Tequita,

First of all, there are lymph nodes (glands) under the jaw as well as salivary glands.  Unless you know what to feel for, you could be palpating either of these.

If it is lymph nodes that you are feeling and they are truly swollen, the proper approach is not to give your pet something to reduce the swelling, but rather investigate to determine why they are enlarged.  Once the cause is determined and the proper treatment for that cause is initiated, then the lymph nodes should reduce in size. 

If the cause of the swelling is in the lymph node itself, such as with a cancer, then the node may have to be removed surgically.

If the swellings are salivary glands, the appropriate treatment will need to be started.

Helpful Buckeye

Thank you! How can I tell if it's lymph or salivary glands? They came on really fast and aren't as large as they were , but concerns me.

Lymph nodes will be further along toward the rear half of the jaw.  Also, based on probability, what you are describing is most likely lymph nodes.  Lymph nodes can enlarge, then decrease in size on their own, especially if there was an infection in that area that then regressed on its own.

Helpful Buckeye

I really appreciate your help. What would cause the lymph nodes to enlarge so quickly , like in an hours time. He came in the house after being in a fenced yard for about 10 minutes favoring his front leg and wouldn't let us pick him up without yelping. Soon his neck swolled way up. Weird!

...and now for the rest of the story, as Paul Harvey used to say.  By chance, was the sore leg on the same side of his body as the swollen lymph nodes?  If so, it sounds like he was bitten or stung by something that caused an allergic reaction.  That would cause fairly rapid swelling, possibly including the regional lymph nodes. 

If that's the way this episode progressed, he should have been back to normal within 24 hours.

Helpful Buckeye

Both sides were swollen. He hurt for about 24 hours before getting back to being able to be picked up. I thought he had he had been bit by something as well , but couldn't find anywhere on him that would prove that. I felt the glands and they run from under his rear jawline towards the center of his neck.