Free webinars from Marion duPont Equine Medical Centre

 The Marion duPont Scott Equine Medical Center has announced a series of “Tuesday Talks” over the next few months.

 Topics to be covered are:

 

Tuesday, February 14:

Jennifer Barrett, DVM, Ph.D., DACVS, DACVSMR - “Let's Get Moving! Regenerative medicine for orthopedic injuries”

"From stem cells to blood-based biologics, the choices for treating tendon, ligament, and joint injuries are myriad. Learn the biology behind the therapies, most notably the evidence supporting their use."  

 

Tuesday, March 14: 

Elizabeth MacDonald, BVMS, MS, DACVIM (LAIM) - “The Scoop on Loose Poop: Equine Diarrhea”

"Diarrhea in the horse can range from mild chronic diarrhea to acute severe diarrhea. The common causes of diarrhea in the horse will be reviewed, along with ways to diagnose the underlying cause, and when to become concerned as an owner." 

 

Tuesday, April 11: 

Megan Marchitello, DVM - “Equine Respiratory Disease: It’s a lung story”

"An overview of the equine respiratory tract and common pathology".

 

Tuesday, May 9: 

Teresa Hopfgartner, DVM “Lumps and Bumps - Common Equine Skin Tumors”

"While cancer is not as prevalent in horses as it is in humans, cancers of the skin are fairly common in horses and most of them are easy to spot. We will be discussing the most common skin tumors in horses - sarcoids, squamous cell carcinomas and melanomas - in horses and discuss how (surgical) treatment is applied and what you can expect following treatment."

 

Each presentation starts at 7 p.m. (EST), will be about one hour long, and is free to attend. Although it is possible to attend in person, a webinar link is also available.

For more details, and to register, go to:

https://aimsbbis.vt.edu/tuesday-talks-2023

Effect of back flexion on kissing spines

(c) Nicole Ciscato Dreamstime.com

The importance of considering the horse’s posture when examining for kissing spines was
highlighted by a recent study. 

Impinging dorsal spinous processes (IDSP “Kissing spines”) can be associated with pain and discomfort, leading to behavioural and performance issues. However, not all horses with kissing spines show clinical signs and the condition may go unnoticed until it is found during a routine check-up or imaging.

 

Diagnosis typically includes radiographic examination of the back, to assess the spaces between the dorsal spinous processes of the vertebrae. 

 

A study by O’Sullivan and colleagues aimed to ascertain if the thoracic vertebral interspinous space distances were increased by using facilitated thoracic flexion to alter the posture in horses diagnosed with IDSP.

 

Carried out at the Veterinary Teaching Hospital of the University of Helsinki, seven horses, (four geldings and three mares) took part in the study. They were presented to the hospital for investigation of back pain or had a previous diagnosis of IDSP (with at least one interspinous space <4mm). Horses with previous surgical treatment of thoracic IDSP were excluded.

 

The researchers compared the radiographic appearance of two sets of radiographs of each horse. 

 

They explain: “All horses were made to stand in a square position, the head was held by the handler and the mouth was kept level with the point of the horse’s shoulder. This position was maintained throughout the initial and second set of radiographs.”

 

The first radiographs were taken in the horses’ spontaneous posture. For the second set, an investigator vigorously scratched along the sternum to produce a lift of the thoracic cage and reduce the lordotic posture of the thoracic spine. At the point of greatest postural change, the radiographer was instructed to take the image.

 

The digital images were anonymised by one investigator.  A second investigator measured the interspinous space and was therefore blinded to the horse and owner identification, as well as the posture of the horse (i.e., either spontaneous or thoracic flexion) when the images were taken.

 

The researchers found that stimulating the horse to flex the spine increased every thoracic interspinous space (IS) distance in horses with IDSP. Furthermore, the changes in IS distances were large enough to decrease IDSP by 1–3 grades.

 

“The largest difference was at the mid-thoracic spine (T7-T13), with a 2.1–3.1 mm change.” They add: “Specifically, the greatest median distance change was between T7-T8 and T12-T13 (3.1 mm and 3.0 mm, respectively).”

 

They suggest that including such a dynamic and functional evaluation in diagnostic examinations may aid IDSP decision making.

 

“The results of this small study demonstrated that the median distance between dorsal spinous processes of the thoracic spine increased following manual facilitation of thoracic flexion and resulted in a reduced thoracic spinal lordosis. The results support the need for a more dynamic and functional evaluation prior to a diagnosis of IDSP, particularly when radiographic grading based on this interspinous distance may result in invasive intervention.”

 

For more details, see:

 

The effect of manually facilitated flexion of the thoracic spine on the interspinous space among horses with impinging dorsal spinous processes of the thoracic vertebrae.

S. O’Sullivan, C.M. McGowan, J. Junnila, H.K. Hyytiäinen,

The Veterinary Journal, 2022, Vol 289,105909.

https://doi.org/10.1016/j.tvjl.2022.105909

(Open access article published under a Creative Commons licence)

Potential new marker for joint infection

(c) Virginia Dreamstime.com

Synovial infections, involving joints and tendon sheaths, are a potentially serious condition in
horses. Early diagnosis and treatment are essential. If not treated promptly, the infection can cause permanent damage to the joint with potentially career-ending and, indeed, life-threatening consequences.

 Usually, a diagnosis of joint infection is confirmed on the basis of synovial fluid analysis - typically looking at the white blood cell count and protein levels.

 

Scientists at the University of Copenhagen have been investigating the potential of neutrophil gelatinase-associate lipocalin (NGAL) as a marker for synovial sepsis

 

NGAL (also known – among other things- as Lipocalin-2) is a protein that is produced in response to injury or inflammation. It is involved in many processes in the body and plays a part in the non-specific immune defences. It acts to limit bacterial growth by sequestering iron, which is required for bacterial growth. Originally identified in neutrophils, it can be produced in other cells, such as kidney tubule cells, in response to damage. In human medicine it has been used for early diagnosis of acute renal injury, and it has been suggested to be a highly sensitive and specific marker of joint infection.

 

Stine Jacobsen and co-workers measured NGAL concentrations in 177 synovial fluid samples obtained from 152 horses suspected of having synovial infection. The aim of the study was to investigate NGAL concentrations in synovial fluid from horses with septic synovitis, horses without septic synovitis, and horses with uncertain status. A full report is published in Animals.

 

The authors explain that, based on the results from the clinical and diagnostic workup on the day of admission, horses were divided into three groups:

 

(1) septic synovitis, defined as a white blood cell count (WBC) >30 × 109/L leukocytes and one (or both) of the following: total protein (TP) >30 g/L and neutrophil granulocyte percentage (neutrophil%) >90. Horses were also defined as septic if there was a positive bacteriology result, (47 samples)

 

(2) non-septic, defined as WBC <5 × 109/L leukocytes, (103 samples), and 

 

(3) uncertain, defined as WBC >5 and <30 × 109/L leukocytes. (27 samples).

 

They found that concentrations of NGAL were significantly higher in the septic synovitis group than in samples classified as non-septic or samples with uncertain status, with median NGAL concentrations in the three groups being 1236, 16.8, and 266.4 µg/L, respectively. 

 

“NGAL discriminated nearly perfectly between septic and non-septic (area under the receiver operating characteristic curve 0.98, 95% confidence interval 0.95–1.00)” they report.

 

“The optimal cut-off value for maximal sensitivity (87.2%) and specificity (75.0%) to discriminate septic samples from those with uncertain status was 444.6 µg/L, with an area under the receiver operating characteristic curve of 0.85 (95% confidence interval 0.74–0.93).”

 

For 35 horses the scientists tested more than one sample taken over the course of treatment. They found that NGAL concentrations declined over time in horses undergoing treatment. 

 

They conclude “NGAL is a novel biomarker that seems to have great potential for identifying septic synovitis and for monitoring the response to treatment of synovial infection in horses.”

 

 

 

For more details, see: 

 

Gelatinase-Associated Lipocalin in Synovial Fluid from Horses with and without Septic Arthritis. 

Stine Jacobsen, Camilla Drejer Mortensen, Elisabeth Alkærsig Høj, Anne Mette Vinther, Lise Charlotte Berg, Ditte Marie Top Adler, Denis Verwilghen, and Gaby van Galen. 2023. Neutrophil 

Animals (2023) 13, no. 1: 29. 

https://doi.org/10.3390/ani13010029

(Open access article published under a Creative Commons licence)

Measuring weaning stress in foals

Foals take at least three weeks to adjust to weaning according to recent research.

(c) Rookie 72 Dreamstime.com

A study in Germany followed a group of foals from the day before weaning for the following three weeks. Kristin Delank and colleagues at the Ludwig-Maximilian-University of Munich aimed to demonstrate the medium-term effects of weaning on foals’ welfare.

 

To achieve this, they monitored the behaviour of a group of foals’ behaviour, and assessed levels of cortisol metabolites in their faeces, over a three-week period beginning the day before weaning. The group consisted of nine Arabian foals (six colts and three fillies), and one warmblood filly.

 

Observations took place at the state stud farm of Baden-Wuerttemberg in Germany. A full report is published by PLoS ONE.

 

“Until weaning, all foals were raised in a group with other dams and their foals, and the housing method was an open stabling with daily pasture time depending on weather conditions” the researchers explain. 

 

“The feeding consisted of grass on the pasture, hay ad libitum renewed three times a day, and for the dams concentrated feed twice a day in the stable. The foals also had access to the concentrated feed of their mothers.”

 

The foals were not all weaned at the same time, but in batches following the stud’s usual routine. Weaning was divided into three blocks, depending on the age and maturity of the foals - the first being in September, the second in October, and the last in November. 

 

“On the day of weaning, a veterinarian sedated the foals before they were transported to a breeding station 18 kilometers from the stud farm.”

 

Behavioural observations were carried out the day before, and the first full day after, weaning, and then at intervals over the following three weeks. An observer recorded the behaviour shown by the foals every five minutes throughout the eight-hour observation session (from 7am to 5pm.) 

 

The researchers report that, before weaning, foals spent most of the time moving. After weaning this changed, and they spent more time standing and resting. Weaned foals showed a significant increase in resting while standing. They also spent more time resting in a lying position during the day for the first eight days.

 

Four behaviours, (“aggressive behaviour,” “passive reaction,” “anxious behaviour,” and “vocalizing”) that were only seen after weaning, not before, were examples of stress-induced behaviours. (See figure) (The researchers suggest that a possible explanation for the increase in stress related behaviour on day 20 was that it coincided with a visit from the farrier.)

 

 

Stress-induced behaviours.

This graphic displays the total count of the shown behaviour for each day. All 10 foals are included. Note that observation day 1 is one day before weaning and observation day 3 one day after weaning.

https://doi.org/10.1371/journal.pone.0280078.g004

To gauge the stress experienced by the foal, the researchers measured the levels of a cortisol metabolite, 11,17-dioxoandrostane, in the faeces. This allowed them to get an indication of plasma cortisol levels without having to collect blood samples and disturb the foals further.

 

They found that all foals had a distinct hormonal stress response to the weaning process, as shown by a significant increase in faecal cortisol metabolite levels. The average cortisol metabolite level the day before weaning was 2.82 ng/g. this rose to 5.56 ng/g on the day of weaning, indicating stress experienced during the weaning process.

 

They report “The stress hormone levels increased until day 5 (i.e., three days after weaning), from day 9 the cortisol metabolite concentration shows a decrease while still being significantly higher (p = 0.001) than on day 0.”

 

Stress hormone levels were checked in six foals 17 days after weaning, when they were still higher than before weaning. Finally, at 19 days after weaning, three foals were tested, and were found to have faecal cortisol metabolite levels similar to the whole group of foals on the day before weaning.

 

The researchers conclude “the foals showed an expected behavioural development and an expected curve of cortisol metabolite values throughout the study. However, it seemed that the changes had not returned “back to normal” at three weeks after weaning. Therefore, we suggest that weaned foals need a minimum of three weeks to acclimate to the new situation.”

 

“It is not possible to accomplish weaning without producing stress in the foal. The goal must be to determine the process that provides the best long-term welfare for the foal.”

 

For more details, see:

 

Behavioral and hormonal assessment of stress in foals (Equus caballus) throughout the weaning process. 

K Delank, S Reese, M Erhard, A-C Wöhr (2023) 

PLoS ONE 18(1): e0280078. 

(Open access article published under a Creative Commons licence)

https://doi.org/10.1371/journal.pone.0280078

Use of blankets in North American horses

(c) Nicole Cascato Dreamstime.com

Blanketing horses in the winter is a widely used, but fiercely debated practice.

Healthy horses maintain their body temperature within a narrow range (98.5°F to 101°F / 36.9°C to 38.3°C) despite a wide variation in environmental conditions.

 

In cold weather they use various physiological and behavioural methods to conserve body heat, such as piloerection, shivering, facing away from the wind. Eating roughage generates heat and so helps maintain body temperature.

 

A study, by Michelle L. DeBoer, at University of Wisconsin – River Falls, Department of Animal and Food Science, and colleagues, investigated the use of blanketing by North American horse owners.

 

They conducted a web-based survey looking at participant demographics, the use of blankets in winter, and the reasons why blankets were used or not.

 

A total of 1450 people completed the survey. Just over half of them reported that they blanketed their horses. A full report of the findings is published in the Journal of Equine Veterinary Science.

 

The researchers found that the use of blankets depends on discipline, housing, and management decisions.

 

Perhaps surprisingly, the geographical region of residence did not affect the frequency of blanket usage. The proportion of respondents who blanketed was similar in all regions, regardless of climate.

 

Those who chose to blanket most of their horses included those participating in English disciplines, professionals, respondents with less than six horses, and those who have been in the horse industry for less than 15 years. 

 

Horse professionals (those earning at least 50% of their annual income from horses) were more likely to blanket (63%), than non-professionals (37%).

 

The authors report that most common air temperature at which respondents blanketed was 0°C (14%) with some choosing to apply blankets at temperatures as high as 10°C (3%).

 

“However, the overwhelming majority chose to use blankets in response to precipitation, (rain, sleet, or snow)(85%) in addition to wind (58%).”

 

They conclude: “This survey highlighted the range of practices and opinions of North American horse owners in response to winter blanketing practices. Based on the results, there is comparable number of horse owners who chose to blanket versus those who chose not to blanket their horses.

 

“While there is consensus among horse owners regarding some blanketing topics, uncertainty continues to surround this management practice. Fortunately, most respondents indicated more research and subsequent dissemination of results on this topic would help horse caretakers better understand the necessity and potential advantages of blanketing”.

 

For more details, see:

 

Winter blanketing practices: An online survey of North American horse owners,

Michelle L. DeBoer, Aubrey L. Jaqueth, Ashley Tuszka, Krishona L. Martinson.

Journal of Equine Veterinary Science,(2022) Vol 113, 103911,

https://doi.org/10.1016/j.jevs.2022.103911.

(https://www.sciencedirect.com/science/article/pii/S0737080622000491)

Long-term treatment of PPID

Long-term use of pergolide to treat horses with pituitary pars intermedia dysfunction (PPID -or
Equine Cushing’s disease) produces clinical improvement in most cases, and improved endocrine test results in some, according to recent work.

Pergolide has become a popular treatment for PPID in horses.  Studies have found that it is generally effective in controlling the clinical signs of PPID and that it is well-tolerated by horses when used for up to a couple of years. However, research into its long-term use has been limited.  

 

A recent study, by Harold Schott and co-workers at Michigan State University, followed the outcome of longer-term treatment in PPID-affected equids from the time they first received pergolide for the rest of their lives. 

 

Dr Schott presented their findings at the 2022 American Association of Equine Practitioners (AAEP) Annual Convention held in San Antonio, Texas. 

Thirty privately owned equids (28 horses and 2 ponies) being treatmed with pergolide for PPID were enrolled in the study. Fifteen started on a dose of one pergolide tablet (1mg)  a day;  fifteen started on 2 tablets a day. The animals were treated for periods ranging up to twelve and a half years.

 

The research team monitored the response to treatment by contacting the owners every three months. They also examined the animals at various intervals until 12.5 years after treatment started.

 

Schott reported that, during the study period, five equids were euthanased for PPID- associated laminitis and 24 died or were euthanased for other age-related reasons. Survival time ranged from 0.6 to 12.5 years. The average (median) survival time was 3.3 years. One equid was still going strong at the end of the study.

 

Owners of 13 equids surviving after five and a half years reported continuing clinical improvement, such as healthier coat condition, better appetite and less frequent bouts of laminitis. At that stage, 75% of equids had normal endocrine test results.

 

Seven of the 15 equids that had started on the low dose of pergolide later had the dose increased to two tablets daily. 

 

Schott pointed out that, although some individuals eventually needed an increased dose, that was not always the case, and some continued to have a satisfactory response to a low dose of pergolide.

 

Generally, owners were satisfied with the response to long-term pergolide treatment. 

 

For more details, see:

 

Long-Term Response of Equids with Pituitary Pars Intermedia Dysfunction to Treatment with Pergolide 

Harold C. Schott II; Julie R. Strachota; Judith V. Marteniuk; and Kent R. Refsal.

Proceedings American Association of Equine Practitioners (2022) vol 68, p230

Horses Inside Out Conference

 There’s still time to get tickets for the Horses Inside Out Annual Conference. 

 Back this year at the Holywell Conference Center in Loughborough, it will be held on Saturday 18^th and Sunday 19^th February.  If you can’t be there in person, you can still attend virtually.

 

An array of expert speakers has been lined up for what promises to be an inspiring meeting. 

Topics to be covered include bitting, nutrition, training the equine brain, rider psychology, hindlimb lameness, hoof care, dental disease and more.

 

For all the details, go to: 

 

https://www.horsesinsideout.com/annual-conference-2023