Infectious Causes Impacting Reproduction. Fetal Mummification Fetus dies, uterus contracts, and fluid is resorbed fetus becomes dry/firm –Thickened.

Infectious Causes Impacting Reproduction

Fetal MummificationFetus 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

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

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)

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

Abortion

• Mechanism:– P4 and PGF2a luteolysis + expulsion of

fetus

• 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.

Abortion

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…

AbortionInfectious Causes:

• Bacterial

– Brucella spp

– Listeriosis

– Leptospirosis

– Arcanobacterium pyogenes

– Vibriosis

• Protozoal

– Trichomonas

– Neospora

• Viral

– IBR

– BVD

• Mycotic

*Especially if abortion storm!*Especially if abortion storm!

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

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

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

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

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

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

• *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

Arcanobacterium pyogenes

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

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

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

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

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”

Infectious Pustular Vulvovaginitis

• Also a Bovine Herpes Virus

• Venereal/mechanical spread

• Genital pustules (balanoposthitis)

• Spontaneous recovery

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

• 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

Bovine Viral Diarrhea Virus (BVD)

cerebellar hypoplasiacerebellar hypoplasia

Bovine Viral Diarrhea Virus (BVD)

Outcome Gestational age at time of in utero infection.

0 - 40 days 40 - 125 125 - 180 > 180 days

Normal, antibody negative calf X X X X

Abortion X X X X

Early embryonic death, resorption X

Mummification X X

Stillbirth X X X

Congenital defects, antibody negative X

Congenital defects, antibody positive X

Persistently infected, "normal" calf X +/-

Normal, antibody positive calf +/- X

Results of fetal infection with BVDV

http://www.livestocktrail.uiuc.edu/dairynet/paperDisplay.cfm?ContentID=220

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

• 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

Bovine Viral Diarrhea Virus (BVD)

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

“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