Genome Sequences of Equine Herpesvirus 1 Strains from a European Outbreak of Neurological Disorders Linked to a Horse Gathering in Valencia, Spain, in 2021.

Five equine herpesvirus 1 (EHV-1) genome sequences with links to an EHV-1 outbreak with neurological disorders after a horse gathering in Valencia, Spain, in February 2021, were determined. All strains showed the closest relationships to strains from Belgium and the United Kingdom, indicating a common source of infection.

Functional electrical stimulation of the left recurrent laryngeal nerve using a vagus nerve stimulator in a normal horse.

The aim of this study was to assess the feasibility of implanting an existing vagus nerve stimulating (VNS) electrode around the recurrent laryngeal nerve. The stimulus response characteristics required to achieve abduction of the ipsilateral arytenoid by the VNS electrode in the normal horse could then be determined. The electrode was wound around the left recurrent laryngeal nerve at the cervical level and connected to a pulse generator. Stimulus response characteristics were obtained by measuring stimulated arytenoid displacement endoscopically in the standing, non-sedated horse. A full and sustained abduction of the arytenoid was obtained with a stimulation frequency of 25 Hz and intensity of 1 mA with a pulse width of 250 µs.

Transrectal ultrasonography of the left adrenal gland in healthy horses.

Little information is available on medical imaging of the adrenal glands in horses. We investigated the feasibility of transrectal ultrasonography to characterize the normal equine adrenal gland. Transrectal ultrasonography was performed in 25 healthy horses using a 7.5 MHz linear array probe at a displayed depth of 8 cm. Transrectal ultrasonography of the right adrenal gland was not feasible. For the left adrenal gland, the left kidney, the abdominal aorta, the left renal artery, the left renal vein, and the cranial mesenteric artery were used as landmarks. The size of the left adrenal gland was variable, but it generally appeared as a long, flat structure with a hyperechoic medulla surrounded by a hypoechoic cortex. The most cranial part of the gland could not be delineated appropriately in 11 horses (44%). The mean (+/-SD) thickness of the gland and medulla was 0.66 +/- 0.15cm (n = 25) and 0.28 +/- 0.09 cm (n = 25) near the caudal pole, 0.87 +/- 0.25 cm (n = 14) and 0.40 +/- 0.18 cm (n = 12) near the cranial pole, and 0.89 +/- 0.18 cm (n = 25) and 0.36 +/- 0.13 cm (n = 25) in the middle of the gland, respectively. The mean (+/-SD) length of the entire adrenal gland and of the medulla was 6.22 +/- 0.77 cm (n = 14) and 5.45 +/- 0.71 cm (n = 6), respectively. Transrectal ultrasonography allowed adequate visualization of the left adrenal gland in horses.

Computed tomography-guided brain biopsy for in vivo diagnosis of a cholesterinic granuloma in a horse.

CASE DESCRIPTION: An 8-year-old warmblood mare was evaluated following an acute onset of neurologic abnormalities. CLINICAL FINDINGS: Computed tomography of the head revealed large masses in both lateral ventricles, and a presumptive diagnosis of cholesterinic granuloma was made. TREATMENT AND OUTCOME: Freehand biopsy of the intracranial masses was performed under computed tomographic guidance, and histologic examination of biopsy specimens confirmed the diagnosis. No adverse effects associated with the brain biopsy procedure were encountered. Clinical signs resolved, and long-term follow-up did not reveal any recurrence of neurologic deficits. The horse was able to return to its previous level of training. CLINICAL RELEVANCE: Findings suggested that computed tomographic-guided brain biopsy is feasible in horses and can be used to establish a diagnosis in horses with intracranial masses.