So we just took a look at the syndromes. Clinical, subclinical different levels of clinical mastitis. So the Subacute, acute, peracute and the chronic. Again, the chronic's kind of in between because a lot of times at subclinical, they have to get these clinical flare-ups. So it gets to be very complicated in how you think about categorizing what's going on in the animals. Another way to think about this, or another way to categorize it is to think about types of mastitis. And this starts to get us into the relationship between the host, the agent and the environment. To there are actually five types that had been identified but these are the two of the major types. Contagious mastitis sometimes called cow-to-cow. So a cow has that type of mastitis and this usually draws us back into what is the pathogen or what is the agent causing this different types? As well as kind of how it happens? Again, cow to cow. So, where is mastitis? Well, it's in the mammary gland and cow is usually don't put their mammary glands together like that. So, we've got to think about other ways of how to go pass from cow to another cow? And you're actually looking at it. This thing called the milking machine. Very often that's what causing this. She had a pathogen in this particular quarter and contaminates this machine. That machine is then put on another cow, potentially can pass that to that other cow. So a lot of times the milking process is really central to passing this contagious mastitis idea. But it's certainly not on the only component of that. The other major type of mastitis is called environmental. So, those pathogens are, there's a reservoir always in the environment, whether it's in the manure, in the bedding, in the water, all sorts of things, so it's around. It also then transfers into the milking parlor in terms of cleanliness of the teats, cleanliness of the udder, cleanliness of the milking machines and so on. And so this is a somewhat different set of pathogens that exists in the environment. And we'll break those out again in another video. So these are two major types. And so as we think about mastitis and how do we solve mastitis cases? Well we're going to start to get you to think in terms of well is of more likely to be contagious mastitis? Is it more likely to be environmental mastitis and just start. It's not an absolute all or none but start how do we think about this process of solving these kinds of cases and understanding what's going on. There are however, other kinds that have been identified, types have been characterized. Teat skin to udder. This is where certain pathogens might actually exist, on the teat skin, and then preparing the cows udder or putting in the milking machine on, again those somehow get inside the mammary gland. Mouth to udder, this is a situation where. Typically in calves if they're fed milk from cows that have mastitis and therefore have pathogens in their milk, then those pathogens colonize or get in the mouth of the calf. That calf suckles another calf that pathogen can potentially get up in the teat of that other calf. And then when she grows up and has a calf and starts lactation she might then have mastitis at that particular point. That's another type. And then flies. Now, flies is really not a type of mastitis, it's a more of a vector. So sometimes we use this expression vector. Pretty much anything, if I'm milking a cow and I get some bacteria on my hand. And then somehow transfer that to a cow, then my hand becomes a vector. In this particular case, flies, because in many cases, especially in the summer time a lot of flies around the farm. Those are a particular kind of a vector and there's a certain kind of pathogens that they might transfer from one cow to another. And so that's why they break this out in that particular case. So let's take a look at it again, a couple of these real fast. Again this idea of teat skin to udder. So again, certain pathogens prefer to live kind of on the skin. And potentially can get into the gland, or get in the milking machine, and be transferred to another cow. Again this idea of the mouth to udder would be the calves suckling each other. And then flies down here again, on the very, very end of the teat. It's usually very moist and Flies like to congregate there, potentially getting pathogens, transferring them to another animal. So let's review very quickly the mastitis syndromes and the types of mastitis. Again, over here are syndromes. We've talked about clinical in these top ones, subacute, acute, and peracute. Mastitis would be clinical, for sure. Then we have the subclinical, in which you can't see the signs. And then we have the chronic, which again is, there's subclinical for a while, you really can't see any signs or anything, unless you look at somatic cell count in the milk. And then they have this clinical episode, where clearly they're going to be one of these guys, up here. And then they go back to being subclinical, so it's going back and forth over time. And again, chronic mastitis can last for a very very long time. And then, types of mastitis, another way of thinking about this particular disease is, is it contagious? This starts to get us into the relationship between again that host, the agent and the environment. How those things all fit together. So again, contagious mastitis or cow to cow mastitis, so there's a pathogen in one cow, in the udder. Somehow that's getting transferred to another cow. And usually through the milking process. Environmental mastitis, again, there's a reservoir of these pathogens in the manure, in the bedding and so on and so forth out there. And so there's always this constant challenge to the mammary gland of these environmental pathogens. And then, some other ones. Teat skin to udder, again, some of those pathogens kind of living on the teat skin. And getting passed through, again from cow to cow usually during the milking process. Mouth to udder, this is usually the calves suckling each other. Although, there's evidence certainly that adult cows will suckle each other, too. And then flies again is a vector. Again, just kind of other ways of breaking down and thinking about how does this particular disease happen. Again thinking in terms of different types of mastitis. So these are just two different ways of saying okay, how do we categorize this very, very complex disease? Either by the response of the mammary gland, or in this case, we're starting to get into that idea of, how does this relate to the agent, the pathogen, the bacterium? And then the environment that the animal is living in.