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The Essential Vaccines You Must Give to Your Dog

There is no need to emphasize the substantial benefits of vaccination. They by far outweigh the risks and the cost.

It is definitely the best way to fight against infections, and prevent the outbreak of epidemics.

Moreover, some vaccines are mandatory in some regions, to prevent the transmission of contagious pathogens to humans (rabies).

But, it does not mean we should “over-vaccinate” our dogs.

Because there are still some risks associated with the administration of vaccines even though they are rare:

Attenuated vaccines can revert and become virulent again. Erythema, spots, allergic reactions or infections at the injection site are also possible. You should always read the legal leaflet that is enclosed in the vaccines package: it lists all the possible adverse events.

The other issue is that vaccines come at a cost that dog owners have to pay for. The money could be spent better than on an unnecessary vaccine injection. Or even worse, an excessive cost could dissuade some owners to do any kind of vaccination or give boosters.

How to vaccinate your dog

Fortunately, a board of international veterinary experts has provided the veterinary profession with recommendations on pets vaccination. They help your vet advise you on the best vaccination strategy for your dog.

The VGG is the Vaccination Guidelines Group of the World Small Animal Veterinary Association. Their recommendations are valid worldwide. They are acknowledged and adapted by other groups of experts at a National level such as the AAHA (American Animal Hospital Association) in the US or the VMD (Veterinary Medicine Directorates) in the UK.

The VGG’s objective is to define guidelines that provide maximum protection to dogs and cats while reducing the vaccine load to a minimum.

Reducing vaccination frequency

In past years, in absence of relevant information about duration of immunity, pets were vaccinated every year. Thanks to new studies [Schultz et al. 2006], we now know that most live attenuated vaccines provide immunity to adult dogs for a minimum of 3 years.

Of course, because of their increased susceptibility to infection due to their immature immune system, puppies need to be vaccinated much more often: 3 times every 2 to 4 weeks starting at 4-6 weeks of age.

Focusing on the most important vaccines

In its recommendations, the VGG also differentiate between the core vaccines and non-core vaccines.

The core vaccines are the vaccines that any dog should receive wherever it lives.

The core vaccines vaccinate against viruses that:

  • cause serious and often fatal diseases
  • are contagious enough to spread rapidly across the dog population
  • can be controlled efficiently by available vaccines
  • are not subject to important regional variation (i.e. potentially existing worldwide)

Non-core vaccines are discussed in Chapter 4. They are optional vaccines that correspond to dog's lifestyle and local exposure to pathogens. It’s up to you and your vet to decide on whether they are necessary for your dog or not.

There are also non recommended vaccines. For them, either the benefit-risk balance is negative or they are unnecessary or even there is little scientific justification for their use. They are not discussed in this guide.

Rabies vaccination represents a particular situation. In many US states or countries in the world, it is a legal requirement to vaccinate dogs against rabies. Moreover, whenever your dog travel abroad, it is very likely that the customs will ask for certificates of vaccination against rabies.

You can check which situation you are in by clicking on one of the link below:

Rabies vaccination is discussed in this chapter.

In the special cases of shelters, kennels or pet stores, because of the financial limitations often encountered in these situations, the VGG recommends a single administration of core vaccines at the time or before the admission.

VGG’s statement:

We should aim to vaccinate every animal with core vaccines.

Non-core vaccines should be given no more frequently than is deemed necessary.

Core vaccines for dogs are:

Core vaccination schedule

Dog core vaccines schedule

Canine Distemper Virus (CDV)

Canine Distemper is a paramyxovirus. It is related to the human’s virus that causes measles.


Your dog can catch the virus from another animal’s nasal and pulmonary secretions. Contamination is usually airborne. Small droplets containing the virus find their way to the mouth, nose or pulmonary mucosa.

Ingestion of infected meat is a less frequent route of contamination.

An infected animal is contagious for several months.

Canine Distemper Virus can contaminate wild carnivorous animals such as foxes, coyotes, wolves, minks, otters, weasels, skunks, martens, fishers, wolverine or raccoons. They constitute a reservoir for the virus. As a consequence, it’s almost impossible to eradicate CDV.

The exposure of your dog to other dogs or to wild animals increases the risk that it catches the disease.

Mechanisms of progression

As for any other virus, Canine Distemper Viruses need a host cell to replicate. Ironically, CDVs replicate in the cells of the primary immune system: macrophages and monocytes located in the lymphatic tissues of the respiratory tract, the cells that are precisely supposed to destroy viruses.

The infection weakens the immune system (= immunosuppression), and the first consequence is an increased susceptibility to bacterial infections.

Then the virus reaches the lymph nodes, the spleen, the thymus, the bone marrow and various mucosal tissues in the digestive tract or in the eyes.

At this stage, if the dog’s immune system isn’t strong enough to react, the infection leads to serious complications, especially on the central nervous system, and often to death.


The Canine Distemper Virus induces a wide range of symptoms. They are not specific to the disease. It makes the diagnosis difficult.

The disease is progressive. It starts by a short period of mild fever and anorexia.

A few days later, the fever worsens, and you will notice your dog shows nasal and eye discharge, it will cough and may vomit if the disease reaches the digestive tract.

Sometimes the dog’s feet enlarge up to three times: this is the hard pad disease.

Depending on the strength of the dog’s immune system, the virus may finally attack the nervous system. In this case, the infected dog develops neurologic symptoms such as a lack of muscle coordination, compulsive movements, intense salivation and paralysis.


The first precaution is to keep the dog away from other dogs so that it can't contaminate them.

As there is no available anti-viral drug that has an effect against Canine Distemper Virus, the treatment is only supportive. It consists of treating the symptoms or the consequences of the infection:

  • anti-infectives against secondary bacterial infection;
  • fluid therapy in case of digestive disorders (diarrhea, vomiting)
  • attempts to control neurologic disorders


If the dog receive rapid and intensive care, and if the symptoms are limited to the respiratory and digestive tracts, it may well recover.

In the case of neurological disorder, the prognosis is guarded and the outcome is often the death of the animal.


Prevention is vaccination.

You may well also try to keep your dog away from contaminating sources: other dogs or wild animals, especially if it is a young puppy.

Vaccination schedule

The vaccination protocols for Adenovirus, Parvovirus and Distemper virus are identical.

The puppy needs to get vaccinated three times. The first administration takes place at 4-6 weeks of age, and then 4 to 6 weeks later for the second and again.

Another vaccination is strongly recommended for dogs at 6 months OR at 1 year, and then every three years (4, 7, 11, ...).

Main references


Canine Adenovirus

There are 2 types of Canine Adenovirus: the type 1 and the type 2. They cause quite different diseases.

But they are closely related and share a lot of common antigens. Vaccines containing live attenuated viruses of CAV type 2 immunize for both CAV type 2 and type 1.

Canine adenovirus type 1 causes Infectious Canine Hepatitis also known as Rubarth disease. It attacks the kidney, the liver and blood vessels.

Canine Adenovirus type 1 id card

Canine Adenovirus type 2 is one of the main causes of the most severe forms of kennel cough.

Canine Adenovirus type 2 id card

Note that adenoviruses are nowadays a popular subject in human medicine research. They are believed to be usable viral vectors for gene therapy in some medical areas such as cancer, innovative vaccines or neurodegenerative diseases.


CAV types 1 & 2 are primarily transmitted by urine, feces or saliva. They may also be spread through the air.

CAV type 2 can be found in other carnivorous mammals such as foxes or coyotes.

This virus is very contagious. Even recovered animals keep on shedding viruses via the urine for months. To prevent the spread of the infection, any infected animal should be kept isolated from other dogs for a long period of time.

Adenoviruses are very resistant in the outside environment where they can survive for several days. Dogs and puppies often get infected by viruses surviving in the environment, without any direct contact with an infected animal.

Mechanisms of disease progression

CAV type 1 is the virus responsible for Rubarth’s disease (i.e. Infectious Canine Hepatitis). The virus first settles in the region of the mouth, tonsils and throat where it replicates for a period of 4 to 7 days.

Then it migrates toward other places in the body: the liver tissue or the blood vessels. It may also colonize the eyes, the kidneys, the spleen and the lungs.

It attacks the walls of blood vessels and affects the clotting ability of blood. Thus, the main consequences are bleeding and hemorrhage.

In the liver, it causes the destruction of hepatocytes (liver cells), and in the kidneys lesions of the glomeruli.

CAV type 2 is one of the causes of tracheobronchitis, the other name for Kennel Cough. Other viruses (Parainfluenza) or bacteria (Bordetella, Mycoplasma) may also cause tracheobronchitis.

The disease occurs more frequently when dogs are kept in the same place (shelters, rescue centers, breeding kennels, or pet stores) hence the name “Kennel Cough”.

After an incubation period of 3 to 10 days the virus colonizes the trachea and the upper respiratory tract. It induces lesions in the epithelium of bronchi and an inflammation of the tonsil and the pharynx.


CAV type 1

Symptoms range from very mild to hyperacute.

Adenoviruses cause fever.

In the milder cases, the fever doesn’t last more than one day. In more acute cases, the fever persists and other symptoms develop. They include apathy, lack of appetite, excessive drinking, eye inflammation, discharge from the eyes and nose, and sometimes belly pain and vomiting.

The increase in blood clotting time induces hemorrhages in many organs. It may cause the gum to bleed. In the most severe forms of the disease, the Central Nervous System is affected. It results in convulsions and/or paresis. You may also, but rarely, notice a lack of coordination in dog’s movements or even blindness.

CAV type 2

The most characteristic symptom is a dry cough that sounds almost as a goose honk.

Other signs include runny nasal discharge and inflammation of the tonsil and pharynx.

Also, as for many other viruses, adenoviruses open doors to bacterial infections that worsen the symptoms.


CAV type 1

In the most serious cases, especially in puppies, adenoviruses type 1 cause death and sometimes very rapidly.

In most cases, dogs recover slowly. But they may develop a liver or kidney disease afterward.

CAV type 2

Of the two adenoviruses, CAV-2 is the less harmful. Most often, the disease is mild and ends within a few weeks.

There are some exceptions though. In weaker individuals, puppies or aging dogs, a secondary pneumonia may develop and lead to a possible death.

Treatment and prevention

No treatment is available against adenoviruses type 1 and 2. Your vet will only treat the symptoms of the disease. It increases the chances your dog’s immune system gets rid of the infection.

Depending on the symptoms, the supportive care may include:

  • anti-inflammatories
  • anti-infectives (for bacterial superinfection)
  • a custom diet plan
  • treatments for the liver or the kidneys.
  • treatments for the control of diarrhea, vomiting or hemorrhages
  • some rest: the dog should be kept quiet and calm

CAV-2 vaccines have less adverse effects than CAV-1 and offer cross protection against both diseases.

Therefore, it is no surprise that available commercial vaccines are made of live attenuated strains of Canine Adenoviruses type 2. They will protect your dog against both CAV type 1 and type 2.

Vaccination schedule

It is the same as for Parvovirus and Distemper virus:

Puppies get vaccinated three times, at 4-6 weeks of age, and then every 4 to 6 weeks.

Adult dogs are vaccinated at 6 months OR at 1 year, and then every three years (4, 7, 11, ...).

Main references


Canine Parvovirus type 2 (CPV-2)

Parvoviruses type 2 attack mainly the digestive tract. They cause diarrhea and vomiting. In puppies, they cause very severe symptoms that often lead to death.

Canine Adenovirus type 2 id card


Canine parvovirus is a very contagious virus.

It can be found in dogs, coyotes, wolves, foxes. Some strains (CPV 2a and 2b) can also infect cats. All these species are reservoirs for the virus.

Canine parvovirus is shed in very large quantities in the feces of infected animals. It is very resistant in the outside environment, and can survive from several weeks to a few years under favorable conditions.

It can be carried under a dog’s foot or hair and disseminated that way. There are more risks of contamination in places usually visited by dogs such as pet stores, breeding kennels or animal shelters.

Canine parvoviruses enter the body through oral contact. The dog or puppy gets the infection by licking itself, or a contaminated ground.

An infected dog usually starts shedding viruses in its feces after an incubation period of only 4 days, and keeps on shedding for weeks well after the symptoms have disappeared. This adds to the contagiousness of the disease.

Mechanisms of progression

After entering the body through the dog’s mouth, the virus first colonizes the mouth’s and pharynx’s tissues and the lymph nodes where it starts replicating.

After 3 to 4 days, it then migrates to various organs. But, it is to the digestive tract that the virus does the most damage.

Intestines are covered with small villi that look like tiny hair. In reality they are thin and long protuberances of the intestinal wall and play a very important role in the absorption of nutriments. The Canine Parvovirus 2 use villi cells to replicate in numbers and eventually destroy them.

Another notable target of the virus is the heart. It causes heart enlargement especially on its left side.


The evolution of the symptoms is rapid. Vomiting episodes precede diarrhea, anorexia and dehydration that require emergency care.

Bacterial superinfection may accelerate and worsen the symptom.

The virus may also cause acute or chronic cardiac failure.


Unvaccinated puppies are very sensitive to the virus. They often die from being infected.

The puppies that survive for the first 4 days of the enteric form of the disease usually recover after one week. But still, few of them may develop a secondary and fatal heart disease.

Adult dogs are more resistant, but some can still die from the infection.

Some dog breeds are reported to be more sensitive to the virus: Alaskan sled dogs, American Staffordshire terriers, American Pit Bull terriers, Doberman pinschers, English Springer spaniels, German shepherds, Labrador retrievers, and Rottweilers.

The good news is that the dogs that survive the infection are immunized.

Treatment and prevention

The treatment consists of controlling the consequences and possible complications of the infection. Basically, infected dogs receive a fluid therapy against dehydration and anti-infectives against possible bacterial superinfection.

Prevention starts by vaccinating puppies according to the recommendations.

Every dog that are or supposed to be infected by the virus should be prevented to disseminate the pathogen. A strict isolation procedure from other animals is recommended. The floors should be cleaned with a bleach-based solution.

Vaccination schedule

It is the same as for Adenovirus and Distemper virus:

Puppies get vaccinated three times, at 4-6 weeks of age, and then every 4 to 6 weeks.

Adult dogs are vaccinated at 6 months OR at 1 year, and then every three years (4, 7, 11, ...).

Main reference



Rabies holds a special place in pet vaccination, because it can be transmitted from dogs, or wild species, to humans. And always turns out to be fatal for both humans and animals, if left untreated.

Rabies also represents an historic step in the history of vaccination. It is the first vaccine ever designed after Jenner’s discovery of the variolation principle (see Chapter 2).

Because rabies is a threat to Public Health, health authorities’ policies aim at eradicating the virus, which is almost done in many developed countries.

Vaccination against rabies is more than a recommendation. It is a legal requirement in many states in the US.

In the European Union, whenever you need to travel abroad with your pet you’ll need to prove that it is properly vaccinated against rabies, either by a certificate, a microchip or a blood test.

You should know what is the regulation in your region. Fortunately, your vet does know it and will provide you with the right information.

Rabies virus identification card


Rabies’s virus affects potentially any warm-blooded animal. But mammals and especially carnivorous mammals are the main vectors of the disease.

This is because carnivorous mammals bite. As the virus is transmitted through saliva to blood, it easily enters the body through an open wound caused by a bite.

The virus can’t break into the body through an intact skin.

99% of human cases of rabies are caused by domestic dogs according to the World Health Organization. But bites by bats is a growing concern since infected bats seem to spread rapidly and their bites often remain unnoticed by the victims.

However, the main reservoir of rabies viruses is wild animals: foxes, coyotes, ferrets, bats, groundhogs…They may infect domestic dogs or cats which then become infecting vectors of the virus.

No need to say that transmission from human to human is very rare.

Mechanisms of progression

After a bite of an infected animal, the virus starts replicating at the wound site. More often it is in muscular tissues. This local replication phase is long; it lasts for 1 to 3 months.

Then the virus reaches peripheral nerves that innervate the muscle. It keeps on replicating whilst moving upward, towards the dorsal root ganglia, the spinal cord and the brain. The progression continuously accelerates. The closer to the brain, the quicker.

By moving this way, instead of circulating in the blood or the lymph, it escapes from the defenses of the immune system.

Once it has reached the brain, it causes brain inflammation (encephalitis). At the same time, the virus disseminates to other organs in the body through nerves.

Because they are close to the brain, the organs within the head are hit first. Especially, the salivary glands are rapidly enabled to spread infecting viruses in the mouth.

Domestic dogs can shed viruses from their saliva for several days before the first symptoms occur. This means in practice that a dog may become infective before the owner has a chance to notice that something is going wrong.


Due to the long incubation period, the symptoms show up several weeks after the dog has been bitten.

The symptoms are neurological. The behavior of the dog suddenly changes. It produces an excessive amount of saliva it can’t swallow. There are 2 forms of the disease.

Furious form

Dogs infected with rabies become very aggressive and threatening. They show their teeth and seem to ignore any kind of danger. They are keen on biting or scratching at any occasion. They bite or eat objects of any nature, or even feces as if there were looking for a way to overcome the discomfort of their excessive salivation.

Of course, they can bite other animals or people. This is the way the disease is transmitted.

This is the “mad-dog” syndrome. This insanity doesn’t last long, no more than a week. The poor dog then falls into a coma and die.

Paralytic form

The owner notices a lack of physical coordination and balance. The throat and the masseter muscles get paralyzed. The dog is not aggressive, but remains contagious and the contact of an open wound allows the transmission of the virus.

Coma and death follow within a short period of time.


Once the symptoms appear, the disease causes the death of the animal within a few days.

Treatment and prevention

As you can understand now, Rabies is quite a serious issue.

It causes the death of tens of thousands people around the world. The situation is quite unequal though, since 95% of them occur in Asia and Africa. In Western Europe, the disease is almost eradicated.

In North America, there are also very few human cases of rabies . But, eradication doesn’t seem achievable here because of the huge wild animal reservoir.

For their own safety, any dog should be vaccinated against Rabies, unless they live in a very safe environment. The vaccination schedule consists of an initial single dose administration followed by boosters every 1 to 3 weeks according to local legal requirements.

Any domestic dog, even vaccinated, that bites a human should be suspected to be rabid and isolated under quarantine for at least 10 days. If the animal develops the symptoms of rabies, it should be euthanized and submitted to laboratory investigations.

If Rabies is confirmed or suspected (in case the animal has not been identified or analyzed), the person that has been bitten should receive a post exposure prophylaxis which consists in:

  • Extensive wound washing
  • A series of vaccination as recommended by the WHO
  • Rabies immunoglobulin, if necessary

Table: Categories of contact and recommended post-exposure prophylaxis (PEP)

Categories of contact with suspect rabid animal Post-exposure prophylaxis measures
Category I – touching or feeding animals, licks on intact skin None
Category II – nibbling of uncovered skin, minor scratches or abrasions without bleeding Immediate vaccination and local treatment of the wound
Category III – single or multiple transdermal bites or scratches, licks on broken skin; contamination of mucous membrane with saliva from licks, contacts with bats. Immediate vaccination and administration of rabies immunoglobulin; local treatment of the wound

Source: World Health Organization

Some US states recommend sticking with the Compendium of Animal Rabies Prevention and Control

Main references