Measuring eye temperature with thermography

The measurement of eye temperature by Infra-red thermography (IRT) is affected by endogenous and environmental factors and does not relate to rectal temperature, a recent study has found. 

The maximal eye temperature (MaxET) measured with IRT has been extensively used in equine research. It is a popular technique as it is non-invasive and does not require direct contact with the individual.

 

A study, by Anna Jannson and colleagues, published in the journal Physiology and Behavior, investigated factors influencing eye temperature in horses when measured using infra- red thermography (IRT) under field conditions.

 

The research team took 791 maximal eye temperatures (MaxET) measurements from 32 horses in Sweden in five different months and on five farms over a 12 month period.

 

They found that in horses observed at rest in their home environment, MaxET is affected by endogenous (sex and breed) and environmental factors (farm, location, and month of the year). MaxET shows no relationship to rectal temperature.

 

The authors point out that these findings have relevance in both clinical and research settings. 

 

“This indicates that eye temperature does not appear to be a sensitive method to monitor for example fever, where rectal temperature is traditionally used.”

 

They add “endogenous (sex and breed) and environmental variation between months were major factors influencing eye temperature and should be considered in the modelling and design of future field experiments.”

 

 

 

For more details, see:

 

An investigation into factors influencing basal eye temperature in the domestic horse (Equus caballus) when measured using infrared thermography in field conditions

Anna Jansson, Gabriella Lindgren , Brandon D Velie , Marina Solé.

Physiol Behav (2021);228:113218

 doi: 10.1016/j.physbeh.2020.113218

Photo by Anna Jannson et al (CC by 4.0)

Feral equids dig wells that benefit others

Research shows that wells dug by feral donkeys and horses benefit other species and the environment.

 

Erik Lundgren and others studied the behaviour of feral equids in the Sonoran desert in the south-western United States. A report of the work has been published in the journal Science.

 

They found that feral horses and donkeys dig their own wells, which are sometimes up to two metres deep. The wells provide benefits for other species and lead to an increase in biodiversity in the surrounding area.

As part of their research,  Erick Lundgren and his colleagues monitored four separate streams in part of the Sonoran desert in Arizona, using camera traps to observe the activity around the wells.

Feral donkey (left and horse digging for water. Photo (c) Erick Lundgren 

The streams usually fill with groundwater but dry up in the summer. The research team surveyed each stream every few weeks over three summers and found that horses and donkeys in the area dig wells there to access the groundwater. 

 

“It’s a very hot, dry desert and you’ll get these pretty magical spots where suddenly there is surface water,” said Lundgren.

"The donkey wells kept water in the system. And these features were used by pretty much every species you could picture, including some surprising ones like black bears, that we didn't expect to see in the desert." 

 

Apart from the donkeys and horses, the team saw 59 other vertebrate species at the wells, 57 of which were recorded drinking from the wells. 

Other species that they caught on camera visiting the wells included mule deer, bobcats, Woodhouse's scrub jay and javelinas.

The team even spotted some river tree species sprouting from abandoned wells, indicating they also serve a role as plant nurseries.

The researchers also found some riparian tree species (ie those that grow alongside water courses) sprouting from abandoned wells, indicating a wider environmental benefit.

For more details, see: 

Equids engineer desert water availability

Erick J. Lundgren, Daniel Ramp, Juliet C. Stromberg, Jianguo Wu, Nathan C. Nieto (deceased), Martin Sluk, Karla T. Moeller, Arian D. Wallach

Science  (2021) Vol 372, Issue 6541, pp. 491-495

DOI: 10.1126/science.abd6775  

 

https://www.youtube.com/watch?v=9tWNOlJ9yoY

 

https://theconversation.com/feral-desert-donkeys-are-digging-wells-giving-water-to-parched-wildlife-159909

Effects of lockdown on horses and owners

 The impact of the COVID-19 lockdown on horses, owners and people working with them, has been
studied in new research. 

The work was conducted at Scotland’s Rural College (SRUC) in collaboration with the Waltham Petcare Science Institute, during the lockdown restrictions imposed by the pandemic.

 

It showed that the coronavirus lockdown had a negative impact on the mental health and wellbeing of horse owners. It also highlighted the need for guidelines on care of horses and ponies at risk of obesity and laminitis during such restrictions.

 

The researchers explored how horse owners and those working with horses were affected by challenges brought about by the Covid-19 lockdown.

 

The study questioned 22 members of the equestrian community in Aberdeenshire, including horse owners, equine veterinarians, and farriers, as well as two welfare centre managers in England. A report of the work is published in the journal Animals.

 

Findings from the interviews indicate that pandemic-related obstacles to communication and limitations on horse owner interaction with their animals were sources of distress and frustration for interviewees.

 

The report also highlighted the stress placed on equine veterinarians who could be at risk of overwork and burnout as they managed their responsibility to protect public health during emergency scenarios such as the pandemic.

 

However, the study also identified several positive outcomes where the equine community undertook action to help overcome financial stresses and social isolation.

 

Ashley Ward, PhD student and lead author of the report, said: “From this study, we have been able to better understand the importance of human-animal interactions and the role that horses played in lessening the detrimental impacts of isolation and anxiety associated with uncertainty around lockdown.

 

She added: “It is also of note that the pro-social actions undertaken by individuals to benefit the community had the potential to improve the wellbeing of those undertaking the activities - as well as the community they sought to benefit.

 

“It is hoped that such information will promote action within the industry to protect the mental health and wellbeing of its community, using actions which combat the issues raised in this research.”

 

In a related study, published in the journal PLoS ONE, the research team assessed the impact of the pandemic on the management of horses and ponies susceptible to laminitis.

 

Their findings suggested that recommendations for supporting the management needs of horses under reduced supervision were not clearly defined, or were not sufficiently disseminated, across the equine industry.

 

“We discovered that lockdown-associated factors had the potential to compromise the welfare of horses and ponies at risk of obesity and laminitis,” said Ashley Ward. “These included: disparate information and guidance, difficulties enacting public health measures in yard environments, and horses having reduced exercise during the pandemic.

 

“Our conclusion was that guidelines should be developed for the care of horses and ponies at risk through collaborative input from veterinary and welfare experts. This would help to reduce the negative impacts of future lockdown events in the UK.”

 

For more details, see:

 

The Human Aspect of Horse Care: How the COVID-19 Pandemic Impacted the Wellbeing of Equestrian Industry Stakeholders 

Ward A, Stephen K, Argo C, Watson C, Harris P, Neacsu M, Russell W, Grove-White D, Morrison P. 

Animals 2021, 11(8), 2163

https://doi.org/10.3390/ani11082163

 

 

COVID-19 impacts equine welfare: Policy implications for laminitis and obesity. 

Ward AB, Stephen K, Argo CM, Harris PA, Watson CA, Neacsu M, et al. (2021) 

PLoS ONE 16(5): e0252340. 

https://doi.org/10.1371/journal.pone.0252340

Donkey medicine and welfare: free information

Despite their similarities to horses, donkeys differ in significant respects.

Recent years have seen an increase in research into the biology and disease susceptibility of this stoic equid. Now to help spread this knowledge, the Equine Veterinary Journal (EVJ) and Equine Veterinary Education (EVE) have collaborated to produce a virtual collection of articles on donkey medicine and welfare. The collection is free to view here until 29 October 2021.

 

The virtual collection addresses the previous shortage of pathophysiological information, with articles on pharmacology, diagnostics, disease prevalence and management practices relating to donkeys as working, companion and production animals.

 

“Economic, cultural, social, religious and medical factors have shaped the use of the donkey around the world,” said Karen Rickards, who edited the virtual collection along with Ramiro Toribio. 

 

“Primarily used for physical work, in some societies they are sources of nutrition or of non-traditional medicines whilst in others they are companion animals and providers of support for human mental and physical well-being. Animal welfare continues to be the major concern with donkeys and mules around the world, and veterinarians can have a positive impact in different ways.”

 

Preventative healthcare is addressed with the study of a companion population of donkeys in the UK and encourages clinicians to focus on client education, promotion of vaccination, regular dental care, strategic parasite control programmes and weight management.

 

Understanding the key welfare issues affecting donkey populations around the world has been an integral part of the work of non-government organisations.  One paper describes the use of the Equid Assessment Research and Scoping (EARS) tool for working equids in Mexico. 

 

Owner involvement in disease awareness and knowledge of disease presentation and risk are important aspects of donkey care. Two papers show how enhancing owner awareness and education can act as starting points to develop preventative health care programmes and promote community-led involvement in disease surveillance and control. 

 

Several papers address decision-making around treatment options, emphasising the need for a good understanding of the pharmacology of the available therapeutic agents in relation to donkeys and the pathophysiology of the diseases, as well as the value of pain assessment and control.

 

Another important aspect of disease detection and management is the availability of accurate diagnostics. Several papers address aspects of diagnostic testing, with emphasis on the caution that must be taken when extrapolating from horses because of the minimal data relating specifically to donkeys.

 

Donkeys are often described as silent carriers of, or as being more resistant to, infectious agents. Two articles demonstrate that they can in fact develop severe clinical signs when exposed to certain known equine pathogens, raising the importance of surveillance, accurate diagnosis, outbreak management, disease control and clear communication and education.

 

With biosecurity a key component of disease control, the introduction of new donkeys to existing populations and the proximity of large numbers of donkeys on intensive donkey breeding farms, are discussed as risk factors for disease introduction and spread. 

 

Less common conditions in donkeys as well as awareness of zoonotic risk are addressed, emphasising the value of owner-driven reporting as part of a disease surveillance and control programme to inform decision making on relevant interventions. 

 

“This impressive collection shines a spotlight on the important advances that have been made to donkey medicine and welfare and helps us to identify the research gaps yet to be filled,” said Professor Celia Marr, Editor of the EVJ.

 

“By sharing this work, we aim to improve disease prevention and enhance the welfare of donkeys around the world as well as highlight the continued importance of owner education and improve the public perception of this enduring species.”

 

The virtual issue will be free to view until 29 October 2021.

 

See:

 

https://beva.onlinelibrary.wiley.com/doi/toc/10.1001/(ISSN)2042-3306.donkey-medicine-welfare.vi