Gastroenteritis in Dogs

Gastroenteritis is inflammation of the gastrointestinal tract (the stomach and intestines).

What are the signs of gastroenteritis?

Gastroenteritis can present as acute or chronic (lasting longer than 2 weeks) clinical signs of diarrhea with or without vomiting. The diarrhea can start as soft stool and may contain some mucus. It can cause blood in the feces (hematochezia), lethargy, nausea and a decreased appetite. 

What causes gastroenteritis?

Gastroenteritis can be caused by a variety of things, usually determined by a diagnostic work up. Some of the more common causes include diet changes, food allergies or sensitivities, GI ulcers, infections (bacterial, viral or parasitic), foreign bodies or foreign material ingestion, toxins or systemic diseases (pancreatitis, kidney disease, liver disease, endocrine diseases, etc). 

How is gastroenteritis diagnosed?

Gastroenteritis is a diagnosis of exclusion. This means that the goal is to eliminate or rule out more serious causes of the clinical signs before making a general diagnosis like gastroenteritis. The first step is the medical history to determine if there are any changes, toxin exposures, previous episodes or any other pertinent information. The next step is a physical examination to assess hydration status, if there is abdominal discomfort and any other physical abnormalities. The final step is diagnostic testing. This may include blood work (cbc/chemistry, PSL (test to look for pancreatitis), x-rays or an abdominal ultrasound. The diagnostic work up depends on the severity of clinical signs, medical history and physical examination. The goal is to have all diagnostics be normal, to rule out other conditions that present similarly. 

What is the treatment for gastroenteritis?

The principal of treatment is based on rehydration and supportive care for clinical signs. Outpatient care will be recommended if clinical signs are mild and hospitalization if they are more severe. Treatment is case dependent but often involves the following:

  • Rehydration - either by intravenous fluids or subcutaneous fluids. 
  • Anti-nausea medications - The most common is cerenia (maropitant) which may be given as an injection under the skin in the hospital or a pill for clients to take home. Both the pill and injection last 24 hours. If your pet is vomiting through this medication, further veterinary care is recommended. 
  • Medications for diarrhea - The most common medications are metronidazole (an antibiotic that also has anti-inflammatory properties in the colon and helps treat certain parasites) and fortiflora (a probiotic sprinkled over food once a day to promote a normal gut flora). 
    • * Please note it is sometimes normal to not defecate for 24-48 hours after significant diarrhea or after starting these medications. 
  • Gastrointestinal protectants - These medications are used to prevent acid build up and therefore ulceration. The most commonly prescribed medications are pepcid (famotidine) and prilosec (omeprazole). Pepcid can be given under the skin as an injection in the hospital and then followed up with at home oral administration. Both of these products can be purchased over the counter at any pharmacy. 
  • Diet therapy - For most cases of gastroenteritis a low fat, easy to digest diet is often recommended. This often includes Hills I/D or Royal Canin GI Low Fat. These diets are continued generally for 4-7 days or until clinical signs resolve. A gradual reintroduction of the former diet is recommended.
    • Boiled chicken and rice is an alternative to a prescription diet if an owner is interested in cooking. It is recommended to feed white meat only with no seasoning. It is very difficult to meet a dog's nutritional needs on just chicken and rice, therefore this diet is recommended only intermittently. 
    • * Diet therapy may be different for dogs that have chronic or recurrent vomiting/diarrhea. 

What is the prognosis?

The prognosis for gastroenteritis is generally very good. Most dogs recover in 24-48 hours. If a pet is not improving over this time frame, further investigation is warranted and a recheck appointment is needed.

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