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Page 1 of 2 Vaccination
Immunity
 Vaccine
These defense mechanisms are similar in man and animals, and they work very well when health is good, but are not so effective when the body is in a run–down state, underfed or weakened, or when there is a state of mental or physical stress.
When an organism succeeds in passing these primary barriers, the body still has resources to use against the invader. The immune system comes into action to manufacture special and specific weapons – antibodies – to use against the organism making the attack.
Puppies
Puppies do have an immune system of their own at birth, but it is not fully developed. Thus nature has arranged for them to acquire some protective antibodies from their mothers. These are called passive antibodies since they have not been produced by the puppy itself. A modicum of passive “Maternal antibody" passes to the puppy while it is still in the uterus, but most comes via the colostrums, the first milk from the dam. Antibodies to disease in the colostrums can only be absorbed by puppies for the first day or so after birth and that time can be much shorter. It is obvious therefore that when the litter is very large or the whelping is prolonged, the early puppies are going to have more opportunity to get colostrums than those born later, so the ability to resist disease may vary between the members of the litter.
The antibodies which the mother passes to her puppies will be to those diseases which she herself has encountered or been vaccinated against. If she has lived a very isolated or protected existence, never met other dogs, and has never been vaccinated, she will have no protection to pass on, and her puppies will be vulnerable to all the infectious canine diseases from their earliest days.
Although the mother will pass on protective immunity through the colostrums, this type of protection will fade quite soon – in fact the amount in the blood halves each week, so the puppy must develop its own antibodies either by encounter with disease or by vaccination if it is to be protected for the rest of its life.
Adult Dogs
Most disease–causing organisms consist mainly of proteins. A healthy body is quick to detect proteins foreign to itself and to set about rejecting them by the production of specific antibodies to the invader. These active antibodies (i.e. they are created by the animal itself) are produced by specialized white blood cells found mainly in the lymph nodes and spleen.
The first time the body encounters a specific disease, or a vaccine, active antibodies may take as long as ten days to be produced, but next time that disease presents itself, memory cells come into action and antibodies are “Manufactured” very quickly, so that the disease does not have the chance to become established. This is why some diseases of man and animals occur only once in a lifetime. For example, measles in man is usually a once–only disease and once an attack has been survived, there will be life–long protection.
Antibodies tend to be very specific and destroy only the microbe (the antigen) which stimulated their production. A blood sample taken from the dog and processed at a laboratory will show if the dog has antibodies to a particular disease circulating in the blood, and sophisticated techniques can often reveal whether the antibody has been made in response to a recent infection or has been present for some time. Antibody levels wane with time, but another encounter with the right antigen will cause a quick resurgence of production.
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