Equine Herpesvirus Type 1 Myeloencephalitis in the Brazilian Amazon

• Published in: Animals (Basel) Vol. 13; no. 1; p. 59
• Main Authors: Barbosa, José Diomedes, Lins, André de Medeiros Costa, Bomjardim, Henrique Dos Anjos, Silveira, Natália da Silva E Silva, Barbosa, Camila Cordeiro, Beuttemmuller, Edsel Alves, Brito, Marilene Farias, Salvarani, Felipe Masiero
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 23.12.2022; MDPI
• Subjects: Abortion; Age; Animal husbandry; Animals; Differential diagnosis; Disease; Encephalitis; Epidemics; Epidemiology; Health services; Hemorrhage; Herpes simplex; Horses; infectious disease; Leukocytes (neutrophilic); Nervous system; nested PCR; neurological clinical signs; Neurological diseases; Neurological disorders; Neutralization; Paresis; Polymerase chain reaction; Rabies; Serology; serum neutralization; Spinal cord; Substantia grisea; Thiamine; Thorax; Vasculitis; Viruses; Vitamin B1; Brazil; neurological clinical signs; nested PCR; serum neutralization; infectious disease; horses
• ISSN: 2076-2615; 2076-2615
• DOI: 10.3390/ani13010059

An investigative and epidemiological study was carried out for equine herpesvirus type 1 (HVE-1) in 10 outbreaks of neurological disease from different farms in the state of Pará, Brazil. 25 horses were studied: six male and 19 females, aged between one and 13 years. A necropsy of six horses was performed, and the others recovered either with or without treatment (T1-vitamin B1 + dexamentasone; T2-vitamin B1 + flunixim meglumine). Animals that received treatment recovered after eight days. The main clinical signs observed were motor incoordination, progressive paresis, thoracic and/or pelvic limbs abducted after induction of clinical examination, knuckling of the hind fetlocks, sagging and swaying of the hindquarters while standing or walking and paresis. All animals were positive: 88% (22/25) in nested PCR and 72% (18/25) in serum neutralization (including three negatives in serology). Focal brownish areas compatible with hemorrhage were found in the white and gray matter of the spinal cord of two animals. On histological analysis, there were perivasculitis and neutrophilic vasculitis in the gray matter of the spinal cord and brain. Based on the evidence, this work proves the circulation of HVE-1 in the Amazon biome, mainly in the state of Pará, Brazil.