Synonyms

No known synonym

Name of the disease in English

Staphylococcus and Sreptococcus mastitis

The disease in brief

It is not possible to clinically distinguish the different mastitis according to the bacterial species involved. Bacteriological investigations show that mastitis manifested by discrete symptoms is more often associated with these 2 species.
Infection of the udder by Staphylococcus occurs mainly during milking; clinical signs are usually moderate. A distinction is made between Staphylococcus aureus and the numerous coagulase-negative species of Staphylococcus which are minor pathogens (Fiche-memo-MA33). We focus our discussion here on the most formidable Staphylococcus aureus.
Infection of the udder with Streptococcus can occur either during milking or while lying down. Three species of Streptococcus are major pathogens of the udder. Str. Uberis the most frequent is transmitted by all routes, Str. Agalactiae almost disappeared from regions where dry-off treatment is systematically practiced remains a threat because it is very contagious during milking, Str. Dysgalactiae, often associated with teat skin problems is transmitted during milking.
After (and before) a clinical episode, these bacteria can persist in the udder at the subclinical stage; they then cause a variable rise in the number of somatic cells in milk, sometimes high with Str. uberis.
The true cure rate (clinical and bacteriological) of these clinical mastitis during lactation and at dry-off is very variable.

Clinic & diagnosis

Most of the time: a few clots in the milk at the start of milking or throughout milking from a slightly swollen quarter. There are of course important variations of this table.

Typical sign of the disease

No description

Pictures

See below

Diagnostic formulas

No description

Differential diagnosis

-Main pathogenic mastitis MA33
-Yeast mastitis (Candida, other fungi) MA22.1
-Mammitis with Protothecia MA21.1

Confirm a suspicion?

Obtain sterile milk whenever treatment failures appear to increase over a period of time. Freeze it, preferably on a preservative support. If the problem of non-cure is confirmed, bring the samples to the laboratory for bacteriological analysis.

Prognosis and treatment

The treatment of these “small” mastitis is difficult if one aims for a bacteriological cure and a return to a cell count <200,000 / ml or <100,000 for a primipara.
While the above-mentioned streptococci remain overwhelmingly sensitive to penicillins G, the frequency of resistance Staphylococcus aureus is high. Faced with such a bacterium, quite often identical from one infected cow to another within the same herd, it is recommended to perform a cefinase test before establishing a care protocol.
These infections heal better during dry-off (under the guise of effective antibiotic therapy for at least 3 weeks) than during lactation. Infections with Staphylococcus aureus are always more difficult to cure than streptococcal infections, whether during lactation (ca. 10 to 30% vs 40 to 70%) or during dry-off (ca. 20 to 50% vs 50 to 90%), which should encourage the prevention of this type of infection.
In lactation, treatment at the start of the infection gives more chances of recovery, treatment of relapses or hard quarters gives much less. Long treatments (5 days or more) have been shown to be more effective than short treatments. It has not been formally established that lactation treatments combining local and systemic routes are more effective than the local route alone.

Prevention

Review the prevention in place as soon as the frequency of this type of mastitis increases in a herd.

References

Blackwell's five-minute veterinary consult-Ruminant; Haskell SRR Ed Wiley-Blackwell p540