Mastitis is something that has been around for as long as people have been milking cows. Simply put it is an infection in the udder of the cow. Thankfully through good milking protocol, keeping cows clean, good nutrition and a few other things our incident rate is very low.
When we do get a case of it, the first thing we do is put the cow in a “sick pen” so that any cows that we think may be sick are the last cows to get milked, this helps prevent them from spreading anything to cows that would normally be milked after them. We then take a sample of her milk and make a culture in a petri dish to determine what kind of mastitis it is. Essentially the dish has 3 different types of agar that will grow the different kinds of mastitis. The 4th section is just a control that will grow virtually anything. The dish is then incubated for up to 48 hours to see what grows on it:
The top left area is the control. So as you can see this mastitis culture is growing in the bottom left area. Unfortunately this means it is a Staph Aureus infection. This is a contagious infection that is also very difficult to treat. In fact treatment is usually ineffective. So as much as we hate to do it, this cow will be sent to market. Luckily like I said, we don’t have a lot of mastitis cases, and only a fraction of the mastitis cases end up being staph. That is why we sell these cows as quickly as possible, it helps prevent her from spreading it to any other cows.
If it were a treatable type of mastitis, the cow would be treated with the appropriate antibiotics and her milk would be dumped down the drain until the required milk with holding time was passed and the antibiotics were out of her milk.