Study into end of life decision making

Deciding when the time has come to end a horse’s life is one of the most difficult decisions an owner has 

to make. In cases of catastrophic injury, the choice may be clear. But it is often not the case in more subtle or long-term problems. However, delaying euthanasia may result in prolonged suffering and has been identified as a key welfare concern.

The attitude of British horse owners towards end-of-life decisions for their horses has been investigated by Catherine Bell and Suzanne Rogers of the Equine Behaviour and Training Association. 

 

They used a survey incorporating 30 welfare scenario statements, which was circulated via social media groups. One hundred and sixty owners responded to the survey. The work has been published in the journal Animals, in a special issue devoted to Horse-Human Interactions and their implications for equine welfare.

 

The authors report that, “In almost all cases, the reasons given for euthanasia were predominantly for physical issues … Most gave very specific answers, with colic (19%) and various types of arthritis and lameness (19%) being the most common primary reasons for euthanasia.”

 

Less specific reasons, such as “pain”, “old age” and/or “quality of life” accounted for 15% of responses.

 

The authors suggest that “it would seem that participants were wanting to select euthanasia for a single physical catastrophic and possibly unresolvable event, rather than a more nuanced decline in welfare towards end-of-life.”

 

They conclude that “physical issues, including even mild lameness, are more likely to factor in an end-of-life decision than issues relating to mental health, and horse owners are less likely to account for subtle welfare issues, potentially leading to the delay of euthanasia and prolonged suffering.”

 

 

For more details, see:

 

Attitudes of the Equestrian Public towards Equine End-of-Life Decisions 

Catherine Bell and Suzanne Rogers

Animals. 2021; 11(6):1776. 

https://doi.org/10.3390/ani11061776

Detomidine for reducing fireworks anxiety

Detomidine gel could be a useful tool to alleviate horse’s anxiety during fireworks according to a recent study.

Fireworks seem to be an increasing problem for horse owners to deal with, no longer limited to just one or two nights a year but becoming a more regular nuisance.

 

Detomidine has proved a useful sedative for allowing minor surgical procedures to be carried out in the standing horse and is widely used for enabling management tasks such as clipping, farriery, dentistry and wound dressing. A recent study by Francesca Dai and colleagues looked at whether it would help reduce anxiety and fear in horses exposed to fireworks.

 

Sixteen horses that had experienced acute anxiety and fear associated with fireworks noise in the past took part in the study, which was carried out on New Year’s Eve.

 

Eight horses were treated with 30 μg/kg detomidine gel (a little less than the licenced dose for sedation – 40 μg/kg ) and eight with a placebo. Treatment was repeated, if necessary, after a minimum of 2hrs.

 

Response to treatment was assessed by the owners. The horses’ behaviour was also recorded on video and assessed by an expert who was unaware of which treatment each horse had received.

 

The work is published in Frontiers of Veterinary Science. The authors report that, when fireworks were present, 75% of the horses given detomidine were scored by their owners as having a good or excellent treatment effect on anxiety and fear. Interestingly, 50% of horses given the placebo were scored as having a good response.

 

Overall, horses of the placebo group showed more restlessness, vocalization, and signs of colic. Horses given detomidine showed a significant decrease in walking behaviour.

Researchers suggest that the effect was not simply due to sedation – as (for at least some of the time) horses were eating.

 

The only adverse effect reported was sweating in one horse after the first dose of detomidine.

 

The authors conclude that detomidine can be used for alleviating horses' fear during fireworks. They suggest that further research with larger treatment groups is needed to confirm the results.

 

 

For more details, see:

 

Use of Detomidine Oromucosal Gel for Alleviation of Acute Anxiety and Fear in Horses: A Pilot Study

Francesca Dai, Julia Rausk,  John Aspegren,  Mirja Huhtinen,  Simona Cannas and Michela Minero

Front. Vet. Sci., (2020) 7:573309.

https://doi.org/10.3389/fvets.2020.573309

Swift Hendra test developed

A rapid point of care diagnostic kit that can detect Hendra Virus has been developed by scientists at the University of Queensland.

Hendra virus is a serious zoonotic infectious disease affecting horses and occasionally humans. It is transmitted by flying foxes shedding the virus in their saliva, urine, aborted foetuses and/or reproductive fluids. Horses are thought to contract the virus by ingesting feed or water contaminated with one of these sources of infection.

 

University of Queensland (UQ) vets can now diagnose the deadly Hendra virus in horses in under an hour, rather than taking days with existing diagnostic techniques.

 

Veterinarian Professor Ben Ahern said a rapid point-of-care diagnostic test to detect Hendra infections in horses has been sorely needed for decades.

 

“Hendra virus kills humans and horses alike – the virus spreads to horses from flying foxes, with an infected horse occasionally passing the infection on to humans,” Professor Ahern said.

 

“Without vaccination, the virus has a case fatality rate of 57% among humans and 79% among horses – it’s incredibly deadly.

 

“Rather than sending samples off to a lab, which risks an outbreak in the meantime, our testing protocol takes routine samples from a possibly infected horse and inactivates any virus that may be present in those samples.

 

“Following a heat treatment step of samples to inactivate the virus, these non-infectious samples are then tested using a handy molecular diagnostics machine – known as a LAMP Genie III – which is about the size of a box of tissues and is battery powered and completely portable.

 

“This process gives us results in under one hour, which is incredibly fast when compared to the many days it may take from collection of samples, getting them tested at an external lab and obtaining results.

 

“Horses aren’t suffering in the interim and humans giving care to them can avoid becoming exposed.”

 

Development of the point-of-care Hendra virus LAMP test has now advanced to the manufacturing stage and commercial kits are currently being produced.

 

Once approved by the Queensland Chief Veterinary Officer, the Genie machine and associated Hendra virus LAMP kits will be available for veterinarians to purchase and use.

 

“Due to the cost and technical training required, these tests will likely be performed by veterinarians or large equestrian bodies with veterinarian assistance,” Professor Ahern said.

 

“However, with the mobile capacity of this testing system, they can go directly to a farm to diagnose a suspected case, expanding treatment options for horses.”

 

For more details, see:

 

https://www.uq.edu.au/news/article/2021/07/no-horsing-around-super-fast-hendra-test-developed

Heart irregularities in Thoroughbred racehorses.

 

Atrial fibrillation is the most commonly recognized disturbance of heart rhythm in athletic horses. It is an important cause of poor performance, and has implications for safety of horse and rider.

In atrial fibrillation (AF) the heart beats with a haphazard, “irregularly irregular” rhythm. The condition may be termed “paroxysmal” (when it recovers spontaneously within 72hrs) or “persistent” (which continues if not treated). 

 

Laura Nash and colleagues studied records of horses racing in Hong Kong over a ten-year period up to July 2017. They looked at the incidence of AF in poorly performing horses, and whether having had a previous episode of AF increased the likelihood of a horse being affected.

 

The full, open access, report of their study is published in the Journal of Veterinary Internal Medicine.

 

They report that, from a total of 96,135 race starts, atrial fibrillation was identified in 4.9% of horses, with an overall incidence of 2.7 episodes per 1000 starts. Many horses were retired after the first episode of AF.

 

Having had a previous episode of AF increased the risk of AF, and recurrence was more likely in horses that had been treated previously for persistent AF, than in horses that had previously had paroxysmal AF.

 

The researchers comment: “We identified a high rate of recurrence in Thoroughbred racehorses after both paroxysmal and persistent episodes of AF. This substantial AF burden could arise from underlying microstructural myocardial lesions and electrical remodelling.”

 

They concluded that, “although horses can have long and successful careers after AF, the arrhythmia should not be considered benign, and the suitability of horses to continue their racing careers should be assessed on an individual basis.”

 

For more details, see:

 

Incidence, recurrence, and outcome of postrace atrial fibrillation in Thoroughbred horses

Laura C Nath, Adrian D Elliott, Joe Weir, Peter Curl, Sarah M Rosanowski, Samantha Franklin.

J Vet Intern Med (2021) 35(2): 1111–1120. 

https://doi.org/10.1111/jvim.16063