Causal agents of cattle poisoning deaths in Spain

The causative agents of animal poisoning in a country are difficult to assess due to the lack of data in this field. The aim of this work is to identify the causal agents of cattle poisoning deaths in Spain, as well as, to evaluate the frequency of each of them. The method used is an epidemiological study, based on the information of an insurance company about these deaths (2000-2005), certificated by veterinary experts who used the anamnesis, necropsy and/or laboratory tests. A total of 33 different causal agents were identified: 20 vegetal agents and 13 non-vegetal agents. The 72.31% of the deaths were caused by plants. The mortality rate was higher in beef cattle than in dairy cattle (27.28 vs. 1.17 deaths per 100,000). The highest mortality rates in beef cattle were caused by plants with hemotoxic effects (13.72 deaths per 100,000), followed by plants with nephrotoxic effects (10.85 deaths per 100,000). By contrast, the non-vegetal agents caused more deaths in milk cows than in beef cattle (1.38 vs. 0.46 deaths per 100,000), highlighting the olive pulp as the main poisoning agent in dairy cattle (0.72 deaths per 100,000). In conclusion, the most important poisoning death causes of cattle in Spain are ferns and the fruits, leaves and sprouts of oak trees (Quercus spp.), probably due to its high lethal dose allows livestock to consume certain amounts of these plants without suffering disease symptoms, when cattle has not covered their nutritional needs