Lecture 10: Bovine infectious infertility and abortion

- transmitted to female during coitus from bull

- infection is established + progressives to uterus

- female gets pregnant

- fetus is lost during coitus --> EED

What is the pathogenesis of tritrichomonas that leads to infertility and abortion?

- reverse stair step

- gradual increase in herd infertility

- apparent conception then return to heats 60-90 days post service

- early abortions (rarely post 150 days)

What could be the herd history seen with tritrichomonas?

- clinical signs are often subclinical

- samples --> preputial scrapping (should bleed some if sample was good)

How do you diagnose tritrichomonas in males?

- cull them because it is a life long infection and they are primary reservoirs

(1 bull can infect and entire herd)

How do you deal with bulls with tritrichomonas?

- clinical signs = repeated breeders

- samples : fetal fluids, uterine contents, cervico-vagal mucus

How do you diagnose a female with tritrichomonas?

- test and cull

- sexual rest for cows for min of 3 cycles

- quarantine and divide herd

- use AI

- use only neg culture or bulls less than 4 yo

- keep fences in good repair

- vaccinate = does not prevent dz

How can you treat cattle with tritrichomonas?

- caused by a gram neg intracelular intracellular

- zoonotic --> undulant fever

- last half of gestation abortions

What is brucella abortus like?

- abortion products = main way

- bulls can be inapparent carriers = uncommon

How can brucella abortus be transmitted?

- transmitted through the MMs

- travels the LN --> bacteremia

- bacteremia --> uterus

- multiplies in chorioallantoic trophoblasts --> fetal bacteremia + chorioallantoic necrosis

- abortion

What is the pathogenesis of brucella abortus?

- abortion --> ~ 5m gestation (late gestation)

What are the clinical signs seen with brucella abortus?

- placentitis

Isolate bacteria from

- fetal tissues --> lungs and abomasum

- uterine tissue

- placenta

How do you diagnose brucella abortus?

- report disease = report

- no available treatment = sad bye bye cow

A cow has tested positive for brucella abortus, what should you do?

- RB51, does not interfere with testing

What is the vaccine cattle can get for brucella abortus?

- encephalitis

- abortion --> last trimester

- neonatal disease

What does listeria monocytogenes cause in cattle?

- listeria monocytogenes

A herd of cattle got into and started eating rotten hay and improperly stored silage. What is your top differential?

- causes abortion in cattle with the infected animal acting sick before, during, or after abortion

- placentitis and fetal septicemia

What are the clinical signs seen with listeria monocytogenes?

- isolation of organism from fetal tissue or placenta

How do you diagnose listeria monocytogenes?

- autolyzed

- foci of necrosis in liver

What do the fetuses look like with listeria monocytogenes?

- pinpoint yellow, necrotic foci on the tips of the cotyledonary villi with focal or diffuse intra cotyledonary placentitis

What can the placenta look with listeria monocytogenes?

- cow normally recovers on its own

How do you treat listeria monocytogenes?

- aim at improving silage storage

- clean up around old wet hay rings

- do not feed rotten material to preg animals

How do you prevent listeria monocytogenes?

- causes weak calves and stillbirths more often than abortion

- controversial role in infertility

- pure culture needed for diagnosis

What is Haemophilus somnus like in cattle?

- granular vulvovaginitis

- different strains and isolates

- salpingitis can lead to infertility

- uncommon common cause of sporadic abortion

What is Mycoplasma and Ureaplasma like a cause of infectious infertility?

- False

True or false

Chlamydia and Salmonella are common causes of bovine abortion

- rarely causes abortions

- transmitted via coitus, instrument, or semen

- pustiles, nodules, ulcers and/or erosions on vulva and penis

What is the venereal form of Bovine Rhinotracheitis (IBR) like?

- causes abortions

- transmitted via MM contact or in aborted fetus/respiratory fluids

What is the systemic form of Bovine Rhinotracheitis (IBR) like?

- Naive cow exposed

- virus replication

- fetal infections

- abortion commonly between 4 and 8 months gestation (storms can occur)

What is the pathogenesis of systemic Bovine Rhinotracheitis (IBR)?

true

True or false

the live Bovine Rhinotracheitis (IBR) vaccine can cause abortions

- Lesions --> autolyzed fetus and/or foci of necrosis in liver and other organs

- Immunohistochemistry and microscopic --> intranuclear inclusion bodies or viral Isolation

How do you diagnose Bovine Rhinotracheitis (IBR)?

- lesions spontaneously resolve in 1-2 weeks

- biosecurity, vaccination, AI with neg semen

How do you treat/prevent/control venereal Bovine Rhinotracheitis (IBR)?

- a single stranded enveloped RNA virus with different genotypes

What is Bovine Viral Diarrhea Virus (BVDV)?

- non-cytopathic genotype

- from vertical transmission prior to 120-150 days in utero

- can spread it horizontally leading to acute infections and more PI animals

What is a persistently infected calf with Bovine Viral Diarrhea Virus (BVDV)?

- 0-5 months of gestation

Bovine Viral Diarrhea Virus (BVDV) is transmitted vertically which is important for infectious infertility and abortion. When during gestation will transmission lead to resorption and still births?

- 0 months to term

Bovine Viral Diarrhea Virus (BVDV) is transmitted vertically which is important for infectious infertility and abortion. When during gestation will transmission lead to abortions?

- 0 - 3 months

Bovine Viral Diarrhea Virus (BVDV) is transmitted vertically which is important for infectious infertility and abortion. When during gestation will transmission lead to EED?

- cerebellar hypoplasia

- hydrocephalus

- alopecia

What are congenital defects with BVD like? (transmitted between 4-8 months)

- could be ill thrift

- intermittent diarrhea

- chronic respiratory dz

- MOST SHOW NO SIGNS

What are the clinical signs of Bovine Viral Diarrhea Virus (BVDV)??

- economic impact of millions of dollars due to effects on reproduction and production

What is the importance of Bovine Viral Diarrhea Virus (BVDV)?

- viral isolation = $ = GOLD STANDARD

- immunohistochemistry $

- PCR (low specificity)

- ELISA $

How do you diagnose Bovine Viral Diarrhea Virus (BVDV)?

- sound security

- vaccines

- control strategies --> detect and elimination PI animals

How do you prevent and control Bovine Viral Diarrhea Virus (BVDV)?

- a minor cause of abortion in sheep and cattle

- teratogenesis is more common (Cerebral malformations, weak calves, stillborns)

How does Bluetongue Virus relate to reproduction?

- Aspergillus fumigatus

What fungus causes 70% of the fungal related abortions in cattle?

- Aspergillus fumigatus

What fungal disease causes ringworm-like lesions on the fetus?

- propagated in winter and spring during high confinement

- ingested --> hematogenous spread --> placentitis --> abortion

What is the pathogenesis like for Aspergillus fumigatus?