Page 518 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Reproductive system: 2.1 The female reproductive tr act 493

VetBooks.ir Management Aetiology/pathophysiology
Coital exanthema is a disease of the external geni-
Partial-thickness and small lacerations are often
undiagnosed or left untreated and heal spontane-
usually venereally transmitted, although other spec-
ously without incident. Very few lacerations appear to talia of the mare and stallion caused by EHV-3. It is
develop into peritonitis. It has been known for mares ulated transmitters include grooming and veterinary
to conceive from a breeding where a laceration has equipment. The initial lesions appear on the mare or
occurred, suggesting that ejaculation through the stallion 5–10 days after an infected mating or con-
tear is rare. Careful monitoring for complications tact with a contaminated fomite. Initially, blistering
for at least 96 hours, plus prophylactic use of broad- of the skin with vesicle formation occurs (1–3 mm
spectrum antibiotics, is usually all that is required diameter), with rapid progression to pustules, which
for dorsal lacerations. Ventral lacerations, which are rupture, leaving shallow ulcers. Rarely, lesions occur
rare, have an increased chance of eventration. The on the lips and nasal mucosa, but the presence of
chance can be reduced by cross tying (to discourage respiratory disease is controversial. It is not known
lying down), plus systemic medications to decrease whether latent infections can occur with this specific
abdominal straining. If the bowel or bladder even- herpesvirus.
trates, it should be protected and washed with sterile
antibiotic solutions before replacement in the vagina Clinical presentation
and vulval suturing. An epidural anaesthetic will stop The clinical lesions usually occur after a mating, but
straining and allow referral to an equine hospital for occasionally they develop spontaneously in mares
surgical replacement and/or bowel resection. If this after minor vulval injuries, damage or surgery. In
is unavailable, euthanasia should be considered. the mare, lesions occur mainly on the vulval lips and
Surgical repair of lacerations with absorbable sutures perineal skin, occasionally on the anus and, rarely, in
in the standing sedated mare under epidural anaes- the vestibule. In the stallion, both the penis and pre-
thesia can be performed in acute lacerations, although puce are affected, particularly in the area of the pre-
this is rare. Some clinicians carry out a Caslick’s vul- putial fold. Stallions may show pain on intromission
voplasty operation when there is a cranial vaginal tear and be unwilling to breed. In both sexes, early in the
in order to reduce the possibility of air aspiration and disease process, there may be swelling and pain in
contamination into the abdominal cavity. the affected areas. In the stallion there may be pain
on urination, especially if the urethral process has
Prognosis lesions. Spontaneous healing occurs quite rapidly in
With small or partial cranial lacerations the prog- 7–10 days in both sexes provided no secondary bac-
nosis is fair. For larger cranial lacerations it is terial infection of the lesions occurs. The discharge
guarded, and for any case with eventration it is poor. from, and the severity of, the lesions will increase if
Lacerations that occur during foaling can interfere bacteria become established. After healing, the site
with foaling and may necessitate a caesarean section of the lesions may be marked by permanent focal
if eventration occurs. areas of lack of pigmentation (see p. 1235).

COITAL EXANTHEMA Diagnosis
Diagnosis is based on clinical signs. Scrapes and
Definition/overview biopsies of fresh lesions will show intranuclear inclu-
Coital exanthema is a sporadically occurring, usu- sion bodies on histopathology.
ally venereally transmitted, EHV infection of both
sexes. Initial blisters, usually on the vulval lips, Management
penis or prepuce, rupture to form ulcers. If they do To help prevent secondary bacterial infections the
not become secondarily infected, these heal within affected areas of skin should be treated symptom-
7–10 days. Preventive applications of antiseptic atically with antiseptic creams. If there are other
creams and the cessation of mating until healing injuries to vulval tissue, these need to be specifically
occurs are all that is required for treatment. treated. Mating for the stallion and mare should