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inflammation of the mammary gland. Although it may be caused by chemical or physical agents, the causes are almost entirely infectious, and mostly bacterial. Clinical signs vary with the severity of the disease, but include pain, heat and swelling of the affected quarter or half or gland, and abnormality of the milk, either as clots or flakes, and wateriness of the liquid phase. Subclinical mastitis is the most important form and is diagnosed on the basis of bacteriological examination or by indirect tests, principally based on the cell count of the milk. Called also mammitis, garget. See also blue breast.
For a summary of the infectious agents which cause mastitis in each of the animal species consult Table 16. See also california mastitis test, wisconsin mastitis test.
acute swelling of the mammary gland accompanied by heat and pain, together with grossly abnormal milk. There may be a slight systemic reaction.
severe, usually peracute clinical mastitis in which one or more quarters become gangrenous. Usually caused by Staphylococcus aureus.
persistent local infection, usually by Staphylococcus aureus, causes granulomas and the collection of pus within them to produce a botryomycotic effect. See also coliform mastitis.
caused by Escherichia coli, Klebsiella spp. or Enterobacter aerogenes. See coliform mastitis.
caused by those bacteria which are resident in bovine udders or on teat skin and are spread primarily during milking. Staphylococcus aureus, Streptococcus agalactiae, S. dysgalactiae are the common causes. Called also 'cow-associated' mastitis.
aimed at reducing new infection rate and the static quarter infection rate; based on dry period treatment, culling or treating infected animals, teat disinfection, teat cup liner sanitization, and milking machine maintenance and correct use.
discarding mastitis milk
milk from infected quarters flushed to waste, not fed to calves.
mastitis dry cow treatment
intramammary infusion with a long-acting formulation, at the time of the last milking for the lactation; may be blanket (all cows) or selective (infected quarters only). See also dry period treatment.
caused by those bacteria which are usually resident in the environment of the cow, especially in the feces, bedding or water. Escherichia coli, Streptococcus uberis are the common infections. See also coliform mastitis.
the teat and much of the quarter are black and cold, the secretion is thin blood-stained fluid and there is a severe systemic reaction. The quarter is lost, and the cow may very well die.
see botryomycotic mastitis (above).
mastitis infection rate
rate of quarters or cows infected with pathogenic bacteria or showing clinical mastitis or, a much more commonly used index nowadays, the percentage of cows with a milk cell count in excess of a stated norm.
NIRD mastitis control program
the basis of all modern mastitis control programs. Named after the National Institute for Research in Dairying (now called the Animal Grassland Research Institute) at Reading, UK, which introduced dry period treatment and teat dipping into mastitis control. Highly effective in reducing the prevalence of contagious mastitis pathogens such as Streptococcus agalactiae, Staphylococcus aureus. Called also 'five point program'.
as for acute mastitis, but there is also a severe systemic reaction and the cow may die of the attending septicemia.
a chronic disease in cattle caused by Nocardia asteroides, also occurs in sows caused by Actinomyces suis.
testing for evidence of inflammation of mammary epithelium, of individual cows or entire herd, by use of milk cell counts, biochemical tests which measure products of inflammation, e.g. NAG-ase test, electrical conductivity.
mastitis in which the only evidence of disease is an abnormality of cell count or other clinicopathological parameter.
a serious disease likely to cause the loss of the quarter and a severe clinical illness. Caused by Arcanobacterium pyogenes and other unspecified cocci. See also Table 16.
mastitis in which the secretion of the quarter is largely pus.
mastitis in which the infection is introduced through the skin into the teat canal or mammary tissue by a penetrating injury; it is usually a mixed infection and causes a suppurative or gangrenous mastitis, depending on the bacteria that are present. The quarter is ruined and the cow may die. See also Table 16.
mastitis treatment withholding times
after intramammary infusion in lactating cow—withhold 72 hours; dry cow intramammary infusion—administered at least 4 weeks before calving, withhold for 96 hours after calving.
not proven to exert beneficial effect. Only vaccination with an autogenous bacterin against Staphylococcus aureus, where the infecting organism is highly antigenic, appears to even reduce the severity of the disease.