my dog dog bit me on the top of my hand and his tooth went in between the small finger and the 4th finger leaving a small puncture wound nothing serious but i now have shooting pain up my arm when i try and bend or straighten it and of course it hurts when i try and close my hand. i have had a tetnus shot mnths ago do i need to get it xrayed or could the nerve tendons inbetween fingers be bruised giving me pain up my arm?
Since it is your dog, I assume it has been vaccinated against rabies. If it has not been vaccinated, you need to contact your doctor.
As far as tetnus is concerned, most Americans are over vaccinated for tetnus, as whenever there is an injury, they get a tetnus booster. This happens, because unless you can provide proof of being vaccinated, you'll get the booster. But, it is actually only need once every ten years. So, you are fine, if it has only been a few months.
As to the wound, animal bites (including human) can be very problematic. Cat and small dog bites are a problem, because it is a puncture wound, with the skin closing over the wound. This can seal the bacteria deep inside the tissues. Large dogs tend to slash, ripping the tissues, and thus are actually less likely to get infected.
Cats and dogs have a particular bacteria in their mouths, that can cause a nasty infection, which is Pasteuralla multocida. They also have the usual staph and strep species as well.
So, the tenderness you are feeling could be coming from a couple of things. One, of course, is an infection. This is more likely if you develop large soft tissue edema, redness, warmth, and/or drainage from the wound. But, some infections are indolent and may take a while to show themselves.
The dog could have gotten one of the extensor tendons. The tendons deep in between the fingers are actually from the intrinsic muscles in the hand. The extrinsic tendons, which are attached to the muscles in the forearm are on the top of the knuckles, though there are little side connections, or intertendonous connection, between the extensor tendons on the dorsum (top) of the hand.
It is possible the extensor tendons have been injured, giving you the pain into the forearm. If the tendon has been transected (cut), then it would be difficult to extend the finger fully, if at all.
If the tenderness does not start to get better soon, or starts to get worse, you might want to see a hand surgeon for an evaluation.