Past few weeks pics..Nice rainbow wierd sore?

[15FOOTER]

Hit the salt first and put some blood on the deck. Stripes were on fire for us last week of April. Then the blues invaded. Went out yesterday in the lake and got blown all over the place. Still got 3 smallies and this beautiful 21" rainbow. Looks like it had a sore on its gill plate if you zoom in. Anyone think its anything disease related? Fish seemed healthy and fought great outside of that. Wouldnt want any diseases in Round Valley.