Equine - Stallion Reproductive Disease Flashcards
Stallions with low libido may benefit from being housed where?
in a harem setting as a single stallion with other mares and removed from the sight and sound of other stallions
How are domestic stallions typically housed?
in bachelor settings
What negative reinforcement methods can lead to erection failure or poor libido?
penile rings, brushes, shock collars, whips, etc.
What stallions is aggressive behavior and/or poor libido be found in?
Young or inexperienced stallions, overused stallions, and stallions with previous breeding injury
What can cause scrotal enlargement/swelling?
Hydrocele, inguinal hernia, varicocele, hematocele, hematoma, abscess, testicular neoplasia, orchitis/epididymitis, and torsion of the spermatic cord
How is scrotal enlargement/swelling classified?
unilateral or bilateral
painful or non-painful
What is a hydrocele?
an abnormal accumulation of serous anechoic fluid surrounding the testes and/or epididymides
How is a hydrocele classified?
painless with frequent unilateral enlargement - may be bilateral
When is the incidence of a hydrocele increased?
in hot summer months
What is hydrocele associated with?
decreased exercise/stall rest, enlarged inguinal rings, and with causes of increased peritoneal fluid
How can a hydrocele effect fertility?
It can lead to decreased fertility and semen quality due to impaired thermoregulation function
How is a hydrocele diagnosed?
via ultrasound
How is a hydrocele treated?
benign neglect if mild and fertility is not affected
treatment ultimately is dependent on cause - can use exercise, hydrotherapy, or a course of anti-inflammatories
What is an inguinal/scrotal hernia?
Herniation of the gastrointestinal contents into the scrotum through the inguinal rings
What breeds are commonly affected by inguinal/scrotal hernias?
breeds with enlarged inguinal rings - Tennessee walking horse, standardbreds, and draft breeds
How are inguinal/scrotal hernias classified?
painful, unilateral enlargement but can be painless if non-incarcerated
What is the standard treatment for inguinal/scrotal hernias?
Surgery - closed castration, ring imbrication +/- truss
Want to preserve spermatogenesis in the remaining teste
What is a varicocele?
abnormal dilation in the veins of the pampiniform plexus
How can a varicocele affect fertility?
it may be the cause of subfertility in stallions
What lesion(s) is a varicocele occasionally found concurrently with?
scrotal hernias, hydroceles, orchitis, or cardiac disease
What is a hematocele?
blood accumulation surround the testes
What is a hematocele a result of?
blunt force trauma such as kicks, falls, and breeding trauma, or a penetrating injury
How are hematoceles treated?
Time, systemic antimicrobials, anti-inflammatories, hydrotherapy
If bad, it may require unilateral or bilateral castration
Testicular neoplasias are relatively ______ and usually ________.
rare; unilateral
What type of neoplasias are found in the testicles?
seminoma (most common), sertoli cell tumor, leydig cell tumor, teratoma
What do seminomas arise from?
germ cells lining seminiferous epithelium
How are testicular neoplasias diagnosed?
Via scrotal ultrasonography
What is the recommended treatment for testicular neoplasia?
castration
True or False: Orchitis and/or epididymitis is a common cause of scrotal enlargement in horses.
false - it is rare
What is orchitis and/or epididymitis commonly associated with?
trauma
Can be due to bacterial and/or viral infection, autoimmune, and/or parasitic migration
How is orchitis and/or epididymitis diagnosed?
ultrasound - increased testicular or epididymal size and loss of normal architecture/echogenicity
What is the treatment of choice for orchitis and/or epididiymitis?
castration most common
What is torsion of the spermatic cord?
less than 180 degree rotation of the spermatic cord that is frequently an incidental finding
When is torsion of the spermatic cord an emergency?
if it has rotated greater than 180 degrees
How is torsion of the spermatic cord classified?
unilateral enlargement
How is torsion of the spermatic cord diagnosed?
palpation and scrotal ultrasound, decreased/obstructed blood flow within the pampiniform plexus and testicular artery, loss of normal architecture
What is the treatment of choice for torsion of the spermatic cord?
unilateral castration
What can cause reduced testicular size?
testicular hypoplasia or testicular degeneration
What is cryptorchidism?
unilateral or bilateral retention of one or both testes - inguinal vs abdominal
How is cryptorchidism diagnosed in presumed geldings?
Antimullerian hormone level (elevated in cryptorchid vs gelding), hCG stimulation test (2-fold testosterone increase), and ultrasound for location
What are the infectious diseases of the penis and/or prepuce?
EHV3, CEM, EVA, and bacterial overgrowth
What are the non-infectious diseases of the penis and/or prepuce?
parphimosis and priapism
What is EHV3?
Coital exanthema
What causes coital exanthema?
Equine Herpes virus 3
What lesions does coital exanthema cause?
vesicles and ulcerations of the penis
How is coital exanthema transmitted?
To mares and/or stallions with active lesions either during live cover or fomite transfer
How is coital exanthema diagnosed?
virus isolation from swabs of vesicle/ulcers
How is coital exanthema treated?
sexual rest for 3 weeks - self limiting
How is coital exanthema prevented?
prevent breeding of stallions with active lesions
What is contagious equine metritis (CEM) caused by?
Taylorella equigentalis
True or False: CEM is highly contagious and reportable.
true
What clinical signs do stallions with CEM have?
none - they are asymptomatic carriers
What clinical signs do mares with CEM have?
infertility, early embryonic loss, mucopurulent vulvar discharge, and endometritis
What must happen in all mares and stallions over the age of 18 months that are being imported into the US (in regards to CEM)?
They must be quarantined, tested, and treated at the time of importation
How is the routine testing for CEM in stallions done?
Take a sample/swab from the urethra, urethral sinus, fossa glandis, and penile shaft, then transferred to aimes transport media and shippe to USDA approved facilities
What causes overgrowth of bacteria?
Loss of commensal bacteria typically due to overuse of disinfectants or washing
What are the common isolated pathogens in cases of bacterial overgrowth?
Pseudomonas, Klebsiella, and E.coli
How can stallion bacterial overgrowth affect the mare?
it can lead to endometritis
What causes Equine Viral Arteritis (EVA)?
Arterivirus
What clinical signs do mares with EVA typically show?
They are most commonly asymptomatic but may have a short term of infertility due to fever
What does EVA cause in mares?
abortions, infertility, and pregnancy loss throughout gestation
What systemic signs can EVA cause?
vasclulitis - subcutaneous edema, periorbital edema, excess peritoneal, pleural, and pericardial fluid, edema within the lymph nodes, intestines, and other intraabdominal organs
How is EVA diagnosed?
virus isolation or PCR within semen and/or serum
What is paraphimosis?
inability to retract the penis within the prepuce
What is paraphimosis frequently associated with? Other causes?
frequently associated with: penile/preputial trauma, edema, and/or hematoma
phenothiazine sedatives in stallions and geldings
can be caused by infectious disease or a debilitating condition
What is the treatment of choice for paraphimosis?
Decrease the edema/swelling - hydrotherapy and compression therapy
Replace the penis within the prepuce - probang or purse string
Support of the penis with a jock strap or pantyhose
What is priapism?
persistent erection without sexual arousal
What can cause priapism?
Phenothiazine administration, trauma, neurologic injury, or conditions associated with a poor BCS
Priapism is a constant cycle of what?
Stagnant blood, venous occlusion, penile erection and rigidity, stretching and injury of the penile nerves, fibrosis of corpus cavernosum and corpus spongiosum, and flaccid paralysis
How is priapism treated?
Hydrotherapy and compression therapy Corpus cavernosum flush Phenylephrine Support the penis from being dependent similar to cases of paraphimosis Reversal of phenothiazines
How is a corpus cavernosum flush performed?
through and through lavage using a 14 or 16 gauge needle, flush with heparinized saline +/- phenylephrine, and remove the clotted blood from erectile tissues and allow for detumescence
What are the common diseases of accessory sex glands?
Blocked ampullae and seminal vesiculitis
What causes blocked ampullae?
blockages due to sperm plugs and/or casts
How is blocked ampullae diagnosed?
Semen analysis - azoospermia or oligospermia with predominate detached heads
Ultrasound - fluid pockets within the ampullae lumen
How is blocked ampullae treated?
Oxytocin and/or prostaglandins and ampullary massage
frequent collections
True or False: Seminal Vesiculitis is rare.
True
What causes seminal vesiculitis?
bacteria - it is of bacterial origin
How will the ejaculate be in patients with seminal vesiculitis?
hemospermia, pyospermia, or flocculent material in ejaculate
What is the treatment of choice for seminal vesiculitis?
endoscopic catheterization of colliculus seminalis for culture, lavage, and/or administration of antimicrobals
Systemic antimicrobials
What is urospermia?
The presence of urine with an ejaculate - may see decreased motility due to increased osmolarity
How is urospermia be diagnosed?
azostix - >30 mg/dl urea nitrogen or creatinine > 2mg/dl
How is urospermia treated?
administration of alpha adrenergic agents prior to collection
In refractory cases of urospermia, what collection method may need to be used?
chemical ejaculation may be necessary in refractory cases
What is hemospermia?
blood present within an ejaculate - may be gross or microscopic contamination
What are the differentials for hemospermia?
urethral rents, habronemiasis, squamous cell carcinoma, EHV3, seminal vesiculitis, or penile mucosal injuries
How is hemospermia diagnosed?
physical examination of penis and urethroscopy
What is a urethral rent?
a tear within the urethral mucosa - it will frequently bleed upon erection
How is a urethral rent treated?
sexual rest, laser coagulopathy, urethrostomy, and corpus spongiotomy
How can habronemiasis lead to hemospermia?
Migration and encystment of stomach nematode
How do you treat hemospermia due to habronemiasis?
give ivermectin +/- corticosteroids to reduce inlammatory response
How do you treat hemospermia due to squamous cell carcinoma?
surgical excision, phallectomy, topical chemotherapeutics
