Firstly, I have to point out I have no medical training or background and ultimately the choice is up to the individual, but in my opinion rabies jabs before you go are not essential for most visitors to Thailand.
Rabies vaccination before you travel
The pre-exposure rabies jabs may be useful for some people, but it is important to note that they will not (by themselves) prevent rabies. If you get bitten by an animal that may be carrying the disease you will still have to visit a hospital (within 24 hours of being bitten) to be injected with the rabies vaccine. In very simplistic terms, what the pre-travel shot does is bide you more time. Therefore, if you are likely to be travelling in very remote areas the pre-travel inoculation could be something to consider. I would suggest that for most tourists and holidaymakers, rabies jabs before you travel are not necessary. The risk of being bitten by a rabid animal is small and if you are unfortunate enough to be bitten by a soi dog in downtown Bangkok or a monkey in Ko Samui, getting to a hospital which can treat you is no problem.
Treatment in Thailand
The animals in Thailand that are most likely to cause concern from a rabies viewpoint are dogs, monkeys and bats. I have been bitten once in all the time I’ve been here and I’m quite sure the animal wasn’t rabid, but as a precaution I went to hospital to have the course of rabies jabs administered. The treatment was cheap and efficient and personally I see no reason to have rabies immunisation before coming to Thailand.
I don’t want to make light of the issue because there is no doubt that some dogs in Thailand carry rabies. If you do get bitten by a rabid animal and have not had the rabies shot in your own country, there is still no need to panic. A visit to a Thai hospital will sort you out without too much drama. The course of jabs has to be administered over a few weeks and depending on the length of your stay in Thailand may have to be completed in your home country.