contents
Pratique Vétérinaire
équine
2012 – volume 44, n°173
> Editorial (Guillaume Fortier) . . . . . . . . . . . . . . . . . . . .3
> Facial deformation and maxillary osteolysis
in a mare (Valérie Deniau et coll.) . . . . . . . . . . . . . 39
A 17-year-old mare had a facial deformity that had progressively wor-
sened over a period of 6 weeks, severe gingivitis and partial obstruc-
tion of the nasal cavities. Examinations show extensive maxillary
osteolysis, hypertrophy of the gingiva and nasal turbinates, and phos-
phorus and calcium imbalances very suggestive of osteodystrophy
secondary to hyperparathyroidism. The mare was euthanised. The ini-
tial diagnostic hypothesis was excluded subsequent to results of
serum parathyroid hormone assay. The necropsic and histological exa-
minations showed maxillary, renal and pericarotidial granulomatous
inflammation associated with infestation by the nematode Halicepha-
lobus gingivalis.
> Ultrasonography and endoscopy of the urinary tract
in adult horses (Claire Forgeard et coll.) . . . . . . . . 45
Despite numerous examinations routinely performed in horses suffe-
ring from conditions affecting the urinary tract, there is also a place
for ultrasonography and endoscopy because the organ can be visuali-
sed using these methods. Ultrasonography and endoscopy are com-
plementary for the establishment of a diagnosis. They also allow good
case monitoring. Increasingly present in everyday practice, ultrasono-
graphy and cystoscopy are used routinely, in a minimally invasive man-
ner, when there is a suspected condition affecting the either the upper
or lower urinary tract.
> Glaucoma in horses (Sébastien Monclin et coll.) . 53
In horses, glaucoma generally develops in a slow and insidious way
and presents with very varied clinical signs. Therefore the diagnosis is
difficult to establish and is often made too late to enable optimal treat-
ment. This article demonstrates the complexity of this disease in
horses and provides a summary of the condition. The article also aims
to help the practitioner to adopt a proactive attitude to this condition
in order to establish early diagnosis in order to instigate prophylactic
treatment (in susceptible individuals) and the most appropriate
therapy.
> What use are statistics?
(Jean-Michel Vandeweerd) . . . . . . . . . . . . . . . . . . . 60
Various factors inherent to the method of scientific study may
influence results: this is termed the bias. Data can also be influenced
by the play of chance. Statistics are used to avoid making erroneous
conclusions by accident and to estimate the probability of being
wrong. This random error is managed by the use of statistical hypo-
thesis testing or the estimation of results in the form of confidence
intervals. Hypothesis testing will conclude the absence or presence of
an effect studied with an error probability less than a value of p
(usually 5%). The confidence interval around a measure of the effect
studied allows estimation of the extent of the effect while ensuring
that this value has a good chance of being true (usually 95%). Statis-
tics also determine the number of individuals to observe, or to use in
a clinical trial achieve the study of the hypothesis posed.
> Factsheet. Intra-articular injections of the fetlock
(Maria Simondon et coll.) . . . . . . . . . . . . . . . . . . . . 65
> Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
6
> Equine herpesviruses: the role of equine
herpesvirus 1 (Stéphane Pronost et coll.) . . . . . . 7
To date, five equine herpesviruses (from EHV-1 to EHV-5) have been
found that infect horses. Among them, the EHV-1 is a major player.
The process of infection with EHV-1 has been well described during
experimental infection. However, in the absence of increased effi-
ciency of existing vaccines, control methods must be based on
methods of prevention on the one hand and management of foci of
infection according to strict procedures on the other. All these
methods can be applied in infections by other equine herpesviruses,
whether respiratory (EHV-4, EHV-2, EHV-5) or genital (EHV-3).
> Vaccination against equine herpesvirus 1
(Romain Paillot) . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Equine herpesvirus 1 (EHV-1) is a pathogenic agent of horses. Its
cycle of infection begins with infection of the respiratory system.
This phase is followed by spread of the virus within the body. Vac-
cination is an important element in preventing infection by EHV-1
and its spread. Different types of vaccines have been developed
and evaluated during the past 50 years. They can be grouped into
two categories: inert vaccines and vaccines containing live atte-
nuated virus or recombinant viral vectors.
> The relationship between the
myelo-encephalopathies caused by equine
herpesvirus 1 and the viral genotype
(Stéphane Pronost et coll.) . . . . . . . . . . . . . . . . . 25
The equine herpesvirus 1 (EHV-1) is responsible for abortions, res-
piratory infections and myelo-encephalopathies. The nature and
severity of the various forms of diseases induced by EHV-1 depends
on several factors such as age, immune status and overall health
of the animal. The recent discovery of two types of strains of EHV-
1 called neuropathogenic strain and non-neuropathogenic strain
raises the question of the potential relationship between the strain
type (genotype) and disease observed (pathotype). Increased risk
of contagion is nevertheless described in the presence of the neu-
ropathogenic strain.
> Management of a focus of infection associated
with equine herpesvirus 1 on a stud farm
(Peggy Moreau et coll.) . . . . . . . . . . . . . . . . . . . . 31
Equine Herpesvirus-1 (EHV-1) may cause respiratory and/or ner-
vous symptoms, as well as abortion. This article describes an out-
break associated with EHV-1 on a breeding farm in Normandy, in
which the three forms of the disease were encoutered over a short
period. The outbreak started with two cases of myeloencephalitis
which presented within a 24 hour period. A polymerase chain reac-
tion analysis allowed for both rapid diagnosis and verification of a
neuropathogenic strain of the virus. One week later several foals
presented with clinical signs of fever and nasal discharge. A non-
neuropathogenic strain of the virus was subsequently identified. A
total of four cases of EHV-related abortions occured over the 4-6
months following the initial cases. The diagnosis and therapeutic
management of the different cases is discussed, as well as the
various measures implemented to contain disease within the stud,
and to avoid spread further afield.
> Forms of equine herpesvirus 1: monitoring by the
Réseau d’épidémiosurveillance en pathologie
équine (RESPE, Epidemiological surveillance
network for equine diseases)
(Christel Marcillaud-Pitel et coll) . . . . . . . . . . . . 37
Vol. 44/n°173 - Pratique Vétérinaire Équine 2012
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