ASK THE VET

with Sue Hengemuehle, DVM

Dear Doctor Sue,

I have a four year old gelding that I'm racing at Prairie Meadows. He has had to run on Lasix since being put on the bleeders list and has run fairly well until recently. He bled his last start and my trainer says that he's bleeding through the Lasix, and that if we can't get it corrected we'll have to retire him. He is not a great race horse but my wife and I have fun watching him, and he is still fairly sound. He got a little swelling in his ankles a few starts ago after a hard race so we put him on Bute and that seems to have taken care of the problem, but now he is bleeding again. Any suggestions?

T.R., Des Moines, Iowa

Dear T.R.,

Sorry to hear your colt has started bleeding through the Lasix. A few things come to mind that may be of help to you. Since Lasix has helped your colt in the past, but now is not correcting the problem, you need to determine what has changed between then and now that may be affecting his respiratory tract. Things that need to be investigated would include infections, allergies due to changes in feed or bedding, irritation secondary to intranasal or intrabronchial medications, and drug interactions of other systemic medications that he is receiving. The only other medication that you mentioned was phenylbutazone. Countless scientific studies have shown that furosemide (Lasix) effectively reduces pulmonary hemorrhage in horses with EIPH ("bleeders"). When phenylbutazone is given along with the furosemide, the pulmonary artery pressures rise back up to the values seen prior to giving the furosemide; it's as if you never gave the Lasix if you give Bute with it. This may be why your horse has started bleeding again. Is your horse still being given Bute for his ankles? Does he need it? Have you determined what the problem was with his ankles? Talk to your trainer and investigate these things prior to retiring your colt. You may not have to give up watching your horse run.

Sue Hengemuehle, DVM

Sue Hengemuehle, DVM is a veterinarian on staff with the Dept. of Animal Science at Michigan State University and has a private equine practice in Okemos, Michigan.