Dr. Shawn D. Frehner

04/04/2025

DO YOU KNOW WHAT CAUSES GRASS FOUNDER?

Spring is a wonderful time of the year, but it may be the beginning of some serious problems for horses vulnerable to grass founder — like horses that are over the age of 10, easy keepers, overweight or cresty-necked.

Laminitis or founder, as it is commonly called, is inflammation of the laminae of the horse’s foot. Laminae are the delicate, accordion-like tissues that attach the inner surface of the hoof wall to the coffin bone (the bone in the foot). A horse suffering from laminitis experiences a decrease in blood flow to the laminae, which in turn begin to die and separate. The final result is hoof wall separation, rotation of the coffin bone and extreme pain. In severe cases, the coffin bone will actually rotate through the sole of the horse’s hoof where it becomes infected and can ultimately lead to the horse having to be euthanized.

Laminitis can be triggered by different causes, like repeated concussion on hard ground (road founder), grain overload, retained placenta, hormonal imbalance (Cushing’s syndrome), obesity, and lush grass.

In cases of grass founder, the sugar fructans produced by rapidly growing grass stimulates an overgrowth of bacteria in the horse’s large intestine. The bacteria produce and release toxins (endotoxins) that are carried by the bloodstream to the foot where they cause damage to the laminae and small blood vessels.

The best way to deal with laminitis is preventing and managing the causes under your control. Consult your equine practitioner for further information and to formulate a plan tailored to your horse's individual situation. If you suspect laminitis, consider it a medical emergency and notify your veterinarian immediately.

03/30/2025

Pasture Safety Check
This image is a stark reminder of why regular pasture checks are crucial! A bolt like this can cause serious injuries to your horses.
When inspecting your fencing, keep an eye out for:
• Loose or protruding nails, screws, or bolts
• Broken or splintered wood
• Sharp edges or exposed metal hardware
• Gaps where a hoof or leg could get caught
Horses are curious, and accidents happen fast—take a few minutes to walk your pastures and ensure they’re safe!

03/22/2025

Unlike humans, horses don’t have collarbones. Their shoulders are held to the rest of their skeleton via a sling of muscles and ligaments instead, often referred to as the “thoracic sling.”

Why is this important? We often ask our equine athletes to perform complex movements that require tremendous strength and coordination, and horses carry the majority of their weight in their front end. Therefore, it is imperative that the bulk of the muscles that support the front end are kept healthy and conditioned, and the horse is trained to use their “motor” — that is, engaging the large hind end muscles as much as possible to avoid excessive weight bearing on the front end.

If the front end of the horse is consistently overweighted or not at an appropriate level of fitness, repetitive biomechanical stresses get transferred down the leg to the smaller ligaments and tendons that were not designed to bear this weight, which can then lead to injury.

Brought to you by the AAEP Horse Owner Education Committee.

03/22/2025

Remember when your parents used to tell you to wait 30 minutes after eating before going for a swim? Unlike us, horses can actually benefit from eating forage before they exercise, as it may help reduce the risk of gastric ulcers.

While a variety of things can contribute to the development of stomach ulcers (medications, diet, stress, etc.), one train of thought is that these areas of irritation result as a consequence of the acid of the stomach splashing against unprotected parts of the stomach lining. When a horse eats forage, the hay can help absorb some of that acid and thus reduce the risk of ulcer formation.

It is important to note that a forage meal (one comprised of long stem hay) provides the most benefit, while eating large volumes of concentrate feeds (such as oats, corn, or other cereal grains) can actually increase the amount of acid within the stomach.
As always, please be sure to consult with your vet regarding further diagnostics and treatments if you have concerns that your horse may have gastric ulcers.

Brought to you by the AAEP Horse Owner Education Committee.

03/10/2025

While we are all looking forward to warm spring days and lush green pasture, the transition from winter hay to spring grass should be planned carefully to mitigate any health risks to your equine. In other words — just because your equine friend is not obese or suffering from a nutritionally related disease, doesn’t mean you should just forget about hay entirely and let your horse eat their fill of spring grass.

Feeding high-quality hay is a good way to satisfy a horse’s urge to chew when they can’t graze and provide essential nutrients at the same time. A mature horse will eat 2-2.5% of its body weight per day; roughage should contribute to at least half of this percentage, but most agree forage should be a minimum of 75% of the horse's diet. Please remember that not all horses are made equal, so a horse's total nutritive requirements will ultimately depend on the individual's age, stage of development, metabolism and workload.

Take-home message: Before making any changes to your equine companion's diet this spring, consult your veterinarian to determine their current weight/body condition score and to formulate a balanced and nutritious ration that meets your horse’s specific nutritional needs!

02/23/2025

This is available right here in Las Vegas. Pretty interesting. And I highly recommend the owners.

02/23/2025

FUN FACT FRIDAY!

Are you familiar with the many adaptations that help your horse stay warm during the cold winter months?

🌾 Hindgut digestion of hay produces the most heat, acting as a small furnace inside of the horse. This is why free choice; good quality hay is so important in the winter.

💪 Horses have a huge muscle mass and muscle activity produces heat. This includes running and playing and even shivering if their body temperature starts to drop. It is important to remember that these activities also will result in a bigger caloric demand so free choice hay and in some cases, grain, is often needed.

🧥 To blanket or not to blanket is a constant debate but either way, as it starts to get cold your horse will grow a thicker coat. If you decide to leave your horse unblanketed you may notice that they look “fluffy”. This is due to a phenomenon called piloerection where the hair stands up to better trap air within. Two layers of the coat also help with warmth. The inner layer is softer and has air pockets to create an insulating layer. The outer layer is coarse and has oils that keep moisture from penetrating the insulating layer and keep the horse warm.

⚖️ Wild horses go into the winter heavier than ideal, and the fat serves as an extra layer of insulation. However, if a horse is going to be kept heavily blanketed and in a barn during the cold weather months this is unnecessary and can lead to obesity related issues.

🦵Their distal limbs (below the knees and hocks) are made of mostly bones and tendons, tissues that are resistant to the cold temperatures.

🦶The hooves have an alternative route of blood circulation through larger vessels that can be used in low temperatures. This is why horses can stand in snow without detrimental effects.

👃A horse’s nose has a robust blood supply and is rounded so that it is less susceptible to frostbite than a human’s nose.
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Courtesy of the AAEP Horse Owner Education Committee

02/12/2025

Get 10 easy-to-follow expert recommendations from equine nutrition specialist Emily Smith to help prevent horse colic from occurring. Read now.

02/11/2025

02/10/2025

Honestly, I thought we were watching Hedley Lamarr for the halftime show. 

02/07/2025

While the number of confirmed equine rabies cases every year is low, talking about this disease remains important because of the potential for human exposure—which does NOT have to involve a bite from an infected horse, as contact of skin or mucosa with the horse’s saliva could be enough to transmit the disease.

Rabies has many faces, but they are all deadly—once a horse shows clinical signs, the animal invariably dies within a few days as there is no treatment.

The good news is that modern vaccines are highly effective and current AAEP recommendations list rabies as one of the “core vaccines” that should be given to all horses annually to maintain immunity (read the full AAEP vaccination guidelines here: https://aaep.org/guidelines/vaccination-guidelines).

Equine rabies is a real risk for all horses, and a public health concern as well. Be sure to set up a regular vaccination schedule with your veterinarian if you haven’t already done so. Remember that strange behavior on behalf of your equine friend is always a valid reason to check in with your horse doctor!

01/23/2025

It’s not uncommon to find horses and ponies living well into their 20s and 30s, thanks to continuous advances in nutrition and health care.

Horse owners have a big impact as well and can help their horses thrive in their golden years through proper management practices like those illustrated in the graphic. But remember, although there is much you can do on your own to keep your older horse happy and spry, some conditions associated with aging require medical intervention.

Scheduling regular visits and keeping a good line of communication with your veterinarian will allow you to respond quickly to any ailments or injuries that could cause your horse a serious or prolonged set back. That means less worry for you, and a better quality of life for your old friend!