Thanks for posting that info. I grew up drinking raw milk from our own cow. Cows with TB and other diseases pass it through their milk, it isn’t only dirty conditions and cow poo that is the culprit. Apparently dad had Suzie tested for diseases because we survived years of drinking raw milk.
In addition to regular vet check-ups, I would guess your Suzie did not have much contact with other cows, which would be the main source of a lot of the infections that cows get. The way cows love to huddle together in small areas, diseases can spread very efficiently!