Abnormal milk, or milk from cows with high SCC should be submitted to the microbiology lab for bacterial culture to know which type of bacteria is causing the mastitis. In general, milk with clots is not specific for any particular bacteria:
Although the contagious organisms, Strep ag and Staph aureus, can cause clinical mastitis, they tend to cause subclinical mastitis. The milk and udder appear normal, but the somatic cell counts are elevated and bacteria can be cultured from the milk. Often farmers report high bulk tank SCC and no clinical mastitis. Occasionally, Staph aureus causes gangrenous mastitis. Cows with gangrenous mastitis are systemically ill and have a red tinged watery milk secretion.
Although the environmental organisms, coliforms and strep-non ag spp. can cause subclinical mastitis, they tend to cause clinical mastitits. In fact, clinical mastitis on the farm is generally caused by the environmental organisms. Usually, both the milk and the udder are abnormal. The clinical infections caused by the Strep-non ag bacteria are not as severe as the infections caused by the coliform bacteria. Cows with coliform bacteria are often systemically ill, have watery secretions and swollen udders.
Clean the teat end with alcohol, and only infuse the tip of the cannula into the teat.
It should be kept in mind that MASTITIS IS DIFFICULT TO TREAT. Some pathogens, notably Strep ag., respond well to intramammary treatment with commercial mastitis treatment tubes. As hard as it is to believe, intramammary antibiotics are probably of minimal help against most bacteria other than Strep ag. that cause mastitis. There is some evidence that treatment with antibiotics of the strep-non ag bacteria will help prevent reoccurrence, and that early Staph aureus infections may respond better to treatment than the chronic Staph aureus infections. Antibiotic treatment of coliform infections has generally been shown to be ineffective, and the mainstay treatment for coliform infections should be supportive (fluids and anti-inflammatories).
A major problem with choosing mastitis treatments, is that when the cow first gets mastitis, the cause of the mastitis is not known. As mentioned before, any bacteria could cause a cow to have clots. While culturing the milk is always a good idea to make an educated treatment choice, practically speaking, by the time the results come back, the cow has either gotten better, stayed the same, or died. Treatment protocols can be set up on the farm based on what kind of mastitis the cow is likely to have, given the history of mastitis on the farm.
The treatment protocol we use on dairy farms, tries to distinguish between the cow that is systemically ill that would benefit from fluids and anti-inflammatories (coliforms), from the cow that has clinical mastitis but is not systemically ill. Cows with hard udders accompanied by watery secretions generally have coliform infections. Our treatment protocol can be used with or without the antibiotics. Some farms want to treat every case of mastitis with some form of antibiotics, and some farms do not want to treat any cases of mastitis with antibiotics because of the possible antibiotic residue problems.
Field Service Treatment Protocol for Mastitis on our Dairy Farms:
The goals of mastitis treatment are:
Follow all recommended milk and slaughter
AMOXIMAST - Treatment repeated at 12 hr
intervals for a total of 3 treatments. Milk withhold is 60 hours
(5milkings). Meat withhold is 12 days.
If no improvement after treatment with Amoximast, wait one day and re-evaluate the affected quarter. Switch to TODAY and use according to the label if the quarter needs further treatment.
TODAY - Treatment repeated at 12 hour intervals for a total of 2 treatments. Milk withhold is 96 hours (8 milkings). Meat withhold is 4 days.
If no improvement, check the culture result, and decide whether to band the cow.