Currently, there are many common infectious diseases in dogs that occur and spread very rapidly and, even with timely treatment, may result in short-term death and can cause malignant transmission. The most effective way to eliminate these infectious diseases is vaccination. Vaccines not only reduce the susceptibility of dogs to infectious diseases, but also increase their resistance to them.
Vaccination has a high success rate, but it is not 100 percent successful. In some dogs, infectious diseases still occur after vaccination, i.e., immunization failure. There are many reasons for immunization failure, and if only the corresponding causes are found and effective countermeasures are taken, the chances of infection can be greatly reduced.
Analysis of causes
The common reasons for immunization failure are as follows.
1. Maternal antibody problem
Newborn puppies or kittens are protected by antibodies obtained from the mother through the placenta or colostrum. When should vaccination begin? This is related to the level of maternal antibodies.
The time that maternal antibodies circulate in the body varies from individual to individual and from antibody to antibody.
Each individual has a period of susceptibility that varies from a few days to a few weeks, during which the level of maternal antibodies is too high to allow the vaccine to work, yet too low to be effective against infectious diseases. During this period, even after vaccination, they can still get infectious diseases. The period of susceptibility also varies from litter to litter and even between individuals from the same litter.
Studies have shown that for microviruses, only 25% of immunizations are effective in puppies at 6 weeks of age, 40% at 9 weeks of age, 60% at 16 weeks of age, and 95% at 18 weeks of age.
2. Too short an interval between vaccination and exposure to infectious diseases
Vaccines do not immediately stimulate the body to produce antibodies as soon as they are administered; it takes a few days to a few weeks to produce effective antibodies, for example, coronavirus does not produce effective protection until 2-3 weeks after the second vaccination.
When a pet is already in the incubation period of a disease or there is a serious parasitic infection at the time of vaccination, vaccination will inevitably result in the pet becoming ill, thus leading to failure of immunization.
3. Different viral or bacterial strains
If the virus or bacterial strain has mutated, then the vaccination will also fail. For example, recently, a mutated strain of microvirus has been found in clinical practice, resulting in failure of routine microvirus vaccination.
4. Damage to the vaccine
Due to improper storage or transportation, weak vaccines may be inactivated and thus immunization failure may occur; vaccines may also fail if the temperature is higher than 4°C during storage and transportation.
5. Improper use of vaccine
The route of vaccination is not done according to the requirements of the vaccine, such as subcutaneous injection, intramuscular injection or nasal drip. There must also be injected according to the dose. Vaccines for dogs are given by head, not by weight, age, etc.
6. Improper immunization procedures
If the interval between injections is too short, interference between vaccines will occur, and if the interval is too long, the effect will be reduced. Usually the interval between injections of two vaccines is 2-3 weeks, except for rabies, of course.
7. Different breeds
Different breeds have different sensitivities and reactions to infectious diseases, and the immunization program may need to be adjusted for more sensitive breeds.
8. Immunodeficiency
If the body’s immune system is defective and cannot produce a normal immune response to the vaccine, it will also fail.
9. During illness
Fever can suppress the body’s immune response to canine distemper virus dd, and infection by certain viruses can also reduce the body’s immune response to the vaccine. Therefore, we always emphasize that dogs need to be vaccinated when they are healthy.
10. Malnutrition
Malnutrition such as vitamin A or E deficiency can also inhibit the body’s normal protein synthesis, thus reducing the immune response.
11. Immunization failure caused by the vaccine itself
(1) Vaccines have a certain expiration date, and expired vaccines cannot be used.
(2) Poor quality of vaccine or poor quality of vaccine diluent (distilled water and saline) may also affect the immunization effect.
(3) Insufficient antigen content of the vaccine itself.
(4) Contamination of the vaccine with other pathogenic microorganisms (especially live vaccines) can interfere with or inhibit antibody production.
(5) Inactivation of inactivated vaccines produced with strong virulent strains is not complete.
(6) Improper configuration (selection) of immune adjuvant.
12. Apparatus used for immunization
Unsterilized syringes, needles and dripping tubes may reduce the performance of vaccines; unsterilized or contaminated diluent may cause impurity of vaccines; using chlorinated tap water to dilute vaccines may reduce the immune activity of vaccines and cause immune failure.
13. Vaccines are used for too long after dilution
The freeze-dried vaccine taken out of the refrigerator at several tens of degrees below zero should be left for some time to reduce the temperature difference with the diluent as much as possible, so that the weak microorganisms in the vaccine will not die due to the sudden rise in temperature.
In summary, this is why there are so many vaccination procedures and why so many immunizations fail. In a word, no vaccine can achieve 100% protection for the vaccinated animals.
Countermeasures
If immunization fails, several countermeasures should be done as follows.
1. Strengthen feeding management and improve the body’s resistance to disease. Strengthen feeding management, feed full-price dog food, pay attention to protein nutrition supply, adapt to supplement vitamins A, D, B, E and various trace elements, reduce various stress factors, deworm reasonably, dispose properly when vaccinating, prevent the dog from being frightened, enhance physical fitness, and improve the dog’s resistance and immunity to diseases.
2. Reasonable medication: According to the nature and symptoms of the disease and the severity of the disease, choose medication scientifically and reasonably and avoid the indiscriminate use and abuse of medication. Do not use disinfectants, antibiotics, anticoccidials and antivirals within a few days before and after vaccination, and choose reasonably to use levamisole, BCG, interferon and other immune boosters to enhance the immune effect. Be careful to use glucocorticoids, cytotoxic drugs and sex hormones to avoid harming immune organs and immune cells and affecting immune response.
3. Develop a scientific and reasonable immunization program. Refer to the recommended immunization procedures in the vaccine manual, and make scientific and reasonable immunization procedures according to the epidemic situation and rules of the region, dog breed, age, past medical history, maternal antibody level and feeding management conditions, as well as the type and nature of vaccines, and adjust them according to specific conditions.
4. Adopt the correct immunization method. Adopt the correct immunization method strictly in accordance with the immunization route recommended by the vaccine manufacturer, use the dilution solution attached to the vaccine, and prepare the vaccine with correct dilution to ensure that the vaccine is in place and the dose is accurate to ensure the immunization effect.
5. Establish a sound immunization system. Dogs should be regularly immunized, and the health condition of dogs should be examined in detail before vaccination, emphasizing that only healthy dogs should be immunized and sick dogs should be effectively treated and not vaccinated.
Attention
Vaccination is a basic guarantee of dog health and a basic obligation of every pet owner. However, do not think that everything will be fine after vaccination, and do not simply not vaccinate your dog because you still get infectious diseases after immunization. A full set of examinations should also be performed after completing the vaccine, and if no antibodies are produced, a new vaccination is required.
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