Poor health of dogs

For example, if parasites are not removed, high fever or even internal heat, etc., it may cause immune failure and allergic reactions. Depending on the body constitution, allergic dogs may develop skin rashes, If you have symptoms such as rapid breathing, inexplicable diarrhea, edema, sunken eyeballs, etc., please send it to the pet hospital as soon as possible. To be honest, 90% or more of cases of immune failure due to dogs’ own health reasons are also the theoretical basis for deworming before immunity.

Improper use of vaccines

Vaccines should not be injected into the buttocks. There is a lot of fat tissue in the buttocks and few immune active cells. The antibody titer produced after injection is low and the antibody decreases quickly.

Vaccine virus mutation

Even if the vaccine produces high titers of antibodies, a small number of dogs may still get sick. This is because viruses can mutate, and existing vaccines target normal viruses. If the surface antigen of the virus mutates, and the vaccinated dog is unfortunately infected with the mutated virus, it is still possible to get sick.

The timing of vaccine injection is wrong

Mostly it is too early. When the transitional antibodies are still abundant, part of the antigen will be offset, and of course the function it can produce will be greater. discount. Or if you fail to follow the doctor's instructions and do not take additional doses for more than a year, of course you may still be infected, because the vaccine effect can only last for one year.

Individual dogs have imperfect immune systems

This situation can be seen as individual differences among dogs.

When the dog is taking certain drugs

Undoubtedly, immunity is the basic guarantee for the health of the dog, and it is also the basic obligation of every dog ​​owner. You should neither think that everything will be fine after vaccination, nor should you simply not vaccinate your dog because you still contract an infectious disease after being vaccinated. A full set of tests should be carried out after vaccination. If no antibodies are produced, the vaccine should be revaccinated (antibody monitoring can be done).

Insufficient vaccine antibodies

Whether the disease can be prevented after vaccination depends on whether the vaccine can stimulate the dog to produce antibodies and the amount of antibodies (expressed by titer). It is generally believed that infectious diseases can be prevented only when the serum antibody titer is greater than 10 international units per milliliter. About 30% of dogs develop antibodies one month after being vaccinated. Antibodies reach the highest level one month after completing the full course of injection. Therefore, before all injections are completed, if the antibody has not been produced or the titer is relatively low, there is still the possibility of contracting the disease, so it is best to measure the antibody titer to check whether the vaccine is working. During this time, dogs must still receive other close precautions.

According to research, dogs can be divided into four groups based on their antibody titers to vaccines:
1. High response group. Serum antibody titers greater than 100 international units per milliliter accounted for approximately 20% of the injections. Dogs in the non-responsive and low-responsive groups may still get infectious diseases after being vaccinated.
2. Medium reaction group. The titer of serum antibodies produced after vaccination is 10 to 100 international units per milliliter, accounting for approximately 65% ​​of the number of injections.
3. Low response group. The titer of serum antibodies produced after vaccination is less than 10 international units per milliliter, accounting for about 10% of the number of injections. This is related to factors such as genetics, older age, obesity, immunosuppression, and immune tolerance.
4. No-response group. Accounts for approximately 5% of injections. The biggest reason why dogs don’t respond to vaccines may be genetics. The ability of injected vaccines to produce antibodies is controlled by type II major histocompatibility complex (MHC) and is a dominant inheritance.

The dog is already infected with the virus

Even if the dog is examined before vaccination and all indicators are normal, it may still not be detected because it is in the incubation period of the disease. The antibodies produced by the vaccine are only effective against viruses in the blood and are ineffective against viruses that have already entered cells. Therefore, if you have been infected with the virus before taking the vaccine, the vaccine will not be effective.

Improper storage of vaccines

Save vaccines according to instructions. If stored for too long, the immune effect will be reduced.