AHT have reported two separate confirmed cases of neurological EHV-1 infection in February in the UK. The cases do not appear to be epidemiologically related and have no obvious links to the high-profile outbreak that occurred in Hampshire in January.
The following reports are available from International Collating Centre (ICC) web resource:
On 7 January 2020, AHT confirmed a case of EHV-1 neurological disease on a premises in Hampshire. The affected horse was an unvaccinated Thoroughbred-cross mare that presented with pyrexia, lethargy, inappetence, lymphadenopathy, limb oedema and ataxia and was subsequently euthanased after becoming recumbent. The positive diagnosis was confirmed by PCR on a nasopharyngeal swab. Nasopharyngeal swabs taken from three mildly clinically affected (but non-neurological) contacts also tested positive for EHV-1 by PCR. The affected premises has voluntarily closed and disease control measures have been implemented under veterinary supervision.
On 24 February 2020, AHT reported a case of EHV-1 neurological disease on a private premises in Worcestershire. The affected horse is a 15-year-old that presented with ataxia and went on to develop urine retention. The case had a history of filled limbs two weeks prior to the onset of neurological signs. A blood sample taken around the time of onset of neurological signs was tested by complement fixation (CF) and found to be positive with a titre of 1/640. There are six direct in contacts and all have swabbed negative to EHV by PCR but one direct in contact has demonstrated a seroconversion to EHV on serological testing (CF). The other five in the group have so far demonstrated stable titres on blood samples taken 14 days apart. Clinical monitoring of these direct in contacts has not demonstrated any abnormalities, including no evidence of pyrexia. The premises is under voluntary movement restrictions. This outbreak is unrelated to the reported EHM outbreak in Hampshire, UK, in January 2020.
On 27 February 2020, AHT reported a case of EHV-1 neurological disease on a premises in East Sussex. The affected horse is a ten-year-old that presented with ataxia. The positive diagnosis was confirmed by PCR on a nasopharyngeal swab and a positive titre on a complement fixation test. There are five in contacts and these have been closely monitored and remain clinically normal to date. Voluntary movement restrictions are in place and clearance testing will be performed.
Members are reminded that the latest Defra/AHT/BEVA equine disease quarterly report, which includes a summary of the Hampshire EHV-1 neurological disease outbreak is available here.