Tuesday, December 27, 2022

Does early castration affect foals’ development?

Male horses are generally castrated to make them easier to manage. Traditionally equine castration (or gelding) has been carried out at the yearling stage (c6-18 months of age). The procedure may be delayed in the hope that doing so will allow the colt to grow more.


A recent study at the National Research Institute for Agriculture, Food and Environment, France, assessed theimpact of very early castration of foals on their morphological and behavioural development.


Juliette Cognie and co-workers compared the effect of early castration at 3 days of age and traditional castration at about 18 months.


The study used 22 male Welsh ponies from an experimental herd and included foals born in three consecutive years. A report is published in the Equine Veterinary Journal.


Eleven ponies were castrated as neonates (ie within three days of birth) and 11 as yearlings /18 months of age. All were castrated using a primary closure technique under general anaesthesia. 


The researchers report that no mare rejected her foal after surgery, and neither did any foal show any behavioural problems – such as refusing to suck - after recovery from the anaesthetic.


The research team followed the ponies’ progress until they were three years old.  They recorded weight and body size measurements - initially monthly until 8 months of age, then less frequently. Behavioural assessments were carried out when the ponies reached one- and three-years of age.


Overall, the researchers found no significant differences in temperament or physical development between horses castrated as neonates and those castrated as yearlings.


They conclude “early castration at 3 days does not interfere with morphological or behavioural development.”



For more details, see:



Early castration in foals: Consequences on physical and behavioural development.

Juliette Cognie, Sandrine Freret, Lea Lansade, Celine Parias Philippe Barriere Amandine Gesbert Fabrice Reigner Stefan Deleuze

Equine Veterinary Journal (2022)



Monday, December 26, 2022

Could analysing saliva help detect Equine Gastric Ulcers?

(c) Dahlskoge Dreamstime.com
Gastric ulcers are widespread in horses – studies have found ulcers in around 60% of sport
horses, and in up to 90% of Thoroughbred racehorses in training. 

Many non-specific signs have been attributed to gastric ulcers. Weight loss, reduced appetite, poor physical condition, dullness, colic, diarrhoea, poor performance and altered behaviour have all been blamed on gastric ulceration. Even so, adult horses with gastric ulcers often show no signs. 


Full assessment and a definitive diagnosis rely on the use of a gastroscope, which although relatively straightforward, is expensive.


In horses showing signs that might be due to gastric ulceration, a simple method of differentiating those with or without ulcers would be very useful.


Analysing saliva has proved useful – for example in behavioural studies where cortisol is measured as an indication of stress, and in assessment of tapeworm infection.


Could analysis of saliva provide a way of differentiating horses with gastric ulcers from normal horses??


In research conducted at the Large Animal Teaching Hospital at the University of Copenhagen the potential use of a panel of salivary biomarkers to detect Equine Gastric Ulcer Syndrome (EGUS) was evaluated.


Alberto Muñoz-Prieto and colleagues enrolled 147 horses in the study. They measured 23 salivary biomarkers and compared the values found in horses with EGUS, with those from healthy animals and from horses showing signs like EGUS but with no ulcers seen on gastroscopic examination. 


The research team found that 17 biomarkers were increased in saliva from horses with EGUS compared to healthy animals. Three of those biomarkers, uric acid (UA), triglycerides (Trig), and calcium (Ca), showed a modest but statistically significant difference between horses with EGUS and horses showing signs suggestive of EGUS but with no ulceration on endoscopy.


A full report of the work is published in Animals. 


The authors suggest that “These analytes could have potential use as biomarkers in horses with EGUS. For example, an ADA value within the range of healthy horses in our study could indicate that the horse is not likely to have EGUS at gastroscopy.” (ADA - adenosine deaminase – has been found to be higher in saliva of horses with gastric ulceration)


“In addition, higher values of UA, Trig, and Ca in a horse with clinical signs of EGUS would indicate a high probability of having EGUS at gastroscopy” they add. 


“These assays have the advantages of being non-invasive and also easy to measure because most of them are commercially available and are often included in the routine biochemistry profiles in clinical pathology laboratories.” 


“Further research using a larger population of horses will be needed to confirm these findings and the potential practical application of these salivary analytes in the diagnosis and treatment monitoring of EGUS.”


For more details, see:


Evaluation of a Comprehensive Profile of Salivary Analytes for the Diagnosis of the Equine Gastric Ulcer Syndrome. 

A Muñoz-Prieto; JJ Cerón; CP Rubio; MD Contreras-Aguilar; L Pardo-Marín; I Ayala-de la Peña; M Martín-Cuervo; I-M Holm Henriksen; JJ Arense-Gonzalo; F Tecles; S Hansen. 

Animals 2022, 12, 3261.


Wednesday, December 21, 2022

Free webinar to update on Horse-Human Interaction research

(c) Photojogtom Dreamstime.com
A free webinar on the work of the Horse-Human Interaction Lab at Texas Tech University will
take place on
 January 4, 2023 at 7:00pm (ET)

Christine Rudd, a PhD candidate in the lab, will talk about her research into Equine-Assisted Services (EAS)volunteers and the relationship between volunteer education, session safety, and horse welfare. 

She’ll also describe some of her research investigating EAS horses’ experiences in some common activities and their implications for future research and equine wellbeing. 

For more details, go to:


Antibiotic use in equine practices in the UK

(c) Monika Wisniewska Dreamstime.com
Equine vets are not doing enough to limit the development of antimicrobial resistance, according to a recent study.

Antimicrobial resistance poses a significant and growing threat to human and animal health. Once antimicrobial resistance develops, it can result in treatment failure in veterinary patients and risks transferring resistant bacteria to people.


The study, by Sarah Allen and colleagues, set out to monitor antimicrobial use in equids in the UK. It was conducted as part of the VetCompass programme at the Royal Veterinary College (RVC) and was funded by the Veterinary Medicines Directorate.


The researchers used anonymised electronic health record data from 64,322 horses, ponies and donkeys in the year 2018, supplied by 39 veterinary practices. They analysed both the prescription data and clinical notes documented within these records.


Their findings highlighted that in 2018, approximately 20% of equids attended by the participating veterinary practices were prescribed an antimicrobial licensed for systemic administration.  Potentiated sulphonamides were the most commonly prescribed class of antibacterial agent. 


However, nearly nine per cent of treated equids received a Category B antimicrobial. The use of these agents, such as quinolones, 3rd- and 4th-generation cephalosporins and polymyxins, is restricted to try to ensure they remain effective for treating serious illness in human medicine.


Bacteriological culture and sensitivity testing was found to be rarely employed, despite its importance in protecting against antimicrobial resistance, by identifying the most appropriate antimicrobial to use. Fewer than one in five antimicrobial courses that included a Category B antimicrobial were supported by culture and sensitivity testing.


The study also identified several important risk factors for increased antimicrobial usage.  The research team found that the highest usage groups of Category B antimicrobials were equids under one year old, Thoroughbreds and racehorses. 


Meanwhile, the most common disorders that were treated with antimicrobials were urogenital (urinary and genital tracts), integumentary (skin and gland organs) and respiratory (airways, lungs and blood vessels) conditions.


Dr Allen said “The surveillance of equine antimicrobial usage helps the veterinary profession demonstrate their commitment to the responsible prescribing of antibiotics in the horse. We hope that by reporting on how commonly antimicrobials are prescribed to horses, and demonstrating where stewardship may be improved, others will look to compare and better their own prescribing of these vital medicines.


She suggests that more needs to be done to encourage the use of culture and sensitivity testing prior to treatment, especially when Category B antimicrobials are concerned. This will help ensure they remain effective and will reduce the risk of antimicrobial resistance developing.


For more details, see:


Use of antimicrobials licensed for systemic administration in UK equine practice

Sarah E. Allen, Kristien L. P. Verheyen, Dan G. O'Neill, Dave C. Brodbelt

Equine Vet J (2022)



Sunday, December 18, 2022

Steaming hay can lead to protein deficiency

 Hay can be treated with steam to reduce the horse’s exposure to inhaled allergens that cause
respiratory disease. Steaming kills potentially harmful microorganisms and binds fungal spores and dust particles to the hay making them less likely to be inhaled

However, new research shows that steam treatment can have an adverse effect on the digestibility of protein in the hay. 


A team of scientists from Martin Luther University Halle-Wittenberg (MLU) has discovered that steam treatment causes a chemical reaction that damages the proteins in the hay and makes them harder for horses to digest. This can lead to signs of nutrient deficiency in the animals and, for example, impair growth or muscle development. A report of the work is published in the journal Animals.


Professor Annette Zeyner from the Institute of Agricultural and Nutritional Sciences at MLU explains: “Many horses suffer from lung problems such as equine asthma. The steaming process virtually eliminates all of the living microorganisms and particles in the hay that could be inhaled during feeding and damage the lungs. In theory, the end result is a very good forage," 


However, her team discovered that the treatment also has its disadvantages as the steam damages the proteins in the hay. 


"A high proportion of the proteins, and the crucial amino acids contained in them, can no longer be digested by the small intestine - in other words the horse lacks these proteins as a result of the steam treatment. However, some of these protein components are essential for horses and they cannot be absorbed in the large intestine," Zeyner continues. 


The researchers demonstrated this by examining various hay samples collected from central Germany. In the steamed hay, they found an increased number of products that are generated by the Maillard reaction, an indication that the proteins in the hay have been damaged. This is a reaction that also takes place when food is cooked, baked or fried and is responsible for browning or the development of flavours. 


"Proteins are composed of amino acids. The steaming damages them and they form new complexes with sugars in the hay," explains the first author of the study, Caroline Pisch, from MLU. This makes them difficult for horses to digest. According to the researchers’ analyses, the treatment reduced the amount of protein that can be absorbed by the small intestine by almost half. The pre-caecal digestibility of the essential amino acid lysine was over 50% lower after steam treatment.


According to Zeyner, this can lead to an undersupply of essential amino acids from the feed, which can be a problem for growing horses or lactating mares; young horses need proteins to grow, and mares need them to produce milk. To make matters worse, protein deficiency causes very unspecific symptoms in the affected animals. These include impaired muscle development and a dull or shaggy coat with so-called "hunger hair" - long isolated hairs in the horse’s coat. 


She suggests that horse owners can counteract this risk by enriching the animals’ diet with protein-rich single feedstuffs such as yeast and soybean meal or high-quality protein-rich compound feeds. 


The report concludes: “steamed hay is still a proper and sometimes the only possible roughage for horses suffering from respiratory diseases such as equine asthma. Essentially, horse diets based on steamed hay should be balanced accordingly."


For more details, see:


Effect of Hay Steaming on the Estimated Precaecal Digestibility of Crude Protein and Selected Amino Acids in Horses

Caroline Pisch, Monika Wensch-Dorendorf, Uwe Schwarzenbolz, Thomas Henle, Jörg Michael Greef, and Annette Zeyner. 

Animals(2022) 12, no. 22: 3092. 


Saturday, December 17, 2022

Help wanted for Canadian quarantine research

(c) Anna Cvetkova Dreamstime.com
Horses travelling to competitions present a risk of bringing infections back home. At the event they encounter other horses and may pick up infectious diseases. As events often last only a few days, horses may return home while incubating the disease, and subsequently infect their stable mates. 

Researchers at the University of Guelph, Canada, are seeking participants for a study entitled “Effectiveness of Equine Facility Quarantine Procedures Following the Arrival of a New or Returning Horse”

The research, conducted at the Ontario Veterinary College, is funded by the Natural Sciences and Engineering Research Council (NSERC), and the Canada Research Chairs program. Principal investigators are Dr. Amy Greer, and Dr. Terri O’Sullivan aided by PhD candidate Gabrielle Turcotte. 

They explain that the research “seeks to examine the effectiveness of a quarantine protocol for an equestrian facility in the case of a potential spread of an infectious pathogen. We also hope to interview equestrian facility owners about the perceptions of risk of travel to off-property equestrian events and existing biosecurity procedures at home facilities.

“With most events in Ontario lasting no more than 4 days, horses can then return to their home facility before showing clinical symptoms of disease, putting the home facility herd at risk. This research study could help your facility evaluate its ability to maintain equine herd health and welfare. Additionally, your insight can have an impact on expectations and importance of quarantine protocols and help inform existing network simulations for equine infectious disease.”

So, if you are based within 90 minutes of Guelph or Toronto, with a horse facility housing between 5 and 20 horses, with more than one horse owner, that engage in off-property events, the research team would like to hear from you.
For more details, go to:

Wednesday, December 14, 2022

Horse training survey

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How do you train your horse?

Ella Bartlett at the University of Bristol is conducting an online survey looking into different horse training approaches, to see how widely they are used, and how people within the equestrian industry view them.


This study forms part of a PhD project which aims to improve our understanding of how horse owners make decisions in relation to the training of their horses.


The questionnaire is open to anyone aged over 18 years, who owns a horse, or has at least one horse on loan/ lease. Participants are welcome from around the world.


Twenty-two questions address topics relating to different horse training methods, including asking about your own approach, training beliefs and role in the equestrian industry. It should take approximately 15 minutes to complete. All responses are anonymous.


To take part, or for more details, see: