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Pet Vaccinations: Practices, Protocols & Importance

Updated: May 4, 2021


What is a vaccine?

A vaccine is a material that stimulates the body of an animal or human being to produce protecting substances called antibodies by the immune system, providing immunity against one or numerous diseases. A vaccine is typically prepared from the causal agent of a disease, its products, or a synthetic substitute, to behave as an antigen without inducing the disease. A vaccine trains the body’s immune system to fight a disease condition that it has not come into contact with before. Vaccines prevent infections instead of treating them [1].


Why are vaccines necessary?

Vaccines are the most effective, efficient and cost-saving means of disease prevention, averting untold misery and avoiding a lot in healthcare costs each year. Vaccines protect animals against devastating diseases, some of which cross to humans (zoonotic diseases) [2] [3]. Vaccines are the main components when it comes to the control of serious infectious diseases, and they are an essential part of the improvement of canine and feline health. For infectious diseases to be under control, a large percentage of the pet population needs to be vaccinated; however, the levels of immunization are much lower. In the majority of cases, the percentage of pets receiving immunization is around 50%, instead of the mandatory 70%, meaning that in most areas there is a large population of pets that are not immunized creating a risk to both pets and their owners [2] [4].


How many types of vaccines are there?

Vaccine types - Infectious & Non-infectious (

There are two types of vaccines, either ‘infectious’ or ‘non‐infectious’ biologically [4].

Infectious vaccines administered in dogs and cats contain organisms that are modified and weakened (attenuated) to decrease virulence (i.e. ‘modified live virus’ [MLV] or attenuated vaccines). However, the organisms are intact and viable and induce immunity by inducing low‐level infection and reproducing within the animal, without producing the disease. The advantage is that these vaccines induce immunity effectively when administered and are more likely to induce robust immunity [1].

Non‐infectious vaccines (i.e. killed or inactivated vaccines) administered in dogs and cats have an antigenically intact virus or organism but inactivated, or a natural, synthetic antigen or the DNA derived from that virus or organism. Non‐infectious agents do not infect, replicate or cause the infectious disease. They require multiple doses (even in an adult animal) to induce protection. Non‐infectious vaccines have a shorter duration of immunity compared to infectious vaccines [2] [3].


Core and non-core vaccines, what is the difference?

Puppy and Kitten

A Core Vaccine is one administered to all animals to protect them against diseases of global significance or where legislation dictates. ALL dogs and cats, irrespective of circumstances or geographical location, should receive core vaccines as they protect them from severe, life-threatening diseases that have worldwide distribution [5].

A Non-Core vaccine is one administered to those animals whose geographical location, local environment or lifestyle risks them to getting certain infections [5].


Table 1: Core and Non-Core Vaccines in Dogs and Cats [5] [6]

Canine Core Vaccines Feline Core Vaccines

Canine Distemper Virus Feline panleukopenia

Canine Parvovirus Feline herpesvirus-1

Canine Adenovirus Feline calicivirus

Leptospira interrogans Rabies virus

Canine Non-Core Vaccines Feline Non-Core Vaccines

Canine Parainfluenza Virus Feline leukaemia virus (FeLV)

Bordetella bronchiseptica Feline immunodeficiency virus (FIV)

Canine Influenza Virus Chlamydophila felis

Borrelia burgdorferi (Lyme) Bordetella bronchiseptica

Canine oral melanoma Dermatophyte vaccines


When should I vaccinate my dog or cat?

Few hours after birth, puppies or kittens get their first protection against infectious diseases through antibodies, which they receive through their mother's milk (colostrum). As such, vaccinating your kitten or puppy early is pointless because these antibodies counteract vaccines preventing them from stimulating the puppy’s body from producing immunity. By around seven weeks, maternal immunity begins to weaken. Therefore, kitten and puppies should get their primary vaccination at about 6-8 weeks and the secondary vaccinations at ten to twelve weeks of age. Kitten and puppies who are vaccinated at an early age as indicated above can mingle with others [5] [4] [7].


Are boosters or repeat vaccinations necessary?

The protection provided by vaccination is not essentially life-long. The vaccine used, the clinical status of the individual animal, the antigens contained in the vaccine, handling of the vaccine by the supplier or veterinarian and other environmental factors affect the duration of immunity. Before a puppy or a kitten is fully protected by vaccinations they need to complete the vaccination courses. However, the immunity (protection) provided by most vaccines wears off in time and at different rates for every specific vaccine. Besides, the level of environmental infection by the organisms that we vaccinate against, which are supposed to sensitize the animal’s body to produce antibodies e.g. infectious hepatitis and distemper, is low. Consequently, it is improbable that a vaccinated animal will come into contact with the wild strain sufficiently frequent to obtain natural boosts to its immunity. Repeat vaccinations are, as such, necessary to maintain adequate antibody titres in these cases. If your pet misses the date of its regular booster vaccination by a year or two, it is all right to begin again with a new course of injections. Most boarding kennels will always require proof of regular vaccinations before considering looking after your pet.


Can pregnant pets be vaccinated?

It is not advisable to vaccinate pregnant pets, especially with modified live vaccines. Also during times of sex hormonal change, like estrus and pro-estrus, vaccination should be avoided. The only time a pregnant queen or bitch can be vaccinated is when the pregnant animal was certainly not or unlikely to have been vaccinated and there is an outbreak of infectious disease [5].


Are vaccination failures common?

Though vaccine production is of high quality, occasionally an individual cat or dog fails to get the full protection. This comes about because of a number of factors that include an already ill pet, a stressed animal, or heritable traits that can cause a cat or dog not to respond to the vaccine [9].

Animals that are vaccine non-responders or low-responders genetically determined that way and should not be used for reproduction, particularly the females as they will not provide adequate maternally-derived passive immunity to their offspring. Breeds especially common with this trait are Black Labrador Retrievers, Akitas and Greyhounds. Vaccine non-Responders are uncommon in felines [10].


Are vaccinations harmful?

After vaccinations, the dog or cat sometimes may seem 'off-colour' for a day or two. Following the vaccination, the injection site may also become tender and swollen. If these effects persist, it is important to take your dog back to see the vet.

Infectious diseases are not very common in cats and dogs because most of them are protected by vaccination. Your pet must receive regular vaccinations to be fully protected against these diseases.


Canine Vaccination Protocol

Table 2: Canine Vaccination Schedule [5]

Vaccines Administration Booster recommendations

Core Vaccines:

Canine Parvovirus Start at 6-8 weeks of age then Annual re-vaccination

every 2-4 weeks until 12 - 16

weeks of age.

Canine Distemper Start at 8 - 9 weeks of age then Annual re-vaccination

virus every 3 - 4 weeks until 12 - 16

weeks of age.

Canine Adenovirus Start at 8 - 9 weeks of age then Annual re-vaccination

virus every 3 - 4 weeks until 12 - 16

weeks of age.

Leptospirosis Start at 8 - 9 weeks of age then Annual re-vaccination

every 3 - 4 weeks until 12 - 16

weeks of age.

Rabies vaccine Start at 8 - 9 weeks of age then Annual re-vaccination

every 3 - 4 weeks until 12 - 16 (National, County laws

weeks of age. must be followed)

Non-Core Vaccines:

Canine Parainfluenza Start at 8 - 9 weeks of age then Annual re-vaccination

Virus every 3 - 4 weeks until 12 - 16

weeks of age.

B. bronchiseptica + Administer a single dose (by the Booster annually where

canine parainfluenza intranasal route) as early as 3-4 exposure is sustained

virus weeks of age.

B. bronchiseptica Two doses are required, 2 to 4 A single dose be

(Kennel cough) weeks apart as early as 3 - 8 administered annually

weeks of age. where risk of exposure is


Canine Influenza Virus 2 initial doses, 2 to 4 weeks Annual re-vaccination

(availability is limited) apart are required where the risk of exposure

is sustained

Canine Herpesvirus Two doses are recommended: Additional vaccination is

(availability is limited) * The first dose is administered limited to subsequent

under the skin (SQ) during oestrus pregnancies where the

(heat) or within the first 10 days risk of exposure/infection

of pregnancy. is likely

* A second dose is administered 1

to 2 weeks prior to parturition


Feline Vaccination Protocol

Table 3: Feline Vaccination Schedule [7]

Vaccines Administration Booster recommendations

Core Vaccines: Feline panleukopenia Start at 6-8 weeks of age then Annual re-vaccination

(Distemper) every 2-4 weeks until 12 - 16

weeks of age.

Feline herpesvirus-1 Start at 6-8 weeks of age then Annual re-vaccination

every 2-4 weeks until 12 - 16

weeks of age.

Feline calicivirus Start at 6-8 weeks of age then Annual re-vaccination

every 2-4 weeks until 12 - 16

weeks of age.

Rabies vaccine Administer a single dose of Annual re-vaccination

rabies vaccine as early as 8 (National, County laws

weeks of age then after 4 must be followed)

weeks of age Non-Core Vaccines: Feline leukaemia virus Start at 6-8 weeks of age then Annual re-vaccination

(FeLV) every 2-4 weeks until 12 weeks

of age or older

Feline immunodeficiency Start at 6-8 weeks of age then Booster annually where

virus (FIV) every 2-4 weeks until 12 - 16 the risk of exposure is

weeks of age. sustained

Chlamydophila felis Start at 6-8 weeks of age then Annual re-vaccination

every 2-4 weeks until 12 - 16

weeks of age

Bordetella bronchiseptica Start at 6-8 weeks of age then Annual re-vaccination

every 2-4 weeks until 12 - 16

weeks of age

Feline infectious Start at 6-8 weeks of age then Annual re-vaccination

peritonitis (FIP) every 2-4 weeks until 12 - 16


Works Cited

[1] S. Cleaveland, M. Kaare, D. Knobel and M. K. Laurenson, “Canine vaccination—providing broader benefits for disease control.,” Veterinary Microbiology, vol. 117, no. 1, pp. 43-50, 2006.

[2] W. J. Dodds, “Vaccine Issues and the World Small Animal Veterinary Association (WSAVA) Guidelines (2015-2017).,” Israel Journal of Veterinary Medicine, vol. 73, no. 2, 2018.

[3] J. A. Serpell, K. A. Kruger, L. M. Freeman, J. A. Griffin and Z. Y. Ng, “Current Standards and Practices Within the Therapy Dog Industry: Results of a Representative Survey of United States Therapy Dog Organizations.,” Frontiers in veterinary science, vol. 7, no. 35, 2020.

[4] M. J. Day, M. C. Horzinek, R. D. Schultz and R. A. Squires, “WSAVA Guidelines for the vaccination of dogs and cats.,” The Journal of small animal practice,, vol. 57, no. 1, 2016.

[5] R. B. Ford, L. J. Larson, K. D. McClure, R. D. Schultz and L. V. Welborn, “2017 AAHA canine vaccination guidelines.,” Journal of the American Animal Hospital Association, , vol. 53, no. 5, pp. 243-251, 2017.

[6] C. Ball, S. Dawson and N. Williams, “Leptospira cases and vaccination habits within UK vet-visiting dogs,” Veterinary Record, vol. 174, no. 278, 2014.

[7] M. A. Scherk, R. B. Ford, R. M. Gaskell, K. Hartmann, K. F. Hurley, M. R. Lappin, J. K. Levy, S. E. Little, S. K. Nordone and A. H. Sparkes, “2013 AAFP feline vaccination advisory panel report,” Journal of feline medicine and surgery, vol. 15, no. 9, pp. 785-808, 2013.

[8] R. D. Schultz, B. Thiel, E. Mukhtar, P. Sharp and L. J. Larson, “ Age and long-term protective immunity in dogs and cats,” Journal of comparative pathology, vol. 42, pp. S102-S108, (2010)..

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