Does anyone have a horse that needs lasix but won't work on lasix?  Per the vet (due to being able to scope) I am giving 5 cc of lasix.  She has been scoped and tends to bleed lightly through 3cc so was bumped up to 5.  And now giving a 5 hour lead time!  This mare BEFORE lasix NEVER had a gate issue and always smoked an indoor pattern.  Has never been amazing outside though.  The first few runs on lasix (3 cc) did improve her times outside despite lightly bleeding through that amount.  Now it takes three people to help get her in.  She just refuses to move her feet.  She has NO adrenaline or excelerated heart beat and she is NOT firing.  She is actually super calm in the holding pen or alley.  Just won't go.   She is running a half a second off of her normal times.  Last winter (no lasix) I had NO gate issue and was winning 2d monies.  Now she is slipping more towards the 4D....  
I do have her on Oxygen Bleeder powder (only 3 weeks in) and their Race and Jail Break.  I had her on MVP airway but switched to the bleeder powder by Oxygen.  I also use flair strips on her.  I am doing interval conditioning during the week.  Any suggestions anyone??

Ulcers. Or pain. You have something else going on. 

This happened to a mare that I run,  I took her off of laxis and started Race Today. It took a bit of time to get the gate issues out of her head,  now she is running better than she did before. Race Today was the best decision I ever made. 

I think they all bleed whether we see it or not.  A starting gate issue tells me they are bleeding, or sore, or hurt, or ulcers, or so many things that can be wrong!  You've eliminated what a source issue is, might check for ulcers or something else. Seems like you have her on the right regmin. . it will just take time for her to heal mentally and physically or refer back to figureing out what else coudl be bothering her.  Never ending.  Your post is on the right track.  You're doing all that you can.

As for my regimen, anything in my barn that is currently being competed on gets a daily supplement as well as something on race day. I have been lucky this regimen has worked and I have had some that were previously on Lasix, but I have not used it with them since my regimen as been working.    

For the daily supplement I like K&C Plus by Cox labs.  https://coxvetlab.com/shop/k-c-plus/ - several places carry it. I am reviewing the Race Day supplmeent that someone else mentioned. One cannot reseach enough.

Day of race. . Clear Passage; Ventapulmin; just depends on the horse and I will even throw a nasal strip on if I feel I need to that day.

Mentally getting over the gate issue will take some time.  Getting the horse feeling better is huge.  Time off this winter will probably help and then when they come back. . .hopefully the gate issue is not too hard to get resolved.  As soon as they realize they are not dreading the job because something was hurting or wrong.. they go back to working. 

Hope we get to hear a good update in the future.  We are constantly falling apart as we age and it is so hard to always be guessing what is going on with our horses. 

Mine wouldn't run on 3 of lasix.  Tried everything. Saw tons of vets.  Had throat surgery.

I stopped running him.  I've had him on Race Today to try and make a come back.  

He hasn't run in 3 years.  Not excited about it because my gut tells me he's going to bleed.

I finally just bought another horse.

Sounds like you have something else going on. I would start with a thorough vetting, and start an ulcer protocol. You may also change up your lasix (maybe try the people version?) Or IV vs IM.. Just a few thoughts. Typically lasix should ADD half a second if its needed. Don't give up! Even lightly bleeding is still bleeding. Maybe some time off is needed. Also include something like race today, and I suggest you give an electrolyte paste before and afer. 

I have a horse that will NOT run on Lasix. I gave him 3 ml 2-3 hours out and he would run 0.5-1 second slower. I stopped Lasix and use Equiresp (soon upgrading to flexineb) as well as Bleeder Daily. He still has some bleeding episodes, but they are few and far between.