The State of the Microchip

The State of the Microchip

The practice of microchipping is becoming prevalent throughout the horse world–but for reasons beyond simply identifying a lost equid.

Photo: Anne M. Eberhardt/The Horse

More horse organizations are requiring owners to use this identification technology

Countless dog and cat owners can attest to the value of microchipping. These are the people who have spent sleepless nights agonizing over their pets’ disappearance and whereabouts until they receive that phone call with the comforting words, “Your dog is at the local animal shelter; we scanned him for a microchip and found your contact information.”

This practice of microchipping is also becoming prevalent throughout the horse world—but for reasons beyond simply IDing a lost equid. Many competitive organizations and breed registries are now requiring it for ease of identifying individual horses.

The Microchipping Process

Microchip implantation is a fairly innocuous process for horses—or any animal, for that matter. After scanning the chip to make sure it’s readable, a veterinarian uses a large gauge needle to inject the chip below the mane into the nuchal ligament on the left side of the neck, about halfway between the horse’s poll and withers. A new mini-chip is now available so that veterinarians can use a smaller-gauge needle for the procedure. This microchip and its surrounding glass-polycarbonate capsule is roughly the size of a grain of raw rice. The injection causes minimal discomfort to the horse and does not leave a scar. The chip is encapsulated within the ligament and unlikely to migrate within the tissue.

The entire process, including the price of the microchip, usually costs less than $100. Upon inserting the chip, the veterinarian scans it again to ensure it’s transmitting readable information. Then the horse owner registers the chip with the appropriate microchip company, as well as the desired sport organization and/or breed registry. This is a one-time process that needs no repeat fee or renewal.

This article continues in the January 2017 issue of The Horse: Your Guide To Equine Health Care. Learn how microchips work, requirements for microchipping, and more when you subscribe now and get an immediate download of this issue!

About the Author

Nancy S. Loving, DVM

Nancy S. Loving, DVM, owns Loving Equine Clinic in Boulder, Colorado, and has a special interest in managing the care of sport horses. Her book, All Horse Systems Go, is a comprehensive veterinary care and conditioning resource in full color that covers all facets of horse care. She has also authored the books Go the Distance as a resource for endurance horse owners, Conformation and Performance, and First Aid for Horse and Rider in addition to many veterinary articles for both horse owner and professional audiences.

Caudal Heel Pain or Navicular: What’s the Right Term?

Q. I’ve heard people use the terms “caudal heel pain,” “navicular disease,” and “navicular syndrome” when referring to a horse that has a lameness associated with the navicular bone and its related structures. Do all of these terms describe the same condition?

A. These terms are similar in meaning; however, technically, they are different.

Caudal heel pain is typically used to describe pain from the heel or back of the foot. A horse with caudal heal pain would respond positively to a palmar digital nerve block. The navicular structures are often included, but the horse could also have pain associated with other structures.

Navicular disease is usually used to describe disease that has caused radiographic changes to the navicular bone.

Navicular syndrome is more encompassing to describe lesions associated with the navicular soft-tissue structures and may not have radiographic abnormalities.

Having said this, all three terms are commonly used interchangeably depending on veterinarian preference.

About the Author

Josh Zacharias, DVM, MS, Dipl. ACVS, ACVSMR

Josh Zacharias, DVM, MS, Dipl. ACVS, ACVSMR, is an Iowa State University College of Veterinary Medicine graduate who practices at Countryside Large Animal Veterinary Services in Greeley, Colorado. His interests include equine lameness, surgery, and podiatry. In addition to working as a surgeon and sports medicine specialist, Zacharias is a farrier with nearly 15 years of experience in therapeutic shoeing applications. Much of his caseload includes Western performance horses.

Yes, Your Overweight Horse is at Risk for Laminitis

Yes, Your Overweight Horse is at Risk for Laminitis

Horses with body condition score of 7 or higher, generalized and/or regional adiposity, larger neck circumference, and decreased height (think pony) were at an increased odds of developing laminitis.

Photo: Michelle Coleman, DVM, PhD

Barn circles might banter about the chubby chestnut with the deep gutter down her back, or jest about the round roan who looks like he could foal any day now. But in a landmark observational case-control study in client-owned North American horses, scientists have demonstrated that these animals are more ticking time bombs than laughing matters—they are at risk for developing the painful and sometimes-fatal hoof disease laminitis. The good news is that many of the laminitis risk factors the researchers identified can be detected early and are modifiable.

“As we all know, laminitis is a disease of considerable importance to both horses and horse owners, with estimated incidence of 1.5% to 34% of horses affected annually, and 13% of horse operations,” said Michelle Coleman, DVM, PhD, assistant professor of Large Animal Internal Medicine at Texas A&M’s College of Veterinary Medicine & Biomedical Sciences, in College Station. “The lifetime risk of a horse developing laminitis is estimated at 15%. We all know that there’s a significant clinical and economic impact of this disease, especially in that there is no effective method or cure, and no effective method for prevention of disease.”

Coleman noted that this disease not only affects horses and horse owners but also veterinarians, who identified laminitis as the top priority for research funding in a 2009 American Association of Equine Practitioners (AAEP) survey of its membership. Coleman presented results from the pasture- and endocrinopathy-associated laminitis (PEAL) study at the 2016 AAEP Convention, held Dec. 3-7 in Orlando, Florida. She and her 15 co-authors in the Laminitis Research Working Group launched the research at the 2011 convention. And while she admitted many of the results were unsurprising, they confirm in no uncertain terms what veterinarians have believed for years and stress the importance of managing laminitis-prone horses very carefully.

Most existing research on laminitis has been conducted in experimentally induced laminitis cases. These approaches do predictably produce laminitis in study horses, but they aren’t an accurate representation of how natural disease occurs. Coleman said the group sought to study naturally occurring cases of disease. “Results of these epidemiologic studies are relevant to naturally occurring cases,” she said. “Our goal was to identify risk factors for development of disease.”

The researchers identified that the most common type of laminitis cases seen in private practice was PEAL, so they set out to investigate what AAEP members in North America were seeing in this type of case by recruiting cases via veterinarians and horse owners.

Coleman and colleagues asked veterinarians to report patients’ signalment (age, breed, sex, etc.), clinical signs, activity level, dietary status, and stable management practices in any case of laminitis within four weeks of onset of clinical signs with an Obel laminitis scale grade of 2 or higher. The scientists excluded horses with a history of laminitis due to toxic causes, grain overload, contralateral weight-bearing (such as in supporting-limb laminitis cases), and any other concurrent hoof disease.

Veterinarians in 32 states and three Canadian provinces responded, reflecting an 18% participation rate. The research team found 550 usable responses from submissions from 109 veterinarians. Ultimately, the study group included 199 cases, which Coleman and colleagues matched with 198 healthy controls, and 153 controls showing lameness (non-laminitic horses lame with a Grade of 3 to 5 lameness in one forelimb only). Some of the team’s key findings included:

  • The onset of clinical signs was greater in the spring and summer compared to the fall and winter;
  • Horses exposed to lush pastures were at an increased risk of developing laminitis;
  • Horses that had a recent stabling change or change in diet were at an increased risk of developing laminitis compared to horses with no recent change;
  • Horses with body condition score of 7 or higher (obese), generalized and/or regional adiposity (fat distribution all over or just in certain areas), larger neck circumference, and decreased height (think pony) were at an increased odds of developing laminitis;
  • Thoroughbreds and Warmbloods were at a decreased risk of developing disease and ponies and Minis were at an increased risk of developing disease
  • Horses that had endocrinopathic disease, such as equine metabolic syndrome or pituitary pars intermedia dysfunction (PPID, also known as equine Cushing’s disease) were at an increased risk of developing laminitis; and
  • Horses with recent glucocorticoid administration (such as dexamethasone or prednisolone) were at increased odds of developing disease though Coleman cautioned that researchers need more supportive evidence of this potential (only 6% of horses met this criteria).

Take-Home Message

Coleman scanned the audience, saying, “I see a lot of blank faces thinking, ‘Well, big surprise: Fat horses founder, steroids put horses at risk, endocrinopathic disease puts horses at risk of developing disease.”

However, she explained, this was the first observational study of only acute or incident cases of laminitis supporting a causal relationship of obesity and laminitis.

“Perhaps we need to think about laminitis in another way,” said Coleman. “What makes horses obese? Maybe obesity is a symptom of a much bigger problem. (We need to think) how can we reduce the burden of laminitis by reducing the burden of obesity? And while this distinction may be subtle, the impact may be profound.”

Similarly, she said, we might need to look at endocrinopathic disease in a new way–very few horses in this study had prior diagnosis of endocrinopathic disease, suggesting that laminitis was the first clinical sign these horses developed. If we can identify horses at risk of developing PPID or EMS early, then perhaps we can reduce the risk of laminitis, she added, suggesting dietary management practices for EMS horses, medical management for horses with PPID, and potential novel therapeutic agents.

The veterinary community’s potential for reducing the burden of laminitis also lies in client education and compliance, she said. “Until now, there has been limited evidence to support what we all think is true, that overweight horses founder and endocrinopathic disease results in laminitis. Now, with more supporting evidence I hope we can use this information to educate our clients.”

Still, in a 2010 study Coleman cited, only 1% of owners of geriatric horses perceived geriatric horse weight gain as an important health issue, so she emphasized that practitioners need to educate their owners early—early diagnosis, early intervention in these cases—to potentially reduce the burden of laminitis.

Coleman said this research was funded by the AAEP Foundation, with generous support from Boehringer Ingelheim.

About the Author

Stephanie L. Church, Editor-in-Chief

Stephanie L. Church, Editor-in-Chief, received a B.A. in Journalism and Equestrian Studies from Averett College in Danville, Virginia. A Pony Club and 4-H graduate, her background is in eventing, and she is schooling her recently retired Thoroughbred racehorse, Happy, toward a career in that discipline. She also enjoys traveling, photography, cycling, and cooking in her free time.

Santa Anita Daily Results and Activity

Early Entries

Friday, January 13 Overnight
Race# Race Type Purse
Race 1 Claiming – $20,000 $25,000
Race 2 Claiming – $16,000 $20,000
Race 3 Maiden Claiming – $50,000 $29,000
Race 4 Claiming – $25,000 $23,000
Race 5 Allowance Optional Claiming – $40,000 $56,000
Race 6 Maiden Special Weight $54,000
Race 7 Allowance Optional Claiming – $75,000 $56,000
Race 8 Maiden Claiming – $20,000 $18,000
Saturday, January 14 Overnight
Race# Race Type Purse
Race 1 Allowance Optional Claiming – $40,000 $56,000
Race 2 Starter Allowance – $16,000 $28,000
Race 3 Claiming – $8,000 $16,000
Race 4 Claiming – $12,500 $20,000
Race 5 La Canada S. $200,000
Race 6 Maiden Special Weight $54,000
Race 7 Maiden Special Weight $54,000
Race 8 Claiming – $50,000 $43,000
Race 9 Maiden Claiming – $30,000 $21,000

Final Entries

Thursday, January 12
Race# Race Type Purse
Race 1 Claiming – $16,000 $22,000
Race 2 Starter Allowance – $40,000 $30,000
Race 3 Claiming – $20,000 $25,000
Race 4 Maiden Claiming – $75,000 $33,000
Race 5 Maiden Claiming – $20,000 $18,000
Race 6 Claiming – $12,500 $16,000
Race 7 Claiming – $32,000 $33,000
Race 8 Maiden Claiming – $50,000 $29,000

Turf Paradise Daily Results and Activity


Wednesday, January 11
Race# Race Type Purse
Race 1 Claiming – $3,000 $7,000 Overnight Overnight Overnight
Race 2 Claiming – $5,000 $8,500 Overnight Overnight Overnight
Race 3 Claiming – $3,000 $7,000 Overnight Overnight Overnight
Race 4 Maiden Claiming – $5,000 $6,300 Overnight Overnight Overnight
Race 5 Claiming – $3,500 $7,000 Overnight Overnight Overnight
Race 6 Claiming – $3,500 $7,000 Overnight Overnight Overnight
Race 7 Claiming – $3,500 $7,000 Overnight Overnight Overnight
Race 8 Maiden Claiming – $5,000 $6,300 Overnight Overnight Overnight

Early Entries

Monday, January 16 Overnight
Race# Race Type Purse
Race 1 Maiden Claiming – $5,000 $3,700
Race 2 Stakes $8,000
Race 3 Allowance $15,000
Race 4 Claiming – $8,500 $8,000
Race 5 Allowance $16,000
Race 6 Starter Allowance – $3,500 $8,200
Race 7 Claiming – $20,000 $15,000
Race 8 Claiming – $8,500 $8,500

Final Entries

Sunday, January 15
Race# Race Type Purse
Race 1 Trials $3,000
Race 2 Trials $3,000
Race 3 Maiden Optional Claiming – $30,000 $12,500
Race 4 Claiming – $8,500 $8,500
Race 5 Claiming – $3,200 $7,200
Race 6 Maiden Optional Claiming – $30,000 $12,500
Race 7 Claiming – $6,250 $9,000
Race 8 Claiming – $3,500 $7,000


16-Apr BRIGHOUSE BELLE 3+ F&M 6.5F $50,000
30-Apr BC CUP DOGWOOD 3F 6.5F $50,000
30-Apr BC CUP STELLAR JAY 3 6.5F $50,000
6-May VANCOUVER SUN 3+ F&M 6.5F $50,000
7-May GEORGE ROYAL 3+ 6.5F $50,000
22-May JIM COLEMAN PROVINCE 3 6.5F $50,000
22-May ROSS MCLEOD 3F 6.5F $50,000
3-Jun STRAWBERRY MORN 3+ F&M 8.5F $50,000
4-Jun JOHN LONGDEN 6000 3+ 8.5F $50,000
24-Jun RIVER ROCK CASINO 3 6.5F $50,000
25-Jun EMERALD DOWNS 3F 6.5F $50,000
1-Jul LT. GOVERNOR 3+ 8.5F $75,000
2-Jul MONASHEE 3+ F&M 8.5F $75,000
15-Jul SUPERNATURAL 3F 8.5F $50,000
16-Jul CHRIS LOSETH 3 8.5F $50,000
16-Jul SPAGHETTI MOUSE 2 6F $50,000
7-Aug PCB CLASSIC 3+ 9F $75,000
7-Aug PCB DISTAFF 3+ F&M 8.5F $75,000
7-Aug NEW WESTMINSTER 2 6.5F $50,000
7-Aug HARD ROCK CASINO 2F 6.5F $50,000
7-Aug SIR WINSTON CHURCHILL 3 8.5F $50,000
7-Aug HONG KONG JOCKEY CLUB 3F 8.5F $50,000
7-Aug BC CUP MARATHON 3+ 9F $20,000
21-Aug CTHS SALES STAKE 2 C&G 6.5F $50,000
21-Aug CTHS SALES STAKE 2F 6.5F $50,000
25-Aug CTHS SALES STAKE 3 & 4 YR OLDS 3&4 8.5F $50,000
25-Aug CTHS SALES STAKE 3 & 4 YR OLDS 3&4F 8.5F $50,000
9-Sep BC DERBY G3 3 9F $150,000
9-Sep BC OAKS 3F 9F $100,000
9-Sep S W RANDALL PLATE 9F $75,000
9-Sep DELTA COLLEEN 9F $75,000
9-Sep JACK DIAMOND FUTURITY 2 C&G 6.5F $100,000
30-Sep FANTASY 2F 8.5F $100,000
1-Oct ASCOT GRADUATION 2 8.5F $100,000
8-Oct BALLERINA G3 3+ F&M 9F $100,000
9-Oct BC PREMIERS G3 3+ 11F $100,000
22-Oct BC CUP DISTAFF 3+ F&M 9F $50,000
22-Oct BC CUP CLASSIC 3+ 9F $50,000
22-Oct BC CUP NURSERY 2 6.5F $50,000
22-Oct BC CUP DEBUTANTE 2F 6.5F $50,000