Sunday, June 26, 2022

Drones for monitoring feral horses

© Mantvydas Krikstaponis
 Drones provide a way to monitor feral horse populations while causing only low levels of disturbance.

Javier Lenzi and co-workers at the Department of Biology, University of North Dakota, evaluated the behavioural response of feral horses in the Theodore Roosevelt National Park in North Dakota, to a fixed wing drone (Trimble UX5), as part of larger surveying project. 


The drone has a 1 metre wingspan, a rear propellor and weighs 2.5 kg. It was flown directly above the animals at an altitude of 120m. Video recordings were analysed by the research team in ten second sections.


They found that, although horses did respond to the presence of the drone, they did not show escape responses, which would have been expected in ground surveys or traditional low-level aerial surveys. Feeding, traveling, and vigilance behaviours increased, while resting and grooming decreased in response to the drone flight.


The researchers also observed the reaction of bison to the drone. Bison also showed increased feeding and travelling and decreased resting and grooming.


Reporting their findings in the journal Drones, the authors suggest that “the drone used in this study might have been perceived by horses and bison as low risk, possibly given the high altitude and small drone size. Our results showed that individuals did not display escape behaviour, and even increased feeding activities in response to drone flights at 120 m above ground level.”


They conclude that that drones “may serve as an appropriate tool for surveys of these species with low levels of disturbance, unlike other stressful sources.”


For more details, see:


Feral Horses and Bison at Theodore Roosevelt National Park (North Dakota, United States) Exhibit Shifts in Behaviors during Drone Flights 

Javier Lenzi, Christopher J. Felege, Robert Newman, Blake McCann and Susan N. Ellis-Felege

Drones (2022), 6(6), 136.

Obesity and cardiovascular changes

 Obesity has a significant impact on the structural changes in cardiovascular tissue in horses, a recent study has found.

Obesity is known to have significant adverse effects on horse health.  Laminitis is an obvious example, but it can also contribute to other problems such as those affecting soundness or fertility


In humans, obesity is recognised as a risk factor for cardiovascular problems. However, until now there has been little research into the effect of obesity on the wider cardiovascular tissues of horses. 


A recent study by Natalia Siwinska and colleagues at the Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences assessed the impact of obesity on the microscopic structure of the heart muscle and selected arteries in horses.


They conducted post-mortem examinations on 19 draft slaughter horses, comparing specimens from twelve extremely obese (body condition score (BCS 9/9) and seven with normal body condition (BCS 4-5/9). They examined specimens of heart muscle and major blood vessels (aorta, pulmonary, coronary and palmar arteries). A report of the work is published in the journal Animals.


The researchers found significant changes in the heart muscle and vessels in obese horses compared with those in normal condition. 


Obese animals had increased amounts of pericardial and cardiac fat, and the intima (the inner layer) of the pulmonary artery, coronary arteries and palmar arteries was thicker, compared with the healthy animals. They also found changes in palmar arteries in obese horses, which had a larger lumen diameter and the lumen-to-total diameter ratio compared to the control group.


The structural changes that they found are like those observed in people. The researchers suggest that these changes “may be an indicator of subclinical dysfunction, which could lead to severe disease.” 


They suggest that the direct effects of obesity on cardiovascular health and function in horses require further exploration



For more details, see:


Influence of Obesity on Histological Tissue Structure of the Cardiovascular System in Horses. 

Siwinska, N.; Janus, I.; Zak-Bochenek, A.; Noszczyk-Nowak, A. 

Animals 2022, 12, 732.

Saturday, June 25, 2022

Worm control in Hungary

For some time now, experts have advocated a targeted or strategic approach to worm control, rather than relying on treatment at regular intervals, because of the growing threat of anthelmintic resistance. 


A traditional approach to equine parasite control, involving rotating anthelmintic treatments at regular intervals, is still widely used in Hungary, according to a recent report. Almost no farms utilize faecal egg counts (FECs) on a regular basis to guide deworming treatments. 


Kinga Joó and her co-workers conducted a study to investigate risk factors associated with strongylid egg counts.The work is reported in Veterinary Parasitology: Regional Studies and Reports.


The research team collected faecal samples from 216 sport and pleasure horses, kept on 13 farms in Hungary. The horses ranged from 5 months to 30 years of age, and had last received anthelmintic (dewormer) treatment at least 60 days previously.


None of the farms involved in the study had previously used FECs to guide deworming treatments on a regular basis. 


Analysis of the results showed:

  • most of the faecal worm egg production was due to a limited number of horses. Only 22% of horses were responsible for 80% of the total strongyle egg output. This is in line with findings of other studies.
  • young horses (less than 5 years of age) had significantly higher FECs than horses 5–17 years old and those aged over 17 years.
  • horses treated with benzimidazoles (eg fenbendazole) at least once a year had significantly higher FECs than equids that had not received benzimidazoles.
  • horses kept at very high stocking densities (>30 horses/ha) had significantly higher EPG-values than horses kept at lower stocking densities.


They conclude “the results demonstrate the value of FEC monitoring and indicate that the efficacy of benzimidazoles should be investigated in Hungary. Moreover, our findings demonstrate that reducing stocking density should be considered in cases of high strongylid FECs.”



For more details, see:


Evaluation of risk factors affecting strongylid egg shedding on Hungarian horse farms

Kinga Joó, Roxána L Trúzsi, Csenge Zs Kálmán, Virág Ács, Szilárd Jakab, András Bába, Martin K Nielsen.

Vet Parasitol Reg Stud Reports (2022) 27:100663

doi: 10.1016/j.vprsr.2021.100663

Friday, June 24, 2022

Can probiotics help reduce parasite shedding in foals?

Probiotics are frequently added to horses’ diets with the goal of promoting a healthy microbial environment in the intestinal tract. But does their use have any effect on the worm burden in the gut?

 Research by Dr Robert Jacobs and colleagues at the Purina Animal Nutrition Center suggests that giving probiotics to foals may reduce the number of intestinal parasites they carry.


The research was presented at the 2021 virtual Equine Science Symposium. An abstract is published in the Journal of Equine Veterinary Science.


Twenty-nine quarter horse foals took part in the study over three consecutive foaling seasons.  Fifteen foals chosen at random were given a probiotic paste twice daily for eight days starting two days after being born. Fourteen foals received no probiotic.


(Each dose of probiotic paste contained 2.5 × 109 cfu each of B. subtilis, B. infantis, and L. acidophilus.)


The groups were managed similarly – being fed twice daily and being turned out into dry lots during the day.


When the foals were 150 days old, the researchers collected faecal samples. The foals had not received any anthelmintic before then. 


Analysis showed that “foals in the treatment group had fewer strongyle (1.07 vs 4.57/gm of feces; P = 0.02) and roundworm eggs (101.33 vs 216.00/gm of feces; P = 0.01) than those from the control group.”


The authors conclude “that the administration of the probiotic paste to otherwise identically managed groups of foals may reduce their overall parasite load. “


They suggest that “further research is needed to understand the mechanisms by which this is occurring and to determine if these effects persist.”


For more details, see:


Probiotic administration post-foaling may reduce parasite shedding in foals

R.D.Jacobs, M.L.Jerina, B.A.Tremayne

Journal of Equine Veterinary Science (2021)

Volume 100, May 2021, 103565

Smoothing the transition for retired Australian racehorses

What physical and behavioural qualities are desired in retired racehorses to help them adapt to a new equestrian career? 

Mollie Buckley, at the Charles Sturt School of Agricultural, Environmental and Veterinary Sciences, in Australia, is conducting research to address the current lack of knowledge about what makes former racehorses succeed in their new occupations. 


She is looking for owners of retired racehorses in Australia to take part in an online survey. The project aims to identify attributes shown in retired racehorses (Thoroughbred and Standardbred) that are enjoying a successful post-racing career.


The survey will ask questions related to the characteristics and temperament of the retired racehorse, both on the ground and when ridden.


Buckley hopes that this research will help the Australian racing industry smooth the process of re-homing racehorses after they retire from the track.

All previous and current owners of retired racehorses are encouraged to participate in the research.


The online survey closes on Monday 25 July, and takes approximately 20 minutes to complete.


For more details, and to complete the survey, go to:

Thursday, June 23, 2022

Eriskay Ponies sought for genetic study

© Thomas Langlands |
 Eriskay pony owners are asked to take part in a genetic study to help protect this critically endangered
native breed.

The Eriskay Pony Society is working with genetics experts at Nottingham Trent University (NTU) and the Rare Breeds Survival Trust (RBST) to carry out the biggest ever survey of Eriskay Pony DNA.


The Eriskay is a small pony, standing 124-138cm (12.0-13.2 hands) high. Traditionally they worked on the crofts (smallholdings), carrying loads such as seaweed, and peat, in baskets (“creels”) slung over their backs. They were also used for light draught work. 


Eriskay ponies are among the last representatives of the original native ponies of the Western Isles of Scotland, and are probably one of the oldest and purest breeds in the United Kingdom. 


Their isolation on the remote island of Eriskay in the Outer Hebrides helped protect them from introduction of other breeds. On many of the Scottish islands, native ponies were “improved” by breeding with larger stallions. This did not happen on Eriskay, leaving a stock of pure-bred ponies.


By the early 1970’s the Eriskay Pony population had dwindled to about 20 animals. Controlled breeding programmes have restored the population to over 400 animals around the world. However, the Eriskay Pony is still classed as “critical” by the Rare Breeds Survival Trust,


The DNA analysis, being carried out by NTU’s Medical Technologies Innovation Facility and School of Animal, Rural and Environmental Sciences, involves Professor Philippe Wilson, Dr Samuel White and Dr Andy Dell. The work is supported by funding from the Horserace Betting Levy Board.


Professor Wilson explained: “We will be employing state of the art genotyping technologies in order to support a detailed understanding of the genetic status of the Eriskay and will work closely with the breed society to really deliver impact directly to the breeders.”


The results of the analysis will be used, in conjunction with the Rare Breed Survival Trust’s Equine Conservation project, to help inform future breeding plans and decision making for this critically endangered breed.


Catriona Rowan, Chair of the Eriskay Pony Society explained: “This is a very welcome step forward in our efforts to protect and promote this ancient yet versatile breed.


“With such a small gene pool we cannot just rely on the look of ponies and studbook information to make our breeding matches. 


She explained “This study, which is open to ANY Eriskay Pony registered with a recognised Eriskay breed Society, either The Eriskay Pony Society or Comann Each Nan Eilean (CENE), will give us a great foundation with which to work. It will be a baseline of information for use in our work with the RBST’s Equine Conservation Project which requires us to provide complex information about our genetic profiles. 


“Our work with Nottingham Trent University will give us assessment of genetic variation and molecular basis of inbreeding within the Eriskay Pony breed which will then be collated in an Eriskay Pony Genetic Archive. 


“It’s easy for Eriskay owners to get involved. Simply apply to us by emailing for a testing kit and we will send it free of charge. It’s a simple process using a hair sample, which must be returned to us by the end of July. 


“The more samples we have the better the overall picture we can build of the breed and the more useful the information will be. And ANY registered Eriskay Pony can make a contribution, no matter the age or breeding status, so it’s a great way for all owners to support the future of the breed.


For more details, or to order a free DNA kit, contact Samples must be returned by the end of July.