Parvovirus Infection in Dogs

What is Canine Parvovirus?

Canine parvovirus (CPV) first appeared in 1978 killing thousands of dogs. It is found throughout the world although incidence in the UK has decreased dramatically with vaccination. CPV infection is characterised clinically with anorexia, vomiting, diarrhoea and weight loss. Severe cases can result in septicaemia and death.

Parvovirus may affect dogs of all ages but is commonly presented in dogs less than 1 year of age. The more severe disease is usually seen in the younger puppies.

How does Parvovirus spread?

The virus is spread through the faeces of infected animals which can contain a high concentration of virus particles. The virus is ingested orally where it proliferates in the tonsils of its new host and then rapidly multiplies in lymph nodes and the intestines. High levels of virus are detectable in the blood 3-5 days post infection although the animals do not show any clinical signs yet. Infected animals start shedding the virus before they show any signs themselves.
The incubation period of CPV is 7-14 days. Infected dogs usually start to show signs of disease within 7-10 days of the initial infection.

CPV is very stable in the environment. It can survive at room temperature for months. Dogs do not necessarily have to come in contact with infected dogs to acquire the infection since the virus can be distributed through the environment on the feet of people and dogs, hair and other objects.

What are the signs of Parvovirus?

• Vomiting
• Diarrhoea (with or without blood)
• Fever
• Rapid weight loss
• Lethargy
• Anorexia

CPV causes severe enteritis. The lining of the intestine becomes very inflamed and in severe cases the lining of the intestine is shed. This can cause septicaemia as bacteria and toxins in the intestine are able to travel across the compromised intestine wall into the blood stream and throughout the body.

What is the Diagnosis of Parvovirus?

There are many diseases which can cause vomiting and diarrhoea in dogs and so CPV can prove a difficult disease for your veterinary surgeon to diagnose. A tentative diagnosis is often made on the basis of a reduced level of circulating white blood cells which can be an indicator of CPV infection. However this isn’t always the case and further diagnostic tests on blood and faeces may be required.

Your vet may also wish to take x-rays of the abdomen and perform ultrasound scans to rule out other possible causes of vomiting and diarrhoea.

What is the treatment of Parvovirus?

• Intravenous Fluids

The vomiting and diarrhoea of CPV and the shedding of the intestinal wall causes severe dehydration and electrolyte imbalances. The treatment therefore is aimed to prevent this dehydration become fatal. The dog is given intensive intravenous fluid therapy and often needs to be hospitalised. Infected dogs pose a great risk to other animals and so will have to be placed in isolation facilities. Other treatments that your vete may choose to prescribe are:

• Antibiotics
• Anti-emetics (drugs to prevent vomiting)
• Analgesics (to help reduce pain)
• Anti-inflammatory drugs (to help control fever and sepsis)

There is a better chance of survival if aggressive treatment is started before the onset of severe dehydration and septicaemia. Some breeds seem more susceptible to the virus and suffer higher fatality rates, e.g. Rottweilers.

Prevention of Parvovirus

Vaccination in dogs is the best method of preventing CPV. Most vaccines for dogs include CPV protection as one part of a combined vaccine. After the initial puppy vaccination course, booster vaccines are usually given once yearly.

Disclaimer

This pet health article is for reference only.

If your pet is showing any symptoms or distress, and you suspect your pet is ill CONTACT YOUR VET IMMEDIATELY.