Parvoviral Enteritis (Parvo) in Dogs


Parvo virus can have symptoms similar to many other diseases. These diseases may include:

  • Dietary indiscretion, which is a common cause of vomiting and diarrhea
  • Food-borne bacterial infection. Some foods can give dogs gas or diarrhea, a similar symptom to parvovirus.
  • Hemorrhagic gastroenteritis (HGE), which is an inflammatory condition of the gastrointestinal tract causing bloody diarrhea.
  • Ileus, a condition in which normal bowel movement is obstructed causing a “functional obstruction” of the intestine
  • Inflammatory bowel disease (IBD), a condition in which inflamed cells clog the intestinal wall causing chronic vomiting, diarrhea and weight loss; biopsy of affected intestine is required for diagnosis
  • Intussusception. This condition is a prolapse or “telescoping” of one portion of the intestinal tract into another, causing partial or complete obstruction of the bowel, a symptom which can also be a complication of parvovirus; X-rays or an ultrasound may be necessary for diagnosis
  • Mechanical obstruction or foreign body, which may be an object ingested by your pet that is stuck in a part of the intestine like a toy, bone or piece of clothing
  • Other viral infections of the intestines, such as coronavirus and other viruses with similar (though not as serious) symptoms of parvovirus
  • Pancreatitis, an inflammation of the pancreas, which is the digestive gland located between the liver, spleen, kidneys, stomach and duodenum
  • Parasites, like intestinal worms that feed on an animal host (some also cause bloody diarrhea, vomiting, weakness, weight loss and lethargy) causing similar symptoms of parvovirus
  • Veterinary care should include diagnostic tests and subsequent treatment recommendations.

    In-depth Information on Diagnosis

    Diagnostic tests are needed to recognize parvovirus, and exclude other diseases, including:

  • Complete medical history and physical examination
  • The ELISA test (CITE-Parvo TEST) The collection and testing of a stool sample is the most practical and thorough method for diagnosis. However, it is possible to get a [false] positive test 5 to 17 days after routine vaccination for parvovirus.
  • A complete blood count (CBC). This helps determine the effect of the virus on the bone marrow. In some cases the ELISA test may be negative while the blood test may point to parvovirus (usually a very low white blood count is found). In this case, your veterinarian will choose the appropriate antibiotic therapy.
  • Serum biochemistry. These tests are not specific for detection of parvovirus, but they do help your veterinarian determine your pet’s hydration status, blood sugar level, kidney function and electrolyte levels. These can help determine the choice of fluid therapy and other medications.
  • Fecal tests. These are performed to exclude the possibility of intestinal parasite infestation (concurrent infection is common).

    Additional diagnostic tests may be recommended on an individual pet basis, including:

  • Abdominal X-rays to exclude the possibility of other problems such as gastrointestinal ileus (paralysis of the bowel), obstruction of the bowel, a foreign substance in the stomach or intestine or an intussusception
  • A barium contrast study, in which the patient swallows or is administered barium
  • An ultrasound, which is an alternate and noninvasive method, may be used to examine your pet’s abdominal organs. An ultrasound is not useful in cases where there is build up of abdominal gas.
  • In-depth Information on Treatment 

    Treatments for parvovirus may include one or more of the following:

  • Serious cases require hospitalization during which IV fluid therapy, antibiotics and anti-vomiting drugs may be administered. Severe cases may require referral to a 24-hour hospital.
  • Milder cases may require outpatient treatment consisting of subcutaneous fluid therapy, antibiotics and anti-vomiting drugs.
  • Daily physical examination by your veterinarian to assess your pet’s progress is vital.
  • Fluid therapy is necessary if your pet is dehydrated, actively vomiting or has diarrhea. Severe cases will most likely require IV fluid therapy consisting of an electrolyte solution supplemented with potassium. If necessary, a bicarbonate supplementation may be required, which is determined after lab testing. In more severe cases where pets have become hypoglycemic (low blood sugar), dextrose (sugar) may be added to the fluid therapy. Milder cases may be treated with subcutaneous fluid therapy, which is administered in the loose skin over the back and more slowly absorbed. Pets with severe cases will almost always require IV therapy for survival.
  • Nutrition. There are different thoughts on feeding dogs with parvovirus. Many veterinarians recommend giving no food or water until vomiting or diarrhea has stopped completely for 12 to 24 hours. Only then will water be offered in small amounts along with small frequent feedings of a bland diet, including such foods as Hill’s Prescription Diet i/d®, Iams Recovery Diet®, Purina EN Diet® or Waltham Low Fat Diet®. Your pet may also be given a bland homemade meal of carbohydrates (boiled rice or potatoes) and protein (lean hamburger, skinless chicken or low-fat cottage cheese) in small amounts. The return to regular dog food must be gradual over a 3 to 4 day period. Other veterinarians recommend feeding despite vomiting. High-protein and high calorie foods such as Hills Science Diet A/D or Eukanuba Max Calorie may be offered as soon as possible.
  • Antibiotic therapy is often used to control secondary bacterial infection. Antibiotics (such as gentamicin or amikacin) must only be given after dehydration is corrected with the proper fluid therapy. Commonly used antibiotics are: cefazolin or ampicillin combined with enrofloxacin, gentamicin or amikacin. Gentamicin and amikacin are administered to your pet especially when there is indication of a very low white blood cell count (neutropenia).
  • Antiemetic drugs may be administered to your pet to control vomiting. Common drugs include: metoclopramide (Reglan®) given SQ or as continuous IV; chlorpromazine (Thorazine®); prochlorperazine (Compazine®), or ondansetron (Zofran®) by injection.
  • Gastrointestinal protectants are sometimes prescribed. Common drugs include: famotidine (Pepcid®), cimetidine (Tagament®) and sucralfate (Carafate®), prescribed only after vomiting is controlled.
  • Parenteral nutrition (such as PPN) may be suggested in very weak puppies with persistent vomiting and diarrhea. This is a special food that is placed in an IV type catheter; parenteral nutrition requires hospitalization.
  • Anti-diarrheal drugs, which help reduce bowel movements, are only prescribed for unresponsive diarrhea. These include: loperamide, oral opiods and diphenoxylate.
  • Pepto-Bismol® (Bismuth subsalicylate) is sometimes administered when vomiting has stopped.
  • Pain medications may also be indicated. Commonly used pain medications include Buprenorphine (Bupernex) and Butorphanol (Torbugesic).
  • Blood products (packed red blood cells or plasma) may be administered with severe blood loss, protein loss, or anemia.
  • Isolating your dog from other dogs is very important throughout treatment of parvovirus.
  • Nursing and caring for your pet is vital throughout treatment. Your pet must be kept clean and dry, and debilitated dogs must be turned frequently. Rectal temperature must be monitored frequently.
  • Worm infestation is treated once your pet is able to eat and drink. The common drug administered is fenbendazole (Panacur®), given orally for three consecutive days or Ivermectin by injection.
  • Prognosis for Dogs with Parvovirus


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