Short, wet grass is the preferred climbing area for my constant enemies, Haemonchus contortus and Strongyloides papillosus. Newly-hatched parasites are naturally programmed to climb grass blades, which are consumed by the goats. Once inside the goat, the parasites go to work sucking blood out of the intestinal walls. Before the parasites die, they lay eggs which are carried out the other end of the goat's digestive system, ending up as poop in the wet grass. There the eggs hatch in the muddy poop, find a blade of grass, etc.
Bottlejaw is a condition where the goat starts retaining water from anemia. The lower skin areas on the goat start to get squishy and loose. The lower portions include the face (sample photo of puffy goat; not horrible) since goats usually have their heads down to graze. Other places that show water retention quickly are the chest and stomach, and around the ankles. During the late, wet spring, when there is plenty of food, a goat might evidence bottlejaw even while its skin is still pink with red blood cells. Whacky and frustrating, but true. When he was younger, Loki was a master at that.
One more advantage of having sheared at the beginning of summer is that I can judge macro animal condition at a glance. There isn't enough hair to hide bottlejaw and some of the other physical nutrition symptoms. Lack of copper causes baldness (never has happened on my farm!). Lack of food - or foot rot - causes skinniness. Lice and ticks are easier to spot, especially around the face.
Another thing that is caused by wet and mud is thrush, or foot rot. I call it athlete's foot when talking to non-goat people because "thrush" makes people think of mouths and "foot rot" sounds so dire. The cause is simple: muddy poop gets up between the goats' toes and causes a dermal infection. It digs under toenails and separates the nail from the toe wall. Left untreated, the goat will go lame. Lame goats don't like to stand much, so they don't eat as much. So thrush is a common cause of skinniness in goats in the late winter and spring. It's easy to treat, but the battle, once joined, is almost constant. (Here's a not so pretty sample photo.)
So, even while I love the lush green pastures, there is a battle going on out there.