It seemed rather dumb to me that Rick didn't say anything. When the animals are being raised as a food source, then the health of the animals is important. It wouldn't take much to wipe out the livestock. Saying to Hershel "hey the pig is acting weird" should have been a no brainer.
It also seemed rather odd that there wasn't a little more concern about the kid, not because of the zombie thing but an illness sweeping through the group would be a potential disaster. Their ability to stay alive depends heavily on their ability to do a lot of physical work, every day. Granted, it'd be impossible to quarantine someone but there might be steps that they could take.
Why do I always do this to myself???