Canine Prostate Diseases Flashcards
1
Q
Prostate anatomy
A
2 lobes, prominent median septum that surrounds urethra
- deep in pelvic canal, not easily found in large breeds
- produces seminal plasma, responsible for fluid components of all 3 ejaculate fractions
2
Q
Testosterone conversions
A
Testosterone from Leydig cells –> 5alpha reductase (prostatic epithelium) –> dihydrotestosterone
3
Q
Physical exam
A
Necessary to palpate prostate per rectum in older dogs, when pelvic obstruction suspected, BSE, semen collection abnormalities
4
Q
Diagnostics
A
- collect and evaluate prostatic fluid
- color, volume, pH, motility, morphology of sperm rich fraction
- color, pH, cytological evaluation of prostatic fluid
- ultrasound
- radiographs
- culture
- FNA, biopsy
5
Q
Benign prostatic hyperplasia
A
Most common disease of K9 prostate!!
- older, intact male dogs: >80% of dogs over 5 years have gross or microscopic evidence of BPH (hyperplasia and hypertrophy)
- no breed predisposition
- result of natural aging and hormonal influences on prostate gland
6
Q
BPH pathogenesis
A
Dependent on testosterone, age
- testosterone converted to DHT in epithelial cells via 5a-reductase pathway
- DHt is key to prostatic stimulation leading to stromal and glandular growth
- estrogen sensitizes prostate to DHT (target of some therapeutic agents)
7
Q
BPH clinical signs
A
- usually absent
- bloody urethral discharge
- hemospermia
- tenesmus
- hematuria
- stranguria
8
Q
BPH - physical exam
A
Usually unremarkable except for prostatic changes
- enlarged prostate on digital exam
- generally symmetrical
- non painful to mild discomfort
9
Q
Diagnostic imaging
A
Prostatomegaly
- dorsoventral prostate dimension is >70% of distance between the sacral promontory and pubis on lateral view
- homogenous, hyperechoic pattern
- small cystic areas
10
Q
BPH - diagnosis
A
Made based on clinical signs, history, PE
- prostatic massage and wash
- FNA
- tru-cut biposy
11
Q
BPH - treatment
A
Required only if clinical signs are present
- castration: 1/2 size within 3 weeks, 70% reduction by 9 weeks
- finasteride
12
Q
Finasteride
A
Inhibits 5a-reductase
- stops conversion of T to DHT
- wide dose range
- treat for at least 2-3 months
- libido is maintained
- castration recommended once breeding is done
13
Q
Prostatic cysts
A
Associated with BPH
- fluid retention from obstructed canaliculi
- creates cavitating lesion filled with fluid (can become an abscess)
14
Q
Prostatitis
A
Acute or chronic
- occur at any age (more common in older dogs with BPH)
- rare in castrated males (concurrent neoplasia)
15
Q
Prostatitis - pathophysiology
A
Glandular changes occur which leads to a disruption of prostatic fluid or urine flow and predisposes gland to infection –> secondary to squamous metaplasia or cysts
- ascending infection
- rarely does prostatits occur in an otherwise normal prostate
16
Q
Defense mechanisms
A
- frequent urination
- urethral pressure
- local production of IgA, IgG
- breakdown in face of bacteria predisposes the prostate to infection
17
Q
Prostatitis - clinical signs
A
- urethral discharge
- hematuria
- pollakiuria or dysuria
- tenesmus
- fever
- caudal abdominal pain
- painful prostate on rectal exam
- anorexia
18
Q
Prostatitis - diagnostics
A
- CBC changes depend on severity and duration (possible neutrophilia with a left shift)
- serum chem unremarkable
- UA shows pyuria, hematuria (urine culture is positive)
- semen evaluation: leukospermia, excessive WBCs in prostatic fraction, hemospermia
19
Q
Ultrasound
A
Profound changes in echogenicity
- focal to diffuse hypoechoic areas
- moth eaten look
- small cystic areas with flocculent fluid
20
Q
Chronic prostatits
A
- much harder to diagnose
- subtle clinical signs
- prostatic massage with culture
- prostate may not be enlarged or painful
21
Q
Common bacteria
A
- E coli!!
- kelbsiella
- staphylococus
- streptococcus
- proteus
- pseudomonas
- will be a single organism 70% of the time
22
Q
Prostatitis treatment
A
Culture and sensitivity results
- highly lipid soluble drugs enter prostate (fluoroquinolones, chloramphenicol, TMS)
- antibiotics w/ high pH enter acidic environment of prostate well (erythromycin, TMS)
- long term treatment (at least 4-6 weeks!!)
23
Q
Prostatic abscess
A
Severe sequela to prostatitis
- abscess can rupture, creating fulminating peritonitis
- treat aggressively
- surgical drainage with omentalization
- US guided aspiration gaining popularity
24
Q
Prostatic abscess - treatment
A
Don’t treat with antibiotics alone
- rarely results in cure due to inability of antibiotics to penetrate prostate and/or abscess
- castration or finasteride
- surgical drainage if needed
25
Prostatic neoplasia
Incidence of 0.2-0.6%
- age at diagnosis: 5-17 years
- increased risk in neutered males compared to intact males
26
What is the most common prostate condition found in neutered males
Prostatic neoplasia
- always palpate prostate at physical exams
- palpable prostate in neutered male should be assumed to be neoplasia until proven otherwise
27
Prostatic neoplasia - clinical signs
- tenesmus (colon impingement)
- weight loss
- stranguria
- dysuria
- systemic illness
- hindlimb weakness or pain (skeletal metastasis)
28
Neoplasia radiographs
Prostatomegaly, irregular border, mineralization, lymphadenopathy, periosteal new bone formation
- met check is warrented
29
Prostatic tumors in dogs are typically _______
Androgen independent
| - poor success rate with dogs (survival time is only a few months)
30
Transmissible venereal tumor
Tropical and sub tropical areas
- only contagious tumor in small animals
- histiocyte cell line
- penis is primary site in males, vagina in females
- cauliflower like mass, very friable, ulcerated mass
31
TVT treatment
- metastasis is rare
- diagnose via cytology, biopsy
- treat with vincristine, adriamycin
- prognosis is good
32
Persistent frenulum
Young dogs prior to puberty
- frenulum is normally lost at time of puberty
- prevents copulation
- corrected with surgery
- heritable in other species
33
Paraphimosis
Failure of penis to retract into prepuce
- lead to ischemic necrosis of penis
- prevent by facilitated retraction of penis into prepuce following breeding
- surgical amputation is needed in severe cases
34
Cryptorchidism
Most common disorder of sexual development in dogs (13%)
- heritable trait
- testicular descent not completed until birth
- should not confirm a case until 4-6 months of age
35
Risk for _____ is higher in retained testicle
Neoplasia
36
How to diagnose cryptorchidism
Cox test
| - GnRH or hCG followed by measurement of testosterone
37
Balanoposthitis
Non specific inflammation of penis
- trauma, neoplasia, infeciton, herpes virus, foreign bodies
- histopath provides a more accurate diagnosis
- treat symptomatically
