Canine Prostate Diseases and Other Male Conditions Flashcards
What does the prostate produce in the dog?
Seminal plasma
What is the prostate responsible for?
Fluid components of all 3 fractions of ejaculate
What pathway converts testosterone to dihydrotestosterone?
5α-reductase
What diagnostics should be done when evaluating the prostate?
Collect and evaluate prostatic fluid
Color, volume, pH, motility, morphology of sperm-rich fraction
Color, pH, cytological evaluation of prostatic fluid
US, radiographs, culture, FNA, biopsy
What is the most common disease of the canine prostate?
Benign prostatic hyperplasia
What dogs most commonly get BPH?
Older, intact male dogs
>80% of dogs over 5 years have gross or microscopic evidence of BPH
95% of dogs affected by 9 years of age
What is BPH the result of?
Natural aging and hormonal influences on the prostate gland
What is BPH dependent on?
Testosterone and age
What is the key to prostatic stimulation leading to stromal and glandular growth?
DHT
What sensitizes the prostate to DHT?
Estrogen
What are the clinical signs of BPH?
Usually absent Bloody urethral discahrge Hemospermia Tenesmus Hematuria Stranguria
What is seen on physical exam of BPH?
Usually unremarkable except for prostatic changes
Enlarged prostate on digital exam
Generally symmetrical however some dogs will have an irregular pattern
Non-painful to mild discomfort
What is seen on diagnostic imaging with BPH?
Prostatomegaly
Homogenous, hyperechoic pattern
May have small cystic areas
What is used to diagnose BPH?
Often made base on clinical signs, history, and PE findings
Prostatic massage and wash
FNA
Tru-cut biopsy
What is the treatment of BPH?
Required only if clinical signs are present
Castration is TOC
Finasteride (Proscar and Propecia) for 2-3 month
What does finasteride do?
Inhibits 5α-reductase
Stops conversion of T to DHT
Is the resolution of BPH faster with castration or medical management?
Castration
What are prostatic cysts typically associated with?
BPH
What are prostatic cysts?
Fluid retention from obstructed canaliculi
What do prostatic cysts create?
Cavitating lesion filled with fluid that can become an abscess
What is prostatitis more common in?
Older dogs with BPH
What is the pathophysiology of prostatitis?
Glandular changes occur which leads to a disruption of prostatic fluid or urine flow and predisposes the gland to infection (secondary to squamous metaplasia or cysts)
Ascending infection
What are the defense mechanisms against prostatitis?
Frequent urination
Urethral pressure
Local production of IgA, IgG
Breakdown in the face of bacteria predisposes the prostate to infection
What are the clinical signs of prostatitis?
Urethral discharge Hematuria Pollakiuria or dysuria Tenesmus Fever Caudal abdominal pain Painful prostate on rectal exam Anorexia
What does CBC with prostatitis depend on?
Severity and duration
What could possibly show up on a CBC with prostatitis?
Neutrophilia with a left shift
What does serum chem show with prostatitis?
Generally unremarkable
What does UA show with prostatitis?
Pyuria, heaturia, urine culture is usually positive (cysto sample)
What is seen on the semen evaluation with prostatitis?
Leukospermia, excessive WBCs in prostatic fraction
Hemospermia
What is found on US with prostatitis?
Profound changes in echogenicity, “moth eaten” look
Small cystic areas with flocculent fluid
Which is harder to diagnose, acute or chronic prostatitis? Why?
Chronic
Very subtle clinical signs, prostate may not be enlarged or painful
What is the common bacteria found with prostatitis?
E. coli** Klebsiella sp Staphylococcus sp Streptococcus sp Proteus sp Pseudomonas sp
How frequently is prostatitis caused by one organisms?
70% of the time
What should be used for treatment of prostatitis?
Highly lipid soluble drugs that enter the prostate (fluoroquinolones, chloramphenicol, TMS)
Antibiotics with high pH that enter the acidic environment very well (enrofloxacin, TMS)
How long does treatment of prostatitis take?
It is long-term, at least 4-6 weeks
What is a severe sequela to prostatitis?
Prostatic abscess
What can a prostatic abscess create if it ruptures?
Fulminating peritonitis
How is a prostatic abscess treated?
Surgical drainage with omentalization is older option
US guided aspiration is gaining popularity
Don’t treat with antibiotics alone
Why does a prostatic abscess rarely result in cure?
Inability of antibiotics to penetrate the prostate and/or abscess
What are the adjunctive treatments of a prostatic abscess?
Castration or finasteride
Surgical drainage if needed
What is the incidence rate of prostatic neoplasia?
0.2-0.6%
What is the age at diagnosis of prostatic neoplasia?
Range: 5-17 years
Median: 10 years
What has an increased risk of prostatic neoplasia?
Neutered males compared to intact males
What is the most common prostate condition found in neutered males?
Prostatic neoplasia
What should a palpable prostate in a neutered male be assumed to be?
Neoplasia until proven otherwise
What are the clinical signs of prostatic neoplasia?
Tenesmus (colon impingement) Weight loss Stranguria Dysuria Systemic illness Hindlimb weakness or pain (skeletal metastasis) Asymmetrical enlargement
What is seen on radiographs in a dog with prostatic neoplasia?
Prostatomegaly Irregular border Mineralization** Lymphadenopathy Periosteal new bone formation
What are prostatic tumors independent of?
Androgen
What is the success rate of treating prostatic neoplasia?
Poor, survival time is typically only a few months after diagnosis
What is the only contagious tumor in small animals?
Transmissible venereal tumor (TVT)
What geographical areas does TVT usually occur?
Tropical and subtropical areas
What is the original cell type of TVTs?
Histiocyte
What is the primary site of TVT in males? Females?
Penis
Vagina
Does metastasis occur with TVT?
Rarely
How do you diagnose TVT?
Cytology
Biopsy
How do you treat TVT?
Vincristine (TOC)
Adriamycin
What is the prognosis with TVT?
Good
When is persistent frenulum seen?
In young dogs prior to puberty
When is the frenulum normally lost?
At the time of pberty
What does a persistent frenulum prevent?
Copulation
How is a persistent frenulum corrected?
With surgery
Is a persistent frenulum heritable?
It is in other species, but it is unknown in the dog
What is paraphimosis?
Failure of the penis to retract into the prepuce
What can paraphimosis lead to?
Ischemic necrosis of the penis
How can paraphimosis be prevented?
Facilitate retraction of penis into the prepuce following breeding
What is needed in severe cases of paraphimosis?
Surgical amputation
What is the most common disorder of sexual development in dogs?
Cryptorchidism (~13%)
Is cryptorchidism heritable?
Yes, but the mode of heritability is unknown
When should a case of cryptorchidism be confirmed? Why?
Should not confirm a case until 4-6 months of age because testicular descent is not normally completed until birth or shortly thereafter
What is there a risk for with cryptorchidism?
Neoplasia in the retained testicle
How can you test to see if an animal is cryptorchid?
Cox test: GnRH of hCG followed by measurement of testosterone levels
How is cryptorchidism treated?
Castration
What is balanoposthitis?
Non-specific inflammation of the penis
What are causes of balanoposthitis?
Trauma Neoplasia Infection Herpes virus Foreign bodies
What can provide a more accurate diagnosis of balanoposthitis?
Histopathology
How do you treat balanoposthitis?
Symptomatically
