Botulinum neurotoxins (BoNTs) are emerging as multipurpose therapeutic compounds for the treatment of several different syndromes involving peripheral and central nervous systems, and muscular and musculoskeletal disorders both in human and veterinary medicine. Therefore, the studies of BoNTs are rapidly developing and identifying newly produced BoNT variants. Efforts should be made to clarify the biological and pharmacological characteristics of these novel BoNTs as well as the natural ones. The high potential of BoNTs as a therapeutic compound for medical syndromes lies on its ability to reach a specific cell type bypassing other cells, thus having mild or no side effects. In this paper the recent developments on BoNTs are reviewed with the aim to analyze the current knowledge on BoNTs biological mechanisms of action, immunogenicity, formulations, and therapeutic applications in the veterinary field, highlighting advantages and drawbacks and identifying the gaps to be filled in order to address research priorities.

Diffuse large B-cell lymphoma (DLBCL) is the most common haematological malignancy in humans and dogs. Several studies disclosed some similarities between the two species, including the constitutive activation of NF- κB pathway as a fundamental underlying pathogenetic mecha-nism. In humans, downregulation of IL-1R8 is implicated in DLBCL development, but its role in dogs has not been explored so far. To gain insight into the pathogenesis of this tumor in dogs, we evaluated the mRNA and protein expression of IL-1R8 in 12 hyperplastic lymph nodes ob-tained from dogs not bearing tumors and from 50 dogs with DLBCL. Moreover, we analysed through qRT-PCR the expression of TLR7, TLR9, MYC, and p52 genes that are known to be in-volved in the IL-1R8 regulatory network. IL-1R8 and p52 were downregulated in DLBCLs com-pared to control lymph nodes (p<0.001), while a higher expression of TLR7, TLR9 and MYC was observed in tumors (p<0.01). Immunohistochemistry confirmed gene expression results, reveal-ing a significantly lower IL-1R8 staining score in DLBCLs compared to control lymph nodes (p<0.0001). Taken together, these results suggest that IL-1R8 downregulation may represent one of the mechanisms driving DLBCL pathogenesis in dogs, mainly through dysregulation of the Toll-like/Interleukin receptors signalling cascade and the aberrant activation of classical NF-κB pathway.