Equine: Stallion Flashcards
what does the spermatic cord contain?
testicular artery
pampiniform plexus
lymphatic vessels
deferent duct
cremaster muscle
is examination of the internal genitalia of a stallion performed in a reproductive examination?
not always
what is testicular size correlated with?
daily sperm output
what does a positive test in the post-ejaculate for venereal disease indicate?
infection of urethra, accessory sex glands, or epididymis
what will libido and mating ability be greatly influenced by?
intended use of the stallion
what can be used in stallions that are not trained to collect into an artificial vagina?
chemical ejaculation
when is semen collected in a breeding soundness exam?
twice, one hour apart
what is evaluated in semen?
gross evaluation of semen quality
pH
volume
concentration
motility
morphology
what can color changes be associated with?
presence of:
debris
blood
urine
purulent material
what is the normal pH of semen?
slightly alkaline: 7.2-7.7
what can you use to find the concentration of semen?
spectrophotometer
hemocytometer
nucleocounter
what does total motility refer to?
percentage of sperm that exhibit any type of movement
what should the appearance of the testicular parenchyma be on ultrasound?
homogenous
gray
slightly granular
what is daily sperm output?
number of sperm available for ejaculation during one day after depletion of extragonadal sperm reserves
what does depletion of extragonadal reserves involve for daily sperm output?
collection from stallion once daily for minimum of 5-7 days
what provides a better reflection of daily sperm output than total scrotal width?
testicular volume: more accurate
what is the normal value for ejaculate volume?
70ml: range 30-250ml
what is the most reliable endocrine assay for cryptorchidism?
anti-mullerian hormone
why is urine in semen (urospermia) and issue?
negatively impacts semen quality and stallion fertility
can induce inflammation in uterus following live cover or insemination
what is hemospermia?
presence of blood in semen
what are the common causes of hemospermia?
lesions on glans penis or external urethral process
seminal vesiculitis
rent or teat in the proximal urethra
what is azoospermia?
ejaculated seminal fluids devoid of sperm
what should investigation of azoospermia seek to establish?
if an ejaculate is produced
what is priapism?
an erection that persists after cessation of sexual stimulation
true priapism is rare in stallion
what are the causes of paraphimosis?
trauma
preputial edema secondary to systemic disease
phenothiazine tranquilizers: acepromazine
what is phimosis?
inability of horse to protrude its penis from prepuce
what systemic diseases can cause paraphimosis?
purpura hemorrhagica
dourine
emaciation
where is the spermatic cord located?
cranial aspect of testicle
where is the tail of the epididymis?
caudal pole of testicle
what should be examined of a horse’s penis and sheath?
ability to extend/retract, erect penis
pathology: ulceration, infection, tumors, abrasions, lacerations
signs abnormal discharge
check for bean in urethral fossa and remove
why might the internal genitalia of a stallion per rectum be performed?
abnormal history
physical examination findings
sub-fertility
abnormal semen parameters
what is the satisfactory minimum total scrotal width?
8 cm
where should you swab for venereal disease?
urethral fossa
urethra
shaft of penis
prepuce
what are the key pathogens for venereal disease?
Taylorella equigenitalis
Trypanosoma equiperdum
equine viral arteritis
equine herpesviruses
piroplasmosis
pseudomonas spp
klebsiella spp
what percentage of horses will ejaculate in response to imipramine and xylazine?
30-75%
what are ejaculates like from chemical ejaculation?
low volume
high in sperm concentration
what fraction of the semen is removed with evaluating semen?
gel fraction
what is the normal semen pH?
slightly alkaline: 7.2-7.7
what does establishing the concentration and volume allow?
total sperm number to be calculated
what does progressive motility refer to?
sperm that exhibit forward motility across the microscopic field or are moving in a large circular path
what are the common defects of the acrosome?
knobbed
roughed
detached acrosomes
what are some common head defects?
under-developed: microcephalic
large: macrocephalic
what may diffuse increased echodensity indicate in the testicles?
testicular fibrosis
what can daily sperm output be used to estimate?
number of mares he can breed daily during the season
what is the range of sperm concentration normal?
30-600 million/ml
120 million/ml
what is the ratio of extender to semen for shipped cooled semen?
at least 3:1 to dilute seminal plasma effects
how many progressively motile and morphologically normal sperm need to be placed in a mare’s uterus to ensure a consistent and optimal chance of conceiving?
500 x 10^6
how can you treat urospermia?
dilute semen
centrifugation of semen
what might cause azoospermia if an ejaculate is produced?
semen outflow obstruction
underlying testicular dysfunction
how can paraphimosis be treated?
elevate and support
lubricate/wrap with emollient antimicrobial dressing
NSAIDs
exercise
hydrotherapy
massage
