If you have just adopted a puppy or dog, you may be wondering which immunizations are actually needed. Vaccines are crucial for the health and prevention of diseases in your puppy. I am a big advocate of immunization because it saved my dog from infections after I had adopted him from the shelter. I no longer have to worry about him mingling with other dogs and he loves socializing!
What are the various types of vaccines available?
Based on various factors, vaccines are divided into different groups.
Types of vaccines | Explanation | Examples |
Core vaccines | These are the vaccines that you must get your dog administered with. They are globally recognized and mandated by the law. For instance, rabies is a deadly disease with a possibility of dog-to-dog as well as dog-to-human transmission. Apart from the severity of the disease, the frequent transmission, and high incidence also determine the status of a core vaccine. | -Canine distemper virus (CDV) -Canine adenovirus (CAD) -Rabies -Parvovirus |
Non-core vaccine | These are the vaccines whose requirement varies according to the prevalence and distribution of a particular disease in a region, immunization status of the puppy and his mother, antibody levels in the blood, and other factors. For instance, in North America, the canine influenza vaccine is licensed due to an influenza outbreak. In the rest of the world, it is not given to puppies. | -Leptospirosis -Bordetella -Parainfluenza -Lyme disease |
Not recommended | These are the vaccines that are generally not needed. The dog can be protected from the infectious agent without an agent (by innate immunity). These also contain some viruses which can cause deadly human outbreaks but do not affect dogs. For instance, considering the COVID-19 pandemic, many pet owners were worried about the immunization of their dogs. The prevention must be practiced but guidelines do not advocate getting any vaccine for this. The other reasons include the absence of reliable data about the efficacy of the vaccine, lack of quality control, sparse prevalence of disease to warrant a public health concern, and a possibility of an adverse reaction, etc. | -Measles -Canine coronavirus -Rattlesnake vaccine –Giardia lamblia -Canine adenovirus type 1 |
What are core vaccines and how should they be given?
Canine Distemper Virus
The CDV is a fatal virus that causes symptoms ranging from gastrointestinal to respiratory problems. The vaccination given is a modified live virus (MLV) or a recombinant type and starts at 6 to 9 weeks. After the initial dose, you should get boosters every 3 to 4 weeks in the series. This goes on until your puppy reaches the age of 14 to 16 weeks. The next dose is given after 1 year. After that, you should take your dog for CDV vaccination every 3 years.
The regularity of series shots and the appropriate interval between two shots are necessary to prevent vaccination failure. The product used can also vary so you should not worry if the vet is not using a single CDV vaccine. Currently, the US has fifty different licensed vaccines available for the CDV. A combination dose of canine adenovirus, canine distemper virus, and parvovirus is given. However, the modified live vaccine (MLV) shows more efficacy than the recombinant or inactive vaccine for canine distemper virus in domestic dogs.

Canine Adenovirus
Canine adenovirus has two types:
- CAV-I
- CAV-II
Both these strains cause diseases with varied symptoms. CAV-I causes hepatitis, fever, depression, and renal problems. In contrast, CAV-II affects the respiratory system only. The former proves lethal but the latter is self-limiting. The disease transmitted through droplets and contact of your dog with infected bodily secretions. The conundrum, however, is that vaccines available for CAV-I have adverse effects. So, it is not recommended to vaccinate your pup with it.
What you can do is to get him a shot for CAV-II. This vaccine is modified live type in variety and illicit an immune reaction that is sufficient for both CAV-I and CAV-II virus. The adverse reactions are also tolerable and your pup feels better within a day. The timeline is the same as the distemper vaccine because they are often given in a combination dose. You should get your puppy the first shot at age of 6 to 9 weeks, then a series of booster spaced 3 to 4 weeks apart until 16 weeks. After this, an annual dose and then a regular triennial dose should be given.
Canine Parvovirus
Canine parvovirus is sneaky and can exist outside the body of the host because it does not have an envelope. This creates environmental transmission and it becomes harder to control the spread. The risk is higher in younger dogs and puppies as parvovirus can rapidly become life-threatening. That is why it is included in core diseases and the vaccine is given along with CDV and CAV in combination. The timeline is also similar to the other two vaccines.
One concern with some canine parvovirus vaccine strains available is that it has high maternal antibody interference. The CPV2b has the lowest antibody interference and can be used safely. The other way is to get your puppy a series vaccine to keep the vaccine levels high in the blood.
Rabies
Rabies has given us a tough time because it is highly fatal. It is also rapidly transmissible and is present in an infected dog’s saliva. The dog-to-human transmission though the animal bite has made it a public health concern and rabies vaccination is available for humans as well.
The legislation on rabies varies but it is globally accepted to get dogs vaccinated against it. The difference lies in the timeline mainly. In California, for example, the legal age of rabies vaccination is 16 weeks but generally accepted guidelines are 12 to 16 weeks. Your dog will need the next dose after 1year and then every 3 years. Some regions keep an annual booster for the rest of the dog’s life instead of a triennial shot. The vaccine used is the killed virus variety.
What are non-core vaccines and does my dog need them?
Such vaccines are not dictated by the law and you are given a choice. The infections are usually self-limiting or do not pose serious health threats. Some are deadly but the risk of exposure largely depends on the habitat of the dog. So, considering the variable factors, it is advisable to discuss it with your vet.
Leptospirosis
Leptospirosis is a serious disease caused by bacteria but does not happen frequently in urban areas. If you have a fenced house with your dog not interacting with wildlife, you can choose not to pinch him with an extra shot needle. I got my dog vaccinated against leptospirosis when I lived in a rural setting for some time. There was a lot of contact with livestock involved and that is a risk factor for leptospirosis. The incidence of this disease also increases after a rainy season, so you might want to keep that in mind.
The recommended way to vaccinate a puppy against leptospirosis is waiting until 12 weeks so that he becomes capable of tolerating adverse effects. Initially, you can get him a series of two to three shots monthly and then booster doses annually if the exposure risk stays. If you shift to an urban environment or think that the exposure has reduced, you can choose not to continue the vaccine.
Bordetella
You should get your puppy a bordetella shot if you plan to enroll him in an obedience class. Many such classes ask for a certification of this vaccine because they are hotbeds for bordetella infection. It is a respiratory disease with bronchitic features caused by bacteria. If you do not intend to send your puppy in a kennel environment, do not waste your money on this vaccine. He won’t need it.
The suitable timing for this shot is at least a week before the potential exposure. The generally accepted verdict is that the intranasal route is the superior route of administration for the bordetella vaccine. If you take your puppy to grooming facilities or boarding frequently, you should repeat his bordetella shot every 6 months.
Parainfluenza
The parainfluenza vaccine is a core vaccine in some regions where outbreaks are common. However, in the US, it is not included in “must-have vaccines”. If you are traveling to any such region or fear a potential exposure, you can get your puppy a modified live variety parainfluenza vaccine. For repeated exposures, you can get him a shot every 6 months.
Borreliosis
This infection spreads through ticks bite and is commonly known as Lyme disease. The transmission of Lyme diseases is less likely due to the nature of the tick lifecycle but if your puppy has a high tick burden, you need to be vigilant. This shot is recommended while traveling to tick endemic regions or for the dogs vulnerable to ticks.
The vaccine is available in a killed or recombinant variety. It can be given at 9 weeks and should be repeated after 3 to 4 weeks. The appropriate time to give your puppy Lyme disease vaccine is a few days before the exposure to a tick-infested area.

What Should You Know About Dog Vaccination?
There are many vaccination schedules available on the internet but they hardly make sense if you are not a professional vet. To eliminate this confusion, you must know some basics of vaccines. Below are some of the terms, you should be familiar with:
Antigen
An antigen is a foreign particle (virus or bacteria) that enters into the dog’s body and triggers an immune reaction. Dogs have a natural immune system, innate to them, that fights harmful pathogens. Vaccines aid and train that system to act in a better way.
The immune system reacts when it identifies any alien particle or “antigen”. The principle of making a vaccine is based on designing an antigen that can modulate the immune system but is not strong enough to cause an infection. This is an active immunization strategy because it uses your dog’s natural immunity to strengthen him against diseases. The antigens are:
- Killed organisms (inactive vaccine)
- Attenuated organisms (modified live vaccine or MLV)
- Recombinant material (genetic subunits or remnants of microorganisms)
These are packed into a delivery medium to make them palatable for dogs. All these formulations with antigen particles have the power to elicit the immune system without causing infection.
Antibody
The immune response in dogs generates specialized cells called antibodies which kill antigens. This happens as a consequence of complex molecular events in the body. To simplify, a vaccine teaches your dog’s immune system to make antibodies and store them. So, when a pathogen invades and tries to cause infection, your canine friend is already equipped to deal with it quickly and does not get sick. We call it the primary response as it is the first exposure and slow in onset. However, besides antibodies, your dog’s body also produces memory cells. These memory cells store in the dog’s body and produce an immediate, rapid, and stronger response when the infectious particle attacks (secondary exposure).

Considerations Regarding Immunization Of Your Dog
Vaccination is done by a vet and the common practice is to take a brief history before designing a vaccination schedule. But being a dog parent, some of the considerations you should keep in mind are as follows:
Age of the Dog
The age of the dog is important due to two reasons.
Underdeveloped Immune system: The puppies and adult dogs have varied immunization needs because the puppies have an underdeveloped immune system and react to vaccines differently. They may need more booster doses spaced over fewer weeks to ensure complete immunity. So, the schedules are designed accordingly.
Interaction with maternal antibodies: Puppies have immunity provided by their mothers to protect them. These maternal antibodies come from the colostrum of the mother produced after the birth of the puppy. It is rich in antibodies that stay in the puppy’s blood for weeks to protect him until his immune system develops enough to fight infections. The maternal antibodies interfere with the mechanism of vaccines. Vaccines have antigens and the maternal antibodies are programmed to bind antigens or foreign particles. So, they consider these vaccines infectious agents and bind with them. The vaccine gets neutralized before it can interact with the immune system, and becomes ineffective.
Resultantly, you may think your puppy is immunized because you have given him his shot but in reality, he stays vulnerable to infections. The maternal antibodies stay in the blood for up to 6 weeks. So, it is recommended to start vaccination in puppies after 6 weeks. Unfortunately, there is no way to be sure of the presence of antibodies. To cover this gap, in initial months, frequent booster doses are given at appropriate time intervals to keep the levels of vaccine high in the blood.
Immunization of Mother
The immunization status of the bitch is important because it tells you about the presence of maternal antibodies. If the bitch was not immunized, there will be no antibodies present in the initial weeks. Sometimes, you may not know the vaccination profile of the mother. For instance, if you have adopted your pup from a shelter, you have to assume that the bitch was not immunized because it is common in the case of stray dogs. Such puppies need immunization as soon as possible with regular booster doses to ensure a constant supply of antibodies to stay healthy.
Habitat and location
The geographical distribution of disease also plays a vital role in deciding vaccination for the dogs. For instance, Rabies is more common in developing countries and the risk of transmission is higher. So, the dog owners in those countries are advised to get frequent rabies booster shots. In contrast, the US has controlled rabies significantly, so only two doses can protect your dog for the whole life. Traveling to such areas also warrants an immunization consideration. Once I was traveling to India with my dog and the US authorities wanted me to get a fresh booster for rabies. The same is true for many other diseases.
The lifestyle and habitat of the dog also determine the vaccination schedule. If you have adopted your dog from a shelter house, he might need more boosters because bugs are more frequent in such settings. Due to the crowd, the transmission is also highly likely. If your dog prefers playing outdoors a lot, you need to be extra vigilant about the vaccination status because socializing increases the risk of disease spread.
What are the adverse effects of vaccines?
The vaccines are generally safe and do not pose health problems unless your dog does not have a healthy immune function. The young, small-breed dogs are generally prone to the adverse effect of vaccination if they receive multiple shots. The duration, however, lasts up to 72 hours and problems are usually mild. The most common side-effects are mentioned below in decreasing order of their frequency:
- Lethargy
- Vomiting
- Anorexia
- Fever
- Diarrhea
- Allergic swelling
- Allergic reaction
- Malaise
- Injection site pain
- Abdominal pain