Bovine Viral Diarrhea Virus and Cattle Health

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Questions and Answers

What is a common consequence of the Bovine Viral Diarrhea Virus (BVD) in cattle?

Improved reproductive performance

Earlier calving

Decreased rates of conception (correct)

Increased fertility rates

Which factor influences how BVD affects a cow's fertility?

Duration of pasture

Breed of the cow

Presence of a bull

Stage of pregnancy (correct)

What can result from infection with the Bovine Viral Diarrhea Virus (BVDV) before 125 days of gestation?

Increased birth weight

Higher milk production

Persistently infected calves (correct)

Improved immunity

What is one of the effects of infectious infertility in cattle?

Delayed return to estrus Signup and view all the answers

Which of the following is NOT a symptom of BVD in cattle?

Increased peak of LH Signup and view all the answers

What is one consequence of increased culling and replacement rates in herds affected by infectious infertility?

Lower herd diversity Signup and view all the answers

How does BVD infection impair the immune response in cattle?

Lowers MHC II expression Signup and view all the answers

What role does PGF2a play in treating reproductive issues in cattle?

Induces estrus synchronization Signup and view all the answers

What is a common consequence of higher levels of IL-6 in the endometrium?

Infertility and repeat breeding Signup and view all the answers

Which causative agent is known to have a venereal transmission route leading to infertility in cattle?

C.fetus subsp. venerealis Signup and view all the answers

What environmental condition in the prepuce contributes to the persistence of Campylobacter and Tritrichomonas?

Microenvironment created by folds Signup and view all the answers

What percentage of sporadic abortions is attributed to Serovar hardjo?

3-10% Signup and view all the answers

Which of the following pathogens does not affect fertilization and early embryonic development?

All of the above Signup and view all the answers

Which condition results from the infections caused by Campylobacter and Tritrichomonas?

Salpingitis Signup and view all the answers

How long do chronic carriers of C.fetus subsp. venerealis typically remain infected?

Months Signup and view all the answers

What is the recommended vaccination frequency for animals in moderate-risk regions for Leptospira?

Twice a year Signup and view all the answers

What is the typical ineffective estrus interval (IEI) for cattle affected by these pathogens?

35 days Signup and view all the answers

Which of the following is true regarding monovalent Leptospira vaccination?

It prevents renal colonization for one year. Signup and view all the answers

What is a recommended practice to reduce infectious pressure in a herd?

Quarantine new animals for four weeks. Signup and view all the answers

What type of vaccination is recommended against Tritrichomonas?

Annual revaccination 4 weeks before mating Signup and view all the answers

What is the main clinical consequence of Neospora caninum infection in cattle?

Reproductive issues and abortion storms Signup and view all the answers

Which is NOT part of the biosecurity measures for a herd?

Importing animals without testing Signup and view all the answers

Which of the following is a characteristic symptom in dogs infected with Neospora caninum?

Encephalomyelitis and myositis Signup and view all the answers

What is the purpose of annual re-vaccination with Leptospira vaccine?

To maintain protection against long-term infertility and abortion Signup and view all the answers

What is the most common consequence of infectious infertility in cattle?

Embryonic death Signup and view all the answers

Which of the following is NOT a common risk factor for embryonic death in cattle?

High protein diet Signup and view all the answers

Fetal mummification can best be characterized by which of the following features?

Mummified fetus with no clinical signs Signup and view all the answers

What defines a 'stillbirth' in cattle?

Fetus is born dead after a full-term pregnancy Signup and view all the answers

Which type of pregnancy loss occurs after day 42 of gestation?

Fetal death Signup and view all the answers

What is the main characteristic of fetal maceration?

Presence of fetid vaginal discharge Signup and view all the answers

Which hormone is primarily involved in the persistence of the corpus luteum during fetal mummification?

Progesterone Signup and view all the answers

Which infection is NOT associated with risk factors for embryonic death?

Brucellosis Signup and view all the answers

What is a significant clinical consequence of BHV-1 infection in pregnant cattle?

Oophoritis and necrosis of the corpus luteum Signup and view all the answers

How does BHV-1 primarily establish latency in cattle?

Persisting in nervous tissue Signup and view all the answers

Which symptom is NOT typically associated with BHV-1 infection?

Increased appetite Signup and view all the answers

What is the most common time frame for abortion due to BHV-1 infection in cattle?

After 4 months of gestation Signup and view all the answers

What effect does BHV-1 infection have on progesterone levels during infection?

Decreases progesterone concentrations Signup and view all the answers

What typically triggers the reactivation of latent BHV-1 infections in cattle?

Stress Signup and view all the answers

What is the causative agent of infectious bovine rhinotracheitis?

BHV-1 Signup and view all the answers

Which reproductive issue is associated with BHV-1 infection after 4 months of gestation?

Stillbirth Signup and view all the answers

What is the maximum time frame for abortion after infection?

4 months Signup and view all the answers

What diagnostic method is NOT used for identifying viral infections in cattle?

Mass spectrometry Signup and view all the answers

Which factor does NOT contribute to the risks associated with Bovine Respiratory Disease Complex?

High nutrition Signup and view all the answers

What is a notable disadvantage of Modified-Live Virus (MLV) vaccines compared to Inactivated Virus (KV) vaccines?

Higher risk of abortion in pregnant animals Signup and view all the answers

What was the abortion rate observed in BVDV vaccination studies?

45% Signup and view all the answers

Which of the following statements about vaccine management is true?

Immune response depends on several factors. Signup and view all the answers

Which vaccine is more likely to require a booster after initial administration?

Inactivated Virus Signup and view all the answers

What kind of immune response do attenuated vaccines stimulate?

Cellular Immunity Signup and view all the answers

Study Notes

Infectious Infertility & Abortion in Cattle

Infectious infertility and abortion in cattle are significant issues affecting animal reproductive efficiency.
Reproductive issues can range from mild decreases in fertility to complete abortion storms.
Specific infections can cause fertilization failure, embryonic death, or fetal death (after day 42 of gestation).
These infections may impact the embryo/fetus, uterine environment/placenta, or corpus luteum (CL).

Pregnancy Loss

Embryonic death occurs before day 42 of gestation.
Fetal death occurs after day 42 of gestation.
Abortion (most common) is the expulsion of a dead fetus.
Stillbirth refers to a full-term fetus born dead.
Mummification is the preservation of the fetus as a dry, contorted mass due to placental fluid resorption.
Maceration is the progressive bacterial digestion of a dead fetus.

Risk Factors for Embryonic Death

Heat stress
Dietary protein deficiency
Genetic merit of cows
Milk yield
Subnutrition (negative energy balance)
Low progesterone concentrations
Infections (Trichomoniasis, Campylobacteriosis, IBR, BVD, Leptospirosis)
Subclinical endometritis
Salpingitis
Mastitis
Genetic gamete defects

Abortion

Abortion is the termination of a pregnancy with fetal death and expulsion.
It is often a result of infection.

Stillbirth

A stillbirth is the birth of a full-term dead fetus.
The lungs of the fetus will not float in water. (indicating lack of respiration).

Fetal Maceration

Fetal death occurs without abortion, with bacterial digestion.
No placentomes and less fetal fluid in the uterus.
The cow may display fetid vaginal discharge and septicemia.
CL persistence and chronic endometrial damage are often associated.
Treatment options include slaughter (for valuable animals) or PGF2a or colpotomy.

Fetal Mummification

Fetal death occurs, with CL persistence.
No clinical signs are present.
Fetal membranes are dry and wrinkled (placental fluid resorption).
The uterus adheres to the fetal shape, forming a dry and contorted mass.
The cervix stays closed during prolonged gestation.

Fetal Mummification (Additional Detail)

Mummification becomes noticeable between 3-8 months of gestation.
Autolysis and fluid reabsorption occur in a sterile environment.
Umbilical vessels constrict, and the placenta becomes congested.
There are no placentomes.
Treatment options involve PGF2a or Colpotomy.

Infectious Infertility Associated Viruses

Leptospirosis
Bovine Viral Diarrhea Virus (BVD)
Infectious Bovine Rhinotracheitis Virus (IBR)

Impact of Infectious Infertility on Reproductive Efficiency

Decreased conception, pregnancy and calving rates
Extended postpartum intervals
Delayed first calving in heifers
Delayed return to estrus and service
Increased abortions
Reduced weaned calf numbers and weights
Increased culling and replacement rates

Bovine Viral Diarrhea Virus (BVD)

BVD can cause embryonic death and abortion.
The outcomes (embryonic death, abortion, congenital defects, and stillbirths) depend on multiple factors, including biotype, genotype, virulence, immunity, stage of pregnancy, and co-infections.
BVD affects cow's fertility by affecting fertilization failures/embryonic death.
Issues like oophoritis, granulosa cell necrosis, and delayed follicular development are observed.

Bovine Viral Diarrhea Virus (BVD) (Continued)

Infection with BVDV NCP (non-cytopathic) occurring within 125 days of gestation can lead to persistently infected calves.
BVD can cause immunosuppression, affecting innate and cell-mediated immunity, as well as humoral immunity.

Bovine Herpes Virus 1 (IBR)

IBR is endemic in livestock farming in America, causing clinical diseases after acute infection or viral reactivation.
IBR can create respiratory and reproductive diseases in animals, including Infectious bovine rhinotracheitis, pneumonia (young animals), effect on embryo, oophoritis, necrosis of CL, abortion.
Abortion is most common during the 4-month gestational period.
Conjunctivitis and encephalitis, along with pustular vulvo-vaginitis, can occur as additional problems.

IBR Latency

IBR has a latency period in nerve ganglia (trigeminal/sacrum).
Stress can reactivate the virus,
Dissemination of IBR takes approximately 10 - 17 days.

Oophoritis by BHV1

BHV1 induces lesions in the ovary (corpus luteum - CL) within 4-9 days post-infection or vaccination.
This leads to lower P4 (progesterone) concentrations.

Abortion Caused by Infections

Infections can cause abortion (placental damage and stillbirth).
The typical abortion time frame is 4-7 months of gestation, but it can also occur weeks or months after infection.
Infections can result in stillbirths, weak calves, and mortality in young calves.

Diagnosis of Infectious Issues

Diagnostic methods include PCR, virus isolation, antigen capture ELISA (ACE), and serology (ELISA, SN).
Fetus tissues such as the kidney, liver, adrenal glands, and lungs are often analyzed.

Bovine Respiratory Disease Complex

Multifactorial and polymicrobial diseases cause significant economic losses.
Low feed conversion and yield, high treatment costs, and mortality.
Stressed calves (young, weaned, transported) are at higher risk.

Vaccination Effectiveness

Vaccines can be effective tools to prevent abortion and infertility.
Factors including stress, extreme climates, nutrition, infectious pressure, vaccination route, age at vaccination, and vaccine management affect vaccine effectiveness.
Attenuated vaccines offer higher and longer-lasting antibodies and may reverse virulence but pose a risk of contamination and immune suppression. In contrast, inactivated vaccines may be safer with lower risk of contamination.

BVD Vaccination Evidence

BVD Vaccination studies show a mixed range of results with regard to abortions and infection rates, but generally indicates that modified-live virus vaccines show a greater efficacy compared to inactivated viruses, especially with regard to the long term efficacy of the vaccination.

Leptospirosis

Leptospira is a zoonotic bacterium that causes septicemia and nephritis in young animals.
There are over 200 serovars and it persists in kidneys and genital tract.
Leptospira can cause infertility, repeat breeding, prolonged pregnancy complications and abortions in animals.
Contaminated standing water is a major source of infection.

Campylobacter & Tritrichomonas

Campylobacter and Trichomonas are obligate pathogens of the bovine genitalia, commonly spread through venereal transmission.
These microbes can also lead to infertility and sporadic abortion in cattle.
Bulls are asymptomatic carriers, and young bulls can clear the infection in weeks, while mature bulls are chronic carriers.
These bacteria do not directly impact early embryonic development but can cause inflammation that results in fetal death (15-80 days).
Cervix and vagina sites remain infected, leading to infertility and lower pregnancy rates.

Neosporosis

Neospora caninum is a protozoan that can cause abortion, weak calves, and stillbirths in cattle.
It also can result in encephalomyelitis and myositis in dogs.
Infection can be transmitted either endogenously (through birth) or exogenously (through ingestion).

Biosecurity Measures

Quarantine and isolate animals with high reproductive performance problems.
Identify and screen animals for infectious diseases.
Employ treatments such as antibiotics.
Avoid crowding animals, especially dairy heifers.
Isolate sick animals and abortions.
Prevent access to standing water
Disinfect boots in animal areas.
Limit contact with wild animals
Quarantine new bulls and perform a diagnosis for Campylobacter and Tritrichomonas before introducing them to the herd.

Vaccination Protocols (Heifers & Cows)

Heifer vaccination protocols involve multiple modified-live virus (MLV) vaccinations.
Cows require vaccination protocols that involve MLV followed by an inactivated vaccine.

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Description

This quiz explores the impact of Bovine Viral Diarrhea Virus (BVD) on cattle fertility and overall health. It covers symptoms, consequences of infection during pregnancy, and related infectious infertility concerns. Test your knowledge about BVD and its implications for cattle management.