Medicinal products in Europe are under the strict control of many organisations headed by the European Directorate for the Quality of Medicines and HealthCare (EDQM) in Strasbourg and its related General European Official Medicines Control Laboratories (OMCLs) Network (GEON). The EDQM works in cooperation with the European Medicines Agency (EMA) and the World Health Organisation (WHO). All of these institutions have one main goal – to protect public health in Europe and around the world. One of the more important effects of the harmonisation of pharmaceutical law in Europe was the introduction of the mutual recognition principle for the Official Control Authority Batch Release (OCABR)/Official Batch Protocol Review (OBPR) certificates in the European Union. The National Veterinary Research Institute (NVRI) in Poland is an example of an OMCL laboratory within the Veterinary Batch Release Network (VBRN) that issues the European certificates. The NVRI is actively involved in the batch release of immunological veterinary medicinal products (IVMPs), with approximately 1,800 certificates for IVMPs issued per year. It is also one of only four veterinary OMCLs that perform Post Marketing Surveillance (PMS) studies including approximately 47 IVMPs per year. All the results of the testing data are sent to the Chief Veterinary Officer, and also to the electronic Network platforms of the EDQM, which enables transparent information exchange.

The aim of the study was to present cases of botulism in animals found in Poland in 2019–2021. The analytical laboratory diagnosis and difficulties that occurred in the interpretation of the results are described. From 2019 to 2021, samples of serum, intestinal content, liver, spleen, kidney, faeces, wet feed, dry feed, ensilage, water and mixed samples of internal organs associated with 10 suspected animal botulism cases were sent to the National Veterinary Research Institute. Samples were analysed using a mouse bioassay and culture methods in combination with ntnh and bont gene detection. Among the ten putative botulism cases, only four (40%) were confirmed in the laboratory on the basis of the detection of botulinum toxin (BoNT) or the ntnh or bont genes. The remaining six (60%) were determined as probable despite observable characteristic clinical signs. The diagnosis of botulism in animals is a very difficult task, made so by the heterogeneity of Clostridium botulinum strains and possible loss of toxinogenicity during laboratory processing or the potential degradation of toxins. Laboratory diagnosis is a complex and problematic process which should utilise different prescribed methods for specific types of sample.