Tetanus in dogs?

All I know if that dogs and cats are much more resistant to the tetanus toxin than humans. I do not know whether the cause of that difference is known.

If a dog has tetanus there is a possibility that the infection is especially severe or the dog has a mutation in one of the targets of the toxin which renders the dog more sensitive. This could be anything in the pathway which leads to the toxin to decreasing the level of inhibition in neurons.

Since the disease is caused by a toxin and not the bacterium directly and the toxin is really potent in contrast to other diseases having tetanus does not necessarily provide immunity against the disease in the future, however the vaccination is against a harmless variation of the toxin, not the bacterium.

Hmmmmm.......Please don't take this as an insult, but I personally don't think that you should advise anyone whether they should vaccinate their dog for this or not. You are studying to be a Vet Tech, but a licensed Veterinarian should be the one who should give out any advice on this subject, not you.

When it comes to this subject, I personally don't think that luck has much to do with it. Just like humans, some dogs have weaker or stronger immune systems than others.

Ask your professor or do your own research otherwise you'll never learn anything.