Mammary Gland, Placenta and Fetus Flashcards
What are the natural defense mechanisms of the mammary glands?
- mechanical barrier
- presence of bactericidal compounds on the surface of the teat canal
- humoral factors in milk
- cellular factors
Streptococcus agalactiae
- what does it cause
- entry
- effects
- contagious mastitis
- entry through teat canal
- healing by fibrosis, with sequel of atrophy of quarters
Staphylococcus aureus
- what does it cause
- effects
- acute mastitis due to alpha-toxin
- abscesses, necrosis, gangrene in cattle
- toxin causes vasoconstriction and ischemia to the udder
Mycoplasma bovis
- what does it cause
- effects
- mastitis, sudden onset of agalactia
- involvement of all 4 quarters
- precipitous drop in milk production
- severe swelling of udder
What does coliform mastitis result in?
- acute and often fatal disease
- potent endotoxin causes vascular damage leading to fluid exudates, hemorrhage, thrombosis, and necrosis
What is contagious agalactia?
disease of goats cause by Mycoplasma agalactiae
Describe simple and complex adenomas
- benign
- simple: proliferation of well-differentiated luminal epithelial cells
- complex: mixed proliferation of secretory epithelial cells and myoepithelial cells
Describe a fibroadenoma
- benign
- mixture of epithelial and stromal cells
Describe a benign mixed tumor
proliferation of glandular and mesenchymal elements
What is mammary fibroadenomatous hyperplasia?
- benign, non-neoplastic proliferation of mammary ducts and connective tissue
- occurs in young intact cats, pregnant cats, and older neutered cats
What is the Chorion?
layer of the placenta that is in contact with the mother
What is the Allantois?
layer of the placenta that contains fetal urine and other fluids arising from the membrane itself
What is the Amnion?
smooth translucent membrane that surrounds the fetus and amniotic fluid
What are amniotic plaques?
foci of squamous epithelium on the internal surface of the amnion
Define Abortion
the expulsion of a fetus prior to the time of expected viability
Define Stillbirth
death of the fetus in the last part of gestation, during the period where it is independently viable
What is Mummification?
What are some causes?
- the fetus is retained indefinitely, and becomes dehydrated
- twinning in horses
- BVDV infection in cattle
- Canine herpesvirus infection
- uterine horn torsion in cats
- Parvoviral infection in sows
What is Maceration?
What can it lead to?
- the dead fetus is retained and infected by bacteria
- may lead to pyometra and maternal death from peritonitis and toxemia
What is Adventitial Placentation?
development of intercotyledonary placentation in cattle as a mechanism of compensation for inadequate development of placentomes
Describe a Campylobacter foetus subspecies venerealis infection
- true genital infection, and an important cause of infertility in cattle
- early embryonic death at 3-4 weeks
- intercotyledonary placentitis and necrosis of the cotyledons
Describe a Tritrichomonas foetus infection
- embryonic death or overt abortion in cattle
- pyometra can be a complication
Describe a Brucella abortus infection
- abortions common at 7-9 months in cattle
- necrotizing placentitis
- aborted fetuses may show signs of pneumonia
Describe a Listeriosis infection
- abortions in last trimester in cattle
- exudative intercotyledonary placentitis
- in the fetus, tiny pinpoint yellow foci of necrosis in various organs
Describe a Ureaplasma diverum infection
- abortions in the last trimester in cattle
- amnionitis: patchy thickening with fibrosis and multifocal areas of necrosis, hemorrhage, and fibrin exudate
Describe Neospora caninum infections
- abortions at 5-6 months of gestation in cattle
- also cause abortions in sheep and goats
- focal non-suppurative encephalitis
- brain needed for diagnosis
What are the 2 most important viral infections that cause abortion in cattle?
Bovine viral diarrhea virus
Akabane virus
Describe Campylobacter feotus subsp fetus infection
- important cause of abortions in sheep
- intercotyledonary placentitis and multifocal necrotizing hepatitis
Describe Chlamydophila abortus infection
- ovine enzootic abortion
- in utero infections in sheep and goats resulting in abortions, still births, or the birth of weak offspring
- acute suppurative to chronic placentitis
Describe Toxoplasma gondii infection
- major role in ovine abortion
- naive ewes develop protective immunity
- infection of cotyledon results in abortion
- lesion: cotyledons are bright to dark red, and have numerous small white nodules
Describe Border disease
- sheep infected with virus can have embryonic or fetal death, abortion, mummification, dysmorphogenesis, and birth of weak lambs
Describe a Coxiella burnetti infection
- Q fever in goats and sheep, zoonotic
- abortions late in gestation
- acute diffuse suppurative placentitis
Describe the umbilical cord abnormalities in mares
- longer cords associated with foal strangulation and necrosis of the cervical pole of the placenta
- shorter cords associated with premature separation of placenta
Describe mare reproductive loss syndrome
- the setae of eastern tent caterpillars embed in submucosa of alimentary tract and created microgranulomatous lesions
- bacteria invades circulatory system
- infections establish in fetus and placenta
What changes can occur in a fetus infected with EHV-1?
- fibrin cast in the trachea
- interstitial pneumonia
- focal necrosis in the liver
- prominent lymphoid follicles in the spleen
Which bacteria causes SMEDI?
porcine parvovirus
What are the two main viruses that cause abortion?
Herpesvirus
Pestivirus
