It is very possible for ruminant animals to get diseases from feeds and water. In fact those are the major ways by which they can contact diseases. Therefore, always ensure that your feeds are of good quality that is safer for your animals as well as your water quality.
With regards to how to know when your ruminant animals are sick, there are many things that can indicate poor state of health in ruminants. The most important thing is that diseases should be suspected anytime you see any deviation from the normal behaviors of animals.
For instance, among signs that may make you suspect disease include the following: the animals fails to eat well as usual, becomes weak, loses weight, may separate self from the herd and walk sluggishly. In some diseases, the animal may breath heavily, there could be sneezing and coughing. In others, the animal may have diarrhea with or without blood.
The hair coat of the animals may appear rough, there could also be discharges from natural orifices in some diseases. Death may result if the disease fails to subside. Any or all of these signs should make a ruminant farmer suspect diseases.