Mare Infertility Flashcards
1
Q
What are the uterine defense mechanisms?
A
- Anatomical Barriers
- Vulva
- Vestibulo-vaginal fold
- Cervix
- Immunologic CLearance
- Neutrophils
- IgA and IgG
- Physical/Mechanical Clearance
- Myometrial contractions
- Cervical relaxation
- Uterine position
- Lymphatic drainage
2
Q
What determines if transient endometritis is cleared or develops into endometritis after uterine invasion?
A
- Normal mare “resistant”
- eliminate bacterial contamination within 24-72 hrs
- Eliminate fluid within a few hours
- “Susceptible” mare
- Poor uterine defense mechanisms
- Delayed uterine clearance
- Poor uterine position (pendulous uterus)
- Unable to eliminate bacteria by 96hrs
- Usually multiparous or older mares
- Develop persistent endometritis
3
Q
What are the different types of uterine infections?
A
- Endometritis - inflammation/infection that involves only the endometrium
- Metritis - infection that progresses deeper into the myometrium
- Typically post-partum mares: dystocia or retained placenta
- At risk of septicemia, endotoxemia, and laminitis
- Life threatening
- Perimetritis - infection that involves the serosal surface
- extension of peritonitis
- Pyometra - accumulation of purulent exudate within the uterus
- not associated with endotoxemia, septicemia or systemic illness
4
Q
What is Endometritis?
A
- Main cause of infertility (failure to conceive, pregnancy loss)
- Acute/Chronic infections, post-mating induced
- Bacterial, venereal or fungal infection
- Post-breeding
- Self-contamination perineal or poor vulvar conformation
- ascending infections, urovagina, pneumovagina
- Iatrogenic
- Uterine therapies and diagnostics
5
Q
How is Bacterial Endometritis diagnosed and treated?
A
- Dx: swab and culture
- Tx:
- intrauterine or systemic antibiotics
- Restore anatomical barriers
- +/- Remove uterine contents
- uterine lavage
- ecbolic medications - Expel fluid
- Oxytocin 10-20 IU IM/IV
- every 2-6hrs
- Uterine contractions for 30-45 min
- PGF2a SID/BID
- dinoprost or cloprostenol
- Uterine contractions for 2-4 hrs
- Oxytocin 10-20 IU IM/IV
- +/- Immunostimulant
- SETTLE®: stimulates production of anti-inflammatory cytokines
- Mycobacterial cell wall fraction
- Labeled for streptococcal endometritis
- SETTLE®: stimulates production of anti-inflammatory cytokines
6
Q
How are Intrauterine Infusion
A
- 60-100 ml volume
- Daily for 3 to 5 days
- During estrus
- Recheck culture/cytology prior to breeding
7
Q
What are Biofilms? Why do they complicate Bacterial Endometritis?
A
- Extracellular polysaccharide matrix
- E. coli
- K. pneumonia
- P. aeruginosa
- S. zooepidemic
- Bacteria and yeast
- Protects bacteria in microcolonies from:
- Host immune system
- Antibodies and antibiotics from reaching bacteria
- In vitro 80% of bacteria from equine uterus capable
- Require ~1000x higher antibiotic concentrations
- Biofilm Tx:
- Buffered chelators: Tris-EDTA or Tricide
- Infuse 250-500 ml Tris EDTA or Tricide on day 1
- Uterine lavage within 24 hrs
- Examine the efflux
- If efflux is cloudy or contains mucus infuse with chelating agent again on day 2
- Antibiotic infusion is began on day 3 following uterine irrigation
- minimum of 5 days
8
Q
What is Pyometra?
A
- Intrauterine purulent exudate
- Impaired uterine clearance
- No systemic signs
- Estrous cycles
- Normal
- Shortened (acute)
- Prolonged (chronic)
- Poor prognosis for fertility
- Treatment
9
Q
What is Post-mating induced endometritis?
A
- Inflammatory reaction mainly from spermatozoa
- Excessive fluid and inflammatory cells accumulate following breeding
- Transient endometritis is normal following insemination
- Clears uterus of excessive spermatozoa, seminal plasma, and contaminates
- Peaks at 10-12 hrs and resolved w/in 24hrs
- Failure to clear w/in 24-72hrs
- May create uterine environment incompatible with embryonic life
- Premature release of PGF2a resulting in luteolysis
10
Q
How is Post-mating endometritis prevented/treated?
A
- Prevention:
- Minimize inflammation - breed 1x per estrous cycle:
- Ecbolic drugs: starting 4-6hrs post breeding
- Oxytocin 10-20IU IM/IV q4-6hrs
- PGF2a
- Dinoprost (5-10mg IM) or Cloprostenol (250mcg IM) SID
- use before ovulation
- Uterine lavage: starting 4-6 hours post breeding
- Decreased uterine fluid accumulation
- Increased pregnancy rate in mares with PMIE
- TX:
- sperm transport to the oviduct is complete within 4-6 hrs
- Physically evacuate uterine contnts
- Ecbolic drugs (Oxytocin, PGF2a)
- Uterine Lavage
- 1-2 L LRS
- 6hrs post mating
- can continue until 3 days post-ovulation
11
Q
What does fluid accumulation during estrus mean?
A
- Can accumulate w/out positive culture/cytology (sterile)
- Fluid alone does not signify endometritis
- May predispose mares to bacterial growth after breeding
- Defect in uterine clearance and/or uterine defense mechanisms may cause fluid accumulation
- Greater than 2cm of fluid during estrus may indicate that mare will be predisposed to post-breeding induced endometritis
12
Q
What causes venereal infertility
A
- Equine Coital Exanthema
- Pseudomonas aeruginosa
- Klebsiella pneumonia
- Taylorella equigenitalis (Contagious Equine Metritis)
13
Q
What is Equine Coital Exanthema? clinical signs?
A
- EHV-3
- Systemic illness uncommon
- secondary bacterial infection
- Venereal
- Incubation 48hrs - 10days
- Clinical signs:
- Unobserved
- Vulvar discharge
- Multiple raised nodules covered by crusty scabs on vaginal mucosa, vulva, penis, and prepuce
- Shallow erosions with irregular but sharply defined margins
- Hyperemia
- +/- loss of libido
- Resolve in 10-14 days leaving areas of depigmented skin
- does not affect fertility
14
Q
How is Equine Coital Exanthema Diagnosed and treated? How could it be prevented?
A
- Dx:
- Clinical signs
- complement fixation (up to 60 days post-exposure)
- Serum neutralization (at least 1 year post-exposure)
- Tx:
- Sexual Rest
- allow ulcers to heal
- Prevent spread of disease
- Antibiotic ointments +/- systemic
- Sexual Rest
- Prevention:
- Sexual rest
- Isolation
- Disposable equipment
- Examine all horses prior to breeding
- Artificial insemination
15
Q
What is Contagious Equine Metritis (CEM)?
A
- Gram negative coccobacillus
- Reportable disease
- Clinical signs:
- Endometritis
- Cervicitis
- Vaginitis
- Copious amounts of vulvar discharge
- Short estrous cycles
- Infertility
- Mares may become asymptomatic carriers
