Inherited Cats

Question
Last winter I inherited an elderly family members' two cats.  The cats were found by a neighbor of hers about 3years ago and the boy (although very large- 18lbs) was still nursing at the time.  The original vet my aunt brought the cats to in Ca thought the mother was about a year and the son about 6 mos at the time (which would put them at 4 & 3 now).  According to my aunt that vet fixed both the cats and gave them all shots at that visit.  They have been strictly indoor cats ever since.

When it came time to move the cats back east to CT- the new vet in CA gave them all shots again and said they both had earmites-particularly the son. I have tried repeatedly to administer the drops to both cats with no luck- these cats are very skittish from being strays, and I can't even get them in the crates to see a vet here for followup. He is the only one who seems to continue to scratch.  My question is: will allowing this to go untreated cause them any permanent harm or just the itching?  He doesn't have any scabs or other signs of irritation- but scratches many times per day.  Are there any other products on the market for earmites that could be administered in a vets office as a one time treatment?

Secondly, I have a question about the success of the male's castration.  Is it normal for him to still have 'urges' for females in heat 3 years after the surgery?  Last night I awakened to terrible howling and finally discovered that a neighborhood cat was cuddled right up to the sliding glass door.  My female was territorial in watching the interaction between her son and this cat and occassionally hissing.  Her son though, was trying to scratch through the glass and howling like I have never heard him do before to get at the cat outside (When he tries to get a squirrell or chipmunk through the window there is none of this noise!  He's a fat cat that usually is pretty lazy)

No matter what I tried (short of opening the door which I feared would lead to my cat getting out), I could not chase away the cat outside- and she(?) was howling too.  This went on for hours until I was so exhausted I finally slept despite the racket.

Am I right to guess that the cat outside was in heat and my male was responding to her?  Is this type of reaction normal for a male fixed 3 years ago?  Is it possible that since he's an indoor male- only around his fixed mother- that maybe the surgery didn't work the first time?  I haven't had any of the other typical unfixed signs like spraying or anything else...
Or do you think his response to this neighborhood cat was purely territorial?

Answer
Alternatives for ear mite treatment would include Ivermectin Injections--a series of 2, 2 weeks apart--or topical application of Revolution monthly.  I would not advise to just let it go as ear mites can lead to secondary infection and they are very uncomfortable.  You can try also giving Chlorphinaramine 2 mg orally twice daily to help reduce the itching to make him more comfortable.

I would suspect that your male cat was neutered correctly but his behavior is a territorial one and not a sexual one.  He was probably scratching to get out to attack her and not try to mate with her.  Males and females still have some sex hormones after de-sexing surgery and will still be able to detect an intact female but usually will never attempt to mount and mate them.