Dr. Runcan

Freemartin

• a female born as a twin w/male & is sterile due to exposure to masculinizing hormones by the male in utero (via blood, anastomosis in placental vasculature)

  • females are XX/XY chimeras

  • have hypoplastic uterus/gonads, no cervix, & shortened vagina (<7cm) w/tuft at ventral aspect of vulva

• occurs in cattle, goats, & sheep

Intersex conditions

• any disorder of sexual development

  • male calicos/mosiac (XXY) - error in chromosomal sex

  • testes w/uterus - error in gonadal sex

  • clitoral enlargement - error in phenotypic sex

Pseudohermaphrodite

• genetics do not match phenotype

  • male: XY, internal testicles, female phenotype

  • female: XX, ovaries, male phenotype

True hermaphrodite

• having both sets of gonads (ovotestes)

Hypospadias

• failure of closure of urinary tract w/abnormal opening

• often assoc. w/disorders of sexual development but can occur independently

Polled-intersex syndrome

• found in hornless goats - Saanens, Toggenburgs, & Alpines

• gene dictating horns & gene causing intersex syndrome located very close together

• goats appear female at birth but begin acting like a buck at puberty

  • usually have testicles (± descent), may lactate

• avoid by breeding to bucks w/horns only

Fetal virilization

• occurs when females given androgens during pregnancy

  • excessive progesterone supplementation in dogs

  • avoid until after day 45 gestation

• female fetuses take on male characteristics

  • normal female internal tract, masculine external genitalia

  • usually sterile

Ovarian remnant syndrome

• signs of estrus in a previously spayed female (7 days to 10yrs post spay)

  • vulvar swelling/discharge, attractiveness to males, mammary development, lordosis/vocalization

• common complication

• most common in L breed dogs + cats on right pedicle

• may also occur w/ectopic ovarian tissue

Ddx for ovarian remnant syndrome

• exogenous estrogen exposure (HRT)

• adrenal or ovarian neoplasia

• uterine stump pyometra, vaginits, UTI (for vulvar discharge)

Dx ovarian remnant syndrome

• Hx: waxing/waning or cyclical signs

• vaginal cytology - cornified cells (only accurate during estrous)

• hormonal assays/stimulation tests

  • serum progesterone (>2ng/mL) measured 3-6wks post-clinical signs

  • LH always positive in spayed animals, recheck positives in 2-4 days to confirm

  • AMH only produced in gonads (post-pubertal animals), positive always means intact

• stimulation tests

• AUS - difficult due to small size of tissue, helps guide Sx approach

• exploratory Sx - perform during estrus or 3-6wks after, typically found on uterine pedicle

Causes of vaginal discharge

• physiologic: proestrus/estrus, lochia (post-partum)

• pathologic: subinvolution of placental sites (post-partum), vaginitis, metritis (post-partum), pyometra

Vaginitis

• inflammation of vagina w/discharge ± infection

• can occur at any age

• typically no signs of systemic illness

Juvenile onset vaginitis

• 8wks-6mos (prepubescent)

• discharge scant & mucoid to copious & mucopurulent

• typically non-infectious - inflammatory neuts on cytology w/o intracellular bacteria

• most resolve w/o intervention, hastened by first estrous cycle

Adult onset vaginitis

• 1+ yr old

• primary: infectious (bacterial vs viral)

• secondary: due to congenital abnormalities, UTI, vaginal foreign body, or low E2

• intact vs spayed doesn’t impact prevalence

Dx of vaginitis

• vaginal culture + cytology (rarely yields pure growth, vagina has normal flora)

• CBC/Chem for comorbidities

• UA for concurrent UTI

• vaginoscopy - congenital abnormalities, foreign bodies, neoplasias

Tx of vaginitis

• often resolves spontaneously

• infectious causes treated w/Abx for ~1wk + probiotics (protect normal flora)

• Sx for congenital issues

• E2 supplementation

Pyometra risk factors

• affects 25% of intact female dogs by 10yrs old (typically >8yrs old)

  • progressive Dz, cystic endometrial hyperplasia predisposes to Dz

• breed predisposition: Bernies, Great Dane, Leonberger, Rotties, Irish Wolfhound

• higher risk if never pregnant

• often happens during diestrus (high progesterone)

Cystic endometrial hyperplasia

• cystic thickening of endometrium developed by intact females over time due to cyclical exposure to estrogens & progestogens

  • much more common in dogs due to prolonged elevation of progesterone

• scar tissue forms around opening of glands, impedes emptying & leads to cyst formation

• predisposes to pyometra but does not necessarily cause Dz

Pyometra pathogenesis

• cervix open during estrus, bacteria of vagina colonize uterus

• bacteria become trapped in CEH cysts, cervix closes during diestrus

• bacteria proliferate → pyometra

Progesterone role in pyometra

• elevated during diestrus to maintain pregnancy (inhibits contractions, closes cervix, stimulates secretion of uterine milk, immunosuppresses)

• creates ideal environment for bacterial growth w/o pregnancy

Complications of pyometra

• E. coli endotoxin enters bloodstream → endotoxemia → renal failure, immunosuppression, sepsis, myocardial infarction, clotting/bleeding disorders, uterine rupture, & death

Clinical presentation of pyometra

• recent estrus (4-6wks ago)

• ± thick odorous vulvar discharge (dependent on whether cervix is open)

• PU/PD

• lethargy, anorexia, V+/D+

  • fever uncommon, more likely hypothermic

Pyometra lab results

• elevated WBCs w/left shift

• mild anemia

• azotemia

• elevated liver enzymes

• high protein + globs

• often concurrent UTI w/same bacteria

Imaging of pyometra

• x-rays: enlarged uterus (does not differentiate pyo vs early pregnancy)

• AUS: thick uterine wall w/hypo-hyperechoic uterine contents (does rule out pregnancy)

Endometritis

• inflammation of uterine lining

• may be secondary to infectious or non-infectious causes

  • infectious: opportunistic bacteria/fungi (commensals of caudal repro tract) due to parturition, breeding, or repro tract manipulation

  • normal uterus clears infection in 1-2 days, susceptible pts get persistent infection until cervical closure → unsuitable uterine environment

• common cause of infertility/sub-fertility in LA (horses + cattle) → economic losses (delayed milk production, cystic ovarian disease, prolonged luteal phase)

Uterine defense mechanisms

• anatomical barriers: vulva, vestibulovaginal sphincter, cervix

• cellular: phagocytosis, chemotaxis, opsonization, & intracellular killing

Risk factors for endometritis

• abnormal repro Hx

• positive endometria culture

• intrauterine fluid accuulation

• abnormal perineal conformation

• abnormal cervix

• unrepaired caslicks

• abnormal repro tract

Clinical signs of endometritis

• mares: large volume of echogenic fluid in uterus during estrus, excessive uterine edema, any fluid in uterus during diestrus, hyperemic cervix

• cows: purulent uterine discharge detectable in vagina 21+ days postpartum

Dx of endometritis

• AUS

• uterine culture via swab, lavage, or biopsy

  • looking for pure heavy growth of one organism

  • cloudy fluid = infection likely

• uterine biopsy w/histopath

  • grading (I-III) used to estimate ability of uterus to carry pregnancy to term

Most common causes of endometritis infection

• bacteria in mare: Strep equi zooepidemicus, E. coli, K. pneumoniae, P. aeruginosia

• fungi in mare: Aspergillus, Candida

• bacteria in cow: E. coli, T. pyogenes, Prevotella, F. necrophorum + nucleatum

• virus in cow: bovine herpesvirus type 4