Lump on neck

I noticed a quarter-sixed circle of flies on my horse's neck about 3 weeks ago. Presently, the spot where the flies were conjigating has swelled to a 3 inch diameter welt, and the flies have began...I noticed a quarter-sixed circle of flies on my horse's neck about 3 weeks ago. Presently, the spot where the flies were conjigating has swelled to a 3 inch diameter welt, and the flies have began...

Story originally posted by: Michael Lowder, DVM, MS

Dear Dr. Lowder,

I noticed a quarter-sixed circle of flies on my horse’s neck about 3 weeks ago. Presently, the spot where the flies were conjigating has swelled to a 3 inch diameter welt, and the flies have began to cluster at a spot about six inches away from the original location.

The current spot is a bit rough and scaley, but no sore is appearant. Can you please advise me if the 3 inch wealt could have been caused by the flies?

I have 11 other horses, and have never witnessed a similiar situation. I intend to have my veternarian inspect the welt, but would greatly appreciate any insight you could give me as it seems that the lump is related to the cluster of flies.

Thank You
Ida

Ida:

Have your vet check for hypodermiasis (warbles). Please let me know what come of this one. I am interested.

Thanks,
Dr. Lowder