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Further update: Genta-Equine 100 mg/ml Solution for Injection for Horses – Adverse events

Actions following the identification of the cause of an increase of adverse event reports following the use of Genta-Equine 100 mg/ml Solution for Injection for Horses.

As a result of the identification of elevated concentrations of histamine as the likely cause of adverse event reports relating to the use of Genta-Equine 100 mg/ml Solution for Injection for Horses, as detailed within our initial notification on 18 December 2024 and update notification on 14 March 2025, it has been agreed that the Marketing Authorisation Holder (MAH) will implement a maximum limit for histamine in the active substance used within the product. 

Due to the critical nature of Genta-Equine to equine veterinary surgeons in the UK, a recall has not been initiated in the UK and the MAH will be allowed to release one or more new batches of finished product which have been shown to contain levels of histamine below the maximum permissible limit. These will be released via the national Specific Batch Control scheme.

We would like to remind veterinary professionals that Dechra (UK distributor) has advised that where there are concerns around using the affected batches of Genta-Equine, treatment with an alternative appropriate antibiotic should be considered. They have also advised that a refund can be received for any unopened bottles.   

We will continue working with the MAH to monitor reports and ensure appropriate actions are carried out as required. 

Symptoms included in adverse event reports 

Reports received include signs of abdominal pain/colic, pawing, restlessness/agitation, groaning, shaking/shivering/fasciculation, Flehmen response, lying down or attempting to lie down, staggering, increased sweating and increased respiratory rate. 

Adverse event reports received may include reports where more than one product was used, the product was used off-label and/or where, on further evaluation, it is considered that there is no causal association between the product and event. 

Reporting of adverse events 

We strongly encourage anyone who is aware of an adverse event to report directly to the MAH. Please provide all relevant information, including the batch number. 

Contact details for the MAH or their local representative can found be on the product leaflet or on the Product Information Database.

The reporting of adverse events is critical to our ongoing monitoring activities in order to protect animal health, public health, and the environment. Find out more about pharmacovigilance at VMD Connect – Adverse Events and Pharmacovigilance.

Updates to this page

Published 27 June 2025