Viral Infection

Information on the causes of canine and feline viral infections such as herpes in cats and dogs.

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  1. What is a Viral Infection?
  2. What Causes Viral Infection?
  3. Diagnosing Viral Infections
  4. Help for Viral Infections
  5. More Information on the Viral Infections

What is a Viral Infection?

Like us, animals are susceptible to a number of different viruses, and as a pet owner, it can be very distressing to see our beloved pets fall ill. A virus is a tiny organism that causes an infection in the body; however, in order for a virus to survive, it must have a host. The time a virus can exist outside the body differs between viruses, but most do not survive long outside the body.

One notable exception to this is the canine parvovirus which can last many months in the outside environment and is resistant to many disinfectants. Once within a host, the virus can attach itself to living cells and reproduce, either killing the cells or altering their function. It will then multiply and produce many more virus particles which cause illness. Most viruses will only infect one type of cell, for example, the viruses causing influenza will only infect cells of the upper respiratory tract.

There are a number of viruses that can affect dogs and cats. Common viral illnesses in cats include cat flu, feline panleukopaenia (FeLV), (FIV), while viral illnesses in dogs include canine distemper, canine parvovirus, and canine hepatitis amongst others. While most viruses affecting our pets cannot be transmitted to humans, one exception is the very serious rabies virus which affects both cats and dogs and can be transmitted to humans.

What Causes Viral Infection?

Both people and animals frequently come into contact with viruses and bacteria, and when they attack, your pet’s immune system takes action to fight off the infection. In some instances, the immune system will destroy an invading virus before signs of infection show; however, very resilient viruses as well as lowered immune systems can result in your pet becoming ill.

Like human viruses, animal viruses are most likely to spread when your pet comes into contact with other animals. Many viral infections are spread in places such as kennels and shelters where animals are in close contact to each other. However, viruses cannot be avoided all together as they can be carried in by the wind, and even brought into households by unsuspecting pet owners. For this reason, vaccinations and immune boosting measures should always be taken as a precaution.

Diagnosing Viral Infection

If your pet shows symptoms of illness then a trip to the vet is often necessary. Your pet’s veterinarian will rely on you to give an accurate description of symptoms, and will also physically examine your pet. Depending on your pet’s symptoms, your veterinarian may recommend some tests before making an accurate diagnosis.

Help for Viral Infection

Treatment of viral infections depends entirely on the virus diagnosed and the severity of the condition. Mild viruses can sometimes be treated symptomatically while more serious viruses require more vigorous treatment. Some viruses such as the Feline Immunodeficiency Virus (FIV) or Feline leukemia (FeLV) cannot be cured and so treatment is usually supportive and aimed at keeping your pet’s immune system as strong as possible.
In many cases, the treatment of viral infections is supportive and aimed at supporting your pet while the virus runs its course. Depending on the virus and symptoms, treatment may include intravenous fluid replacement, anti-vomiting or anti-diarrheal medication, and bronchodilators such as aminophylline for wheezing and coughing.

Because antibiotics are ineffective in the treatment of viruses, they are often not recommended, however, in some cases antibiotics are given as a preventative to guard against possible secondary bacterial infections. Frequently recommended antibiotics include doxycycline or trimethoprim-sulfa. Remember that after a course of antibiotics, your pet’s immune system may become weakened so be sure to take necessary measures to increase immune functioning if antibiotics are necessary.

Lastly, there are a number of vaccines available to protect your pet from a variety of viral infections.

More Information on Viral Infection

Tips for guarding against viral infections
  • The first step in guarding against viral infection in your pet is to help boost their immune system. This can be done my ensuring your pet is eating a healthy high-quality diet, getting sufficient exercise and providing your pet with natural immune boosting supplements that they would usually have access to in nature.
  • Vaccinate your pet against serious disease. While annual vaccinations may not be necessary, a simple blood test called a titer test can determine which vaccines your pet needs. If you are planning to put your pet in a kennel when you go away, then getting your pet vaccinated against certain illnesses is a good idea.
  • Avoid letting your pet have contact with other unvaccinated pets.
  • Make sure your pet has a clean sanitation area that is not used by other foreign animals.
  • Minimize the exposure you pet has to harsh chemicals. Cleaning products, pest repellents, and even certain pet products and medications contain large amounts of harsh chemicals that can be damaging to your pet’s immune system. When possible, opt for more natural alternatives.
  • As an animal lover, it’s hard not to empathize with a lost or stray cat or dog and immediately take it into your home and offer it a warm bed. However, this could endanger the health of your other pets. Always take stays to the vet or a nearby shelter first.


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