Adrenocortical, thyroid and oxidative stress evaluation in dogs naturally infected with Ehrlichia canis

• Grant number: 12/10207-9
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: September 01, 2012
• End date: March 31, 2015
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Clinics and Surgery
• Principal Investigator: Mirela Tinucci Costa
• Grantee: Mariana Cristina Hoeppner Rondelli
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil

Abstract

Ehrlichiosis in dogs, caused by the bacterium Ehrlichia canis, is a hemoparasitosis with worldwide distribution and multisystemic nature, with clinical and hematological consequences, that leads to pancytopenia, bleeding and weight loss. The severity of the clinical manifestations can lead the animal to death, either by their hematological changes as possible consequent immuno-inflammatory, oxidative and hormonal alterations. Studies regarding the hormonal impairment and oxidative stress due to the severity of infection and inflammation, which are known to occur in dogs with ehrlichiosis, are scarce. Given the importance of maintaining the balance of hormonal and oxidative mechanisms in animal health, it is of clinical interest to understand the behavior of the hypothalamus-pituitary-adrenal and hypothalamic-pituitary-thyroid axis in multisystemic diseases, as naturally acquired infection with Ehrlichia canis in dogs, as well as the possibility of oxidative stress contributes to the severity of clinical signs. Thus, these assessments will be conducted: serum cortisol and dehydroepiandrosterone (DHEA-S) sulfate before and after stimulation with synthetic adrenocorticotropic hormone (ACTH); serum thyroid stimulating hormone (TSH), total T4, free T4 (tetraiodothyronine) and anti-thyroglobulin autoantibodies; and nitric oxide, lipid peroxidation and activity of glutathione reductase, at the time of diagnosis and following treatment with doxycycline hyclate [5 mg/kg (Group I, n=6) and 10 mg/kg (Group II, n=6) every 12 hours for 30 days]. Serum samples of healthy dogs (n=6) from the Veterinary Teaching Hospital´s kennel will be used as control group, in order to be compared to the results of Groups I and II. The identification of the occurrence of such disturbances may be useful to understanding the etiology, pathogenesis and therapeutic approach for ehrlichiosis in dogs. (AU)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

RONDELLI, Mariana Cristina Hoeppner. Avaliação adrenocortical, tireoideana e do estresse oxidativo de cães naturalmente infectados por Ehrlichia canis. 2015. Doctoral Thesis - Universidade Estadual Paulista (Unesp). Faculdade de Ciências Agrárias e Veterinárias. Jaboticabal Jaboticabal.