Your dog’s health can deteriorate quickly, even without the earliest signs to warn you. When this happens, we often wonder if we could’ve done something to catch up on it. But in many cases, these conditions are difficult to predict, expect, and prepare for. 

One of these is acute gastroenteritis in dogs, the sudden inflammation of the stomach and intestines. This condition is characterized by sudden diarrhea and vomiting. While most cases are mild and short-lived, others can progress into more dangerous conditions.

Acute Hemorrhagic Gastroenteritis (AHGE) and Acute Hemorrhagic Diarrhea Syndrome (AHDS), two different names for a serious condition that requires urgent care. While AHDS can be messy, most dogs can make full recoveries. 

With that, let’s talk more about acute gastroenteritis in dogs.

What Causes Acute Gastroenteritis in Dogs?

The most common causes of acute gastroenteritis in dogs stem from anything that irritates the lining of your dog’s stomach and intestines. This can be anything from simple food to some serious infections. 

Dietary Indiscretion

One of the leading reasons for acute gastroenteritis in dogs is when they eat something they shouldn’t. While it's adorable that they’re naturally curious, it can be dangerous when they eat dangerous items such as spoiled food, trash scraps, and sharp objects. 

When they do, the foreign objects overwhelm the digestive system, triggering inflammation in the stomach and intestines. This often results in abrupt digestive symptoms, with vomiting as a common one. 

Changes and Issues With Food

Changing your dog’s food too quickly can also be the source of this digestive problem. From switching brands, types of food, or even the amount, even the smallest changes can potentially trigger gastrointestinal upset. 

Additionally, any food allergies or intolerances can also cause acute gastroenteritis in dogs. Some dogs may have them, while some may not. Those that do have them can have reactions to common food allergens such as beef, chicken, dairy, wheat, or artificial additives. 

This happens when the food they eat causes an inflammatory response, irritating the lining of the gut and stomach. 

Infections

Certain viruses and bacteria are also known to cause inflammation, notably:

• Canine Parvovirus. CPV works by attacking the lining of the stomach and intestines, especially in puppies. As a result, affected dogs will experience impaired nutrient absorption and intestinal damage. 

• Canine Distemper Virus. CDV works a little differently. While it does attack the lining of the gastrointestinal system, it also suppresses the immune system of dogs. This makes them vulnerable to secondary infections. 

• Salmonella. Salmonella spreads through the ingestion of contaminated food, water, and feces. The bacteria release toxins in the stomach and intestines, which damage their lining. 

• Escherichia coli. E. coli also spreads through the ingestion of contaminated material, as well as direct contact with it. Some strains can attach to the intestinal lining. 

Parasites

Intestinal parasites can also cause acute gastroenteritis in dogs and chronic gastrointestinal problems. Common examples include Giardia, hookworms, and coccidia. These parasites work by attaching themselves to the intestinal wall, interfering with nutrient absorption. They also irritate the lining and trigger an immune response, further damaging the gastrointestinal tract. 

Medications and Toxins

Dogs that ingest human medications, toxic substances, and chemicals can also experience acute gastroenteritis. Common examples include cleaning products, prescription medicines, and pesticides. 

Even human foods and ingredients such as grapes and xylitol can cause irritation within the gastrointestinal tract. Canine medication used improperly can also be the reason. 

Stress

Your dog’s emotions can also have direct physical effects on the digestive tract. Dogs that get anxious during travel, car rides, loud noises, or vet visits can develop stress-induced acute gastroenteritis. 

This happens because the gut and brain are interconnected by the gut-brain axis. When a dog gets stressed, it triggers a release of hormones that disrupt the function of the digestive system. 

Other Health Issues

Other health conditions, such as tumors and kidney disease, can also be the cause of acute gastroenteritis in dogs. Kidney disease can result in a buildup of toxins, leading to gastrointestinal irritation.

Dogs at Risk of Acute Gastroenteritis

While this disease can affect any type of dog, some factors can increase the risk. This includes genetics, age, and history of GI problems. 

Acute gastroenteritis is common in small and toy dog breeds compared to larger ones. This is because they generally have shorter and smaller digestive systems, while some have sensitive ones. Because of their small size, they are also prone to dietary indiscretion.

Age is also a factor. Due to their young age, most puppies will still be unvaccinated, and some are just in the midst of completing their schedules. Because of this, they can be more prone to infections. This age group also tends to be more curious, being susceptible to dietary indiscretion.

Also, dogs with a history of other related gastrointestinal issues are more likely to experience acute gastroenteritis.

What Are the Symptoms of Acute Gastroenteritis in Dogs?

If your dog shows any of the signs, it can be difficult to be sure. The condition presents similar symptoms to other milder diseases, so a keen eye is recommended. Here are the common signs of acute gastroenteritis in dogs:

• Vomiting. Vomiting is often the first visible sign of trouble. The vomit may have food, bile, clear fluid, or foam, all of which signal stomach irritation. 

• Diarrhea. The stool in affected dogs will appear watery or loose. Your dog may also have more frequent episodes of pooping. 

• Lethargy and Weakness. You may see your dog wanting to rest and sleep more often, rather than play like its normal routine.

• Loss of Appetite. Some dogs may stop eating, even if they are given their favorite food and treats. 

• Abdominal Pain and Discomfort. Some dogs may tense their belly, whine, or hunch over when their abdomen is touched. 

Severe symptoms, often signaling Acute Hemorrhagic Diarrhea Syndrome, include:

• Bloody Diarrhea. In severe cases, dogs will have bloody diarrhea. The blood is an indicator of the inflammation in the intestinal lining. 

• Dehydration. As a result of vomiting, dehydration is to be expected. This can be seen as dry gums, sunken eyes, and reduced skin elasticity. 

• Rapid Heart Rate. An increased heart rate can be a possible symptom as the heart works harder to improve circulation. 

• Restlessness or Pacing. Affected dogs may appear unsteady and agitated. They may constantly move around the house.