Scottish laminitis research

Native-breed pony owners across the north east of Scotland are asked to help in new research into

laminitis.

Two linked research projects, by Philippa Davies and Ashley Ward, PhD students at Scotland’s Rural College (SRUC), will explore why some animals are more susceptible than others. The researchers also hope to establish suitable management strategies to help reduce the occurrence of pasture- associated laminitis.

Obesity, increased blood insulin and low levels of adiponectin are known to be associated with increased risk of laminitis. But not all such cases will develop laminitis. On the other hand, some ponies that are not overweight will develop the condition. 

One project will explore the way individual ponies metabolise the pasture. By examining faeces and urine of individual animals, the researchers hope to find differences that could help identify those at greater risk of developing the condition.

A second project will look at the composition of Scottish pony pastures and evaluate, among other things, the sugar content of the different grass species throughout the year. The researchers hope to establish associations between the chemical composition of grass and laminitis risk.

“Grasses high in sugars are considered to be unsuitable for animals prone to laminitis, but not enough is known about what this means in practical management terms.”

The projects are the result of collaboration between SRUC, WALTHAM Petcare Science institute and Aberdeen University’s Rowett Institute.

SRUC’s Dr Pippa Morrison, one of the supervisors on the studies, said: “We know that for many owners of horses and ponies, the possibility of their animal developing laminitis is a constant worry and a very real concern.

“When it happens, laminitis can arrive with little or no warning and can be quite shocking. All too often animals suffer extreme pain and the consequences can be devastating.

“These studies have been carefully designed to help us better understand some of the risk factors associated with laminitis, both at the pony and pasture level, and may help to identify animals at increased risk and those for which recurrence of the disease is more likely.”

Owners willing to take part in the research will complete a questionnaire and allow the researchers to collect samples from the pasture and ponies.

Philippa and Ashley are looking for healthy native-breed ponies aged four years old and over, with no previous diagnosis of PPID (equine Cushing’s disease), to take part in these studies.

If you are interested in getting involved, or if you would like more information, please contact: projectPAL@sruc.ac.uk

Alternative treatment for foal pneumonia

Pneumonia caused by Rhodococcus equi is an insidious, often fatal, infection of foals. It causes

abscesses in the lungs and can prove challenging to treat. A combination of two antimicrobials, azithromycin (AZM) and rifampicin (RIF), is widely used for treatment. Combination therapy is necessary as bacteria rapidly develop resistance to rifampicin if it is used on its own.

However, rifampicin is important for treatment of tuberculosis in humans, and there is mounting pressure to reduce its use in veterinary medicine. This has led to a search for alternative treatments.

A report in the Equine Veterinary Journal by Wetzig and colleagues has shown that a different combination of antibiotics is no less effective for treating Rhodococcus equi bronchopneumonia in foals.

In their study, they found that foals treated with azithromycin (AZM) and doxycycline (DOX) responded similarly to those treated with AZM – RIF.

A total of 240 foals with mild to moderate bronchopnenumonia were included in the controlled, randomised and double‐blinded clinical trial. They were divided into three treatment groups:

• AZM (5mg/kg) + DOX (10mg/kg) twice daily 
•  AZM (10mg/kg) + RIF (10mg/kg) once daily
• Untreated controls.

Progress of the condition was monitored by physical examination and thoracic ultrasonography, performed by individuals unaware of which treatment each foal was receiving.

Foals whose condition worsened were considered treatment failures and were removed from the study.

The research team found little difference between the recovery rate of foals in the two treatment groups. Of the AZM-DOX group, 80 of 81 foals recovered, compared with all 81 foals in the AZM-RIF group. Only 57 of 78 control foals recovered without treatment.

The researchers conclude that AZM-DOX is as effective as AZM-RIF in treating mild-moderate bronchopneumonia in foals. They suggest that doxycycline is likely to be a suitable alternative to rifampicin in such cases.

For more details, see:

Efficacy of the combination of doxycycline and azithromycin for the treatment of foals with mild to moderate bronchopneumonia

M. Wetzig, M. Venner, S. Giguère

Equine Vet Journal (2019) 

https://doi.org/10.1111/evj.13211

How do we measure a horse's quality of life?

An individual horse’s welfare depends on more than just having food, water and appropriate shelter. Their emotional well-being, or “quality of life”, is an important piece of the welfare puzzle. 

However, it is unclear what measurements are sufficiently accurate and reliable to help objectively assess this area of a horse’s welfare. A group of researchers from the United Kingdom, New Zealand and Australia have teamed up to address this.

The researchers completed two systematic reviews of studies in horses. One review focused on identifying equine behaviours that could reflect the horse’s mood and general well-being, - in other words, how they feel. The other review focused on physical measures of equine emotion, such as heart rate. The initial results of these reviews were presented on August 19, 2019 at the 15th annual International Society for Equitation Science (ISES) conference held at the University of Guelph.

Natalie Waran, from the Eastern Institute of Technology, New Zealand, presented on the findings related to equine behaviour. This review included 75 publications. Some of the behaviours they looked at included: feeding behaviour, types of interactions with humans and other horses (e.g. were they friendly or agonistic), and interest in the environment. They found that these types of everyday behaviours, and responses to training, were the clearest indicators of a horse’s emotional state. 

Waran adds “Examples of behaviours that indicated a positive emotional state were increased feeding behaviour, friendly social interactions (between horses and with humans) and interest in the environment. Examples of behaviours that indicated a negative emotional state were decreased feeding behaviour, negative social interactions, reduced interest in the environment and increased repetitive non-functional movement patterns”. 

She concludes that “these behaviours should help form the basis of assessment criteria so that horse owners and carers can assess and improve the quality of life of the animals under their care”.

Hayley Randle, from Charles Sturt University, Australia, presented on the results from the physical measures related to a horse’s emotion.  

Randle explains “Heart rate (HR), heart rate variability (HRV) and cortisol are the most commonly measured physiological indicators of equine emotion. Other suggested indicators include eye temperature, respiratory rate and salivary alpha amylase but many of these lack validation in relation to association with emotional state. There were methodological problems with all of the measures we looked at, such as the lack of standardisation of reporting and interpretation.” 

She concludes “The physical measures of equine emotion looked at in this review revealed that these may have limited use when assessing horse welfare.  A comprehensive set of measures that takes into account the horses experiences at any one time is needed to assess equine welfare and his/her overall quality of life.”

Kate Fenner, ISES council member, expanded on the importance of this presentation. “This research is an important step forward in equine welfare assessment”, she says, “We need studies like this that can help us identify consistent indicators of quality of life in order to build reliable welfare assessment tools that evaluate every domain of equine welfare.”  

For more details, see:

Indicators on the outside: Behaviour and equine Quality of Life

C. Hall, R. Kay, H. Randle, L. Preshaw, G. Pearson, N. Waran

Proceedings 15th Equitation Science Conference (2019) p54

Indicators on the inside: Physiology and equine Quality of Life

H. Randle, C. Henshall, C. Hall, G. Pearson, L. Preshaw, N. Waran

Proceedings 15^th Equitation Science Conference (2019) p55

The Proceedings are available:

https://equitationscience.com/previous-conferences/2019-15th-international-conference