Canine Herpesvirus

Canine herpesvirus has a worldwide distribution and low environmental resistance. However, while active, it can seriously affect your pet's health. That's why we wanted to dedicate an entire article to studying it.

At Soyunperro, we'll give you a summary of its most important characteristics, from an introduction to treatment and prevention.

Introduction to Canine Herpesvirus

This type of virus has low environmental resistance, unable to withstand excessive heat and sensitive to a wide variety of conventional disinfectants. It mainly affects immunocompromised animals or those that haven't yet fully developed immunity, such as puppies.

There are several species of the virus; specifically, canine herpesvirus has been shown to have high specificity for the external receptors of cells in certain tissues. Although it has low environmental resistance, once infection occurs in a dog, it spreads through the body very quickly, destroying cells in the body, normally in the respiratory tract.

Transmission occurs through direct contact with secretions from the mucosa of the respiratory tract via the oral or nasal route, or from the reproductive tract, such as vaginal mucosa. There's evidence of transplacental transmission to puppies if a pregnant female is infected with this virus. This makes it particularly relevant in places housing groups of animals, such as breeding facilities, kennels, etc.

Symptoms of Herpesvirus

Sometimes the affected cells belong to the kidneys or reproductive tract, but this last location is usually asymptomatic (sometimes with inflammation). The other location most frequently affected is the respiratory tract. So, the group most affected will be young puppies just a few weeks old.

However, adult dogs with no other underlying conditions aren't exempt from getting infected, but since their immune system is fully developed, it's normal for them to respond to it with hardly any symptoms. If they do show any, they'll be similar to those of kennel cough (deep coughing).

In newborn puppies, we may observe stillborn individuals if the mother became infected during pregnancy. If they catch it within a few weeks of life, the prognosis will be fairly guarded, since they may show symptoms such as:

• Anorexia, lethargy, and weakness.
• Vomiting and/or diarrhea.
• Nasal and eye discharge.
• Hepatomegaly.
• Ataxia and possibly blindness.
• Possible sudden death.

Diagnosis

As with all conditions, the first protocol step by the vet should be based on a history of the pet, along with a general physical exam. We can be guided somewhat by the symptoms the animal shows, although sometimes these can be so varied and nonspecific that it will be hard to link them.

Complete bloodwork can be done, in which elevated liver enzymes (transaminases) may be found, a sign the liver is being affected, along with a decrease in total platelets.

The vet can take a nasal sample from the pet and send it to the lab to run more specific molecular tests that help detect canine herpesvirus, such as PCR, for example.

Treatment and Prevention

We can't wait for the result to start treating symptoms, since this is a disease capable of causing mortality in puppies. So, there's no specific treatment against this virus, meaning the solution will be to symptomatically relieve the animal.

In adults showing symptoms like coughing, anti-inflammatories such as meloxicam may be enough. However, in puppies, treatment needs to be more conservative, since they're the individuals at risk in this condition.

Their treatment will focus on rehydrating intravenously, reducing mucus with mucolytics such as bromhexine, boosting the immune system with products such as impromune, eliminating symptoms like vomiting or diarrhea, and a wet recovery or intestinal diet (depending on the case).

Since this disease has a guarded prognosis, it's best to prevent it. Prevention starts with maintaining proper hygiene, applying relatively high temperatures, and disinfecting places housing groups of animals, such as kennels or breeding facilities.

The virus is quickly destroyed in the environment using conventional disinfectants, so maintaining a cleaning protocol is an important part of managing health and preventing canine herpesvirus.

Over the years, vaccines have also been used in female dogs to create antibodies in the mother, which she then transmits through colostrum (first breast milk) to her puppies.