FOI release

FOI2025/00363 - Insol equine sweet itch vaccine adverse events

Published 19 March 2026

Your request

Any recorded adverse reactions after off-label use (in sheep specifically) of Insol equine sweet itch vaccine.

Our reply

Insol Dermatophyton suspension for injection for horses, dogs and cats is not an authorised veterinary medicinal product (VMP) in the United Kingdom in any species.

Insol Dermatophyton is a product authorised outside of the UK for the active immunisation of horses, dogs and cats against dermatophytosis caused by Trichophyton verrucosum, Trichophyton mentagrophytes, Trichophyton sarkisovii, Trichophyton equinum, Microsporum canis and Nannizzia gypsea for the purpose of reducing the risk of a clinical infection due to these fungal species, and as a therapeutic measure for accelerating the healing of clinically visible skin changes in animals infected with dermatophytosis caused by these fungal species.

There are no adverse event reports for Insol Dermatophyton within our electronic adverse event reporting database where the product was administered to sheep.

Please be aware the data provided are not subject to independent verification and the VMD does not guarantee their accuracy. The figures are based on adverse events submitted to the VMD for the purposes of pharmacovigilance.   

We have included all adverse event reports. This includes: 

• where an adverse event has occurred that is already listed on the Summary of Product Characteristics
• where more than one product was used
• when the product was used off-label, that is using a medicine in a way that is not specified on the product’s label, including prescribing of unauthorised medicines following the prescribing cascade
• where, on further evaluation, there were other reasons for the adverse event occurring such as underlying illnesses or an alternative cause for the clinical signs seen.

Duplicate cases are combined, however if there is doubt as to whether two cases are true duplicates then both cases will be included. VMD databases change over time as new and follow-up information is constantly being received and reviewed. 

Evaluation is dependent on the accuracy and quality of data received from veterinary professionals and animal owners, and reporting frequency can vary over time (reporting frequency may be affected by a product being new to the market or social media interest, for example).  

Although adverse event report information can be useful to provide a general overview of a product, it is important for any clinical decisions regarding the use of a product to be based on a risk-benefit discussion specific to the animal or group of animals being administered the product. An overall frequency of an adverse event occurring for a product does not reflect the actual risk for an individual animal, as there are many individual factors that may contribute to the likelihood of an adverse event occurring.  

All medicines whether for human or animal use come with risk, and the benefits of use in wider populations need to outweigh the potential risks.

Information on adverse events that have been known to occur following administration of a particular authorised veterinary medicinal product are summarised in sections 3.6/4.6 of the Summary of Product Characteristics (SPC).  The SPC is a document describing the properties and the officially approved conditions of use of a medicine. The SPC and associated product information are updated as new information is available, and the latest version of an SPC can be found on our publicly available Product Information Database. We continually assess and update our findings relating to products used within the United Kingdom and should there be sufficient data to suggest that an SPC requires alteration or that another appropriate action is required, this will be carried out within the required timeframe, as set out by the current legislation surrounding that veterinary medicinal product or region.   

Pharmacovigilance updates are published on gov.uk at https://www.gov.uk/guidance/urgent-safety-updates-for-veterinary-medicines; this also includes any updates involving non-veterinary medicines used in animals. To receive these pharmacovigilance updates via email, please click on the ‘Get emails about this page’ button.