top of page
  • Etalon Admin

Anhidrosis Validation Study: Samples Needed from "Non-Sweaters"

Summer is here! That means lots of hot and sweaty days at the barn with your horse... right? But what if your horse isn't sweating as much as they probably should be? Etalon Diagnostics’ geneticist, Dr. Laura Patterson Rosa DVM, PhD, performed extensive research on chronic (or long-term) anhidrosis in the horse, investigating the possible genetic causes. Her work was recently published, unraveling the findings of four years of research. Horses, like humans, rely mainly on sweat to regulate their body temperature; anhidrosis is a loss of the sweat response and can result in life-threatening overheating in horses. Previous epidemiological studies demonstrated an increased frequency among individuals with a family history, suggesting a genetic or heritable component to the condition. This is what Dr. Patterson Rosa set out to determine - what is anhidrosis’ genetic cause? Her initial findings identified a strong candidate variant in a gene related to potassium channel function. Dr. Patterson Rosa and Etalon Diagnostics’ team of researchers are launching a validation study to confirm her findings, and we need your help! Do you know a horse with chronic anhidrosis? Read on to learn how to participate in this important study.


A live Q&A session will be held with Dr. Patterson Rosa on Thursday, June 3rd at 5PM EST/2PM PST with more information on the study! Don't miss this opportunity to chat with an expert. Watch live on Etalon's Facebook and Instagram pages @etalondx.


DEADLINE TO SUBMIT SAMPLES: June 30th, 2021

Requirements for the study:

- Mail in a pulled hair sample from affected horse (directions below)

- Include proof of diagnosis by Veterinarian of chronic anhidrosis (horse has suffered from anhidrosis for longer than a year or one single season, with no signs of improvement) and complete health history profile of the horse. Diagnosis, breed, and horse health history can be uploaded into your horse's account at www.etalondx.com. (Please provide us with as many details as possible!)


Participants will be hand-selected by Etalon’s team, as there are a limited number of spots available for registered Warmbloods and stock-type horses (Quarter Horses, Paints, Appaloosas, and Thoroughbreds). It is important to note that, for this particular study, participant horses must have a veterinary diagnosis of chronic anhidrosis (lasting longer than one year).


Anhidrosis is the medical term describing a compromised or complete inability to sweat in response to increased body temperatures, due to exercise or environmental high temperatures. This condition is dangerous or life-threatening for horses. Horses thermoregulate primarily through sweating, which is responsible for cooling 65-70% of the body temperature. Although cases of anhidrosis are widespread in the hot and humid regions of the southeastern United States, they are also reported in cooler climate regions like the North US, Canada and even Ireland. It can affect several breeds of horses, although previous studies have demonstrated an increased incidence in Thoroughbreds and Warmbloods.


The condition’s onset can be gradual or acute. Increased respiratory rate and lack of sweat after exercise are the most common initial findings. In situations that should cause copious sweating, affected animals produce minimal sweat – perhaps a small amount under a saddle pad – when all other horses are completely lathered. Severely affected horses might not even be able to tolerate turnout on hot days; they will stand outside in distress with an extremely high respiratory rate and body temperatures higher than 104 degrees Fahrenheit.


Horses suffering from acute cases may have elevated respiratory rate and an elevated temperature that requires an extended period of time to return to normal, yet most of these go back to sweating normally after a season or two. Yet, horses with chronic cases of anhidrosis - called “Chronic Idiopathic Anhidrosis” or CIA - have a history of lack of sweat response, sometimes even all year long. For these, even moving to a cooler climate region may not help them recover the ability to sweat. These were the cases targeted by Dr. Patterson Rosa’s study, as their severe inability to thermoregulate puts them in danger of overheating, collapsing and even dying. You can learn more about anhidrosis here.


Participants will be hand-selected by Etalon’s team, as there are a limited number of spots available for registered Warmbloods and stock-type horses (Quarter Horses, Paints, Appaloosas, and Thoroughbreds). It is important to note that, for this particular study, participant horses must have a veterinary diagnosis of chronic anhidrosis (lasting longer than one year).


To submit samples, visit www.etalondx.com and click “order”. Create an online profile and click “Order Testing”. Choose package “STUDY_ANHIDROSIS” to send in your sample free of charge. Those whose samples are included in the study will receive follow-up information for results and publications. Mail hair samples to: 405 El Camino Real, #234 Menlo Park, CA 94025 For more information or if you have questions, give us a call at (650) 380-2995 or send us an email at study@etalondx.com.



383 views0 comments
bottom of page