Nancy Diehl, VMD, MS

Prior to attending veterinary school, Dr. Nancy Diehl completed a master’s degree in animal science while studying stallion sexual behavior. Later, she completed a residency in large animal internal medicine at the University of Pennsylvania’s New Bolton Center and worked in equine practices in Missouri and Pennsylvania. Diehl also spent six years on faculty at Penn State, where she taught equine science and behavior courses and advised graduate students completing equine behavior research. Additionally, Diehl has co-authored scientific papers on stallion behavior, early intensive handling of foals, and feral horse contraception. Currently she is a practicing veterinarian in central Pennsylvania.

Articles by Nancy Diehl

How Do I Get My Horse to Load in a Trailer?

An equine behavior expert offers training tips for making trailer loading drama free. Read More

Can a Mare's Personality Change After Her First Foal?

Dr. Nancy Diehl addresses a question about why a mare might respond differently to training after having her first foal. Read More

Orphan Foal Behavior

An equine behavior expert offers advice on raising and training an orphan foal to reduce future unwanted behaviors. Read More

Normal Mare and Newborn Foal Behavior

Find out what to expect as your mare goes into labor and during your foal's first hours of life. Read More

Managing Breeding Stallions

Dr. Nancy Diehl offers advice on keeping stallions happy and safe during routine handling and breeding. Read More

Differences Between Mares and Geldings

Dr. Nancy Diehl addresses common behavior differences between mares and geldings and their causes. Read More

What's an 'Alpha' Horse?

Dr. Nancy Diehl shares her thoughts on dominance in horses and using the term "alpha" to describe a lead horse. Read More

Are Horses Smart or Not, or Good or Bad?

Dr. Nancy Diehl weighs in on how to tell if a horse is intelligent, or whether he's inherently good or bad. Read More

Managing a Head-Banging Horse

My gelding has started banging his head against the trailer wall. Read More

Punishment and Horses

Does punishing horses work to deter them from certain behaviors, and when is punishment appropriate for a horse? Read More

Why Do Horses Weave?

Find out why a horse might start weaving and what, if anything, you can do about this stereotypy. Read More

Why Does a Horse Rest a Hind Leg?

A vet and horse behavior expert shares how to distinguish between normal hind-leg resting behavior and lameness. Read More

Pulling Ponies Won't Quit Grass Grabbing In-Hand

Learn how to keep ponies, Miniature Horses, and full-sized horses from pulling and grazing when you lead them. Read More

What Does 'Sacking Out' a Horse Mean?

Learn how to get your horse to accept new and scary objects or sounds. Read More

Messy Gelding vs. Tidy Gelding

An equine behavior expert addresses a question about two geldings with very different poop patterns. Read More

Sunspot Spooking

Find out why horses spook at sunspots on the ground and what you can do to correct this behavior. Read More

Why Does a Horse Whinny?

Learn about equine vocalization and how horses might or might not use whinnies to communicate. Read More

Why Do Horses Nicker?

Dr. Nancy Diehl explains what we know--and don't know--about a horse's nicker. Read More

Help! My Horse Keeps Tossing His Head at Mealtime!

A veterinarian and equine behavior expert addresses a possible learned head tossing behavior at feeding time. Read More

Why Do Young Horses Champ Their Mouths?

Discover the possible reasons a foal or young horse might "gum" at an adult horse. Read More

Do Equine Genetics Influence Behavior?

An equine behavior expert and veterinarian explains the role that genetics play in a horse's behavior. Read More

Do Horses Learn by Watching Each Other?

Sometimes it seems like horses pick up behaviors from each other. But it might be for reasons different than you think. Read More

What Can I Do About My Horses Rushing the Gate?

An equine behavior expert and veterinarian offers tips on handling horses that crowd and rush the gate at mealtime. Read More

What's the Difference between a Vice and a Stereotypy?

Dr. Nancy Diehl considers the use of "vice" and "stereotypies" when referring to horse behavior. Read More

Why Does a Horse Shake His Head?

What causes horses to shake their heads, and how can this issue be resolved? Read More