1 yr old chihuahua puppy neutered now lump near right back rib/leg area

Have my 1yr chihuahua puppy neutered few days later wife and I noticed a lump near his back rib right hip area, it's a nickel size soft moveable, he seems normal as usual but notices, he looks at you when you touch it, but he is in no pain...also he has a his rabbies shot...maybe a allergic reaction? Or ? Thoughts?

Hello - sometimes the Rabies jab can cause a thickening in the skin, and sometimes this can even be in a surprising place on the dog if the injection was given s/c eg when the patient was asleep.   Other possibilities include swelling after other injections or even fluids, although fluid lumps should disappear quite quickly.  Obviously the timing of its appearance doesnt rule out other reactions, lumps and bumps, abscesses, insect bites, tumours, swollen lymph nodes etc so please do consider running this by your vet / asking for triage, especially if you are concerned that it is changing or deveoping.  Your vet or emergency team will help you to decide how soon the patient needs to be seen.