My 1 1/2 year old boxer is generally very playful and energetic. A few days ago she became lethargic, but did not lose her appetite or quit drinking. I noticed a knot on the side of her neck. Now the knot is much smaller and she has all her energy back. Any ideas?

I'm not a vet, could it have been possible that she was stung or bitten by an insect. Also in humans when we get a virus our lymph nodes will swell, not sure if that is possible with dogs. If she were mine as long as she was eating and the knot was going away I would just watch her, but if it swelled up again I would take her to the vet.

That's what I was thinking. I have looked and cannot find any bite wounds or stings. It almost seems like a swollen muscle. She is acting completely normal now (after much anxiety and praying from me!) And she's been playing well with our other boxer so I will put her on operation watch the dog! Thanks for the response.

Just an update... over the weekend the knot on Macy's neck went down and now you can barely tell she ever hurt herself. She is full of energy now too! Thank you for the help. I will definitely continue to use this website!

Just an extra thing to watch out for... Boxers are very prone to mast cell tumors, which release histamine, the chemical responsible for allergic reactions. This doesn't exactly sound like what you are describing (usually is more of a "hives" type reaction), but it bears watching. Go over the dog very carefully for any lumps or bumps that are present.

Call your vet and tell him what happened, just to be sure. Not trying to alarm you, just one of those breed related things you need to be aware of.