Viruses of the Genital Tract and Pregnant Uterus Flashcards
Methods of horizontal genital tract infections?
- Venereal
2. Other sites
Methods of vertical transmission of genital tract infections?
- Placenta
- Genital tract
- Milk
What may reproductive failure to to viruses be caused by?
- Viral replication in foetal tissues
- Damage to placenta blood vessels
- Stress and pyrexia
- Combinations of all
How can carrier animals shed virus without obvious clinical signs?
Semen
Resp secretions
Faeces
2 main methods o lab diagnosis of viral diseases causing reproductive failure?
- Detection of virus
2. Detection of anitbody
Lab diagnostic methods to detect virus? Problems?
PCR
Virus isolation
Antigen detection
Problems: If sample is not fresh viruses lose infectivity and nucleic acids/protein degrade
Lab diagnostics to detect antibody in repro? Problems?
Antibody detection in foetal fluids
Serology of the dam
Viruses of the horse reproductive tract?
EHV
EAV
Equine papillomavirus 2 = SCC
Name the 3 herpesvirus affecting the horse reproductive tract and what they cause…
- EHV-1
- Abortions
- Resp disease
- Paralysis - EHV-3
- Genital pustules but not abortion - EHV-3
- Respiratory disease
- Rarely isolated abortions
Describe the cycling of EHV1
- Infections of young horses
- Recruitment of new hosts into cycle
- Establishment of viral latency
- in CNS - Reactivation of virus from latency
- Nasal shedding of infectious virus
Results of EHV1 infections in pregnant mares?
Abortion in last third trimester
Fresh foetus
Lung oedema
Multifocal necrosis in liver, lungs and spleen of foetus
Diagnosis of EHV1 abortions?
PM of foetus and placenta
PCR
Microscopic examination of tissue staining
EHV1 immunostaining
Prevention/control of EHV?
Isolate pregnant mates during last trimester
Vaccination of all horses of premises
Combination vaccines of EHV1&4
Collect foetus and placenta for testing
Paired serology samples from mare to test for rising antibodies
Equine arteritis virus:
- Notifiable?
- Entry route
- What cell does it infect?
- Notifiable
- Via resp tract or semen
- Infects macrophages and endothelial cells
Clinical signs of EAV?
Some subclinical Fever Depresion Conjunctivitis Periorbital and leg oedema Abortion
Diagnosis of EAV abortion?
Clinical signs
Investigate travel history
Diagnosis aborted foetus/semen by virus isolation or PCR
High virus-neutralising antibody levels in mare at time of abortion
Rising post-abortion anitbody titres
Problems with EAV diagnosis?
Stallions can shed virus in semen without clinical signs
May be subclinical
Virus persists in accessory glands of stallion
Control of EAV?
Movement restrictions
Vaccinations of stallions - Confirm AB negative before
When is EAV notifiable?
Clinical signs are observed in the stallion
Evidence of EAV by semen or blood testing
Clinical signs/lab results indicate EAV in mare mated/AI within past 14 days
Viruses of the reproductive tract of cattle?
- BVDv
- BHV1
- Schmallenberg
- Bluetongue
- Bovine papillomavirus 1
BVDV:
- Shedding
- Spread to foetus
- Shed in resp secretions, faeces and semen
2. Haematogenous spread to foetus via the placenta
What is the ovine equivalent to BVD?
Hairy Shaker Disease/Borders Diseases Virus
What happens when BVD infects non-pregnant naive cattle?
Scour, milk drop, reduced WBCs, mild illness
Cows produce antibodies 2 weeks after infectiond
What happens when BVD infects naive animals in the first trimester of pregnancy?
Virus terminates pregnancy and reduces fertility
Some calves survive and born as a PI
Cows produce anitbodies 2 weeks after infection
What happens when BVD infects naive animals in the second trimester?
Virus causes abortion or deformities in calves
Cows produce antibodies 2 weeks after infection
What happens when BVD infects naive animals in the third trimester of pregnancy?
Foetus born weak or can be normal healthy calf
Cows produce antibodies 2 weeks after infection
BVD abortion diagnosis?
PM examination of aborted foetus with PCR of lymphoid tissue
Histopathology with IMHC
Maternal serology
Prevention and control of BVDv?
Endemic in the UK
Identify and remove PIs
Vaccination of dams
Accreditation of herds as BVDFree
What does bovine herpesvirus 1 cause?
IBR - infectious bovine rhinotracheitis
IPV - infectious pustular vulvovaginitis
IBP - infectious balanoposthitis
Abortions
How is BHV1 spread?
Venereal
Aerosol
Describe IPV in cattle..
Painful genital lesions
Swelling
Frequent urination
Tend to be selflimiting
Describe BHV1 abortions…
Following resp infection May occur weeks after infection Predominantly at 4-8 months gestation Necrosis of foetal lungs and liver Abortion uncommon in the UK
Diagnosis, prevention and control of BHV1?
PCR of foetal tissues/serology
Latent herpesvirus reactivation = prevent stress
Isolate and test new stock
Vaccination with DIVA vaccines
What are DIVA vaccines?
Differentiate between infected and vaccinated animals = marker vaccine
Schmallenberg virus:
- Spread
- When does infection occur?
- Tropism for virus
- Arbovirus (midges)
- Infection of dam in early preg
- Neurotropism (innervation damage so foetus cannot do exercises in utero
Clinical signs of schmallenberg virus?
Arthorogryposis
Hydranencephaly
Diagnosis of schmallenberg?
PCR (brain tissue)
HIstopath
Foetal serology
Maternal serology
Bluetongue
- Spread
- Clinical signs
- Diagnosis
- Notifiable?
- Arbovirus (midges)
- Abortions (pyrexia) and hydranencephaly
- Diagnosis:
- PCR
- Serology - Yes
Viruses of the reproductive tract in the dog?
Canine herpesvirus 1
Clinical signs of reproductive CHV1?
Fading puppy syndrome Screaming puppies Poor regulation of body temperature Organ necrosis Haemorrhages esp in kidneys
Prevention of CHV1?
Vaccination of pregnant bitches
Keep pups warm
Viruses of the cat reproductive tract?
- FeLV
2. Feline parvovirus
