14yr old dog sick

Question
few days back my 14yr old was having a wound in his leg,by
mistake we applied an expired antiseptic to it.Now the
wound is heeled but due to that expired antiseptic
reactions he has developed swelling in his leg.I consulted
a vet but he only suggested me a pill for swelling and
pain.Would that be right at this situation.He has also
developed kind of tumors in his lower neck and leg.My dog's
front
left leg is already paralyzed,and he is overweight,its
getting really difficult to make him walk now.please
suggest something

Answer
Expired antiseptics don't usually cause any swelling, they just are not as effective. Something else is causing the swelling in the leg. It could be that the infection is deeper than you think and that the it is only healed on the outside of the skin.

The only way to know is to have the vet look at it.

I have no way of knowing what the tumors might be. Overweight dogs tend to grow more fatty tumors than dogs that are thin. They are deposits of fat in a lump under the skin.
While usually benign, they can grow very large and sometimes turn into bad tumors.
I have no clue what 'pill' he recommended for swelling and pain since you did not mention it.

Have your vet look at the leg and see how deep this infection is. He should be on antibiotics at the very least for the leg.