Bovine Infectious Infertility and Abortion Flashcards
Define early embryonic death
fetal death less than 8 weeks
define stillbirth
fetal death greater than 260 days
What type of organism of Listeria monocytogenes?
gram positive coccobacillus
Where is Listeria monocytogenes found?
concentrated in rotting hay and improperly stored silage
Describe the pathogenesis of Listeria monocytogenes infection
- ingestion
> replication in monocyte-macrophage
> placentitis and fetal septicemia
> abortion
What are the clinical signs associated with Listeria monocytogenes infection?
- abortion in last trimester
- cows appear sick before, during, and after abortion
How is Listeria monocytogenes diagnosed?
- isolation of organism in fetal tissues and placenta
What are the gross lesions caused by Listeria monocytogenes?
fetus
- autolysed
- foci of necrosis in liver
placenta
- pinpoint yellow, necrotic foci on tips of cotyledonary villi
What type of organism is leptospira?
aerobic spirochete
Describe the pathogenesis of leptospirosis
- incubation 4-10 days
> bacteriemia
> localizes and persists in renal tubules
> shedding
What are the clinical signs associated with leptospirosis?
- often none
- hemolytic anemia
- hepatic/renal disease
- abortion
- photosensitization
How is leptospirosis transmitted?
urine, placental fluids, milk, semen
How is leptospirosis diagnosed?
- dark field microscopy
- fluorescent antibody of fetal kidney and maternal urine
- PCR of fetal and maternal tissue
How is leptospirosis treated?
- limit exposure
- vaccinate
- can vaccinate in outbreak and give tetracycline
What type of organism is Brucella abortus?
gram negative coccobacillus
Describe the pathogenesis of Brucella abortus
- transmitted via mucus membranes
> lymph nodes > bacteremia > uterus
> multiplication in chorioallantoic trophoblasts
> fetal bactermia and chorioallantoic necrosis
> abortion
How is Brucella abortus transmitted?
- primary transmission via mucus membranes
- bulls can be carriers
- can be transmitted by intrauterine deposition of frozen semen from carrier bulls
What are the clinical signs associated with Brucella abortus?
- abortion: after 5th month of gestation
- RFM and metritis follow abortion
- some give birth to weak calves that die soon after
How is Brucella abortus diagnosed?
isolation of organism
- fetal tissues, uterine tissue, placenta
placentitis
- intercotyledonary areas dry, thickened, and cracked
- “Moroccan leather”
Describe the control of Brucella abortus infection
- reportable (zoonotic)
- routine serologic testing
- no treatment for positives
- vaccination of heifers
What two organisms are found in the normal female reproductive tract?
Mycoplasma
Ureaplasma
What is caused by Mycoplasma and Ureaplasma infection?
- granular vulvovaginitis
- salpingitis
- sporadic abortion
What is caused by Haemophilus somnus?
weak calves and stillbirths more often than abortions
What type of organism is Campylobacter foetus veneralis?
gram negative microaerophilic rod
How is Campylobacter foetus veneralis transmitted?
- transmitted via coitus
- also via fomites
Describe the pathogenesis of Campylobacter foetus veneralis infection
- coitus > colonizes in vagina and cervix > uterus and oviducts > infection > EED
What are the clinical signs associated with Campylobacter foetus veneralis infection?
- delayed return to estrus
- vaginitis, cervicitis, and endometritis rare
- less than 10% abort
- no signs in bulls
How is Campylobacter foetus veneralis infection diagnosed?
Clarks media
- preputial scraping
- vaginal mucus
- fetal abomasal contents, placenta
How is Campylobacter foetus veneralis controlled?
- cull bulls or don’t breed
- cows usually clear in 3-6 months
- vaccinate before breeding season
- use AI
What kind of organism is Tritrichomonas foetus?
What does it look like?
- flagellated protozoa
- 3 anterior and 1 posterior flagella
- pyriform shape
How is Tritrichomonas foetus transmitted?
- via coitus
- bulls are primary reservoirs
Describe the pathogenesis of Tritrichomonas foetus infection
- transmitted to females via coitus
> establish infection in vagina and progress to uterus
> causes fetal loss
How is Tritrichomonas foetus treated and controled?
- test and cull bulls
- use AI
- sexual rest for cows
- quarantine or divide herd
- vaccines
How is Neospora caninum transmitted?
- ingestion of dog feces
- primarily transmitted vertically
What are the clinical signs associated with Neospora caninum?
- no clinical disease in dam
- calves are normal, weak, or aborted
- abortion in 3rd trimester
How is Neospora caninum diagnosed?
- IHC on fetal tissues and placenta
- serologic testing
What is the causative agent of Infectious Bovine Rhinotracheitis?
Bovine Herpesvirus 1
What is the most frequently diagnosed cause of viral abortion in North America?
IBR - bovine herpesvirus 1
How is bovine herpesvirus transmitted?
- airborne possible
- venereal form: coitus, instruments, semen
- systemic: mucus membranes
What are the clinical signs associated with the systemic form of bovine herpesvirus?
- abortion storms
- +/- respiratory signs
What are the clinical signs associated with the venereal form of bovine herpes virus?
pustules, nodules, ulcers, and erosions on vulva and penis
How is bovine herpesvirus diagnosed?
- lesions (autolysed fetus, foci of necrosis on organs)
- IHC and microscopic exam confirms (intranuclear inclusion bodies)
How is bovine viral diarrhea virus transmitted?
- vertical (forms PI)
- PI are primary source (shedding)
- via fomites
What causes a persistently infected calf?
fetus infected in utero prior to day 120-150
What are the clinical feature of a PI calf with BVDV
- most show no signs
- chronic respiratory distress
- intermittent diarrhea
How is BVDV diagnosed?
- virus isolation (gold standard)
- immunohistochemistry
- PCR
- ELISA
What type of virus is bluetongue?
Orbivirus
How is Bluetongue transmitted?
Culliocoides species
What is caused by Bluetongue?
- abortion
- teratogenesis more common
(cerebral malformation, weak calves, stillbirths)
Describe the pathogenesis of Aspergillus fumigatus infection
- ingestion
> hematogenous spread
> placentitis
> abortion
What lesions are associated with Aspergillus fumigatus infection?
placenta
- necrosis of cotyledons
- thickening of intercotyledonary space
fetus
- skin has mycotic plaques
What is hydrallantois?
abnormal accumulation of allantoic fluid during 5-10 day period of last trimester
What is hydamnios?
gradual accumulation of excessive amniotic fluid
What is the progesterone source during the first 150 days of gestation?
luteal origin
What is the progesterone source during days 150-250 of gestation?
placenta
