Exercise arrhythmias and
sudden death in horses – a
review
Cristobal Navas de Solis, Swiss Institute of Equine Medicine, Berne
Arrhythmias are a common finding in
horses during and immediately after
exercise and in many cases are not likely
to be clinically relevant. However, there
is a presumption of a link between
exercising arrhythmias and poor
performance and also in cases of sudden
cardiac death.
The author reviews the literature on
the aetiology, detection and treatment
of arrhythmias in horses and draws
comparisons with knowledge of the
equivalent conditions observed in human
athletes. Studies suggest that the risk of
sudden death due to cardiac arrhythmias
in horses is extremely low at less than
30 cases per 100,000 race starts but
those incidents can have catastrophic
consequences for the human rider and
for public perceptions of welfare in
equestrian sport.
He notes that it is impossible to
guarantee that a horse is safe to undergo
exercise. The clinician’s role should be
to estimate the likely risk and to offer
appropriate advice to both the individual
rider and the racing authorities.
Equine Veterinary Journal 48 (4): 406-414.
Effect of different bedding
materials in stables on equine
behaviour
Agnieszka Kwiatkowska-Stenzel and
others, University of Warmia, Poland
The quality of bedding material in a
stable is important for the occupant’s
welfare by absorbing moisture and
providing an insulating layer. The
authors examined whether the type of material used has any effect on
behaviour by recording the activities
of horses housed on straw, peat moss
with shavings or crushed wood pellets.
They found that using straw bedding
resulted in significantly longer periods
lying down than the two alternative
bedding materials. The longer time spent
in recumbency on straw was correlated
with a lower incidence of unwanted
behaviours such as crib chewing,
pacing and overt aggression towards
neighbouring horses.
Journal of Equine Veterinary Science 42 (1):
57-66.
Abortion in thoroughbred
mares after consuming
buttercups
Thomas Swercszek, University of
Kentucky, Lexington
Buttercups are known to be toxic in livestock and a potential cause of
abortion in cattle but grazing animals
will usually avoid eating a plant that
they find unpalatable. The author
describes an incident involving
thoroughbreds grazing pasture in
central Kentucky infested with bulbosus
buttercups (Ranunculus bulbosus).
Seven
mares aborted and two fillies with
gastrointestinal and neurological signs
had to be euthanised. Post-mortem
examination showed ulcers and erosions
in the stomach and large intestine. The
surviving mares recovered after being
moved to buttercup-free pasture and
all conceived successfully in the next
breeding season.
Journal of the American Veterinary Medical
Association 248 (6): 669-672.
Diagnosis, management
and prognosis for
haemoperitoneum in the
horse
Jan Hawkins, Purdue University,
West Lafayette, Indiana
Haemoperitoneum is a relatively
uncommon cause of blood loss
anaemia in the horse, usually resulting
from abdominal trauma, reproductive
abnormalities, post-surgical
haemorrhage or abdominal neoplasia.
The author outlines a strategy for
dealing with such cases, beginning with a
full clinical examination and abdominal
palpation per rectum, followed by transabdominal and transrectal
ultrasound.
Treatment will require
immediate stabilisation with intravenous fluids, followed by surgery to manage
the source of the bleeding, ideally using minimally invasive laparoscopic
techniques.
Equine Veterinary Education 28 (7): 364-
366.
Associations between
temperature, pollen levels
and asthma in horses
Michela Bullone and others,
University of Montreal, Quebec
Severe equine asthma or heaves may
affect up to 20% of horses living in
temperate environments. The risk
increases in winter with prolonged
stabling and exposure to dust and
other airborne pollutants. The authors
investigate the effects of higher
temperatures on clinical signs of horses
with recurrent disease.
They show that
high temperatures and humidity can
both exacerbate existing problems. The findings highlight the need to provide
temperate conditions for affected horses
especially during disease exacerbations
or unavoidable exposure to stable
antigens.
Equine Veterinary Journal 48 (4): 479-484.
Techniques for the assessment
of hind limb lameness in
horses
Rhodes Bell and others, University of Missouri, Columbia
Lameness in horses has traditionally
been assessed through the subjective
judgements of experienced clinicians
but there is increasing interest in the
use of objective measurements. The authors examine the value of force
plate and body-mounted inertial sensor
measurements for investigations into
hind limb lameness in horses.
Their
study provides preliminary evidence
that inertial sensor measurements of
asymmetric vertical pelvic movement
may provide information relevant to the
nature of hind limb lameness (i.e. push
off-type versus impact-type lameness).
American Journal of Veterinary Research 77
(4): 337-345.
Evaluation of an implant
for use in prosthetic
laryngoplasty in horses
Harry Markwell and Eric Mueller,
University of Georgia, Athens
Laryngeal hemiplegia is a performance-
limiting condition that affects up to
35% of horses. Prosthetic laryngoplasty
is an accepted surgical treatment for the
condition with success rates of up to
78%. The authors describe the results
of an ex vivo mechanical evaluation of a proprietary device, a Sternal ZipFix
implant, for prosthetic laryngoplasty.
They conclude that this implant is less
suitable for use in such procedures
than a single strand of USP 5 braided
polyester suture material (TiCron). The
implant is considerably stronger and
stiffer than the suture material but there
is a high risk of arytenoid cartilage
fracture during placement.
Veterinary Surgery 45 (4): 450-455.
Antimicrobial resistance
trends among equine
Salmonella isolates
Kevin Cummings and others, Texas A&M University, College Station
Salmonella enterica is an important
disease agent in horses, causing
diarrhoea, fever, colic, dehydration and
septicaemia. Antimicrobial use in horses
with salmonellosis is controversial and
generally restricted to those cases with
severe neutropaenia, persistent pyrexia
or an indwelling intravenous catheter.
The authors examined the antimicrobial
resistance patterns in 464 salmonella
isolates from horses in north-eastern
United States between 2001 and 2013.
Overall, the results suggest that current
antimicrobial use in equine practice is
not contributing to the emergence of
resistant Salmonella strains.
American Journal of Veterinary Research 77
(5): 505-513.
Clinical findings in cases of
severe hyponatraemia in
foals
Niamh Collins and others, Scone Equine Hospital, Scone, New South Wales
Severe hyponatraemia in foals is defined
as a serum sodium concentration
of less than 122mmol/L. There are
several different pathophysiological
mechanisms that can be responsible
for excessive retention of uid
or excessive loss of sodium.
The
authors investigated the prevalence
of hyponatraemia in foals admitted as
medical emergencies to an intensive
care unit, and collate the clinical ndings, diagnostic results and clinical findings. They found the prevalence
of severe hyponatraemia in 1,718
admissions was 4%, with the majority
showing no significant clinical
manifestations and most cases having a
favourable outcome.
Australian Veterinary Journal 94 (6): 186-
191.
Bone marrow and adipose
tissue stem cells in treating
meniscal lesions
Maria Gonzalez-Fernandez and others, University of Leon, Spain
The meniscus is a semilunar brocartilaginous tissue in the stifle
joint, which heals poorly after injury
because of its limited blood supply.
The authors examined the ability to
regenerate an equine meniscus using a
collagen repair patch scaffold seeded
with mesenchymal stem cells derived
from bone marrow or adipose tissue.
Promising results were obtained using
stem cell implants obtained from both
tissue sources. They note that these findings may have applications in the
treatment of human joint disease.
American Journal of Veterinary Research 77
(7): 779-788.
Reduced tongue tone in
a case of equine motor
neurone disease
Matthew Robin and others, University of Liverpool
Equine motor neurone disease is a
condition characterised by generalised
weakness and muscle atrophy, and
associated with degeneration of motor
neurons in the ventral horns of the
spinal cord. The authors describe a
case in a seven-year-old Welsh pony
gelding, which presented with unusual
clinical signs of diffuse neuromuscular
weakness and marked accidity of the
tongue.
Their findings were consistent
with an atypical form of the disease
that should be considered when
attempting to differentiate EMND
from similar conditions, such as
botulism.
Equine Veterinary Education 28 (8): 434-
438.
Peritoneal fluid
immunocytochemistry in the
diagnosis of B-cell lymphoma
Maria Carolina Duran and others, University of Saskatchewan, Saskatoon
A 17-year-old Arabian gelding was
admitted to a university equine hospital
with signs of dullness and abdominal
distension. On physical examination
the patient was quiet but alert and
the distension only became apparent
after removal of the turnout blanket.
Gastrointestinal neoplasia with
suspected diffuse peritoneal metastasis
was diagnosed on ultrasonography
and peritoneal fluid analysis. The
owner elected for euthanasia and
declined a post-mortem examination
but immunohistochemistry analysis of
the peritoneal fluid indicated a case of
B-cell lymphoma.
Canadian Veterinary Journal 57 (6): 601-
604.
