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
