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Reducing exposure to pathogens in the horse; A preliminary study into the survival of bacteria on a range of equine bedding types

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Aims: Compare the rate of growth of four microbial strains that cause disease in the equine, on four commonly used types of bedding. The moisture holding capacity of each bedding type was also tested. Methods and results: Microbial strains included, Streptococcus equi, Streptococcus zooepidemicus, Fusobacterium necrophorum, Dichelobacter nodosus and Dermatophilus congolensis. The bedding types tested were Pinus syvestrus (Scots pine shavings), Pinus nigra (Corsican pine shavings), Picea sitchensis (Sitka spruce shavings), Cannabis sativa (hemp) and chopped wheat straw. A suspension of each microbial strain was spread in triplicate on agar media and incubated in its optimal growth conditions. The viable count (colony forming unit per ml) was determined for each bacterial strain for the five different bedding types. Pinus syvestrus bedding resulted in significantly less (p =0.001) bacterial growth of all strains tested. Conclusions: Factors resulting in the inhibition of bacterial growth include the anti-bacterial effects reported in the Pinacea family and the physical properties of the bedding substrate. Research is currently focussed on the diagnosis and management of disease. Prevention of disease is also important for matters of biosecurity. Strategies should include the provision of a hygienic environment and the use of specific types of bedding. Significance and impact of the study: Bedding choice has implications for global equine health and disease prevention as well as potential benefits in other animal species. This article is protected by copyright. All rights reserved.
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Reducing exposure to pathogens in the horse: a
preliminary study into the survival of bacteria on a range
of equine bedding types
K. Yarnell
, M. Le Bon
, N. Turton
, M. Savova
, A. McGlennon
and S. Forsythe
1 School of Animal, Rural and Environmental Sciences, Nottingham Trent University, Southwell, Nottingham, UK
2 School of Science and Technology, Nottingham Trent University, Nottingham, UK
antimicrobials, diseases, microbial
contamination, streptococci, veterinary.
Kelly Yarnell, School of Animal, Rural and
Environmental Sciences, Nottingham Trent
University, Brackenhurst Campus, Southwell,
Nottingham NG25 0QF, UK.
2016/1683: received 1 August 2016, revised
13 September 2016 and accepted 17
September 2016
Aims: To compare the rate of growth of four microbial strains that cause
disease in the horse, on four commonly used types of bedding. The moisture-
holding capacity of each bedding type was also tested.
Methods and Results: Microbial strains included Streptococcus equi,
Streptococcus zooepidemicus,Fusobacterium necrophorum, Dichelobacter nodosus
and Dermatophilus congolensis. The bedding types tested were Pinus sylvestris
(Scots pine shavings), Pinus nigra (Corsican pine shavings), Picea sitchensis
(Sitka spruce shavings), Cannabis sativa (hemp) and chopped wheat straw. A
suspension of each microbial strain was spread in triplicate on agar media and
incubated in its optimal growth conditions. The viable count (colony-forming
unit per ml) was determined for each bacterial strain for the five different
bedding types. Pinus sylvestris bedding resulted in significantly less (P=0001)
bacterial growth of all strains tested.
Conclusions: Factors resulting in the inhibition of bacterial growth include the
antibacterial effects reported in the Pinacea family and the physical properties
of the bedding substrate. Research is currently focussed on the diagnosis and
management of disease. Prevention of disease is also important for matters of
biosecurity. Strategies should include the provision of a hygienic environment
and the use of specific types of bedding.
Significance and Impact of the Study: Bedding choice has implications for
global equine health and disease prevention as well as potential benefits in
other animal species.
Management and control of disease is an ongoing con-
cern in the equine industry due to its potential economic
and welfare implications. One of the key aspects of dis-
ease control is decreasing exposure to pathogens which at
the most basic level includes the provision of a clean liv-
ing environment for the horse (Equus caballus). Many
disease-causing pathogens can be transmitted indirectly
through sharing of contaminated fomites (Timoney and
Kumar 2008) which could include horse equipment,
clothing or bedding.
Development of improved diagnostic tests and treat-
ment protocols are contributing to the improved
management of disease outbreaks in horses (Waller
2013). However, it is also important that preventative
measures be explored. Domestic horses may spend up to
23 h per day standing in their stables (Webster et al.
1987) and the bedding materials within those stables have
previously been implicated as being a primary source of
pathogenic bacteria (Hogan et al. 1990). Therefore, fac-
tors related to equine management need to be evaluated
including the provision of a suitable bedding material
that offers the most hygienic environment for the horse.
Bedding material has been evaluated for properties
such as dust production (Elfman et al. 2009), moisture
absorbency (Borhan et al. 2014), impact upon equine
behaviour (Werhahn et al. 2010) and airborne
Journal of Applied Microbiology 122, 23--29 ©2016 The Society for Applied Microbiology 23
Journal of Applied Microbiology ISSN 1364-5072
contamination with straw bedding having higher levels of
microbial contamination compared to paper and wood
shavings (Tanner et al. 1997). Water holding capacity is
of particular importance, as excess moisture in the form
of urine in the horse’s bed can contribute to foot prob-
lems (Hinchcliff et al. 2013) and gaseous ammonia for-
mation which is known to have detrimental consequences
upon the equine respiratory tract (Clarke 1987).
Common plant-based bedding materials used in horse
stables include straw, hemp and wood shavings (Borhan
et al. 2014). Horse owners will select their bedding type
based on availability, cost and ease of disposal (Wheeler
and Zajaczkowski 2002). If the bedding used in horse sta-
bles were able to resist equine-specific pathogens then
this has implications for the prevention and control of
disease; yet to date, limited investigation of direct bacte-
rial resistance of the bedding types available to horse
owners has been carried out.
Tanner et al. (1997) found a significant increase in
airborne microbial contamination in stalls with
straw bedding when compared to stalls with wood
shavings and paper-based bedding. The authors sug-
gested the latter may be the most acceptable bedding
types when considering microbial contamination within
a stable.
Wood shavings used in equine bedding are sourced
from the Pinacea family and many species within this
family have been shown to have antibacterial effects
including Pinus nigra (Sarac et al. 2014), Pinus sylvestris
(Rauha et al. 2000) and Picea sitchensis (Liu et al. 2011).
Evidence shows the most consistent antibacterial and
antifungal properties are associated with extracts of
the Pinus species and these effects may be associated with
polyphenols in the wood (V
alimaa et al. 2007). However,
research is primarily based on food hygiene and thera-
peutics (V
alimaa et al. 2007) involving bacteria such as
Escherichia coli and Staphylococcus aureus (Rauha et al.
This study investigated the survival of four bacteria
that can cause disease in horses on four commonly used
equine bedding types.
Equine strangles is caused by the bacterium Streptococ-
cus equi and results in significant welfare and economic
cost throughout the world (Waller 2013) with approx.
1000 outbreaks of strangles in the UK alone each year
(Ivens et al. 2011). Strangles is currently the most
frequently diagnosed infectious disease of horses world-
wide, responsible for high morbidity and occasional mor-
tality of infected animals (Waller 2013). The bacterium
gains access to the horse through the nose or mouth and
transmission of the disease occurs by direct contact with
an infected horse or contaminated equipment (Lindahl
et al. 2011).
Streptococcus equi is believed to have evolved from an
ancestral strain of Strep. equi subspecies zooepidemicus
(Webb et al. 2008). Streptococcus zooepidemicus strains are
highly diverse and can cause disease in a variety of other
species including humans (Waller 2013). Streptococcus
zooepidemicus is part of the normal commensal popula-
tion of the upper respiratory tract and reproductive tract
in horses, however, Strep. zooepidemicus is also known as
an opportunistic pathogen during period of immune vul-
nerably or stress (Rasmussen et al. 2013; Velineni et al.
2014). In the equine species, Strep. zooepidemicus is asso-
ciated with inflammatory airway disease (Wood et al.
2005), and uterine infections in mares (Smith et al.
Thrush of the equine hoof is recognized as a bacterial
infection which in severe cases may result in permanent
lameness (Petrov and Dicks 2013). The condition is asso-
ciated with Fusobacterium necrophorum even in the
absence of Dichelobacter nodosus. This is different from
footrot in cattle and sheep, which is caused by the syner-
gistic action of both types of bacteria (Petrov and Dicks
2013). The condition is degenerative and is commonly
associated with poor foot hygiene and dirty bedding
(Hinchcliff et al. 2013).
Distal limb dermatitis (mudfever) has been associated
with the bacteria Dermatophilus congolensis (Colles et al.
2010) and although it is not found free living in the envi-
ronment, its zoospores can survive for long periods of
time (Pilsworth and Knottenbelt 2007). The condition
results in infection of the epidermis and is believed to be
spread by direct contact between animals and through
contaminated environments. Mudfever commonly affects
the lower limb of horses (Pilsworth and Knottenbelt
2007) and as such reduction of bacterial spores in bed-
ding that is in contact with the lower limb for prolonged
periods would be desirable.
Due to the potential risks associated with the contami-
nation of the horses’ environment and pathogen trans-
mission, it is important that equine bedding be
objectively assessed for its ability to resist bacterial sur-
vival and growth.
The aim of this study was to (i) compare the rate of
growth of the four bacteria described, on four commonly
used types of equine bedding under controlled laboratory
conditions and (ii) compare the moisture-holding capac-
ity of each bedding type.
Materials and methods
Bedding types, bacterial strains and reagents
The bedding types tested were P. sylvestris (Scots pine
shavings), P. nigra (Corsican pine shavings), Pi. sitchensis
Journal of Applied Microbiology 122, 23--29 ©2016 The Society for Applied Microbiology24
Bacteria and equine bedding K. Yarnell et al.
(Sitka spruce shavings), Cannabis sativa (hemp) and
chopped wheat straw. Prior to microbiological testing, all
bedding (2 g pooled sample) were placed in a glass bea-
ker covered with aluminium foil and autoclaved at 121°C
for 15 min. Isolates of E. coli and De. congolensis from
Nottingham Trent University’s culture collection were
retrieved from frozen storage (80°C). Streptococcus equi,
Strep. zooepidemicus and Di. nodosus were commercially
sourced (LGC Standards and Public Health, Middlesex,
England). All nutrient agar and broth were purchased
from Oxoid Thermo Fisher Scientific (Basingtoke, UK)
and Defibrinated Horse Blood was purchased from TCS
Biosciences (Buckingham, UK).
Bacterial count methodology
Each bacterial strain was streaked from the frozen stock
onto appropriate agar media. Microbial strains, media
and incubation conditions are listed in Table 1. After
incubation, purity of the cultures was assessed through
morphological assessment on the plate and Gram stain,
and a single fresh colony was used to inoculate the broth
culture. The culture was diluted at 1 in 10 in fresh broth
overnight and 07 ml of the dilution was used to inocu-
late 2 g of each bedding type. The inoculation dose was
determined for each strain; Strep. zooepidemicus 779
CFU, Strep. equi 55910
CFU, E. coli 529
CFU, Di. nodosus:15910
CFU and De. congolen-
sis:161 910
CFU. Bedding with bacterial inoculant
was incubated overnight at room temperature (Di. no-
dosus was incubated anaerobically). After incubation, the
bedding was mixed with 18 ml of 085% saline and
homogenized in a Stomacher 400 (Seward, Worthing,
UK) for 1 min at 265 rev min
. The suspension was
decimally diluted in saline and spread in triplicate on
their respective agar media and incubated in their
optimal growth conditions. The viable count (colony-
forming unit per ml) was determined for each bacterial
strain for the five different bedding types.
Bacterial count data analysis
All data were logarithmically (log10) transformed prior to
statistical analysis and are expressed as mean value and
standard error of three replicate per bedding. All log-
transformed data were normally distributed and one-way
ANOVA was used to compare bacterial count between the
bedding types. The Tukey post hoc test was used to deter-
mine pairwise significance between groups. Data analysis
was performed using IBM SPSS ver. 23 software (IBM Cor-
poration, Armonk, NY, USA) and Differences were con-
sidered significant at P005.
Moisture-holding capacity methodology
Each bedding type was investigated for basic moisture-
holding capacity under laboratory conditions. Bedding
was supplied in its original dried form by the manufac-
turer. One hundred grams of dried mass of each bedding
type was weighed (Salter, Kent, UK) and placed into a
mesh basket measuring 25 cm by 25 cm and weighing
350 g with a collecting tray placed underneath. Equine
urine collected noninvasively from one horse with a
specific gravity of 11 was then syringed into the bedding.
The container size was calculated by taking the approxi-
mate size of a stable of 35by35 m and scaling this
down to a workable size in the lab of 25 cm by 25 cm.
The same was done with the amount of urine, with an
average of 7 l of urine produced per day scaled down to
466 ml. Room temperature throughout the trial was
14 21°C and humidity was 47 56% rh.
Moisture-holding capacity was calculated on a weight
basis by periodically reweighing the basket (wet
weight container weight (350 g) weight of bedding
Table 1 Microbial strains used during the study
Microbial species
number Media Incubation requirements
Streptococcus equi NCTC 9682 Nutrient agar/broth 24 h at 37°C
NCTC 7023 Nutrient agar/broth 24 h at 37°C
Blood agar base no. 2 +5% defribrinated horse blood/nutrient
Anaerobically for 48 h at 37°C
Dermatophilus congolensis NCTC 5175 Blood agar base no. 2 +5% defribrinated horse blood/nutrient
48 h at 37°C
Dicelobacter nodosus ATCC
Tryptone soya agar +5% sheep blood/cooked meat broth +1%
5 days
This table provides details of the microbial strains used during the study, their collection number, growth media used and incubation
Journal of Applied Microbiology 122, 23--29 ©2016 The Society for Applied Microbiology 25
K. Yarnell et al. Bacteria and equine bedding
(100 g)). This was carried out at 2, 4, 6, 8, 10 and 24 h
post introduction of urine. As it is recommended that
urine and faeces be removed from stables at least once a
day, no further measures were taken beyond 24 h. Each
trial was repeated three times for each bedding type and
a mean weight for each time point calculated. A one-way
repeated measures ANOVA was used to compare wet
weights between each bedding type.
Microbial results
Results from the microbial count after overnight incuba-
tion with each bedding type are shown in Table 2. Three
of five strains tested, E. coli, Di. nodosus and De. con-
golensis were not detectable (limit of detection
CFU ml
) when incubated with Corsican pine, Scots
Pine and Sitka Spruce.
There was a significant difference in Strep. zooepidemi-
cus counts between bedding type as determined by the
one-way ANOVA (F(4, 10) =9291, P<0001). According
to the Tukey post hoc test, all bedding were statistically
different from each other except Corsican pine and Scots
pine, with straw showing the highest count, and Corsican
pine and Scots pine the lowest count for Strep. zooepi-
There was also significant differences in Strep. equi
counts between bedding type (F(4, 10) =262,
P<0001). Counts in hemp and straw were significantly
higher than in Scots pine and Sitka spruce while Corsican
pine showed the lowest count for Strep. equi.
Escherichia coli counts were significantly higher in
hemp compared to straw (F(1, 4) =12506, P<0001).
However, there were no significant differences in the
Di. nodosus and D. congolesis counts between hemp and
straw (P>005).
Overall, hemp and straw showed the highest colony
counts for all bacterial strain tested while Corsican and
Scots pine showed the lowest colony counts.
Moisture-holding capacity results
There was a significant difference in the moisture-holding
capacity between all bedding types, F(3, 56) =1062,
P=0001 with the pine-based bedding absorbing signifi-
cantly more urine when compared to all other bedding
types (Fig. 1). The amount of urine absorbed increased
over time up to a period of 24 h for the pine and hemp
bedding at which point no further measurable absorption
took place. The amount of urine absorbed increased over
time up to a period of 8 h for the spruce and straw bed-
ding after which no further measurable absorption took
place (Fig. 2).
Pine bedding presented with significantly less bacterial
growth for each of the bacteria types tested when
Table 2 Mean SE of Log viable count (CFU ml
;n=3) for each bacterial strain incubated overnight with different bedding type
Bedding type Streptococcus zooepidemicus Streptococcus equi Escherichia coli Dichelobacter nodosus Dermatophilus congolensis
Hemp 645 0020
526 0015
440 0026
2434 0219 483 0018
Straw 713 0008
489 0012
540 0010
3021 0126 473 0052
Corsican pine 285 0087
333 0039
Scots pine 304 0111
411 0013
Sitka spruce 436 0011
425 0322
Pvalue <0001 <0001 <0001 0081 0130
LOD, limit of detection.
Mean with different letters differ significantly within column (P005).
95% CI weight (g)
Spruce Hemp Straw
Bedding type
Figure 1 Mean moisture-holding capacity by weight for each of four
bedding types tested. This figure shows the mean moisture-holding
capacity by weight (g) (SD) of each bedding type of pine, spruce,
hemp and straw. Pine bedding held significantly (P<0001) more
moisture when compared to all other bedding types.
Journal of Applied Microbiology 122, 23--29 ©2016 The Society for Applied Microbiology26
Bacteria and equine bedding K. Yarnell et al.
compared to other commonly used equine bedding sub-
strates including hemp and straw. Furthermore, wood-
based bedding of pine and spruce absorbed and retained
significantly more urine and continued to do so for up to
24 h when compared to the other bedding types tested
which absorbed urine for up to 8 h.
With regard to the moisture-holding capacity, it must
be stressed that this trial took place in a laboratory set-
ting. In a horse’s stable, moisture will be introduced spo-
radically to the bedding over a longer period each time
the horse passes urine. Therefore, the bedding will have a
chance to absorb this moisture and dry out before the
introduction of further urine. This part of the trial was
conducted to gain a basic idea of the moisture-holding
capacity. Results may be different if this trial were to be
repeated in field conditions and is an area of future
Hemp and straw bedding continued to absorb mois-
ture for a total of 8 h. This is still satisfactory in terms of
equine hygiene as most horse owners will remove dirty
bedding twice per day. Further work must now be carried
out in field conditions to ascertain the rate at which
moisture is removed by each bedding type and how
much moisture each bedding type is capable of absorb-
ing. This is important as the amount of free urine in the
horses bed could contribute to bacterial growth by pro-
viding a source of nitrogen.
The bacteria types tested pose varying levels of disease
risk for the equine species ranging from the discomfort
of distal limb dermatitis associated with De. congolensis
to the significant welfare and economic implications of
strangles caused by the bacterium Strep. equi. Recent
work on pathogen control strategies in sheep suggest that
the environment may assist persistence of footrot caused
by Di. nodosus, one of the bacteria tested during this
study and one which costs the UK farming industry £24
million per year (Nieuwhof and Bishop 2005). Footrot
occurs in winter in housed sheep, therefore, Di. nodosus
must also survive on bedding long enough to be trans-
mitted between animals and Green and George (2008)
suggest that damp bedding is an ideal medium for sur-
vival. As pine bedding produced the least bacterial growth
and the largest moisture-holding capacity during this
study, this suggests pine-based bedding to be a suitable
choice for housed sheep as well as for horses to prevent
spread of disease and poor foot health. Transmission of
the bacteria from one animal to another will always occur
via the surface on which they are kept Green and George
(2008). It is therefore important that further work be
carried out to improve knowledge on bacterial survival
and transmission in a range of bedding substrates and
It is not clear at this stage for this particular study why
pine-based bedding produced the least bacterial growth
but there are a number of factors to consider. Evidence
suggests that equine health improves (foot and respira-
tory health in particular) when horses are stabled on
pine-based product and this could be due to the reported
pathogen-resisting properties of pine (Kim and Shin,
2005; Zeng et al., 2012).
alimaa et al. (2007) tested 30 species of hard and soft
wood trees for their antimicrobial activity and reported
that by far the most consistent antibacterial and antifun-
gal properties were associated with extracts of Pinus spe-
cies. The authors suggest that this antimicrobial effect is
associated with stilbenes, a polyphenol found in the
wood. This compound may be lost in the processing of
the bedding or with age of the wood and so other factors
that could contribute to the bacterial resistance must be
One factor to consider would be the physical proper-
ties of the bedding itself, including moisture holding
capacity. Animal urine provides a source of nitrogen
which assists bacterial growth. If the bedding substrate
Weight (g)
Time (h)
Figure 2 Mean (SD) wet weight over time
for each of four bedding substrates tested.
This figure shows the mean (SD) wet
weight of each bedding type of pine shavings
(black), spruce shavings (white), hemp (grey)
and straw (hatched) over a 24-h period.
Bedding was weighed at 2 h post
introduction of urine (466 ml) and then at 4,
6, 8 and 24 h post introduction of urine.
Each bedding was tested three times and a
mean calculated.
Journal of Applied Microbiology 122, 23--29 ©2016 The Society for Applied Microbiology 27
K. Yarnell et al. Bacteria and equine bedding
used can remove and hold urine then this will inhibit the
growth of the bacteria. During this study pine-based bed-
ding produced the least bacterial growth and was also the
most absorbent substrate which supports this theory.
During this study pine and spruce bedding reduced the
growth rate of bacteria in a controlled laboratory setting.
It is therefore important that these lab findings be tested
in field conditions. If the bedding substrate used as part
of a horse’s management can reduce survival and spread
of disease-causing pathogens, then this has an application
in biosecurity measures for the equine industry. Bedding
is used not only in the horse’s own stable but in horse
transporters, temporary stables at competitions and
equine stabling at veterinary centres, all of which are uti-
lized by many different horses and are key areas where
disease prevention is paramount. Bedding choice may be
one way of reducing disease risk in these scenarios.
As well as identifying and managing disease, prevention
of pathogen transmission needs further research. Horse
husbandry, in particular choice of bedding substrate, can
potentially make an important contribution to prevention
or reduction of disease outbreak.
The authors thank BEDMAXTM for providing the bed-
ding materials tested during the study and for part fund-
ing of the project in collaboration with Nottingham
Trent University. We also thank Samantha York and her
stallion Oakring Chadun for on demand provision of the
urine used in the trial.
Conflict of Interest
This project was part funded by BEDMAXTM who also sup-
plied three of the bedding substrates tested. Nottingham
Trent University and the authors of this study have no
commercial or personal relationships with this company.
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K. Yarnell et al. Bacteria and equine bedding
... Streptococci from sawdust immediately after it had been placed in the cubicle, increasing to more than 10 8 cfu/g after the bedding had been in place for 48 hours and Streptococci were recovered at levels greater than 10 8 cfu/g six days after the fresh sawdust was applied to the housing (Hogan and Smith, 1997 (Yarnell et al., 2017). This may suggest that sawdust derived from coniferous tress may have greater antibacterial properties than deciduous trees, which agrees with research investigating the antibacterial effects of essential oils from conifer trees (Hong et al., 2004;Lee et al., 2009). ...
... Species differences between streptococci have been noted in terms of recovery rates from chopped straw, with S. zooepidemicus (10 7 cfu/ml) having higher recovery rates after 24 hours than S. equi (10 4 cfu/ml), following inoculation of each at 10 5 cfu/ml (Yarnell et al., 2017). This suggests that there are differences in survival and potential replication between different Streptococcus spp and could be related to different nutritional requirements or environmental adaptations between different streptococci species. ...
... Poor air quality (e.g., due to low air turnover, high levels of dust or ammonia) in some indoor stabling environments can contribute to respiratory problems [84,85], and some hoof problems can be created or exacerbated by prolonged periods of restricted movement (e.g., thrush in stabled equids) [86,87]. The inhibition of natural levels of locomotion and the associated hoof capsule expansion, contraction and blood circulation that would occur in free-ranging equids and, also, potentially unhygienic underfoot conditions if standing in soiled or damp bedding are contributing factors to hoof problems [88]. ...
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Equestrian sports, including racing (e.g., flat, steeple-chasing, harness or donkey derby); show-jumping; cross-country; dressage; polo; polocrosse; endurance; carriage driving; vaulting and hunting; are hugely popular in the UK, and they involve a significant number of people, both as participants and spectators, and tens of thousands of equids. In this paper, we discuss animal welfare as a complex and disputed issue, clarifying what the term means and how it can be measured. We review many aspects of welfare risk to equids used for sport, addressing issues encountered throughout their lives, including housing, feeding, veterinary intervention, shoeing, handling, training, breeding and equipment. This is followed by a unique exploration of the institutions and social processes influencing equine welfare. The institutional components comprise the rules of competition, the equids, attributes of the stakeholders and the space where participants strive to achieve a common purpose. We endeavour to untangle the most significant elements that create barriers or provide opportunities for equine welfare improvement. We expose the challenges faced by a broad range of stakeholders with differing ethics, attitudes and values. Evidently, there are many welfare risks to which equids used in sports continue to be exposed. It is also evident that significant improvements have occurred in recent times, but there remains a barrier to reducing the risks to an acceptable level. We conclude with recommendations regarding a process for change, involvement of stakeholders and management of knowledge to improve equine welfare that involves identifying and prioritising the risk factors and ultimately leading to interventions, further research and/or education.
... An increase in the number of horses to care for means that standards of care in a yard do, as was highlighted, slip, and one of the key aspects of disease control is decreasing exposure to pathogens, which at the most basic level includes the provision of a clean living environment for the horse. Many disease-causing pathogens can be transmitted indirectly through sharing of contaminated fomites [31], which could include horse equipment, clothing or bedding [32]. A lower number of staff means there are more horses per person to muck out and care for, which means less time can be spent in each box, especially when the morning routine must be completed in time to ride out. ...
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The purpose of this paper is to highlight some of the key challenges to racehorse welfare as perceived by racing industry stakeholders. The paper draws upon statements and transcripts from 10 focus group discussions with 42 participants who were taking part in a larger study investigating stakeholders’ perceptions of racehorse welfare, which participants recognised as maintaining the physical and mental well-being of a performance animal. Analysis of the 68 statements participants identified as challenges produced nine themes. Among these, 26% (18 statements) of the challenges were health related, whilst 41% (28 statements) focused on the effect staff shortages were having on the racing industry. Staff shortages were perceived as affecting standards of racehorse care and the opportunity to develop a human–horse relationship. Poor employee relations due to a lack of recognition, communication and respect were perceived as having a detrimental effect on employee attitudes, behaviour and staff retention which, in turn, can have a sequential effect on the welfare and health of horses in training. Although the number of challenges produced is small (68), they emphasise the perceptions of stakeholders closely associated with the racing industry.
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Air quality has a direct influence on the health, welfare and performance of animals as well as on the health of farm workers undertaking different tasks in livestock buildings. Furthermore, air pollutants emitted from livestock buildings can reduce air, water and soil quality and potentially undermine the health of nearby residents. There is ample evidence that the respiratory health of various livestock species can be compromised by poor air quality. High concentrations of noxious gases, dust and airborne microorganisms might reduce production efficiency and the general welfare of farm animals. In some herds, a large portion of the lungs of slaughter pigs may show signs of acute or chronic pneumonia, pleuritis or other respiratory diseases. In broilers, birds with lung lesions account for about 30% of all rejections at meat inspection. Farm workers can be exposed to a range of noxious gases in animal buildings and above slurry pits, causing illness and, in some exceptional cases, mortality through suffocation or poisoning during agitation of slurry that can release toxic hydrogen sulfide gas. Long-term exposure to particulates in pig and poultry buildings might affect the respiratory health of farm workers. Dust in animal buildings contains many biologically active substances such as bacteria, fungi, endotoxins and residues of antibiotics (as a result of veterinary treatments) that are suspected to be hazardous to human health. Epidemiological studies have demonstrated that working in pig confinement buildings is associated with symptoms of chronic bronchitis (cough and phlegm), asthma-like symptoms such as wheezing and shortness of breath during work. Exposure to dust in piggery buildings causes an immediate inflammation of the airways in many individuals. Longterm studies indicate that work inside pig buildings doubles or triples the incidence of respiratory symptoms. Residents living close to livestock buildings can be exposed to dust and bacteria, which might produce negative health effects. It is well-documented (within and outside of this book) that livestock farming is a source of many different emissions. Airborne emissions include ammonia, methane, nitrous oxide, and particulates such as dust and microorganisms. In addition, other potentially harmful substances such as heavy metals, antibiotic residues and components of disinfectants might be emitted from livestock building via air ventilation, slurry and/or solid manure. The impacts of these emissions are potentially damaging to ecosystems, even at considerable distances away from the farms. Livestock farming also contributes significantly to total anthropogenic greenhouse gas emissions, which are thought by many to influence climate, and many countries have now undertaken steps to reduce these emissions. This book concentrates on the nature and amounts of aerial pollutants arising from livestock production and their impacts on the health and welfare of farm animals, and the workforce, as well as on the environment. We hope that this book will be useful for farming professionals, academics, students, policy makers, business leaders, regulatory bodies and agricultural consultants.
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Streptococcus equi subsp. zooepidemicus is the pathogen most commonly isolated from the uterus of mares. S. zooepidemicus is an opportunistic pathogen and part of the resident flora in the caudal reproductive tract. The aim of this study was to investigate whether a genotypically distinct subpopulation of S. zooepidemicus is associated with endometritis in the mare, by genotyping and comparing uterine S. zooepidemicus strains with isolates from the vagina and clitoral fossa. Mares with (n = 18) or without (n = 11) clinical symptoms of endometritis were included. Uterine samples were obtained using a guarded endometrial biopsy punch, whereas a swab was used to recover samples from the cranial vagina and the clitoral fossa. If S. zooepidemicus was present, up to three colonies were selected from each anatomical location (max. 9 isolates per mare). Bacterial isolates were characterized by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). S. zooepidemicus was isolated from the endometrium of 12 mares. A total of 88 isolates were analyzed by PFGE: 31 from the endometrium, 26 from the cranial vagina and 31 isolates from the clitoral fossa. For MLST 21 isolates were chosen. Results demonstrated a higher genetic similarity of the isolates obtained from infectious endometritis compared to isolates obtained from the caudal reproductive tract. In conclusion, we demonstrate for the first time that a genetically distinct group of S. zooepidemicus is associated with infectious endometritis in the mare.
This unique resource provides the most up-to-date, in-depth coverage of the basic and clinical sciences required for management of the equine athlete. The unique treatment of exercise physiology and training within a clinical context, together with a detailed review of all diseases affecting athletic horses, makes this the most comprehensive text available. Provides a thorough grounding in the basic physiology of each body system, and in particular the responses of each body system to exercise and training. The internationally renowned team of contributors has created the ultimate reference for veterinarians, students, horse-owners, and all those involved in the world of equine athletics.
It can be a challenge to find suitable horse bedding materials that provide higher moisture absorption, better animal comfort, greater fertilizer values, and improved indoor environment. Our first objective was to determine the water absorption capacity (WAC) of two bedding materials, flax shive (FS) and pine wood shavings (PWS), commonly used by equine facilities. The second objective was to measure ammonia (NH3), hydrogen sulfide (H2S), and greenhouse gas (GHG) concentrations emitted from these bedded stall surfaces. In this study, the WAC of bedding materials were measured at 0.5, 1, 2, 3, 4, 6, 8, 12, and 24 hours in the laboratory. A total of eight horses were used for a 14-day study period. Of these, four horses (group-1) were bedded with FS and the other four (group-2) were bedded with PWS for week-1. In week-2, bedding materials were switched between the two groups. Ammonia and H2S were measured in situ. For GHG measurement, air samples (methane [CH4], carbon dioxide [CO2], and nitrous oxide [N2O]) were collected 152 mm above the bedded stall surface in Tedlar bags using a vacuum chamber and analyzed for GHG using a gas chromatograph. The WAC of FS was 56% greater than the PWS. There were no significant differences in NH3, H2S, CH4, CO2, and N2O concentrations between the two bedding materials (P>.05). Nutrient contents between fresh and soiled bedded samples for each bedding type were different (P <.05). Measured nutrient contents between fresh FS and PWS and bedded FS and PWS bedding materials were similar (P >.05).
Streptococcus zooepidemicus (Sz) is a tonsillar commensal of healthy horses but with potential to opportunistically invade the lower respiratory tract. Sz is genetically variable and recombinogenic based on analysis of gene sequences including szp, szm and MLST data. Although a variety of serovars of the protective SzP are commonly harbored in the tonsils of the same horse, lower respiratory infections usually involve a single clone. Nevertheless, isolation of specific clones from epizootics of respiratory disease has been recently reported in horses and dogs in N. America, Europe and Asia. In this report, we provide evidence suggestive of lateral gene exchange and recombination between strains of Sz from cases of respiratory disease secondary to experimental equine herpes 1 virus infection in an isolated group of weanling horses and ponies. Nasal swabs of 13 of 18 weanlings with respiratory disease yielded mucoid colonies of Sz following culture. Comparison of arcC, nrdE, proS, spi, tdk, tpi and yqiL of these Sz revealed 3 Clades. Clade-1 (ST-212) and 2 (ST-24) were composed of 7 and 3 isolates respectively. ST-24 and 212 differed in all 7 housekeeping as well as szp and szm alleles. Two isolates of Clade-1 were assigned to ST-308, a single locus variant of ST-212 that contained the proS-16 allele sequenced in ST-24. One isolate of ST-308 contained szm-2, the same allele sequenced in Clade 2 isolates; the other was positive for the szp-N2HV2 allele of Clade 2. These observations are consistent with gene transfer between Sz in the natural host and may explain formation of novel clones that invade the lower respiratory tract or cause epizootics of respiratory disease in dogs and horses.
The effects of three different bedding materials (straw, wood shavings, and straw pellets) on the behavior of six warmblood horses (four mares, two of them with foals) housed in single stalls were analyzed. Each material was used for 2 weeks in three consecutive runs. The behavior of the horses was videotaped and analyzed on the first and last 3 days for each bedding alternative in the last of the three runs. The time budgets for the behaviors including standing, eating, lying, occupation with bedding material, and other were generated. Compared with straw pellets and wood shavings, the application of straw bedding led to a significantly higher frequency and longer duration of occupation with bedding material and in turn, shorter fractions of standing and other behaviors. The total duration of lying was significantly longer on straw than on straw pellets. Straw pellets resulted in the least mean recumbency duration per occurrence of this behavior. Because occupation is one of the important functions that bedding material is supposed to fulfill, we concluded that in regard to horse behavior, straw bedding was the best among the three materials analyzed. Further investigations with a more homogeneous group of probands are necessary to verify the observed behavioral reactions.
Strangles, caused by the host adapted Lancefield group C bacterium Streptococcus equi sub-species equi (S. equi), is one of the oldest recognised infectious diseases of horses and continues to cause significant welfare and economic cost throughout the world. The ability of S. equi to establish sub-clinical persistent infections primarily in the guttural pouches of convalescent horses has been instrumental to its success. However, the implementation of simple control measures that permit the identification and treatment of persistently infected carriers can prevent further outbreaks of disease at a local level. This review summarises some of the molecular mechanisms exploited by S. equi to cause disease. New qPCR and iELISA diagnostic tests replace culture methodologies as the gold standard for the detection of infected animals. A strategy to maximise the effective application of these tests to direct management methods for the eradication of S. equi infection is presented and the role of preventative vaccines is discussed. In contrast to current understanding, emerging data illustrates the dynamism of the global S. equi population and potential consequences for the effectiveness of currently available vaccines. The ability to use modern vaccines alongside conventional biosecurity and screening procedures will be critical to the large-scale prevention and even eradication of strangles, providing an opportunity to finally break the stranglehold that this disease has on the world's equine industry.
The costs of three major endemic sheep diseases in Great Britain, gastro-intestinal (GI) parasites, footrot and scab, were estimated and compared with costs for other diseases from another study. Disease costs include lost performance, preventive measures and treatment of affected animals. The most costly disease, of those studied, for the British sheep industry is infestation with GI parasites, with estimated annual costs of £84 million. Annual costs for the other two diseases are £24 million for footrot and £8 million for sheep scab. This compares with literature estimates of £20 million for Chlamydial abortions and £12 million for toxoplasmosis. For sheep scab most costs are for preventive measures, therefore, short of eradication, a reduction in incidence will have a limited effect on costs. For GI parasites, costs are linearly related to the severity of the infestation and a reduction of the disease will have a proportional effect on the costs to the industry. For footrot about half the costs are for preventive measures, the other half is for lost production and treatment. A reduction in the incidence of footrot has a proportional effect on the £10 million associated with loss of production and treatment of infected animals. It is concluded that gastro-intestinal parasites and footrot are two sheep diseases in Britain for which a reduction of severity or incidence will have a large impact on costs of production.
The aim of this study was to determine which of the two species, Fusobacterium necrophorum or Dichelobacter nodosus, are associated with hoof thrush in horses. Fourteen hoof samples, collected from eight horses with thrush and 14 samples collected from eight horses with healthy hooves, were examined for the presence of F. necrophorum, Fusobacterium equinum and D. nodosus. Only isolates with phenotypic characteristics representing Fusobacterium could be cultured. Total DNA extracted from the 28 hoof samples was amplified by using DNA primers designed from gene lktA, present in F. necrophorum subsp. necrophorum, F. necrophorum subsp. funduliforme and F. equinum, and gene fimA, present in D. nodosus. The lktA gene was amplified from five of the 14 infected hoof samples and from one hoof sample without thrush. The DNA sequence of the amplified ltkA gene was identical to the lktA gene of the type strain of F. necrophorum (GenBank accession number AF312861). The isolates were phenotypically differentiated from F. equinum. No DNA was amplified using the fimA primer set, suggesting that F. necrophorum, and not D. nodosus, is associated with equine hoof thrush. Hoof thrush in horses is thus caused by F. necrophorum in the absence D. nodosus. This is different from footrot in sheep, goats, cattle and pigs, which is caused by the synergistic action of F. necrophorum and D. nodosus.