Infectious Causes Impacting Reproduction

1. Infectious Causes Impacting Reproduction

3. Fetal Mummification Fetus dies, uterus contracts, and fluid is resorbed  fetus becomes dry/firm Thickened uterus CL present on ovary No palpable cotyledons No membrane slip No fremitus in uterine artery Palpable mass in uterus

4. Fetal Mummification • Most common at 4-6 months of gestation, but may go beyond gestation length • Genetic (uncommon)– Jerseys, Guernseys, certain Holstein families • Torsion of umbilical cord • Infectious diseases that cause minimal inflammation: • Campylobacter fetus • BVDV • Tx: • PGF2a IM to lyse CL and expel fetus in 2-3 days +/- 2nd dose in 96 hrs if needed • Manually remove with lube • C-section

5. Fetal Maceration • Fetal death with partial cervical dilation  uterine contamination  bacterial growth (great medium!) • Any age of gestation • CS: abdominal straining, foul fetid vulvar discharge, fever, anorexia, milk production +/- diarrhea • Rectal: distended swollen uterus, gas crepetation in fetus • Prognosis for future reproduction POOR - treatment not always successful, endometrial damage extensive • Tx: • Cervix dilated: fetus removed manually with LUBE and SLOW manipulation. Re-examine for 2nd fetus! • Cervix closed: PGF2a +/- oxytocin (less successful than with mummies; may not be functional CL)

6. Abortion • Severe maternal illness: • Infectious diseases: high fever, inflammation (mastitis, pneumonia, virus…) • Toxins: plants and chemicals (nitrates, moldy sweet clovers, fescue molds, lupines, gossypol in cottonseeds, and industrial pollutants…) • Hypoxia (anemia, pneumonia…) • Endotoxemia • Placentitis: • Hematogenous • Ascending via cervix • Fetal origin: • Fetal stress → death

7. Abortion • Mechanism: • P4 and PGF2a  luteolysis + expulsion of fetus

8. Abortion • Due to the degree of autolysis and edema of fetuses in utero after death but before expulsion, gross placental/fetal lesions are not usually diagnostically significant.

9. Abortion • What tissues samples shall I send off ? • Fetal membranes/aborted fetus – BEST! • Fetal lung, liver, intestines, brain, kidneys… • Maternal serum, urine, vaginal discharge… • FRESH, keep cool • Better too many than too few samples…

10. Infectious Causes: Bacterial Brucella spp Listeriosis Leptospirosis Arcanobacterium pyogenes Vibriosis Protozoal Trichomonas Neospora Viral IBR BVD Mycotic Abortion *Especially if abortion storm!

11. Brucellosis “Contagious abortion”, “Bangs disease” • Brucella abortus • ZOONOTIC – Undulent fever in humans (via milk) • Eradication program ~rare in US herds, but still in free-ranging bison/elk • Highly infectious – spread via aborted fetus, placenta, vaginal discharge, milk, or semen from infected bull • Lesions – chorionic placentitis, Moroccan leather appearance, focal necrosis of cotyledons, thickened intercotyledonary areas with yellow exudate

12. Brucellosis • Abortion usually between 5th-8th month of gestation • Also frequently causes retained placenta, weak calves and infertility • Dx: serology/culture of fetal abomasal fluid, lung, and liver, placenta, uterine fluid, milk, serum, seminal plasma • Prevention/Control: Official calfhood vaccination • RB-51 vaccine (“bangs” vaccine) + Official USDA Brucellosis eartag + official ear tattoo • Calves 4-10 months of age • By state and federal brucellosis program personnel and USDA accredited veterinarians

13. Listeriosis • “Circling Disease” • Listeria Monocytogenes • ZOONOTIC • Widespread in environment; transmission via ingestion of poorly fermented silage • Fever, weight loss, endometritis, encephalitis • Lesions: suppurative placentitis, small white foci on fetal liver and cotyledons, fibrin in fetal body cavity

14. Listeriosis • Abortion usually during 3rd trimester • Sporadic or abortion storm • Retained fetal membranes • Control: stop feeding spoiled material, isolate aborting cows • Broad Spectrum Antibiotics  milk withdrawal due to milk residues! • NO vaccine in US

15. Leptospirosis • Leptospira interrogans serovars hardjo & pomona • Transmission via infected urine, placental fluids, milk, or contaminated environment/water source • Abortion from 4 months to term • +/- yellow MM, blood tinged urine and milk • Weak calves or infertility is also common • Dx: Culture - organisms in fetal kidney • Tx: Vaccinate annually

16. Arcanobacterium pyogenes • Abortion at any stage of pregnancy • Normal inhabitant in nasopharynx of many cows, also in abscesses, NOT in fetuses or fetal membranes = always significant! • Bloodstream  endometritis & placentitis (diffuse with a reddish brown to brown color) • Fetus: autolyzed, with fibrinous pericarditis, pleuritis, or peritonitis possible, as well as bronchopneumonia • Dx: culture from placenta or abomasal contents • NO effective bacterin available

17. Arcanobacterium pyogenes • *Important cause of pyometra post-calving in DAIRY cows! • Diagnosed at pre-breeding check (~ 40 d post calving) • Occurs when cow ovulates in face of A. pyogenes in uterus  pyometra • Usually uterine contaminates are expelled from uterus during normal involution process • Pre-disposing factors: dystocia, RFM, metritis

18. Vibriosis • Campylobacter fetus subsp venerealis • Bulls are asymptomatic carriers, permanent carries when > 4 yrs • Venereal transmission organism attacks conceptus  early embryonic death (occasional abortions ~ 4-7 months of gestation) • Cows develop immunity and conceive, and maintain the disease in the herd (carriers) • Dx: Blood agar culture of preputial smegma, fetal abomasal contents, vaginal/cervical mucous • Tx: ID and cull carriers, topical antibiotic ointment • Control/Prevention: AI, prevent re-infection, blood culture all non-virgin bulls 6-8 weeks before breeding season, VACCINATE cows and bulls

19. Trichomoniasis • Trichomonas foetus • Bulls are asymptomatic permanent carriers • Venereal transmission organism attacks conceptus • Cows develop immunity and conceive (carriers) • *Important cause of pyometra post-breeding in BEEF cows • CS: infertility, pyometra, abortion • Dx: microscopic isolation of organism (preputial smegma or vaginal/cervical mucous) with Diamond’s medium (Klaas modification) • Control/Prevention: AI, use of virgin bulls • NO vaccine available

20. Neospora • Neospora caninum • Cycles between canids and ruminants – oral or vertical transmission • Mid-gestation abortion (~4-6 months), pre-mature calf, birth of impaired calf, or normal calf • Brain hemorrhage, myocarditis

21. Oocysts ingested while grazing •  Sporozoites released, enter SI  reticulo-endothelial system • Tachyzoites = invade different tissues, placenta  fetus in pregnant animals • Bradyzoites = dormant, within tissue cysts (found mainly in neural tissue) • In future pregnancies, bradyzoites  tachyzoites  invade the fetus via the placenta

22. Infectious Bovine Rhinotracheitis (IBR) • Acute, contagious Bovine Herpes Virus • Infertility, respiratory infections, conjunctivitis, abortion storm usually > 5 months gestation • RFM, placental edema/vasculitis • Fetus: red serous body fluid, white foci on liver/lungs • Tx: Vaccinate annually “red nose”

23. Infectious Pustular Vulvovaginitis • Also a Bovine Herpes Virus • Venereal/mechanical spread • Genital pustules (balanoposthitis) • Spontaneous recovery

24. Bovine Viral Diarrhea Virus (BVD) • Affects the digestive, respiratory, immune, nervous and reproductive systems • BVD Type I and Type II, each with: • Cytopathic (CPE) strains  cellular vacuolation and cell death • Non-cytopathic (non-CPE) strains  no visible cytopathic change in cell cultures

25. Bovine Viral Diarrhea Virus (BVD) • BVD infection in-utero: • Slows fetal growth  lower birth weight, bone growth • Abortion (at any trimester) • Early embryonic death • Stillbirth • Congenital Birth Defects (eye, thymus, brain) • Arthrogryposis • PI Calves (immunotolerant and persistently infected shedders) • Normal calf born with antibodies to the BVD virus cerebellar hypoplasia

26. Bovine Viral Diarrhea Virus (BVD) Results of fetal infection with BVDV http://www.livestocktrail.uiuc.edu/dairynet/paperDisplay.cfm?ContentID=220

27. Bovine Viral Diarrhea Virus (BVD) • Mucusal disease: • PI calf (infected in-utero from 42-125 d of gestation with non-CPE strain, seem normal, but have no immunity to the virus) • + encounters CPE strain after birth (vulnerable to severe effects of the CPE cell-killing strain) • ~6 months – 2 yrs old • High mortality

28. Bovine Viral Diarrhea Virus (BVD) • BVD infection after birth: • Usually 6 months to 2 yrs of age • CS: vary depending on the virulence of the strain • Viremic  develop antibodies  clear virus within 7-10 days • Subclinical (estimated 70-90% of BVDV infections) • Mild elevation in body temp, drop in milk production • Clinical = Acute BVD • Depression, fever, inappetence, nasal discharge, transient leukopenia, thrombocytopenia, petechial hemorrhages, diarrhea, high morbidity, low mortality • Eliminate Carriers = CULL! • VACCINATE before breeding

29. Mycotic Abortion • Aspergillus, Absidia, Mucor, Rhizopus, Candida • More in WINTER when cattle housed/fed inside • Injury to respiratory/GIT  hematogenous  uterus  severe necrotic placentitis • Thick, leathery cotyledons + intercotyledonary placenta • Abortions in 3rd trimester • Head and neck lesions on fetus

30. “Given the low diagnostic success rate, the high cost of laboratory work, and the low profit margin in both the beef and dairy industries, veterinarians should not attempt to make an etiologic diagnosis in every abortion. Instead, veterinarians should become concerned if fetal loss is >3-5% per year or per month.” ~ The Merck Veterinary Manual