Vaccination is one of the most effective ways to protect a dog from severe infectious diseases. Thanks to widespread vaccination, many illnesses are now seen much less frequently, but this by no means indicates that they have disappeared. As soon as vaccination coverage drops, dangerous infections quickly return.
In this article, we will look at what is included in a multivalent (“six‑component”) vaccine, which diseases it protects against, why some puppies receive an additional DP shot, why puppies are vaccinated several times in a row, and how long immunity lasts after vaccination.
What is a multivalent vaccine?
A multivalent vaccine is often called a “six‑component vaccine” or simply “the six‑way shot”.
The name reflects the fact that a single injection protects the dog at the same time against several of the most common and dangerous infectious diseases.
Most modern multivalent vaccines provide protection against:
- parvoviral enteritis (Parvovirus);
- canine distemper (Canine Distemper);
- infectious canine hepatitis (Canine Adenovirus‑1);
- canine adenovirus respiratory infection (Canine Adenovirus‑2);
- canine parainfluenza (Canine Parainfluenza);
- leptospirosis (Leptospira).
It is important to understand that different manufacturers may vary slightly in vaccine composition. In addition, for leptospirosis there are products containing two or four of the most common bacterial serovars.
Despite the name, the goal of all modern multivalent vaccines is the same: to protect the dog from infections that can lead to severe illness or death.
What is the DP (DP+) vaccine?
Sometimes puppies receive an additional DP or DP+ shot even before the standard vaccination schedule begins.
This vaccine protects only against two diseases:
- canine distemper;
- parvoviral enteritis.
These two infections are considered the most dangerous for very young puppies.
Why is the DP vaccine needed?
Puppies are born with virtually no own immunity. Their main protection comes with colostrum, which is why it is so important that the newborn starts nursing from the mother as early as possible. Maternal antibodies contained in colostrum protect the puppy during the first weeks of life, and as long as there are enough of them, they help defend the puppy against infections.
But there is a downside: maternal antibodies can neutralize the vaccine and interfere with the development of the puppy’s own immunity.
The problem is that it is impossible to know in advance exactly when the level of maternal antibodies will drop in a particular puppy.
In one puppy this happens earlier, in another later.
That is why at a certain point the puppy may end up in the so‑called “immunological window”—a situation where maternal protection is already insufficient, while its own immunity after vaccination has not yet formed.
The DP vaccine helps shorten the duration of this risky period.
Most often it is recommended for puppies at about 6 weeks of age when there is a high risk of infection.
For example:
- if the puppy lives in a kennel;
- if there has recently been parvovirus in the home;
- if there are many dogs in the surrounding area;
- if the veterinarian considers the infection risk to be increased.
It is important to understand that DP does not replace multivalent vaccination.
After a DP shot the puppy still follows the regular age‑appropriate vaccination schedule.
Why are puppies vaccinated several times?
This is the question owners ask veterinarians most often, since at first glance it seems logical to give one shot and get immunity.
However, a young puppy’s immune system works differently from that of an adult dog:
After birth, the puppy receives protective antibodies from the mother, which gradually break down over the first months of life.
While their level is high, they protect the body, but at the same time they can make vaccination ineffective.
A veterinarian cannot know which particular shot will be the first truly “effective” one, so the multivalent vaccine is given several times in a row at intervals of a few weeks.
This schedule significantly increases the likelihood that at least one of the shots will be given at the exact moment when the immune system is already able to form full protection.
Therefore, skipping any of the vaccinations is not recommended, even if the previous one caused no complications.
Parvoviral enteritis
Parvoviral enteritis is one of the most dangerous infectious diseases in dogs and one of the leading causes of death in unvaccinated puppies worldwide.
Even today, despite modern treatment methods, this disease remains a serious challenge for both owners and veterinarians.
The virus is extremely resistant in the environment: it can survive in soil, on grass, shoes, clothing, and other surfaces for many months.
This means that a puppy does not necessarily have to come into contact with a sick dog—sometimes it is enough just to be in a place where an infected animal was present several months earlier.
Even after recovery, the dog continues to shed the virus in its feces for at least three weeks, remaining a source of infection for others.
The incubation period is usually 3 to 7 days, and once the first symptoms appear, the puppy’s condition can deteriorate literally by the hour.
The most characteristic signs are:
- severe vomiting;
- bloody diarrhea;
- complete refusal of food;
- profound weakness;
- rapid dehydration.
The danger of the disease is related not only to the virus itself. Due to severe intestinal damage, bacteria begin to enter the bloodstream, causing severe toxemia, and rapidly progressing dehydration further worsens the animal’s condition.
Treatment of parvoviral enteritis requires round‑the‑clock monitoring, intensive fluid therapy, antiemetic drugs, pain management, antibiotics, and constant assessment of the patient’s status.
Even when treatment is started promptly, the prognosis remains guarded, and the cost of hospitalization can reach thousands of shekels.
This is why vaccination remains the most effective method of protection.
Why can’t you walk a puppy that isn’t fully vaccinated?
Almost every new owner asks this.
Early socialization is indeed critically important for the development of a stable canine temperament, but during this period the risk of contracting parvovirus is significantly higher than the potential benefits of ordinary walks.
Full immunity develops not immediately after the first or second shot, but only about a week after completion of the primary vaccination series. Until that point the puppy remains vulnerable.
This does not mean that the puppy must be completely isolated from the outside world—on the contrary, exposure to new people, sounds, cars, different surfaces, and the urban environment is very important.
The best compromise is to take the puppy outside in your arms, in a carrier, or in a stroller, without letting it touch the ground or come into contact with other dogs and their excretions.
This approach helps reduce infection risk while not missing the critical socialization period.
Canine distemper
Canine distemper is another severe viral disease which, thanks to vaccination, is now seen much less often than a few decades ago.
Unlike parvovirus, this virus does not survive well in the environment: it is quickly destroyed by sunlight, drying, and most household detergents.
Infection usually occurs through direct contact with a sick dog or its secretions.
A particular danger of the virus is that an infected dog starts shedding it before the first signs of illness appear, so an apparently healthy animal can already be infectious.
Distemper affects several body systems at once.
The disease usually progresses in stages:
- First, conjunctivitis and eye discharge appear.
- Later, cough, nasal discharge, and other signs of respiratory tract involvement develop.
- Then vomiting and diarrhea may occur.
- At the later stages, the virus attacks the brain and nervous system, causing neurological disorders.
Possible symptoms include:
- discharge from the eyes and nose;
- cough;
- fever;
- refusal of food;
- vomiting and diarrhea;
- seizures;
- incoordination.
One of the characteristic signs is thickening and hardening of the nasal planum and paw pads.
Even after recovery, the disease can leave lifelong consequences. Some dogs develop myoclonus—rhythmic, involuntary muscle jerks that may persist constantly.
If the disease is contracted during the tooth‑replacement period, tooth enamel may be damaged, which will remain visible in adulthood.
Prevention is therefore much safer and more effective than treatment.
Infectious tracheobronchitis (“kennel cough”)
Despite its name, kennel cough is not a single disease but a whole group of infections that affect the upper respiratory tract in dogs.
Most often several pathogens are involved at once, the most common being:
- canine parainfluenza virus (Canine Parainfluenza Virus);
- canine adenovirus type 2 (Canine Adenovirus‑2);
- the bacterium *Bordetella bronchiseptica*.
It is parainfluenza virus and adenovirus that are included in the multivalent vaccine.
The infection is highly contagious and spreads especially quickly in places where many dogs are kept together:
- kennels;
- boarding facilities for pets;
- shelters;
- dog shows;
- training grounds;
- dog parks.
The main symptom is a dry, hacking, paroxysmal cough.
Many owners describe it the same way: “It’s like something is stuck in the dog’s throat.”
This is exactly how the disease usually looks.
In most cases, kennel cough resolves on its own within 1–2 weeks, but in young puppies, senior dogs, and immunocompromised animals it may be complicated by pneumonia.
Is a separate Bordetella vaccine necessary?
Yes, such a vaccine exists.
It provides additional protection against *Bordetella bronchiseptica* but is not part of the routine vaccination schedule.
Most often it is recommended:
- before a stay at a dog boarding facility;
- before dog shows;
- before a prolonged stay in a kennel;
- for dogs that regularly interact with many other dogs.
Ideally, this vaccination should be given about two weeks before the expected exposure.
It is important to understand that even after vaccination a dog can still develop kennel cough, since the syndrome is caused by several different microorganisms, but in vaccinated dogs the course of the illness is usually much milder.
Infectious canine hepatitis
Infectious hepatitis is caused by canine adenovirus type 1 (CAV‑1).
This severe viral disease primarily affects the liver, but can also involve the kidneys, eyes, and blood vessels.
Possible symptoms include:
- high fever;
- marked lethargy;
- refusal of food;
- vomiting;
- diarrhea;
- jaundice;
- abdominal pain.
In some dogs, after recovery, a characteristic corneal opacity develops, known as “blue eye”.
Fortunately, this disease is now extremely rare, and the reason is simple: mass vaccination.
Interestingly, modern multivalent vaccines usually contain canine adenovirus type 2 (CAV‑2) rather than CAV‑1.
This is because a CAV‑2 vaccine provides cross‑protection against both of the following diseases:
- infectious canine hepatitis;
- canine adenovirus respiratory infection.
At the same time, it causes far fewer side effects than the older CAV‑1 vaccines.
Leptospirosis
Leptospirosis is the only bacterial infection among the core diseases against which most dogs are vaccinated.
It is also a zoonosis, meaning it can be transmitted to humans.
The causative agents are bacteria of the genus Leptospira.
There are many different leptospiral serovars, but modern vaccines protect only against the most common ones.
Some multivalent vaccines include protection against two serovars, while newer products protect against four, providing broader coverage.
How does infection occur?
Most often infection occurs through contact with urine from an infected animal, or with water and soil contaminated by such urine.
The bacteria survive especially well in a moist environment.
Once in the body, leptospires spread via the bloodstream and primarily affect:
- the kidneys;
- the liver.
The disease may therefore be accompanied by:
- high fever;
- refusal of food;
- vomiting;
- dehydration;
- jaundice;
- acute kidney failure.
When diagnosed in time, leptospirosis responds well to antibiotic therapy.
However, once severe kidney or liver damage has developed, the prognosis becomes much more guarded.
Why is leptospirosis vaccination given more often?
This is one of the most common questions from owners.
Immunity to the viral components of a multivalent vaccine usually lasts significantly longer, so after completion of the puppy series and revaccination at one year of age, most viral components are recommended once every three years.
Protection against leptospirosis is less durable.
For most modern vaccines it lasts about 12 months, so annual revaccination remains the most common recommendation.
In some countries, there is a growing practice of giving viral components every three years, while vaccinating against leptospirosis annually.
This makes it possible to maintain reliable protection specifically against diseases for which immunity wanes more quickly.
Which vaccines does a dog in Israel need?
Modern veterinary medicine is gradually moving away from the principle of “giving every shot every year”.
Today, vaccination schedules are built around how long immunity to particular diseases lasts.
After a properly completed puppy series and a booster at one year of age, immunity to most viral infections lasts significantly longer than one year.
In many countries, including according to WSAVA (World Small Animal Veterinary Association) guidelines, adult dogs receive boosters against core viral infections every three years, while leptospirosis vaccination is recommended annually.
At the same time, the final vaccination schedule is always determined by the attending veterinarian, taking into account the dog’s age, lifestyle, region, and risk of exposure.
Example of a modern vaccination schedule
Puppies
- 6 weeks — DP vaccine (if indicated).
- 8–9 weeks — first multivalent vaccine.
- 10–12 weeks — second multivalent vaccine.
- 12–16 weeks — third multivalent vaccine.
- from 3 months — rabies vaccine (in accordance with Israeli law).
Young dogs
- 1 year — booster with a multivalent vaccine.
Adult dogs
- multivalent vaccine — every 3 years;
- leptospirosis vaccine — annually;
- rabies vaccine — according to current Israeli legislation;
- kennel cough (Bordetella) vaccine — if indicated, about two weeks before expected contact with many other dogs.
Keep in mind that the schedule may vary depending on the vaccine used, the animal’s health status, and the veterinarian’s recommendations.
Recommended preventive program
In addition to vaccination, a complete preventive program includes protection against the most common parasites.
For dogs living in Israel, you can follow the schedule below.
Assuming you are following the vaccination schedule recommended by your veterinarian.
The key takeaway
Today many dog owners have never encountered parvovirus, canine distemper, or infectious hepatitis, and this is a major achievement of modern veterinary medicine.
It can sometimes seem as though these diseases have disappeared, but in fact they have simply become much less common precisely because of vaccination.
As soon as vaccination coverage drops, dangerous infections quickly return, which is why preventive shots remain one of the most effective ways to protect your dog’s health.
Remember: vaccination is not just following your veterinarian’s recommendations. It is a chance to prevent diseases whose treatment may be far more difficult, more expensive, and, unfortunately, not always successful.
