There are 2 tips to help with this:
Obtain a bowl designed to promote slow eating. These are dog food bowls with permanent obtrusion which gently yet effectively force a dog to eat around them, which aids in slower eating. There is a reduction of air that is swallowed... and food is ingested, and therefore digested, at a slow rate.
Keeping your Pug's bowl and adding an element called a portion pacer. It is a safe stainless steel orb that sits in the bowl, and similar to the above method, keeps a dog from gulping his food down. It can help a dog eat 4 to 8 times slower.
More frequent yet smaller meals can help. If you normally feed your Pug once per day, try switching to twice per day (making sure that the actual amount does not increase). While some adult dogs can do fine with one main meal per day, plus snacks, some Pugs do better with 2 or even 3 smaller meals.