When we think about illness in our canine friends, we think about the basics: colds, parasites, wounds, infections, breaks and sprains. And while most of us practice proper vaccination protocols to help protect our furry friends, the reason behind WHY we do this may be unclear. Viral illnesses can play a big role in a dog’s health, not just in puppyhood but throughout their entire lifetime. Here are the top five viral illnesses affecting dogs, how they work, and how preventive care including vaccination can help keep dogs safe for life.
A virus is an “organism” that reproduces via inserting itself into a cell and becoming part of that cell’s DNA. It then uses the cell to replicate the virus before killing the cell and allowing the newly formed viruses to escape and infect other cells. While a virus isn’t alive in the sense of a bacteria or other organisms, it is capable of reproducing and causing havoc. Many of the symptoms and signs of illness seen with viruses are part of the response to the virus infecting the cell and a way to help the virus spread its DNA to other cells in the body and hosts outside of it (such as sneezing!)
When the body is vaccinated, it produces T-cells and other white blood cells designed to recognize that virus, target it, and destroy the cells/virus before it is able to reproduce and infect other cells. Vaccination works by creating those antibodies through the use of live-modified viruses (which are unable to reproduce properly) or killed virus DNA.
There is always a small risk of the vaccine virus reproducing or the immune system creating a hyper-response to it, however in most cases the antibodies will just be stored for use at a later time until needed. Over time, these antibodies may “lose” their memories, requiring re-vaccination to update the body and bring it back to a safe level of antibodies to work properly against illness.
Vaccines are also important for “herd immunity” or protection of other animals that may not be able to be vaccinated due to illness, birth defects, immune problems and more. If the other animals surrounding those that cannot be vaccinated are protected, they are less likely to spread the virus to the un-vaccinated animal, keeping them healthier and safer.
What Is It: Distemper is a viral illness that can affect the respiratory system, the gastrointestinal (GI) tract and nervous system. As the disease progresses, it moves from basic respiratory symptoms such as coughing, fever, nasal and eye discharge, to GI symptoms of diarrhea, vomiting, and difficulty breathing. In its more progressed stages, neurologic symptoms begin including tremors, repetitive movements, jaw tightening and convulsions. Distemper can be spread not only between dogs, but from some wildlife. 
Why It’s Bad: Distemper is a problem as it can easily be mistaken for other less harmful illnesses in its earliest or weakest stages. Distemper is also very easily spread among heavily frequented areas such as kennels, dog parks, animal shelters and areas of high wildlife population. The illness can also spread rapidly with symptoms not appearing until the dog is very ill and very contagious. Distemper is spread through airborne contact as well as use of contaminated objects such as food and water bowls. It can also be spread to unborn puppies if the mother dog becomes ill during her pregnancy.
Treatment & Prevention: With most viral illnesses, treatment involves palliative care, or treating secondary symptoms. Antivirals may be used, however antibiotics are only used if there is a secondary infection as they aren’t effective against viruses. Most dogs will require hospital care to treat fever, dehydration and protect against respiratory failure and injury. Dogs that are infected may also need to be quarantined from other animals to prevent spread.
Luckily, Distemper is a viral illness that is part of nearly every puppy vaccine protocol. Distemper is part of the DHPP (Distemper, Hepatitis, Parvovirus, Parainfluenza) vaccine for puppies and is given in 3-4 doses at 8-16 weeks of age, then every 1-3 years after. As most dogs are vaccinated against this, the number of cases of distemper has decreased and outbreaks are less common.
What Is It: “Dog Flu” or Canine Influenza has been making the news in recent months due to several outbreaks across the US and Canada as the virus spreads. Canine Influenza is much like the flu in our human counterparts. While it mostly affects dogs, Canine Flu can also affect ferrets, and has even infected some cats! The Canine Flu can mimic other illnesses such as Bordetella (Kennel Cough) however it lasts for longer and can cause a high fever leading to dehydration. Other symptoms include respiratory issues such as coughing and wheezing, and discharge from the nose and eyes.
Why It’s Bad: The flu affecting canines is HIGHLY contagious, and can occur year-round unlike its human counterpart which tends to spike in colder months. This illness can also be extremely detrimental to the very young (puppies) and the very old (senior pets) that may be immunocompromised. Due to being an airborne virus much like the human flu, it can also spread easily in heavily populated areas such as parks, grooming salons, kennels and shelters.
Treatment & Prevention: Treatment depends on the severity of symptoms, and in most cases home-care for 2-3 weeks is all that is needed until symptoms subside. The important factor is keeping dogs hydrated and eating to help combat symptoms. In severe cases, hospitalization is recommended so that the dog can be monitored and treated.
Vaccination for Canine Flu is more complicated due to a new strain appearing in North America in late 2015. Up until that point, only one other strain of Canine Influenza was known, and a vaccine had been available for it since 2004 . A new vaccine is in the works for the latest strain, and the earlier vaccine is recommended for any dog that may frequent populated areas.
What Is It: Parvovirus, or Parvo, is probably the second most well-known virus affecting dogs. While commonly thought of as an illness affecting only puppies (where it is most common), parvovirus can affect dogs of any age, especially those that aren’t vaccinated. Symptoms of Parvo are mostly gastrointestinal and include bloody vomiting and diarrhea, dehydration, fever, lethargy and loss of appetite. Some forms of parvo may also affect the heart .
Why It’s Bad: Parvo is one of the MOST contagious illnesses for dogs and the virus can remain live in environments such as soil for up to 6 months! This means that proper cleaning of the environment of affected dogs is extremely important to prevent the spread of illness. Bleaching, special anti-viral cleaners, tossing or removal of shared objects, bedding and toys and more are needed to prevent the spread of this disease. In many cases, the affected dog will need to be hospitalized and quarantined due to the severity of symptoms.
Treatment & Prevention: Parvo can easily be tested for with a fecal swab at a vet with results within 15 minutes. Treatment involves caring for symptoms including dehydration and fever, as well as preventing loss of energy from lack of appetite. Antibiotics may be used in some cases if a secondary infection has taken hold. Medications to prevent vomiting and diarrhea as well as IV fluids for electrolytes and hydration are important.
The Parvo vaccine is another one of the combination puppy vaccines most puppies get in their DHPP series at 8-16 weeks of age. This vaccine is then boostered every 1-3 years. Most dogs affected by parvo are either not vaccinated properly, too young for vaccination, or were never vaccinated through adulthood. Parvo is one reason why veterinarians recommend puppies are vaccinated prior to puppy kindergarten and dog park outings!
What Is It: Named for the fact that most dogs in kennels or shelter environments get it, Bordetella (Kennel Cough) is one of the most common illnesses of dogs that frequent parks, kennels, grooming parlors, daycares and shelters. It comes in two forms; viral and bacterial, and can cause symptoms such as a heavy choking cough, nasal and eye discharge, fever and loss of appetite. While mild in most cases, severe cases may result in secondary infections or even pneumonia .
Why It’s Bad: While not bad in severity, kennel cough is more of an annoyance due to its easy ability to spread in areas where dogs frequent. Most dogs transmit it in environments where they interact with others, such as boarding, playtime at the dog park, or a grooming session. This makes bordetella extremely opportunistic, and easily spread among pets.
Treatment & Prevention: In most cases, the only treatment needed is palliative care to prevent dehydration, decrease coughing, and keep the eyes and nose clear of discharge. Depending on the cause of kennel cough, antibiotics may or may not be used. Cough medications can also be used in severe cases where coughing is impeding daily activities. Dogs affected by bordetella will need to be kept away from other dogs until symptoms subside to prevent spreading the illness.
Viral bordetella can be prevented with vaccination and is an optional vaccine you can give at home or through your vet. Most kennel cough vaccines will need to be given every 6 months to 1 year, and are given orally or through the nose.
What Is It: Rabies is the most well-known viral illness of dogs due to the fact that rabies is a zoonotic disease (one that is transmissible to humans). Rabies can also affect every other mammal species, making it hard to control the illness. In most cases, rabies is fatal once contracted. Signs of rabies include nervous system issues, hypersensitive responses, dislike of water, foaming, and paralysis. Rabies happens in three progressively worsening phases: the prodromal phase, the furious phase and the paralytic phase .
Why It’s Bad: Rabies is bad due to its high mortality rate, ability to affect almost any mammal including humans, and incubation time which can affect its spread. Rabies is in almost every country in the world (barring some isolated islands or islands with extreme quarantine protocols), and can appear almost anywhere . In affected countries, vaccine protocols for pets and controlled vaccination of wildlife has helped to decrease the incidence of rabies. Bites are the most common spread of the illness, when the skin is broken and infected saliva enters it.
Treatment & Prevention: There is no treatment protocol for rabies due to the severity of the illness and high mortality rate. Dogs and other animals suspected to have rabies are euthanized and a sample of brain tissue is sent to a lab for testing and confirmation. Animals that have bitten a person or other animal that do not have a vaccine history for rabies are quarantined for up to 10 days and may be euthanized for testing if they show symptoms of illness.
In most locations, rabies vaccination is REQUIRED by law due to the severity of the illness in other animals and pets and people. Vaccination occurs in dogs first at 6 months of age, then again a year later, and once every three years after. Most locations will require proof of rabies vaccination to allow travel, registration and licensing, or acceptance into a kennel, hotel or boarding program. Rabies can only be vaccinated for by a licensed veterinarian, and requires a veterinary signature to validate the vaccine.
While some of the above viruses affecting dogs may sound scary, they can be easily prevented with proper vaccine protocols and care to help boost the immune system. In addition to a dog’s vaccination routine, owners can add healthy supplements, nutritious and balanced food and a good exercise regimen to ensure good health. For more ways to keep your dog healthy, check out our other blog post: 15 Ways to Keep Your Dog Safe & Healthy.
A healthy dog is more likely to be able to combat an illness, may have less severe side effects or respond better to veterinary treatment than a dog that is already ill. Vaccination and good health are key to ensuring a long life, preventing spread of illness to pets that may not be able to be vaccinated, and ensuring everyone stays safe and happy!
All images provided by Creative Commons/Pixabay.
 “Canine Distemper.” AVMA (American Veterinary Medical Association). Web. 31 May 2016. https://www.avma.org/public/PetCare/Pages/Canine-Distemper.aspx
 “Canine Influenza: Pet Owner’s Guide.” AVMA (American Veterinary Medical Association). Web. 31 May 2016. https://www.avma.org/public/PetCare/Pages/CanineInfluenza.aspx
 “Disease Risks for Dogs in Social Settings.” AVMA (American Veterinary Medical Association). Web. 31 May 2016. https://www.avma.org/public/PetCare/Pages/Disease-Risks-for-Dogs.aspx
 “Kennel Cough in Dogs.” PetMD. Web. 31 May 2016. http://www.petmd.com/dog/conditions/respiratory/c_dg_canine_tracheobronchitis
 “Parvo in Dogs.” PetMD. Web. 31 May 2016. http://www.petmd.com/dog/conditions/infectious-parasitic/c_dg_canine_parvovirus_infection?page=show
 “Rabies in Dogs: Symptoms, Diagnosis, Treatment & Vaccination.” Pet Education. Drs Foster & Smith. Web. 31 May 2016. http://www.peteducation.com/article.cfm?c=2+2102&aid=347
 “Rabies-Free Countries and Political Units.” Center for Disease Control and Prevention, 2015. Web. 03 June 2016. http://www.cdc.gov/importation/rabies-free-countries.html