Urea poisoning in cattle: a brief review and diagnostic approach / Intoxicação por ureia em bovinos: breve revisão e abordagem diagnóstica

Urea is an organic compound characterized as a white, solid, and hygroscopic substance. It is recognized as a source of non-protein nitrogen (NPN) and is widely used as a partial replacement for protein in cattle diets due to the ability of the ruminal microbiota to convert it into microbial protein. Despite the advantages of using urea, it also has limitations, particularly the proximity between metabolizable and toxic or fatal doses. Furthermore, for safe use, a period of adaptation is necessary for the animals. Poisoning is characterized by rapid and generally fatal development, which is frequent in non-adapted animals but can also occur in those with previous adaptations. The aim of this study was to characterize the clinical, epidemiological, and pathological aspects of urea poisoning through a brief review and a retrospective study. In addition, interviews were conducted with veterinarians who frequently send diagnostic material to the Laboratory of Anatomic Pathology of the "Faculdade de Medicina Veterinária e Zootecnia" (LAP-FAMEZ) to assess their perception of the outbreaks of urea poisoning. The objective was to obtain a comparative scenario between published cases and those received by the laboratory while considering the real situation of this condition in the field. During this retrospective study, only four outbreaks were investigated; in one, the diagnosis was possible through experimental reproduction. Of 35 interviewees, 88.9% said they had seen more than one case compatible with urea poisoning, but 87.5% did not perform a necropsy and/or send material to confirm the diagnosis. The results show that the reality of urea poisoning may be very distant from that reported in previous studies due to the difficulty often observed in the diagnostic approach, so we developed a flowchart aiming to provide a useful guide for field veterinarians.

A ureia é um composto orgânico, que se apresenta como uma substância branca, sólida e higroscópica, e é reconhecida como fonte de nitrogênio não proteico (NNP), sendo amplamente utilizada como fertilizante e também como substituto parcial de proteína em bovinos devido à capacidade da microbiota ruminal de convertê-la em proteína microbiana. Apesar das vantagens que envolvem o uso da ureia, ela também apresenta limitações, a principal delas é a proximidade entre doses metabolizáveis e tóxicas ou fatais, e para que seja utilizada com segurança é necessário um período de adaptação dos animais. A intoxicação é caracterizada por evolução rápida e geralmente fatal, sendo frequente em animais não adaptados, mas pode ocorrer naqueles com adaptação prévia. O objetivo deste estudo é caracterizar os aspectos clínicos, epidemiológicos e patológicos da intoxicação por ureia por meio de uma breve revisão e um estudo retrospectivo. Adicionalmente foram realizadas entrevistas com médicos veterinários que frequentemente enviam material para diagnóstico no Laboratório de Anatomia Patológica da Faculdade de Medicina Veterinária e Zootecnia (LAP-FAMEZ) com o objetivo de avaliar a percepção dos mesmos em relação aos surtos de intoxicação por ureia, na expectativa de se obter um quadro comparativo entre os casos recebidos pelo laboratório e levantamentos publicados e a real situação desta condição a campo. No período do estudo retrospectivo, foram acompanhados apenas quatro surtos, sendo que em um deles foi possível diagnosticar por reprodução experimental. Dos 35 entrevistados, 88,9% afirmaram ter atendido mais de um caso compatível com intoxicação por ureia, mas 87,5% deles não realizaram necropsia e/ou envio de material para confirmação do diagnóstico. Foi possível observar que a realidade da intoxicação por ureia pode estar muito distante daquela relatada em estudos anteriores, e devido à dificuldade muitas vezes observada na abordagem diagnóstica, desenvolvemos um fluxograma na expectativa de que ele constitua um guia útil para veterinários de campo.

Feline aortic thromboembolism diagnosed by thermography

Background: In cats, arterial thromboembolism is one of the most devastating diseases, with an acute presentation, andis often caused by undiagnosed cardiomyopathy. Defined as the obstruction of one or more arterial lumens by emboli,the arterial thromboembolism is responsible for hypoperfusion signs. As the temperature of the skin surface is directlyrelated to tissue perfusion, thermography can be promising for the early diagnosis of thromboembolism. Therefore, thisstudy reports the importance of thermography as a complementary examination for the diagnosis of thromboembolism inthe abdominal aorta of a domestic cat.Case: A 4-year-old mixed-breed cat weighing 2.95 kg was presented with a history of sudden onset paraplegia, apathy,and pain when handled, with greater intensity in the sacro-coccidian region. During physical exam, it was noted that thefemoral artery pulse was undetectable bilaterally during manual pulse measurement. Superficial and deep sensitivity inthe pelvic limbs and proprioception were also absent and the plantar cushions and nail beds of the posterior limbs werepale to cyanotic. Thermographic images revealed that the temperature of both hind limbs was lower than that of forelimbs,with difference of 3.2ºC and 2.9ºC between the left and right limbs, respectively. Doppler ultrasonography revealed theabsence of pulse and flow in the femoral arteries bilaterally. Electrocardiography revealed sinus tachycardia, with a heartrate of 250 bpm. Echocardiography revealed dilation of the left atrium and concentric cardiac hypertrophy. After 24 h, dueto the worsening of the clinical condition and unfavorable prognosis, the animal was euthanized and sent for necropsy.Necropsy revealed that the arterial lumen of the caudal abdominal aorta and bifurcation of the iliac arteries were obliterated...

Feline aortic thromboembolism diagnosed by thermography

Background: In cats, arterial thromboembolism is one of the most devastating diseases, with an acute presentation, andis often caused by undiagnosed cardiomyopathy. Defined as the obstruction of one or more arterial lumens by emboli,the arterial thromboembolism is responsible for hypoperfusion signs. As the temperature of the skin surface is directlyrelated to tissue perfusion, thermography can be promising for the early diagnosis of thromboembolism. Therefore, thisstudy reports the importance of thermography as a complementary examination for the diagnosis of thromboembolism inthe abdominal aorta of a domestic cat.Case: A 4-year-old mixed-breed cat weighing 2.95 kg was presented with a history of sudden onset paraplegia, apathy,and pain when handled, with greater intensity in the sacro-coccidian region. During physical exam, it was noted that thefemoral artery pulse was undetectable bilaterally during manual pulse measurement. Superficial and deep sensitivity inthe pelvic limbs and proprioception were also absent and the plantar cushions and nail beds of the posterior limbs werepale to cyanotic. Thermographic images revealed that the temperature of both hind limbs was lower than that of forelimbs,with difference of 3.2ºC and 2.9ºC between the left and right limbs, respectively. Doppler ultrasonography revealed theabsence of pulse and flow in the femoral arteries bilaterally. Electrocardiography revealed sinus tachycardia, with a heartrate of 250 bpm. Echocardiography revealed dilation of the left atrium and concentric cardiac hypertrophy. After 24 h, dueto the worsening of the clinical condition and unfavorable prognosis, the animal was euthanized and sent for necropsy.Necropsy revealed that the arterial lumen of the caudal abdominal aorta and bifurcation of the iliac arteries were obliterated...(AU)

Approaches for a field diagnosis of abamectin poisoning in calves / Abordagem para um diagnóstico a campo da intoxicação por abamectina em bezerros

An approach for the diagnosis of an abamectin outbreak in calves in the field is described and discussed. In a Midwestern Brazilian property, nine out of a 52 newborn calves were affected and died, making up for morbidity, mortality, and lethality ratios of 17.3%, 17.3%, and 100%, respectively. Major clinical signs included tremors in various muscle groups, inability to stand, and difficult, wheezing breathing. Each affected calf had been treated subcutaneously with abamectin (0.4mg/kg/body weight). No lesions were found at necropsy or at histological examination. Major diseases of newborn calves were included in the differential diagnosis.(AU)

Uma abordagem para o diagnóstico de um surto de abamectina em bezerros a campo é descrita e discutida. Numa propriedade do Centro-Oeste brasileiro, nove de um lote de 52 bezerros de 3 dias de idade foram afetados e morreram, perfazendo quocientes de morbidade, mortalidade e letalidade, respectivamente, de 17,3%, 17,3% e 100%. Os principais sinais clínicos incluíam tremores em vários grupos musculares, incapacidade em se manter em pé, e respiração difícil e estertorosa. Cada bezerro afetado havia sido tratado por via subcutânea com abamectina, na dose de 0,4mg/kg/peso corporal. Não foram encontradas lesões na necropsia, nem no exame histológico. As principais doenças de bezerros recém-nascidos foram incluídas no diagnóstico diferencial.(AU)

Approaches for a field diagnosis of abamectin poisoning in calves / Abordagem para um diagnóstico a campo da intoxicação por abamectina em bezerros

An approach for the diagnosis of an abamectin outbreak in calves in the field is described and discussed. In a Midwestern Brazilian property, nine out of a 52 newborn calves were affected and died, making up for morbidity, mortality, and lethality ratios of 17.3%, 17.3%, and 100%, respectively. Major clinical signs included tremors in various muscle groups, inability to stand, and difficult, wheezing breathing. Each affected calf had been treated subcutaneously with abamectin (0.4mg/kg/body weight). No lesions were found at necropsy or at histological examination. Major diseases of newborn calves were included in the differential diagnosis.(AU)

Uma abordagem para o diagnóstico de um surto de abamectina em bezerros a campo é descrita e discutida. Numa propriedade do Centro-Oeste brasileiro, nove de um lote de 52 bezerros de 3 dias de idade foram afetados e morreram, perfazendo quocientes de morbidade, mortalidade e letalidade, respectivamente, de 17,3%, 17,3% e 100%. Os principais sinais clínicos incluíam tremores em vários grupos musculares, incapacidade em se manter em pé, e respiração difícil e estertorosa. Cada bezerro afetado havia sido tratado por via subcutânea com abamectina, na dose de 0,4mg/kg/peso corporal. Não foram encontradas lesões na necropsia, nem no exame histológico. As principais doenças de bezerros recém-nascidos foram incluídas no diagnóstico diferencial.(AU)

Approaches for a field diagnosis of abamectin poisoning in calves

ABSTRACT: An approach for the diagnosis of an abamectin outbreak in calves in the field is described and discussed. In a Midwestern Brazilian property, nine out of a 52 newborn calves were affected and died, making up for morbidity, mortality, and lethality ratios of 17.3%, 17.3%, and 100%, respectively. Major clinical signs included tremors in various muscle groups, inability to stand, and difficult, wheezing breathing. Each affected calf had been treated subcutaneously with abamectin (0.4mg/kg/body weight). No lesions were found at necropsy or at histological examination. Major diseases of newborn calves were included in the differential diagnosis.

RESUMO: Uma abordagem para o diagnóstico de um surto de abamectina em bezerros a campo é descrita e discutida. Numa propriedade do Centro-Oeste brasileiro, nove de um lote de 52 bezerros de 3 dias de idade foram afetados e morreram, perfazendo quocientes de morbidade, mortalidade e letalidade, respectivamente, de 17,3%, 17,3% e 100%. Os principais sinais clínicos incluíam tremores em vários grupos musculares, incapacidade em se manter em pé, e respiração difícil e estertorosa. Cada bezerro afetado havia sido tratado por via subcutânea com abamectina, na dose de 0,4mg/kg/peso corporal. Não foram encontradas lesões na necropsia, nem no exame histológico. As principais doenças de bezerros recém-nascidos foram incluídas no diagnóstico diferencial.