10/09/2026
🐴 The Horse You Tried… Is It the Horse You're Bringing Home? 🧪
Recently, our team has seen an uptick in pre-purchase toxicology screens coming back positive for trazodone, a medication that can have a calming, sedating effect on horses.
🤔 Why does this matter?
A horse with trazodone in its system may seem quieter and more reserved during your trial. Slower, Less reactive to the leg and the external stimuli and ultimately easygoing in a new environment.
But once the medication wears off, the horse that arrives at your barn may have a lot more energy than the one you rode, and may not be the right fit for you, your goals, or your program.
🧪 What toxicology testing does
During your pre-purchase exam, we pull a small blood sample that's screened for calming agents, pain medications, and other substances that could mask a horse's true temperament or soundness. The blood sample is then prepped to be sent off to a specialized equine toxicology lab. This gives you a clearer picture of the horse you're actually committing to.
🔬 How the testing works
Your horse's blood sample is sent to a specialized equine toxicology lab, where it's analyzed using LC/MS/MS (liquid chromatography/ mass spectrometry/ mass spectrometry). This means the lab separates the sample into its individual components and identifies them with a high degree of accuracy. It's the same type of highly sensitive technology used in competition drug testing.
Our standard pre-purchase screen checks for more than 30 drugs, including common sedatives, tranquilizers, anti-inflammatories, pain relievers, corticosteroids, and local anesthetics.
💊 Common substances that can change what you see:
🔹 Bute (phenylbutazone): An anti-inflammatory pain reliever that can hide lameness or discomfort during your trial and exam.
🔹 Ace (acepromazine): A tranquilizer that can make a horse appear calmer and more laid-back than normal.
🔹 Dormosedan (detomidine): A sedative that can dull a horse's reactions and energy level.
🔹 Rompun (xylazine): A commonly used sedative that can make a horse seem quieter and less responsive.
🔹 Reserpine: A longer-acting tranquilizer that can keep a horse subdued for days.
🔹 Trazodone: A calming medication we've been seeing more often, which can take the edge off a horse's natural energy.
Any of these can change how a horse looks, moves, or behaves, which means the horse you fall in love with during your trial may not be the same horse once it's home.
💡 Our recommendation
Yes, it's an added cost. But compared to the investment of a purchase or lease, and the time, training, and safety that come with finding the right match, it's a small price for peace of mind.
✅ Buying? Add toxicology to your PPE.
✅ Leasing? Add toxicology to your PPE.
Never skip this step.
📞 Planning a pre-purchase exam? Contact PHD Veterinary Services at 352-538-9165
