Reproductive System Flashcards
Describe the three phases of the canine estrus cycle
- Proestrus:
Estrogen rises –> vulva enlarges –> serosanguinous vaginal discharge –> attraction of males - Estrus:
Estrogen declines –> triggers LH surge –> ovulation –> female is receptive (behavioral estrus) –> progesterone begins to rise - Diestrus:
Progesterone is secreted from corpus luteum –> uterus prepares for implantation
Describe the role of progesterone
Produced by ovary after heat (estrus)
o After ovulation, follicle corpus luteum –> makes progesterone (diestrus)
o Required for normal pregnancy
Stimulates endometrial glands (increasing number and secretion) and prepares wall for fertilized ovum
What are the types of ovarian cysts?
Non-functional: incidental finding typically discovered when imaging/routine OHE
o Minimal to no clinical signs, may be identified at any age
o Surgical excision is curative, still want to submit for histopathology
Functional: hormone producing, arise from ovarian follicles
o Follicular cysts produce estrogen (most common)
o Luteal cysts produce progesterone (rare in dogs)
What are the clinical signs associated with the most common type of functional ovarian cyst?
Follicular cysts
Causes prolonged stage of estrus
What type of ovarian cyst might be associated with pyometra?
Progesterone-releasing cysts
What is the signalment associated with ovarian cysts?
Young adults (dogs
What is the treatment and prognosis of ovarian cysts?
Surgical excision is curative
Why can pyometra be associated with ovarian neoplasia?
Chronic release of progesterone as in a functional granulosa cell tumor causes endometrial hyperplasia and immunosuppression of the uterus, making bacterial proliferation more likely
What are the different tissues of origin for ovarian neoplasia and why is tissue-type significant?
Tissue of origin dictates effects of tumor
Epithelial: adenoma/adenocarcinoma - space occupying masses only
o Causes vague signs of inappetance, vomiting, lethargy, etc.
Stromal: granulosa cell tumor - functional
o Progesterone –> pyometra
o Estrogen –> persistent proestrus/estrus
Germ cell: dysgerminoma, teratoma, teratocarcinomas (tend to occur in young animals)
What is the general likelihood of metastatic disease with ovarian neoplasia?
Uncommon, 20-30%
Is metastatic ovarian disease more common in dogs or cats?
Cats
What is the significance of a metastatic, functional ovarian tumor?
More complicated than simple excision, but adjunctive treatment may improve survival
Functional tumors (estrogen) can cause irreversible bone marrow suppression
What is the prognosis for a solitary (non-metastatic) ovarian tumor?
complete exision is curative
What is the etiology of ovarian remnant syndrome?
Surgical error - ovarian tissue left behind at OHE, or tissue dropped into the abdomen that has revascularized
What are the clinical signs of ovarian remnant syndrome?
Recurrence of estrus cycle (even 2-3 years later)
Vulval swelling, behavioral estrus
Why is vaginal bleeding not typically seen with ovarian remnant syndrome?
The uterus has been removed
How is ovarian remnant syndrome diagnosed in the dog?
- Vaginal cytology (easiest)
o Mimics normal heat cycle, must be done in standing heat
o Inconsistent in cats - Hormone assays
o Elevated estrogen and progesterone, low LH
o Cats may require lutenization first
Where should you look for the remnant when treating ovarian remnant syndrome?
Caudal pole of right kidney
How does ovariectomy differ from OHE?
Removal of ovary alone
o No risk of secondary effects (eg. pyometra) because hormones have been removed
Ligate ovarian vessels as for OHE –> ligate uterine vessels at proper ligament –> excise ovary
Which hormone is necessary for pyometra?
Progesterone
What is the most common bacteria found in pyometra?
E. coli
What are the typical historical findings of a dog with pyometra?
Recent heat cycle (4-8 weeks ago) Polyuria/polydipsia Systemic illness – variable (anorexia, lethargy, vomiting, fever) Abdominal pain/guarding Vaginal discharge – purulent
Why is PU/PD associated with pyometra?
PU/PD caused by bacterial toxins that inhibit ADH in PT of kidney
What is the difference between open and closed pyometra, and how does that relate to severity of systemic signs?
Open cervix - discharge seen, but less systemically severe
Closed cervix - more severe
How is pyometra diagnosed?
CBC/Chem consistent with sepsis/SIRS o Neutrophilia with left shift o Mild thrombocytopenia o Hypoalbuminemia o Mild cholestasis (bilirubin, liver enzymes up)
Radiographs (good), US (ideal) showing large fluid-filled uterus
How should a pyometra case be stabilized?
Stabilize with IV fluids +/- colloids
IV antibiotics – empirical therapy for gram negative (usually ampicillin/enrofloxacin)
Treat for SIRS if necessary
List the treatment options for pyometra, which is preferred, and why
- OHE (preferred – better prognosis, no risk of recurrence)
- Medical management
Prostaglandin F2alpha – smooth muscle, cervix
Systemic antibiotics
Close monitoring
What are the indications that would make medical management of pyometra acceptable?
NOT systemically ill
OPEN only
Owner highly motivated and aware of risks
Why is medical treatment of closed pyometra contraindicated?
Prostaglandin + closed cervix = rupture
What is the likelihood of medical management preserving fertility in a pyometra case?
50%
What are the differences between the ‘standard’ OHE and OHE for pyometra?
Large incision – xiphoid to pubis
Usually no need to break suspensory ligament
Milk purulent material away from cervix
Ligate prior to clamp placement – friable!
Use noncrushing clamps (Doyen)
Iatrogenic rupture possible!
What is the usual history of a dog with metritis?
Post partum (12 hours to 1 week)
What are the clinical signs of a dog with metritis?
Systemic illness
Foul-smelling reddish-brown discharge
What is the etiology of metritis?
Dystocia
Obstetric manipulation
Retained fetus or placenta
Devitalized uterine tissue
How is metritis diagnosed?
What diagnostic procedure is not helpful?
Primarily based on timing following parturition
Vaginal cytology not helpful (degen neutrophils and intracellular bacteria are normal postpartum)
CBC/Chem changes similar to pyometra
Imaging – similar to pyometra
What are the indications for medical treatment of metritis?
Valuable breeding animal
Good response to initial therapy
No devitalized tissue/retained placenta or fetus
Is treatment of metritis an emergency?
Yes, depending on severity
Which surgical procedure is typically used for metritis?
What is the prognosis?
OHE
Good prognosis
What is the impact of OHE on lactation
No effect on milk production
What is the pathophysiology of cystic endometrial hyperplasia?
Excess progesterone –> glandular tissue becomes cystic –> uterus fills with secretions –> cysts may become hemorrhagic
What history and clinical signs are compatible with cystic endometrial hyperplasia?
Failure to conceive
Patients usually bright and alert
How is cystic endometrial hyperplasia diagnosed?
US for cysts
Is treatment of cystic endometrial hyperplasia an emergency?
Not typically
What are the treatment options with cystic endometrial hyperplasia?
What are the prognoses and which treatment is preferred?
OHE - good prognosis, preferred
-necessary with hemorrhage (hematometra)
Medical therapy - if valuable breeding animal and no vaginal bleeding
What is uterine torsion?
What causes it?
Rotation of uterine horn on long axis
Associated with dystocia, also reported with CEH, pyometra, etc.
Is uterine torsion a surgical emergency?
Yes
How is uterine torsion treated?
Should the torsed fetus be derotated?
OHE + removal of viable pups by c-section
DO NOT derotate
What are the signalment, cause, and treatment options for uterine prolapse
More common in cats
Complication of parturition, up to 48 hours following final fetus
- Manual reduction
- OHE - prevents recurrence
What is the relative risk of benign vs. malignant uterine neoplasia?
Benign: minimal signs, often incidental
Malignant: likely metastatic, prognosis guarded
Is malignant uterine neoplasia more likely in dogs or cats?
Cats - variable in origin
In dogs most commonly benign leiomyomas
List the 6 critera for diagnosing dystocia
- Prolonged gestation (>68 days)
- Signs of toxemia during gestation
- Stage 1 lasting >24 hours
- No puppies >36 hours after temperature drop
- Active stage 2 contractions >30 minutes
- > 4 hours between puppies
Which breeds are prediposed to dystocia?
Brachycephalic
What are the contraindications to medical treatment of dystocia?
Active contractions >30 minutes Fetal malposition (determined on palpation) Fetal distress (determined by US – fast or slow HR)
What are the two surgical treatments for dystocia?
How do they differ?
- C-section (hysterotomy)
2. En-bloc OHE: simultaneous OHE and dystocia treatment
What is the holding layer for closing incisions in the uterus?
Submucosa
What suture would you use to close incisions in the uterus?
3-0/4-0 absorbable monofilament One layer (continuous) or two (+inverting)
What is the prognosis for dogs undergoing surgery for dystocia?
99% survival
What is the prognosis for puppies going through dystocia?
87% survival 2 hours post-op (lower for brachycephalic breeds)
What are the anatomic indications for an episiotomy approach to the vagina?
Anything caudal to the pelvis (vestibular and vaginal lesions)
Access to just cranial of urethral opening (incision limited dorsally by rectum)
What is the proper positioning, incision, and closure for an episiotomy approach?
Position as for perineal surgery (leg drop)
Incise on midline from vulvar opening (median raphe)
Expect moderate hemorrhage
Close in 3 layers: mucosa, muscle + SQ, skin
What are the anatomic indications for a ventral approach to the lower reproductive tract?
Intrapelvic and abdominal lesions
What is the difference between a caudal abdominal approach and a transpelvic approach to vaginal surgery?
Caudal abdominal approach:
- ventral midline incision
- limited access to lesions caudal of cervix
Transpelvic:
- ventral approach through pelvis (osteotomy)
- very invasive, requires muscle elevation and bone removal
What is the etiology of vestibulovaginal stenosis?
Congenital developmental anomaly (no basis for genetic transmission) involving retained embryonic epithelial tissue
What are the 3 forms of vestibulovaginal stenosis?
- Vertical septum (double vagina)
- thin band of mucosa oriented dorsoventrally - Annular lesion (imperforage hymen)
- ring-shaped narrowing
- includes mucosa and submucosa +/- musularis - Hypoplasia
- narrowed section of vaginal vault
- uncommon
What are the clinical signs associated with vestibulovaginal stenosis?
Recurrent vaginitis +/- UTI
Difficulty or pain with breeding
Urinary incontinence
How is urinary incontinence related to vestibulovaginal stenosis?
Will repair of the stenosis improve the incontinence?
Usually due to other urinary abnormalities
Surgery will not improve incontinence
How is contrast vaginourethrogram used to diagnose vestibulovaginal stenosis?
What alternative diagnostic is considered best?
Iodinated contrast used to measure the maximum and minimum diameter of the vagina - ratio used to determine severity of stenosis
Vaginoscopy provides direct visualization of stenosis
What are the indications for treatment of vestibulovaginal stenosis?
Breeding dogs
Spayed dogs with clinical signs
What general criteria are used to determine treatment of vestibulovaginal stenosis?
Lesion type and location
What are the treatment options for a simple septal vestibulovaginal stenosis?
- Digital breakdown ineffective
1. Episiotomy with mucosal resection at lesion attachments
2. Endoscopic laser ablation / scissor resection
Why is mucosal resection not an option in anular vestibulovaginal stenosis lesions?
What treatment is preferred?
Annular lesions are prone to stricture
- Vaginal resection and anastomosis (if caudal to pelvis)
- Vaginectomy of cervix to uretheral opening (if intrapelvic)
What is the etiology of a recessed vulva?
Conformational abnormality (vulva is covered by skin)
What is the impact of prepubertal OHE on the incidence of recessed vulvas?
NO relationship
What is the impact of obesity on the incidence of recessed vulvas?
NO relationship
What clinical signs are associated with recessed vulvas?
Often asymptomatic
Skin fold dermatitis/vaginitis
Urine pooling may cause recurrent UTI or apparent incontinence
What procedure is typically recommended for the treatment of recessed vulva?
Episioplasty (‘vulvoplasty’)
Resection of extra skin, appose and close tissue
What is the prognosis for treatment of recessed vulva?
Good
Complications are rare and recurrent signs almost always resolve
What history and signalment is compatible with vaginal edema?
Young dogs in the first few proestrus/estrus cycles
What is the etiology of vaginal edema?
Mucosa becomes edematous –> protrudes from vulva –> tissue subject to drying/trauma
How is vaginal edema typically treated
Edema resolves with end of cycle (though will recur), lubricate and reduce until then
OHE/OVE resolves and prevents recurrence
Resection of tissue is alternative for breeding animals
How is vaginal prolapse differentiated from vaginal edema and neoplasia?
Entire circumference of vagina prolapses, creating a ‘donut-shape’
What are the etiologies of vaginal prolapse?
Secondary to dystocia, constipation, forced separation
How is vaginal prolapse typically treated?
Manual reduction and OHE
What is the typical signalment associated with reproductive neoplasia?
Older (>10), intact female dogs
What is the relative likelihood of benign vs. malignant vaginal neoplasia?
80% benign (leiomyoma most common)
What is involved in the staging workup of vaginal neoplasia?
CBC/Chem/UA
thoracic rads
abdominal US
Biopsy required to determine malignancy
How is benign vaginal neoplasia typically treated?
Full-thickness resection of vaginal wall at base of mass
What is the most common type of vaginal malignant neoplasia?
What are the characteristics of that malignancy?
Leimyosarcoma
Relatively low risk of metastasis
Locally invasive
Survival good with local control of tumor
What is involved in surgical treatment of malignant vaginal tumors?
Aggressive resection (2-3 cm) via vulvovaginectomy
What breed may be predisposed to malignant mammary tumors?
German Shepherds
What is the relative likelihood of malignant mammary tumors in dogs, male vs female?
Most common neoplasm in female intact dogs, 50% are malignant
Extremely rare in males, more likely benign
Is it more common to have single or multiple mammary tumors?
Multiple
Why is it important to remove all mammary tumors, and to test each one histopathologically?
Malignant transformation is possible
May see different histologic subtypes within the same dog
What is the difference between canine mammary hyperplasia and neoplasia?
Hyperplasia occurs after heat cycle and will regress
Typically multiple masses only a few mm in diameter
What tests are recommended in the workup of canine mammary neoplasia and why?
- Minimum database
- Three-view thoracic radiographs - 25-50% of malignancies have mets at initial diagnosis
- Abdominal US/CT/MRI - especially for caudal mammary masses d/t drainage to iliac LNs
What is the value of cytology (FNA) in the workup of mammary tumors?
Questionable value - cannot definitively r/o malignancy and treatment is the same whether benign/malignant
Can differente mammary tumor from other masses
List the 5 criteria of malignancy in mammary tumors
- Rapid growth
- Size (>1cm diameter)
- Fixed to skin/underlying tissues
- Poorly circumscribed
- Ulceration or inflammation
What are the appropriate margins for wide excision of a potentially malignant mammary tumor?
2-3 cm circumference, fascia and muscle plane deep
What are the differences between the 4 excision procedures for mammary tumors?
What are the indications for each?
- Lumpectomy
- removal of solitary, small mass located between glands or at periphery
- contraindicated with any COM - Simple mastectomy
- indicated for solitary masses, 1-2cm, within gland - Regional mastectomy
- indicated for multiple tumors in adjacent glands
- remove 1-3 or 3-5
- rarely used since likelihood of metastasis is great - Chain (radical) mastectomy
- indicated for mulitple masses throught chain, tumors in gland 3 with any COM, or solitary masses anywhere with multiple COM
Which mastectomies are typically staged, and why?
Bilateral chain mastectomies
Risk of dehiscence is too high if done at the same time, stage 4-6 weeks apart
What is the prognosis for a benign mammary mass removal?
Good with complete resection
Describe the three stages of labor, including the events preceding and following it
• Temperature drop (
What size mammary masses are most likely to be benign in dogs?
What is the median survival time of malignant mammary disease?
1-2 years if no metastasis
What main factor of malignant mammary tumors is associated with longer survival?
Size (smaller tumors = longer survival)
What is the prognosis for dogs with metastatic mammary disease?
Poor.
80% recurrence with LN mets
MST 5 months
What is the influence of OHE/OE on the risk of developing mammary tumors in dogs?
OHE prior to 1st estrus –> 0.5% risk
OHE before 2 years reduces risk
OHE after 2 years, no effect
What other procedure is typically recommended at the time of mastectomy?
Which procedure is performed first?
OHE
OHE performed first to avoid seeding tumor into abdomen
How is an inflammatory carcinoma differentiated form a standard mammary tumor?
Multiple glands affected in both chains with edema, erythema, and pain of affected glands
Is inflammatory carcinoma likely to be metastatic?
Highly likely
What is the prognosis of inflammatory carcinoma?
Poor, MST
Is surgical treatment usually recommended with inflammatory carcinomas?
No
What is the relative likelihood of malignant mammary tumors in cats?
90% malignant (adenocarcinoma)
Male and female rates similar
How does OHE affect the development of mammary tumors in cats?
Prior to 6 months = 10% risk
Prior ot 1 year = 15% risk
When is surgery of feline mammary tumors indicated?
Which procedure is typically selected?
Recommended if no metastasis
Chain mastectomy
No evidence that simultaneous OHE increases survival
When is adjunctive therapy recommended for feline mammary tumors?
Always
What 3 factors predict a good prognosis for feline mammary neoplasia?
- Size:
3 years
>3cm = MST ~6 months - Surgery
More aggressive = better survival - Histologic grade
How is fibroadenomatous hyperplasia differentiated from feline mammary neoplasia
Characteristic appearance (cat boobs), definitive dx on histopath if needed
What signalment is associated with fibroadenomatous hyperplasia in cats?
Young (
Which hormone induces fibroadenomatous hyperlasia in cats?
What conditions is it associated with?
Progesterone-dependent
Complicated by trauma, infection, necrosis
Which surgical procedure is used to treat fibroadenomatous hyperplasia and why?
Which approach is preferred?
OE/OHE (remove the hormones)
Flank approach
Define: cryptorchidism
failure of either testicle to descend into the scrotum
At what age can cryptorchidism be diagnosed definitively?
6 months
How is cryptorchidism transmitted?
Genetically, with small breeds predisposed
What are the potential sequelae of cryptorchidism?
Sterility in affected testicle (always)
Suppression of spermatogenesis in normal testicle
Highly prone to neoplastic transformation
Prone to torsion
Often atrophied
Where can prescrotal testicles usually be palpated?
in SQ between inguinal ring and scrotum
How can testicles in the abdomen or inguinal region be located?
Abdominal US
Exploratory laparotomy
*recall origin is at caudal pole of kidney
What procedures are used when performing castration of a cryptorchid dog?
Remove abnormal testicle first
Prescrotal - incise directly over testicle
Abdominal - caudal celiotomy incision (skin adjacent to prepuce) –> divide preputial muscle and vessels –> midline linea incision –> follow testicular artery or vas deferens
In which patients is testicular torsion more common?
Abdominal cryptorchids
What are the clinical signs associated with testicular torsion?
May be mild (anorexia lethargy) to acute abdomen (marked pain, shock)
How is testicular torsion diagnosed?
Ultrasound, palpation
Is testicular torsion a surgical emergency?
Yes
What is the prognosis for testicular torsion with or without surgery?
Good with surgery
Fatal without
In cases of testicular torsion, should the testicle be derotated before it is ligated
no
Which condition predisposes to testicular neoplastic transformation?
Cryptorchidism
Can neoplastic testicles be functional?
Yes, functionality is common
How are functional testicular tumors associated with other secondary characteristics?
Feminism syndrome
- Sertoli cell tumors (estrogen)
- alopecia, prostate disease, gynecomastia, bone marrow suppression
Testosterone
- interstitial cell tumors
- perineal hernias
What is the likelihood of metastatic disease with testicular tumors?
Rare,
Which surgical procedure is recommended for the treatment of un-metastasized testicular neoplasia?
What is the prognosis?
Bilateral castration with scrotal ablation
Surgery may be curative
What is scrotal ablation?
Removal of the scrotum along with castration
When is scrotal ablation indicated?
Neoplasia
Torsion
Castration of older, large-breed dogs
What is ligated and divided during vasectomy?
Vas deferens
Why does vasectomy have no effect on testosterone-related disease?
Testicles still intact
What is hypospadias?
incomplete formation of the penile urethra
What is the breed predilection for hypospadias?
Boston Terriers
How is hypospadias treated?
Urethrostomy proximal to abnormality
Excision of exposed mucosa and penile remnants
What is paraphymosis?
Inability to retract penis into prepuce
What causes paraphymosis?
Congenital - narrowed orifice, shortened prepuce
Acquired - trauma, infection, priapism (persistent erection)
What are the medical treatments for paraphymosis?
Reduce edema/swelling -hyperosmolar solutions -cold/heat Reduce paraphimosis -lube
What are the indications for surgical treatment of paraphymosis?
Recurrent condition
Small diameter preputial opening
Necrosis
Why is castration indicated for acquired paraphimosis?
In cases of priapism it will resolve the problem
When is penile amputation indicated in paraphimosis?
Necrosis
What is phallopexy?
Attaching of penis to prepuce
What procedure is indicated for tumors of the penis and prepuce?
Penis - penile amputation
Prepuce - preputial reconstruction
What are the common tumor types arising from the penis and prepuce?
Penis:
TVT, papilloma, squamous cell, mast cell
Prepuce:
mast cell, TVT, melanoma
Which penile tumor is not treated surgically?
TVT - tx with vincristine
What is important about mast cell tumors of the prepuce?
More malignant than other sites
What two components are necessary for reconstruction of the prepuce?
Epithelial surface (local, haired skin) Mucosal surface (oral cavity)
What are the CS and PE findings with benign prostatic hyperplasia?
CS: dyschezia, dysuria
PE: palpation of symmetrically enlarged, pain-free prostate
How is benign prostatic hyperplasia differentiated from other prostatic disease?
US shows characteristic homogenous enlargement of prostate
How is benign prostatic hyperplasia treated?
Castration
What are the two components of the etiology of prostatitis?
Ascending infection from the urethra (E. coli most common)
Pre-existing BPH
What are the clinical signs of prostatitis?
Dyschezia, dysuria, pain on urination/defecation, +/- purulent penile discharge
How is prostatitis differentiated from other prostatic disease?
Palpation - bilobed, symmetrical, painful!
US - heterogenous prostate with pathognomonic flocculent fluid
What are the ramifications of severe cases of prostatitis?
Rupture –> septic shock, peritonitis
What is the sx treatment for mild vs. severe cases of prostatitis?
Mild - castration
Severe - exploratory laparotomy and omentalizaiton + castration
What is omentalization of the prostate?
Bringing omentum into or through abscess cavity to improve drainage
What is the typical signalment of a dog with prostatic cysts?
Older, intact males
What are the clinical signs associated with prostatic cysts, and how is it differentiated from other prostatic disease?
Large, discrete mass in caudal abdomen
May be asymptomatic
‘Double bladder’ on US
Fluid aspiration is brown/watery
Which surgical procedure is indicated based on the structure of a prostatic cyst?
All cysts - castration
Small with limited attachment - surgical resection
Large or capsular/urethral communication - partial resection and omentalization
What is the prognosis for treatment of prostatic cysts
Good with sx
How is urinary incontinence related to prostatic cysts?
Resultant of anatomical changes in urethra by cyst, not the surgery
What is the most common type of prostatic neoplasia?
Adenocarcinoma
How common is prostatic metastatic disease?
80% at the time of diagnosis
What is the effect of castration on the incidence of and prognosis for prostatic neoplasia?
Castration –> increased incidence and risk of metastasis
What clinical signs are compatible with prostatic neoplasia?
dysuria, hematuris, urinary retention, dyschezia
lameness d/t bone mets
large, asymmetrical prostate on palpation
What treatment is recommended for prostatic neoplasia?
Palliative:
- tube cystotomy
- urethral stent
Sx treatment not typically pursued d/t guarded prognosis
