As we continue along our tour of common cat issues, we will look at the most common infection seen in cats: Herpesvirus. Unlike herpes in humans, the virus does not require direct physical contact between patients to be transmitted. Instead, the virus can be passed via droplets from the nose or eyes similar to COVID. In addition, we have seen transmission between contaminated surfaces and cats. So, we see a lot of this particular disease.
In cats, the virus likes to set up shop in the soft, wet tissues of the nose and eyes. One similarity to the human form is that, once transmitted, the virus doesn’t always make the patient sick. Instead, it may hide out and “hibernate” within the cells of this tissue. However, wthe body becomes stressed, the virus will cease it’s slumber, sensing that it’s home in the host is in danger. It will then begin destroying the tissue it lives in to make more viruses and leave the body like sailors jumping ship. That damage to the tissues will then allow bacteria to invade and cause secondary infections. This manifests as severe swelling and discharge of the eyes (conjunctivitis) and wet, snotty nasal disease.
Treatment is difficult as with any virus. Mostly, we focus on dealing with the bacterial components of the disease by using antibiotics and other supportive care to get the body healthy again. This way, the body’s own immune system can start getting things in check. However, some severe cases require the use of newer anti-virals. One benefit of COVID has been the increased production of this otherwise uncommon treatment option. So, we are getting new help with this aspect of the disease. Once the virus is at rest, we try to keep it this way. Like people, cats never get rid of Herpesvirus and we do our best to prevent outbreaks. Decreasing stress is the most beneficial thing owners can do. When this is not possible or enough, the two most common treatments for this are pro-biotics and hyaluronate eye drops. These two things have shown the most effectiveness at keeping the virus at-bay.
Vaccination is the most important prevention of herpes disease in cats. Luckily, we have been doing this for decades using the feline “distemper” combo vaccine. Even if your cat isn’t a carrier, the virus can still be brought into the home by owners. So, we still consider this a core vaccine. In the cats that are carriers, the vaccine has been hsown to lessen the clinic signs associated with the virus by keeping the immune system robustly “educated” against the virus. This leads to faster and better responses during a stress-induced outbreak.