Circovirus Infections in Dogs

Canine circovirus is a virus that has just been discovered in the last few years and has been implicated in the illness of several dogs, as well as some fatalities. It is closely related to porcine and avian circovirus but is its own distinct virus.

Not every dog that contracts canine circovirus will encounter any symptoms, but those that do will generally experience a great deal of vomiting and diarrhea caused by inflammation of the tissues in the intestines, and you may also find blood in the patient’s excretions. Development of symptoms may be related to contracting multiple illnesses at once which increases the workload on the immune system.

A newly discovered virus in dogs, canine circovirus may cause symptoms such as severe diarrhea and vomiting, particularly when combined with other illnesses.

In many cases, the canine circovirus causes no symptoms at all and passes unnoticed. The flu-like symptoms that dogs exhibit when they are affected by canine circovirus are fairly non-specific and could be indicative of several diseases or disorders: 

• Abdominal pain
• Diarrhea or bloody diarrhea
• Enlarged lymph nodes 
• Lethargy
• Vomiting

Types

Although canine circoviruses are relatively new, other circoviruses have been commonly reported in both birds and pigs for quite some time. 

• Avian - Circoviruses are known to affect both parrots and cockatoos in the psittacine family, and is better known by the name Psittacine beak and feather disease; it can be debilitating and even fatal to either type of psittacine but tends to be more intense for cockatoos than for true parrots
• Porcine - The variety of circovirus that attacks pigs is more closely related to the canine circovirus than the avian circovirus is, and when it was first seen in Canada it was known as postweaning multisystemic wasting syndrome

This is a recently discovered virus, and its transmission methods are not fully understood at this point. Direct contact with an infected animal’s vomit or feces certainly would increase the likelihood that the disease could be contracted. Although the porcine circovirus is known to spread through respiratory secretions, it is uncertain if the canine variety is also spread in this manner. Not every dog that contracts the virus will fall ill, but any weaknesses in the immune system would amplify the chances.

Canines can experience vomiting and diarrhea for a number of reasons from toxins to simply eating too fast or eating food that is too fatty or greasy. If the vomiting or diarrhea is excessive, lasts longer than a day, or is accompanied by bleeding or extreme lethargy, a call to the veterinarian should be made as soon as possible, and a visit to the clinic may be recommended. 

When you bring your pet into the clinic, they will typically start with a physical examination including diagnostic tests such as a biochemical profile, complete blood count, and a urinalysis. Indications of a virus will likely be found in the animal’s feces and can be identified by a test known as a polymerase chain reaction, or just PCR. Initial research indicates that a large majority of the animals who fall ill are also carrying other viral or bacterial infections. The diagnostic tests will also help your veterinarian to uncover any additional infections or disorders that may be present so that they may also be treated.

At this time there is no cure for canine circovirus, so treatments for dogs that are exhibiting symptoms for this condition are largely supportive. Supportive treatments for dogs that are presenting with vomiting and diarrhea will typically include intravenous fluids, which will not only prevent dehydration but will also provide a way to correct any imbalances and administer needed medications.

As this illness is often found concurrently with other infections, either antibacterial or antifungal medication may be required to treat the underlying illness, allowing the patient’s immune system to concentrate of the virus. If your dog has been diagnosed with this or any other contagious viruses, your animal should avoid contact with other animals until the virus has cleared their system. This not only prevents the dog from spreading the illness but may prevent them from picking up other illnesses that may exacerbate the situation. 

The prognosis for dogs that are diagnosed with circovirus is usually good, but there have been a few cases of fatalities, even after aggressive treatment. As with many other viruses, the best treatment for this illness is prevention. This virus frequently infects animals without causing any symptoms, so determining which dogs may be carrying the disease and which are not may not be possible with the naked eye, so general disease prevention is important. This means maintaining your dog’s overall health so that their immune system isn’t compromised, promptly picking up any feces, and preventing your dog from coming into contact with other dog’s feces.