SA 4 Flashcards
When is the earliest you can make a definitive diagnosis of cryptorchisim in the dog?
> 6 months old
tell me the timeline of testicular descent in the dog
- testes pass through inguinal canal 3-4 days after birth
- testes reach final position in scrotum by 35 days
- inguinal canal remains open until 6 months –> free movement of testes
how do you define puberty in the male dog?
first ejaculation that contains sperm
how does male puberty timing differ between dog breeds?
earlier in smaller breeds, later in larger breeds
what is the average age of male dog puberty?
7-10 months
many dogs will not ejaculate until > 1 year
why do you collect semen in a dog?
- part of BSE
- assessment of fertility
- for cytology and culture
- to perform artificial insemination
how do you collect semen in male dogs?
- manual ejaculation (most common)
- electroejaculation reported but unnecessary
describe how to manually collect semen from dogs
- get dog ready (pheromones, swab from bitch from estrus, GnRH)
- get semen collection cone ready
- 2 handlers (1 w/ the teaser, other with the male)
- complete exposure of penis
- water-based lubed
- massage of bulbs glandis
- dog will indicate he wants to step over by lifting 1 hind leg – this mimics the tie
- collect the semen
should you use testosterone to prime a male dog for manual semen collection?
nope!
should you use latex for semen collection in the dog? why or why not?
nope
decreases motility of sperm
tell me about the fractions of the collected semen in a dog
- fraction 1: pre-sperm fraction; small vol
- fraction 2: sperm-rich fraction
- fraction 3: prostatic fluid
semen collection in the dog can be attempted again within ____ of previous collection, but some males will not ejactulate more than _____.
1 hour
once a day
semen quality is best when collecting no more frequently than _____ in the dog.
2-5 days
dog semen samples should be held at what temp?
room temp
dog semen:
1. what vol?
2. what concentration?
3. total sperm in 1 collection?
4. you analyze a drop of undiluted semen for what?
- 1-50 mL (avg 4ml)
- depends on prostatic fluid
- 300 million to 2 billion
- motility (>70%)
dog semen morphology:
1. normal sperms expected to be at what %?
2. what stains do you use to assess?
3. list 3 preparation artifacts.
4. how do you minimize artifacts
- > 80%
- eosin-nigrosin or diffquik
- detached heads, bent tails, reflex midpieces
- placing it on heated stage
spermatogenesis in the dog takes… how long?
62 days
how can you tell if theres a repro tract infection based on semen culture?
an anaerobic culture > 10,000 CFU/mL
what are the common bacteria involved in repro tract infections in male dogs?
- brucella canis
- staph
- strep
- e. coli
- klebsiella pneumoniae
what is the number of motile spermatozoa necessary for successful AI in the dog?
> 150 million
how can you extend the life of semen you wish to use for AI the dog?
an extender (20% egg yolk-based extender is superior, but you can also use equine skim milk semen extenders)
what 3 broad ways can you prevent fertility in the male dog?
- orchiectomy
- sclerosing agents
- medical suppression
tell me the difference between performing a bilateral orchiectomy before and after puberty in the dog
before: no development of male behaviour (mounting and roaming)
after: some male behaviour shown, but there can be reduction (some are learned behaviour)
what is neuterosol?
a sclerosing agent
how does neuterosol prevent fertility in the male dog?
non-sx sterilant (zinc gluconate)
what is important to know about neuterosol?
- ulceration of the scrotum at injection site is possible (1-2%)
- testosterone not completely eliminated
- low incidence of scrotal pain upon palpation within the first 3 days after injection
when using neuterosol, complete sterility may take up to ____ to achieve in post-pubescent males.
60 days
how much vol of neuterosol do you inject?
based on the testicular width as determined by measuring each testis at its widest point
what are the options for medical suppression of fertility in the male dog?
- GnRH implants
- medroxyprogesterone acetate (MPA)
with GnRH for fertility suppression, there is an initial ____ and then a ____.
stimulation
down-regulation
is megestrol acetate (MGA) an effective contraceptive?
nope! not even at high doese
when using medroxyprogesterone acetate (MPA) for fertility suppression, are LH concentrations suppressed?
nope
what is cryptorchidism?
testicular descent does NOT happen by 6 months of age (unilateral or bilateral)
cryptorchidism has a high incidence in what breeds of dog?
Boxers
small breeds
inbred cocker spaniels and miniature schnauzers
cryptorchidism: teste can be retained ____, although most are retained ____.
intra-abdominally
inguinal
true or false: it’s ok to breed dogs with cryptorchidism
false
it is a heritable, autosomal recessive trait
true or false: retained testes are predisposed to neoplasia
true
retained testes are ____ than descended testes (size). retained testes are capable of ___ but not ____.
smaller
steroidogenesis, not spermatogenesis
which 2 tumors are retained testes at higher risk for?
Sertoli cell tumors
seminomas
the spermatic cord of retained testes is predisposed to ___.
torsion
how do you diagnose cryptorchidism?
- history (castrated but male behaviour)
- palpation of inguinal region (inguinal LNs and fat may feel like small retained testes)
- rectal palp (prostate is enlarged in intact dogs)
- challenge test: baseline blood sample, GnRH injection, take blood in 60 mins –> testosterone goes from low to high
- AMH: produced by Sertoli cells only, high in intact males (>2ng/mL)
how do you treat cryptorchidism?
- surgical removal (follow ductus deferent leading to retained testes)
- orchipexy
- medical tx using GnRH or hCG –> questionable success, not recommended
what is the second most common tumor type in male dogs? what is the first?
2nd: testicular neoplasia
1st: skin tumors
for dog testicular neoplasia, the mean age at dx is ___. what breed is at increased risk? what are the 3 most common types?
- 9 years
- Boxers
- sertoli cell tumor, seminoma, leydig cell tumor
true or false: Sertoli cell tumors are the most common tumor type of retained testes
true
which breeds are predisposed to developing Sertoli cell tumors?
Boxers and Weimaraners
true or false: Sertoli cell tumors often become malignant.
false
you suspect a dog has a Sertoli cell tumor. how do you know which testis is affected?
the affected testicle is enlarged
Sertoli cell tumors result in a paraneoplastic syndrome called ____. what are the clinical signs?
- feminization syndrome
- bilateral symmetrical alopecia
- pancytopenia (BM suppression)
- cystic benign prostatic hyperplasia
- gynecomastia and galactorrhea
- attractiveness to other males
- cornfield cells in preputial mucosa
what is a seminoma?
tumor of the germ cell of the testicles
which breed is predisposed to seminomas?
German shepherds
true or false: seminomas often become malignant
false
seminomas can result in a paraneoplastic syndrome that is unexplained. what are the clinical signs?
- alopecia
- hyperpigmentation of the trunk
- non-insulin responsive diabetes mellitus
- prostate disease
what is another name for Leydig cell tumors?
interstitial cell tumors (ICT)
is there a breed disposition for leydig cell tumors?
nope
what is a leydig cell tumor / interstitial cell tumor?
tumor of scrotal teste
true or false: cryptorchidism predisposes to ICT/leydig cell tumors
false
true or false: leydig cell tumors often become malignant
false
true or false: leydig cell tumors are often incidental findings at necropsy and are usually less than 1 cm in diameter
true
Leydig cell tumors can result in a paraneoplastic syndrome. what is the cause?
hyperestrogenism or hypertestosteronism
both reported
the paraneoplastic syndrome seen with Sertoli cell tumors is because of what?
increased estrogen secretion
spermatic cord torsion is also called?
testicular torsion
true or false: spermatic cord torsion is a common disorder
false
the signs of testicular torsion in the dog often present as?
acute abdomen
true or false: spermatic cord torsions are more common in retained testes
true
how do you treat spermatic cord torsions?
surgical removal
you just removed these testicles from a dog. why?
testicular torsion
orchitis and epididymitis more commonly occurs in what age of dog?
young
what is the most common cause of orchitis and epididymitis?
infectious
what is going on?
orchitis and/or epididymitis
how does Brucellosis present in the male dog?
orchitis/epididymitis, scrotal dermatitis, oligospermia, and infertility
true or false: when dealing with canine brucellosis, castration will decrease shedding, reduce risk of infection, and zoonosis
true
why are scrotal hernias bad?
scrotal swelling, ischemia and necrosis of entrapped tissue
what is a hydrocele? why do they occur?
collection of fluid in the vaginal process
due to impaired lymphatic drainage, lymphosarcoma, inguinal hernia, spermatic cord torsion
the canine prostate is a _____-dependent organ. prostatic growth is regulated by _____.
androgen
5alpha-dihydrotestosterone (DHT)
DHT is a potent ____.
androgen
tell me how testosterone gets to be DHT
testosterone –> 5alpha-reductase –> DHT
what is the most common prostatic disorder?
benign hypertrophy
benign hypertrophy of the prostate is present in most dogs of what signalment?
intact male dogs >6 years
what are the clinical signs of prostatic benign hypertrophy?
may be absent, tenesmus, persistent or intermittent hematuria
usually no systemic signs
what are the ddx for prostatic benign hypertrophy?
prostatitis, neoplasia, cysts
how does the prostate look when a dog has benign prostatic hypertrophy?
non-painful, symmetrically enlarged prostate
how do you diagnose benign hypertrophy of the prostate in dogs?
- rectal exam
- culture of ejaculate to rule out prostatitis
- biopsy to rule out neoplasia
- definitive diagnosis only be biopsy
- US exam
how do you treat prostatic benign hypertrophy?
remove androgen
- castration = tx of choice
- finasteride = blocks action of 5alpha-reductase
prostatic cysts are associated with what?
androgen-dependent BPH
prostatic cysts usually occur in what signalment of dog?
older, larger-breed dogs
what are the C/S of prostatic cysts?
lethargy, anorexia, tenesmus, bloody urethral discharge
is medical treatment of prostatic cysts possible?
nope
most commonly, prostatitis occurs because of ____. it can also occur by what 2 methods?
- ascending of urethral flora
- hematogenous spread & spread from testes or peritoneal cavity
what is the most common pathogen involved with prostatitis? name some other ones
E. coli
staph, proteus, klebsiella, pseudonomas
prostatitis is more common in ____ dogs secondary to ____.
intact, BPH
prostatitis in neutered males is secondary to what?
prostatic neoplasia
what are the C/S of:
1. acute prostatitis?
2. chronic prostatitis?
- febrile, anorectic, urethral discharge
- may be asymptomatic, urethral discharge, straining to defecate
prostatic abscesses present as?
fever, caudal abdominal pain, peritonitis, septic shock
how do you diagnose prostatitis?
- urinalysis via cysto –> prostatic fluid is secreted constantly and drains into bladder
- culture of ejaculate - the prostatic fraction
true or false: urine culture is diagnostic for prostatitis?
false. it is not diagnostic for prostatitis but can localize inflammatory process
what is the most common prostatic disease in neutered dogs?
malignant adenocarcinomas
true or false: other prostatic diseases predispose to prostatic neoplasia.
false
how do you diagnose prostatic neoplasia?
biopsy
how do you tx prostatic neoplasia? is the prognosis good or bad?
- complete prostatectomy
bad –> often metastasized at time of dx, urinary incontinence in >50% after sx
you see a dog with a “red pea” coming out of his penis. what is that?
urethral prolapse (prolapse of the distal urethra)
urethral prolapse has the pathognomonic C/S of what?
red pea
how do you treat urethral prolapse?
surgery. medical tx ineffective
true or false: fx of os penis is common in dogs and the cause is often known.
false. it is not common and the cause is often unknown
tell me how to fix fractures of the os penis
- surgical reduction (place screw dorsally!)
- perineal or scrotal urethrostomy
why are fractures of the os penis bad (apart from being painful and sucky?)
ventral deviation of the penis causes an obstruction, causing dysuria
