trazadone is trazadone, unless you’ve gotten it compounded or something. I had 29 50mg tablets left over from when my GP gave me an Rx to see if it would help my insomnia, and I took 1/2 of one and it was horrible for me so I never took another, so the first day of boy’s traz I used the rest of them and decided to actually put my tongue on it - SO bitter! I got 3 different shipments from Allivet after that (150mg tabs) and they were equally as bitter.
BUT, different horses, just like people, have slightly different taste receptors, so some horses may not taste its bitterness well