The 30 opinions published over the last 5 years covered natural plant products (such as gossypol and theobromine), persistent organic pollutants (such as DDT and hexachlorobenzene), heavy metals (such as arsenic and mercury), fluorine and mycotoxins (such as aflatoxin B1).
In most cases, the CONTAM Panel identified no risks to animal health resulting from feed intakes at the maximum authorised levels, provided good animal feeding practices are followed. However, adverse effects on animal health could not be excluded for some substances, such as deoxynivalenol in pigs, mercury in cats, gossypol in sheep and theobromine in dogs and horses.
http://www.efsa.europa.eu/EFSA/efsa_locale-1178620753812_1211902444045.htm?WT.mc_id=EFSAHL01