3.4 Genital tract infectious diseases

3 pathogens detected by placental mZN impression

Obligate intracellular organisms

• Chlamydia abortus (EAE)

• Brucella

• Coxiella

Preferable site for bacterial culturing in an abortion

Foetal stomach contents

• if unavailable = liver and lung

3 false -ve scenarios for placental mZN impression smearing

• Autolysis 

• Degradation

• Pathogen present but not homogenous throughout tissue → undetected

Name 1 disease in abortion that cannot be detected via PCR.

Schmallenberg - infects early during pregnancy

4 mechanisms of abortion due to infectious disease and examples

• Placentitis - interrupts foetal blood supply

  • Strep equi zooepidemicus, Brucella, Coxiella, Campylobacter etc

  • (not toxoplasma - intercotyledonary spaces are OK)

• Necrosis and endothelial damage to foetal tissues

  • EHV (liver) /EVA (endothelium)

• Viral replication in foetal tissues

  • Schmallenberg

• Stress and pyrexia due to dam infection

  • basically anything, esp pigs early 

3 notifiable horse repro diseases

• EVA

  • only in stallion (persists in accessory glands)

  • and mare if inseminated within 14 days

• CEM

  • Taylorella equigenitalis (gram +ve coccobacillus)

  • (certain capsule types of Klebsiella)

  • (certain Pseudomonas)

• Dourine

  • Trypanosoma equiperdum

  • Exotic

5 pathogens causing equine metritis

• Strep equi zooepidemicus

• E. coli

• Enterobacter

• Klebsiella

• Pseudomonas

Lesions in EHV abortions

Multifocal lesions in liver, lung, spleen

3 pestiviruses

• Border disease

• BVDV

• Classical swine fever 

Pathogenesis of nonpregnant V pregnant animal repro diseases

• Normally nonpregnant = ascending, pregnant = haematogenous

• Horse = ascending most common - cervix does not close properly

How should campylobacter be cultured?

Fastidious - culture with charcoal and antibiotics

2 category 3 pathogens

DO NOT CULTURE (but both intracellular anyways)

• Coxiella burnetti

• Brucella

Toxoplasma diagnosis

Placental PCR

• therefore in sheep abortions = providing placenta is important

Border disease diagnosis

Lymphoid tissue (thymus or spleen) PCR

Schmallenberg type of virus and tropism

• Orthobunyavirus

• CNS - kills neuronal stem cells

3 brain findings of schmallenberg

• Hydrancephaly (skull filled with CSF)

• Cerebellar + cerebral hypoplasia

• No gyri

2 notifiable ruminant abortion diseases

• Bluetongue (esp 3 and 8)

• Brucella

What 2 outcomes can happen when BVDV infects the first trimester of pregnancy? (2)

Calf is not immunocompetent

• Persistent infection

• Embryonic or foetal death

  • resorption, absorption, mummification

What 2 outcomes can happen when BVDV infects in the second trimester of pregnancy?

• Foetal death

  • Abortion, mummification

• Congenital deformities (esp day 125-175)

When do congenital deformities happen during BVDV infection? List 4 types of deformities.

Day 125-175 (of 280)

• Cerebellar hypoplasia (most common)

• Thymic atrophy

• Cataracts

• Bone growth plate arrest

Most common cow abortion cause in UK

Neospora

Neospora diagnosis (3 ways)

• PCR brain tissue

• Brain + heart histology

  • encephalopathy, meningoencephalitis, myocarditis → confirms not incidental finding

• Immunohistochemistry

4 bacterial causes for abortion in cows

• Salmonella dublin

• Bacillus licheniformis

• Listeria

• Leptospira

How do you stain Aspergillus?

• Silver staining - fungal hyphae

• Periodic acid schiff staning after culture in Saboraud’s dextrose agar → can see conidiophores

How do you diagnose leptospira abortion?

• Cannot culture and visualise under microscope

• Therefore serology, PCR, immunofluoresence

How does bluetongue cause abortion?

Pyrexia → systemic disease in dam

Bluetongue V BVDV CNS pathogenesis

Bluetongue - cerebellum is left intact

• both have hydrancephaly or porencephaly (brain fluid filled cysts)

How does porcine parvovirus cause reproductive disease? (2)

• SMEDI (stillbirth, mummification, embryonic death, infertility)

  • NOT ABORTION → delivered at full time

• Piglets killed one by one → different maturation degrees

PRRS classification and tropism

• Arteriviridae

• Lymphoid tissue - thymus and spleen

What is porcine circovirus associated with and how is it diagnosed?

• Myocarditis

• Histopathology + IHC

4 notifiable pig repro diseases

• Brucella suis (UK free)

• Aujeszky’s (suid herpesvirus 1)

• CSF

• ASF

Which disease in pigs is at risk of moving westward to the UK?

African swine fever

What virus is Aujeszkys and how can it affect dogs and cats? (3)

• Suid herpesvirus 1

• Dogs and cats eat infected pigs

• Lung oedema and death

When does canine herpesvirus infect puppies?

Contact with vaginal tract → therefore during or shortly after parturition

3 signs of canine herpesvirus 1

• Widespread haemorrhage (esp kidneys)

• Necrosis in different organs

• Intranuclear and inclusion bodies

Why is canine herpesvirus infection worse in puppies?

Herpesvirus functions cooler at 37C → puppies are not as good at thermoregulating to 38-39C

Notable canine genital infectious disease

Brucella canis

• endemic in N america

2 cat relevant repro infectious diseases

• Feline leukaemia → abortive

• Feline panleukopenia → congenital abnormalities (cerebellar hypoplasi)