Dogs lead the pack when it comes to swallowing things that they shouldn't, but surprisingly cats can also swallow things that are bad for them. One of the worst things is string and we have a post on that very subject. They also have an odd affinity for needles and even thumbtacks. James F. writes:
Unfortunately, James, the only course of treatment is endoscopic removal of the object by a veterinarian. The procedure will require x-rays to find where the object is in Arti's gastrointestinal tract but it won't require surgery or a long recovery period.
If you try to get him to vomit it up, the sharp end can do damage on the way out. If you leave the thumbtack to come out on its own, it could damage his intestinal tract and create huge problems down the road, possibly leading to Arti's death. The only safe way to remove it is with an endoscope.
It's imperative that you take him to the vet immediately. Arti's depending on you. Many vets have programs where they will perform a procedure and then accept payment over time. This shouldn't be extremely expensive but it's absolutely necessary for Arti. We certainly hope you're able to find a way to get him the treatment he so desperately needs.