Ocorrência e etiologia dos processos anemiantes em bovinos e o uso de suplementos de minerais e vitaminas para tratamento: um estudo retrospectivo de 2002 a 2020

Abstract

Copper, cobalt and iron, whose deficiencies are associated with the development of anemia in ruminants, have different relevance in the context of probable deficiencies and intoxications. Copper and cobalt are linked to deficiencies in large areas of Brazil while iron deficiency rarely occurs in cattle, except in animals fed exclusively on milk and secondary to blood loss. However, oral or parenteral iron supplementation is widely used. In this context, the objective was to evaluate the specialized literature regarding the occurrence and main causes of anemia in young and adult cattle, the products available for treatment and the conditions of use. A retrospective study of anemia in cattle was carried out based on the blood count results of 1405 young and adult cattle, asymptomatic and with different diseases, from different origins, by manual or automated methods, performed between 2002 and 2020. Anemia was identified in 694 ( 49.4%) samples, with greater frequency for normochromic normocytic (34.9%) followed by macrocytic (15.4%). Most cases were mild (76.6%) with a predominance of normochromic normocytic (45%). Asymptomatic and diseased calves showed anemia (21.9% and 39.8%, respectively). Also with a predominance of the normocytic form, hypochromic in asymptomatic patients (54%) and normochromic in patients (55.3%). The identified cases are probably related to chronic blood loss, mainly due to external or gastrointestinal parasites, in addition to hemoparasitosis, and in some cases due to chronic poisoning by fern (Pteridium sp.) or copper deficiency. Eighty-two commercial products containing vitamin B12, iron, copper and cobalt were identified as single components or in associations, with indication for oral (22/82 - 26.8%) or parenteral (60/82 - 70.2%) application in cattle. adults and/or calves with anemia. Of these, 17 products for parenteral application contained only iron and 19 only vitamin B12. The association between iron and vitamin B12 was more common in products for parenteral application (12/60 – 20%) and in products for oral use, the association between iron, copper and cobalt prevailed (7/22 – 31.8%). The doses indicated for parenteral iron application (0.01g to 3g per application) varied greatly depending on the number of applications and suggested intervals, highlighting that in seven products the interval and duration of treatment were not identified. In the mixed formulations, the most frequent elements were iron (50/82), B12 (47/82), cobalt (19/82) and copper (17/82) in association with other minerals and vitamins, in addition to amino acids, glucose, dextrose and other components. The ease of access and the lack of clear information in the package inserts of these products makes it difficult to correctly indicate and can lead the producer to increase the dose and time of use of the products, increasing the risk of poisoning.