As they lick their coat some of the hair is swallowed and in time balls up. Hence the name. In addition to daily brushing there are many petrolatum based products on the market which, when given regularly, seem to help. Vomiting, diarrhea, weight loss and change in appetite are all alerts. Do not expect to always see evidence of parasites in the stool.
Veterinarians routinely perform microscopic fecal examinations to search for eggs of parasites.
There are many plants which are poisonous to cats. Ornamental plants include daphne, wisteria, gold chain, rhododendron, azalea, lilly of the valley and yew. Symptoms vary from plant to plant. More detailed information can usually be obtained from a regional poison control center.