, Addison's disease, and diabetes mellitus.
To determine the cause of vomiting, note whether it is repeated, and if so, whether it is sporadic or persistent. How soon after eating does it occur? Is it projectile? Inspect the vomitus for blood, fecal material, and foreign objects.
If the dog vomits or retches repeatedly, bringing up a frothy, clear fluid, this suggests a stomach irritation such as acute gastritis. However, persistent vomiting also occurs with life-threatening diseases such as acute pancreatitis, gastric outflow obstruction, intestinal obstruction, and peritonitis.
Persistent retching without bringing up any vomitus is typical of bloat. Repeated vomiting along with diarrhea suggests acute infectious enteritis.