Unit 4 - Equine Reproductive Flashcards
What are the common infectious causes of abortion?
Bacterial or fungal placentitis
Equine herpesvirus 1
Equine viral arteritis
What are the less common infectious causes of abortion?
Leptospirosis
Salmonella
Neorickettsia risticii
What FAD causes abortion?
Dourine
What are the non-infectious causes of abortion?
Mare reproductive loss syndrome
Twins
Umbilical torsion
Congenital defects
What are the etiologic agents of placentitis?
Streptococcus species E. coli Pseudomonas species Klebsiella species Staphylococcus species Nocardiform actinomycetes Aspergillus fumigatos Mucor species
What is the most common route of infection that results in placentitis?
Ascending infection via cervix > hematogenous
How does placentitis result in abortion or premature delivery?
- Placental infection
- Pro-inflammatory cytokines and prostaglandin release
- Abortion or premature delivery
What clinical sigs are associated with placentitis?
Premature udder development, vaginal discharge
What is associated with a poor prognosis where placentitis is concerned?
vaginal discharge
What will you see on ultrasound in a patient with placentitis?
Hyperechoic fetal fluids
Placental separation
Increased or decreased fetal heart rate
Thickening of the uterus and placenta
How can placentitis be diagnosed?
Ultrasound
Monitoring of progesterone, estrogen levels, and acute phase porteins
How is placentitis treated?
Antibiotics, anti-inflammatories, and progesterone
What is the etiologic cause of rhinopneumonitis abortion?
EHV1»_space; EHV4
T/F: Rhinopneumonitis is the most prevalent viral cause of abortion.
True
How is rhinopneumonitis transmitted?
Via respiratory secretions, contact with fomites, or aborted fetuses
Where does EHV-1/4 multiply?
In lymphoid tissue - lymphocytes carry it to the rest of the body
What clinical signs are associated with rhinopnuemonitis abortions?
Usually there are no clinical signs in the mare preceding abortion - death of the fetus at expulsion or later succumb to respiratory failure
Normal placenta
When during gestation do rhinopneumonitis abortions occur?
9th or 10th month of gestation
How is rhinopneumonitis abortion diagnosed?
Histopath, IHC, PCR
What will you find on histopath in an aborted fetus due to rhinopneumonitis?
Necrotic foci with intranuclear inclusions in many tissues, especially the liver, lung, and thymus
How is rhinopneumonitis abortion prevented and controlled?
Pregnant mares should be housed separately from other horses on the farm
New arrivals should be quarantined
Vaccination at 5, 7, and 9 months of gestation during each pregnancy
What is the etiologic agent of equine coital exanthema?
EHV-3
How is equine coital exanthema transmitted?
By breeding and contact
What clinical signs are associated with equine coital exanthema?
On the external genitalia of both sexes - papules, vesicles, pustules, and scabby erosions
Lesions can coalesce to large erosions
What behavior may stallions exhibit if they have equine coital exanthema?
They may be reluctant to breed
What causes equine viral arteritis abortion?
the establishment of viremia following respiratory disease
Where is equine viral arteritis shed (for abortions)?
in semen
What clinical signs are associated with equine viral arteritis abortion?
Subclinical or mild infection or significant respiratory disease
Abortion 2-6 weeks following infection
When during gestation can equine viral arteritis abortions occur?
Any time between the 3rd and 10th month of gestation
How is equine viral arteritis abortion diagnosed?
VI or PCR on fetal tissues is the best
No lesions
How is equine viral arteritis abortion prevented and controlled?
Unvaccinated stallions should be tested immediately
Vaccination
T/F: EVAV vaccine-induced antibody cannot be differentiated from infection-induced antibody
True - it is strongly recommended to submit sera for testing prior to initial immunization
What are the more common serovars of Leptospira that result in abortion?
Pomona and kennewichi
How is Leptospira transmitted?
Oral ingestion of urine-contaminated water
What clinical signs are associated with leptospirosis abortions in the mare?
Fever, hemoglobinuria, icterus, renal failure, and late term abortion
Equine recurrent uveitis
What clinical signs are associated with leptospirosis abortions in the fetus?
Emaciation, icterus, grossly abnormal liver, kidney, and lungs
How is leptospirosis abortion diagnosed?
PCR, FA tests, Warthin-Starry silver stain
How is leptospirosis abortion treated?
Antibiotics - Oxytetracycline, penicillin
How is leptospirosis abortion prevented and controlled?
Isolate the affected animals
Vacciantion
What are the common infectious causes of failure to conceive?
General bacterial metritis/endometritis
What is the FAD cause of failure to conceive?
CEM
What are the non-infectious causes of failure to conceive?
Seasonal anestrus, gonadal dysgenesis, granulosa-theca cell tumor, persistent CL
What is the etiologic agent of contagious equine metritis?
Taylorella equigenitalis
T/F: Although CEM has been IDd and eradicated, it is still considered an FAD and is frequently IDd in the US.
true
T/F: T. equigenitalis is an obligate parasite of horses.
True
How is CEM transmitted?
Either venereal via natural breeding, AI, or vertical
T/F: Mares become lifelong carriers of T. equigenitalis.
False - they can resolve the infections themselves
What clinical signs are associated with contagious equine metritis in mares?
Acute endometritis following breeding - copious purulent discharge, failure to conceive
Either become infected or chronic carriers
What clinical signs are associated with contagious equine metritis in stallions?
They do not exhibit any clinical signs
How is contagious equine metritis diagnosed?
Culture at accredited labs only
PCR
How is contagious equine metritis treated?
Thorough washing of external genitalia in stallions and mares
Rinsing and application of a topical antibiotic
Repeat for 5 consecutive days
What are the import requirements for CEM?
Any horse that is sexually intact and over 731 days of age originating from a region/country affected by CEM is subject to quarantine before being allowed into the US
Need 2 negative semen tests
What are the export requirements for CEM?
Semen extenders must contain abx active against T. equigenitalis
Embryos need to be collected in fluid containing an antibiotic active against T. equigenitalis
What are the general recommendations for CEM in the united states?
Culture active breeding stallions annually prior to breeding or colelction
When collecting stallions and hand mating - wear gloves, use disposable bucket liners, dedicated AV for each stallion, disposable wraps for phantom, tail wraps
Veterinary products - disposable vaginal speculums, wear gloves, use disposable bucket liners
