Friday, May 26, 2023

Call for colic research

 Clinicians and scientists are invited to submit abstracts for the upcoming 14th International
Equine Colic Research Symposium, set to be held in Scotland next year.

This event, held every three years, and organized in rotation by the American Association of Equine Practitioners and the British Equine Veterinary Association, will take place in Edinburgh on July 10th to 12th, 2024.


The Colic Research Symposium presents a unique opportunity for equine veterinarians to absorb and digest the latest knowledge, clinical practice and scientific advances in the treatment and prevention of colic, from the world’s leading international equine gastroenterology experts.


Spanning 2.5 days, the symposium encompasses a wide array of topics delivered through concise 12-minute oral presentations. These presentations will cover diverse subjects such as surgical techniques, treatment methods, parasitology, gastric ulceration, endotoxemia, pharmacology of intestinal motility, colic complications, epidemiology, digestion physiology, the intestinal microbiome, and metabolomics. 


Each session will be followed by three minutes for questions and discussion. 


Poster sessions will be held during the first two days, providing an opportunity to explore additional research beyond the oral presentations and enabling delegates to review and discuss the work with presenters.


Clinicians and scientists have until 1 February 2024 to submit abstracts of recent work that they wish to present at this meeting. See:


For more details of the 14th International Equine Colic Research Symposium, see:

Risks of colic surgery

 Despite advances in anaesthesia and surgical techniques, there is still a significant risk
associated with equine colic surgery. It is a major surgical procedure that carries inherent risks such as anaesthetic complications, postoperative infections, and failure of the surgical site to heal properly.

In addition, colic surgery is usually performed under emergency conditions, when the horse’s health is already compromised.  


Even with successful surgery, horses with colic will likely require intensive care and monitoring in the postoperative period, which can be costly and time-consuming. It is important for horse owners to be aware of the risks associated with colic surgery and to have a frank discussion with their veterinarian about the potential outcomes and prognosis. Early intervention and prompt surgical treatment can improve the chances of a positive outcome, but it is not a guarantee of success.


To better assess the risk factors for colic surgery, researchers in Italy reviewed records of horses subjected to colic surgery in three referral centres between 2018 and 2021.

In a study published in the journal Animals, Alessandro Spadari and his colleagues from the Veterinary Teaching Hospitals at the Universities of Bologna, Perugia, and Turin, examined data from 451 horses that underwent colic surgery. The researchers found that the short-term survival rate for all horses who underwent surgery was 68.5%, and for those that recovered from both the surgery and anaesthesia, the survival rate was 80%.


The study also identified several potential risk factors that could affect the outcome of the surgery, including age, body condition score (BCS), packed cell volume (PCV), and total plasma protein (TPP) before and after surgery, amount of reflux, type of disease, type of lesion, duration of surgery, surgeon's experience, and the amount of intra- and postoperative fluids administered.


Through multivariate analysis, the researchers found that PCV at arrival, TPP after surgery, and BCS had the highest predictive power for short-term survival after colic surgery. 

Horses with a body condition score (BCS) of less than 4 out of 9 were found to have a higher risk of a negative outcome in the study. Additionally, horses that arrived at the referral centre with a packed cell volume (PCV) greater than 50% and total plasma protein (TPP) levels below 5.7 or above 7.4 had a poorer prognosis than horses with other values.


The type of lesion also played a significant role in the outcome of the surgery, with horses diagnosed with large colon volvulus, pedunculated lipoma, and small intestinal volvulus having the worst prognosis.


The authors of the study suggest that their findings may aid surgeons in making informed decisions and communicating the risks to referring veterinarians and horse owners. They recommend conducting additional prospective studies to validate the impact of the predictive indices examined in this research on short-term survival.



For more details, see:


Short-Term Survival and Postoperative Complications Rates in Horses Undergoing Colic Surgery: A Multicentre Study. 

Spadari, A.; Gialletti, R.; Gandini, M.; Valle, E.; Cerullo, A.; Cavallini, D.; Bertoletti, A.; Rinnovati, R.; Forni, G.; Scilimati, N.; Giusto, G. 

Animals 2023, 13, 1107.

Thursday, May 25, 2023

Is it possible to breed less “spooky” horses?

Identifying genes that influence horses
tendency to react to danger (c) UF/IFAS
Wild horses possess an instinct to stay vigilant, constantly on guard against potential predators. This innate behaviour remains ingrained even in domesticated horses, causing them to be easily frightened and alert to potential dangers. 


Horses often struggle to differentiate between genuine threats and harmless objects, such as a plastic bag floating past a riding arena. As a result, some horses may react to these perceived dangers by rearing, bolting, or bucking, creating hazardous situations for both themselves and their riders.


University of Florida researchers are working to identify genes that influence horses’ tendency to react to these “spooky” plastic bags. Identifying these genetic traits would be a first step towards one day selecting or breeding horses for the temperament types we prefer. These research results might be a decade away.


Samantha Brooks, associate professor of equine genetics at the University of Florida Institute of Food and Agricultural Sciences, along with her team, conducted an experiment on several groups of young horses from the UF/IFAS breeding program to gain insights into startle responses.


The horses wore wireless heart-rate monitors and were loose in a round pen. At set intervals, an umbrella was opened quickly within the animals’ line of sight. The team analysed the animals’ behaviour and change in heart rate throughout and after the initial startle reaction.


“We can’t read their minds,” said Brooks. “Their heart rate tells us what is going on inside that we cannot see from reading their body language alone. It was interesting to see the stories their heart rates told us.”


The team found that two clear groups of horses emerged from the data. The first group was startled by the umbrella opening, had a spike in heart rate, maintained a reactive or hyper-alert state including more time spent looking and moving away from the umbrella. The second group startled much like the first group to the umbrella opening, but with a different outcome. The horses experienced a spike in heart rate but then calmed quickly and carried on with their day. These animals perceived the stimulus and found it startling but did not to go through the behavioural patterns of avoidance and fear like the first group.


“Horses have adapted over thousands of years to live with people,” said Brooks. “Some of those changes include a reduction in startle response and are really helpful to better understand the horses we work with today.”


Now that two clear groups have emerged, the team will take this information and develop a study to differentiate the genetic components that make up how horses react to fear. Blood and hair samples were taken from each horse in the study for future analysis.


They plan to conduct a genome-wide association study (GWAS) in which the genome of the horses is scanned to identify genetic variations that differ between the two groups, By analysing a large number of genetic variants across the genome, they hope to identify regions or specific genetic markers that are associated with behavioural startle reactions.


Knowing how genetics influence behaviour can help horses and owners find their right fit.


“Understanding each horse’s genetic makeup will help you understand the type of animal you need,” said Brooks. “If we learn early on what this animal’s natural tendencies are most likely to be, we can make educated decisions on training and future careers to give the horse the best shot to grow into their potential, rather than becoming a problem or danger.”


Additionally, understanding a horse’s reaction to uncomfortable situations can make a difference in how they are handled for medical procedures, transportation and more.


“It’s important to know these traits because it can impact how we care for horses overall,” said Barclay Powell, a Ph.D. student working on the project. “This will be hugely important to the veterinary field as well. It’s not only helpful for the people handling the animals, but also for the horses’ welfare.”


“It doesn’t matter if the horse is a racehorse, therapy animal or driving a carriage, an unplanned startle response is generally a problem,” said Brooks. “We are just beginning to scratch the surface of this. It might take us 10 years or more to really have a clear understanding, but it is worth the effort.”


Funded by the National Institute of Food and Agriculture, this project was a collaboration between scientists and students studying equine genetics, behaviour and welfare science.


For more details, see:


Behavioral and Physiological Reactions to a Sudden Novel Object in the Weanling Horse: Quantitative Phenotypes for Future GWAS

Barclay B. Powell, Kelsey C. Horvath, Tyeler L. Gilliam, Kimberly T. Sibille, Andreas Keil, Emily K. Miller-Cushon, Carissa L. Wickens and Samantha A. Brooks

Genes 2023, 14(3), 593;

Thursday, May 18, 2023

Multiple drug resistant bacteria common in horses’ mouths


(c) Patricia Smith
A recent study examined the normal bacterial populations in healthy horses’ mouths and foundsigns of antimicrobial resistance among many of them.

The study linked to the growing interest in an approach that recognises that the health of humans, animals, and the environment are interconnected. “One Health” emphasizes the idea that the health of all living things is intertwined and that addressing the health challenges of one sector can have a positive impact on the others.


The study, conducted by Jose Pimenta and colleagues from the University of Trás-os-Montes and Alto Douro in Vila Real, Portugal, only included horses that had not received any antimicrobial therapy.


The researchers collected samples from the gingival (or gum) margin and cultured them in selective media. The isolated bacteria were then identified and subjected to antimicrobial susceptibility testing.


Out of the samples, the researchers identified fifty-five Gram-negative bacterial isolates, of which 89.5% were zoonotic, meaning they have the potential to spread from animals to humans. Additionally, 62% of the isolates were bacteria commonly found in the environment but can also affect humans.


Of the bacteria that were isolated, 48 (96%) demonstrated resistance to at least one agent in three or more antimicrobial categories, indicating multiple drug resistance (MDR). 


Resistance was widespread towards macrolides (81.8%), β-lactams (55.4%), and quinolones (50%), while sulfonamides showed relatively lower resistance (27.3%), along with tetracyclines and amphenicols (both at 30.9%). Additionally, a significant proportion of the isolates (51.5%) displayed resistance to carbapenems. (Carbapenems are a class of antibiotics that are restricted for almost exclusive use in human medicine in hospital facilities.) 


The presence of multiple drug resistant bacteria in horses' mouths, as revealed by this study, holds significance not only for equine health but also for human health. It highlights the potential transfer of antimicrobial resistance between animals and humans, emphasizing the need for a coordinated and holistic approach to combat MDR.


The authors conclude: “This study shows that the equine commensal oral microbiota contains zoonotic and potential pathogenic strains that could be easily widespread through other animals, the environment, and humans, with saliva being a potential vehicle. The overall antimicrobial MDR presented by these bacteria is particularly worrying considering the absent of antimicrobial contact of the horses included, which gives relevance to the transmission of MDR strains and genes between animals.”

For more details, see:



Pimenta, J.; Pinto, A.R.; Saavedra, M.J.; Cotovio, M. 

Equine Gram-Negative Oral Microbiota: An Antimicrobial Resistances Watcher? 

Antibiotics 2023, 12, 792.

Monday, May 01, 2023

Group-living horses better at following human cues

The horse's owner pointing to a bucket
The horse's owner pointing to the bucket on their left side
Credit: Oceane Leirhmann
 Horses living in large enclosures and kept in groups of three or more are better at following human directional cues compared to those kept in separate paddocks, according to recent research in Finland. The study's findings also suggest that horses' familiarity with the human giving the cues has no significant impact.

“It has been observed in earlier studies that horses with access to a pasture with other horses showed better learning performance and were less aggressive towards humans than horses kept in individual stables. Therefore, we wanted to explore whether horses’ social and physical environment affect their responsiveness to human indications,” says the lead author of the study, Doctoral Researcher Océane Liehrmann from the Department of Biology at the University of Turku.


The study involved an international research team comprising members from the University of Turku and the University of Helsinki in Finland, as well as the National Research Institute for Agriculture, Food and Environment (INRAE) in France. They observed and analysed how horses responded to human cues based on their living conditions. Additionally, they examined whether horses reacted differently when given cues by their familiar owners versus strangers. 


To conduct the tests, the researchers recruited 57 leisure horses that were privately owned and located in the Turku region of Finland.


During the study, the human informant, who was either the owner or a researcher, stood between two buckets with a piece of carrot hidden in each. An assistant led the horses to stand in front of the informant, who then moved toward one of the buckets, looked at it, and pointed to indicate that the horse should go to that bucket. The horse was released and had the choice of going to the pointed bucket or the other one. If the horse followed the human's indication and approached the pointed bucket, the informant rewarded it by opening the lid and letting the horse have the carrot. However, if the horse chose the other bucket, the informant caught the horse, and it did not receive a carrot. This process was repeated ten times per horse, and the researchers analysed how often the horses followed the human indication over the ten trials.


“Interestingly, horses living in groups of at least three individuals chose the pointed bucket more often than the horses living alone or in dyads. Similarly, horses living in pastures or big fields for at least 8 months per year followed the human indication more often than the horses living in stalls or small paddocks”, Liehrmann describes.


During the study, horses living in large pastures also tended to live in bigger groups, while most horses living in small paddocks were either alone or with only one other horse. So, it was hard to tell whether the results were influenced more by social deprivation or by the lack of space and enrichment.


“However, domestic horses living in larger groups may benefit from stronger cognitive stimulation. Indeed, having the choice of interacting with various individuals promotes complex social situations from which the horses can learn and improve their socio-cognitive skills.  This may also explain why horses living in groups had better success in the task that involved communication with humans,” Liehrmann notes.


In addition, the researchers discovered that the horses' ability to complete the task was not influenced by the familiarity of the person giving the indication. The success rate was comparable regardless of whether the informant was the owner or a stranger. This finding is inconsistent with previous experiments conducted on the same group of horses. In an earlier study, Liehrmann and her research team found that familiarity with the handler could impact a horse's behaviour in novel situations.


“Our hypothesis is that the context may play a role when investigating the effect of human familiarity in human-animal interactions.  In a more stressful environment, animals may rely more on a familiar human than on a stranger, while in a positive context, where animals already feel safe and benefit from a food reward, the identity of the interacting human may matter less”, says Liehrmann.


She adds: “Overall, our study shows that the living conditions of the horses had an impact on their ability to follow human indications. The living and social environments of horses are a challenge and open to debate in the equestrian world. These results support the idea that offering an appropriate environment to horses by providing access to pasture and the ability to freely interact with their own kind could contribute to the development of their social behaviour and extend to interaction with humans.”


For more details, see:


What drives horse success at following human-given cues? An investigation of handler familiarity and living conditions

Océane Liehrmann, Camille Cosnard, Veera Riihonen, 

Alisa Viitanen, Emmi Alander, Plotine Jardat, Sonja E. Koski, Virpi Lummaa & Léa Lansade 

Animal Cognition (2023)


For a video, see: