Anaphylactoid reaction caused by sodium ceftriaxone in two horses experimentally infected by Borrelia burgdorferi.

BACKGROUND: Lyme borreliosis is a disease transmitted by ticks to mammals, especially in horses and humans. Caused by a spirochete Borrelia burgdorferi, it can result in lameness, arthritis, carditis, dermatitis and neurological signs. Anaphylactoid reactions are severe responses caused by direct action of substances (drugs, toxins), which can pose risks to life. Still poorly documented in horses, these reactions are caused by the effects of inflammatory mediators such as histamine, kinins and arachidonic acid metabolites. The last two are the most clinically relevant for the species. CASE PRESENTATION: The simultaneous occurrence of anaphylactoid reaction in two horses experimentally infected by Borrelia burgdorferi undergoing intravenous treatment with ceftriaxone sodium is reported. It was administered 4.7 × 10(8) spirochetes intradermal and subcutaneous applications in both horses to evaluate clinical aspects of the Lyme disease, 95 days before the application of sodium ceftriaxone. During the administration, one horse (a gelding) showed immediate and severe anaphylactoid symptoms such as urticaria, dyspnea, tachycardia, and eyelid edema, which were controlled by injecting dexamethasone. After 1 day, it expressed signs of abdominal discomfort, caused by severe bloat, which was treated surgically via celiotomy. Subsequently, this gelding had piroplasmosis and severe anemia, requiring treatment with an antimicrobial and blood transfusion. Second horse (a mare) showed signs of hypotension during the application of the antibiotic, which disappeared only when the application was interrupted. Days after the event, the mare developed moderate large colon bloat, which was treated with medication only. Subsequently the mare was evolved into the prodromal phase of laminitis in one of the forelimbs, which was treated for 10 days with non-steroidal anti-inflammatory and rheology modifying drugs and cryotherapy. CONCLUSIONS: From the two cases presented here, it does appear that sodium ceftriaxone can induce anaphylactoid reactions in horses infected by Borrelia burgdorferi, which may evolve into colic syndrome, laminitis and the occurrence of opportunistic infections. However, further evidence should be collected in order to draw definite conclusions.

Brazilian borreliosis with special emphasis on humans and horses.

Borreliosis caused by Borrelia burgdorferi sensu lato is a cosmopolitan zoonosis studied worldwide; it is called Lyme disease in many countries of the Northern Hemisphere and Lyme-like or Baggio-Yoshinari Syndrome in Brazil. However, despite the increasing number of suspect cases, this disease is still neglected in Brazil by the medical and veterinary communities. Brazilian Lyme-like borreliosis likely involves capybaras as reservoirs and Amblyomma and Rhipicephalus ticks as vectors. Thus, domestic animals can serve as key carriers in pathogen dissemination. This zoonosis has been little studied in horses in Brazil. The first survey was performed in the state of Rio de Janeiro, and this Brazilian Borreliosis exhibits many differences from the disease widely described in the Northern Hemisphere. The etiological agent shows different morphological and genetic characteristics, the disease has a higher recurrence rate after treatment with antibiotics, and the pathogen stimulates intense symptoms such as a broader immune response in humans. Additionally, the Brazilian zoonosis is not transmitted by the Ixodes ricinus complex. With respect to clinical manifestations, Baggio-Yoshinari Syndrome has been reported to cause neurological, cardiac, ophthalmic, muscle, and joint alterations in humans. These symptoms can possibly occur in horses. Here, we present a current panel of studies involving the disease in humans and equines, particularly in Brazil.

Brazilian borreliosis with special emphasis on humans and horses

Abstract Borreliosis caused by Borrelia burgdorferi sensu lato is a cosmopolitan zoonosis studied worldwide; it is called Lyme disease in many countries of the Northern Hemisphere and Lyme-like or Baggio-Yoshinari Syndrome in Brazil. However, despite the increasing number of suspect cases, this disease is still neglected in Brazil by the medical and veterinary communities. Brazilian Lyme-like borreliosis likely involves capybaras as reservoirs and Amblyomma and Rhipicephalus ticks as vectors. Thus, domestic animals can serve as key carriers in pathogen dissemination. This zoonosis has been little studied in horses in Brazil. The first survey was performed in the state of Rio de Janeiro, and this Brazilian Borreliosis exhibits many differences from the disease widely described in the Northern Hemisphere. The etiological agent shows different morphological and genetic characteristics, the disease has a higher recurrence rate after treatment with antibiotics, and the pathogen stimulates intense symptoms such as a broader immune response in humans. Additionally, the Brazilian zoonosis is not transmitted by the Ixodes ricinus complex. With respect to clinical manifestations, Baggio-Yoshinari Syndrome has been reported to cause neurological, cardiac, ophthalmic, muscle, and joint alterations in humans. These symptoms can possibly occur in horses. Here, we present a current panel of studies involving the disease in humans and equines, particularly in Brazil.

Exercício em esteira não elevou a temperatura do casco de equinos / Exercise on treadmill did not enhance the temperature of the equine hoof

Objetivou-se avaliar em equino a influência do exercício progressivo e intenso realizado em esteira de alta velocidade sobre a temperatura de regiões da pele, incluindo face, pescoço e quartela, e do casco, incluindo coroa, parede e sola. Utilizaram-se cinco equinos Puro Sangue Árabes, desferrados, com idade média de 8±0,7 anos, sendo duas fêmeas e três machos, com peso corpóreo médio de 420±10kg. A intensidade de esforço foi determinada por meio da quantificação do lactato sanguíneo. As temperaturas foram determinadas com o auxílio de termógrafo, antes, durante e após o exercício. Realizou-se análise de variância seguida pelo teste de Tukey, sendo P≤0,05. A lactacidemia aumentou, principalmente nas velocidades intensas. Houve redução das temperaturas das regiões da face, pescoço e quartela após o exercício e diminuição das temperaturas da parede, coroa e sola do casco durante o exercício, enquanto a temperatura da manta de rolamento da esteira não se alterou em nenhum momento. Constatou-se indiretamente que a perfusão sanguínea do casco diminuiu durante o teste de esforço tanto em sua fase aeróbia como na anaeróbia. Nenhuma das intensidades de esforço foi capaz de alterar a temperatura da manta de rolamento da esteira. A temperatura do casco diminuída como decorrência fisiológica do esforço físico imposto, retornou aos valores normais após o término do exercício.

The objective of the study was to evaluate the influence of intense and progressive exercise performed on a high speed treadmill on the temperature of the skin of the face, neck, pastern, and hoof, including the crown, sole and wall. Five unshod Arabian horses were used, with a mean age of 8±0.7 years, two females and three males, average body weight of 420±10kg. The exercise intensity was determined by quantification of blood lactate concentrations. Temperatures were determined with thermography before, during and after exercise. The effect of exercise on the temperature of the anatomic structures studied was evaluated by ANOVA for repeated measures followed by Tukey test, with P≤0.05. Blood lactate increased, especially at more intense speeds. There were decreases in temperature of the regions of the face, neck and pastern after the exercise, of the wall, crown and sole of the hoof during the effort. The temperature of the moving belt blanket bearing did not change at any time throughout the test exercise. It was found, indirectly, that the blood perfusion in the hoof decreased both during the aerobic and anaerobic phase of the exercise test. None of the effort intensities was able to change the temperature of treadmill moving belt. The temperature of the hoof reduced as a physiologic consequence of the exercise and returned to normal values after the end of the test.