CD117 is a transmembrane tyrosine kinase growth factor receptor expressed by a variety of normal human cell types, including germ cells, immature myeloid cells, and mast cells. To evaluate the pattern of CD117 expression in dogs and cats, we applied a polyclonal antibody on paraffin sections from 44 samples of normal tissues and 104 tumors. In both species, strong immunoreactivity was observed in mast cells, interstitial cells of Cajal, and in mast cell tumors. Among gastrointestinal mesenchymal neoplasms, tissues from five dogs and one cat revealed strong CD117 expression, enabling us to identify them as gastrointestinal stromal tumors (GISTs).

Growing evidence indicates cannabinoid receptors as potential therapeutic targets for chronic pain. Consequently, there is an increasing interest in developing cannabinoid receptor agonists for treating human and veterinary pain. To better understand the actions of a drug, it is of paramount importance to know the cellular distribution of its specific receptor(s). The distribution of canonical and putative cannabinoid receptors in the peripheral and central nervous system of dogs is still in its infancy. In order to help fill this anatomical gap, the present ex vivo study has been designed to identify the cellular sites of cannabinoid and cannabinoid-related receptors in canine spinal ganglia. In particular, the cellular distribution of the cannabinoid receptors type 1 and 2 (CB₁ and CB₂) and putative cannabinoid receptors G protein-coupled receptor 55 (GPR55), nuclear peroxisome proliferator-activated receptor alpha (PPARα), and transient receptor potential vanilloid type 1 (TRPV1) have been immunohistochemically investigated in the C6–C8 cervical ganglia of dogs. About 50% of the neuronal population displayed weak to moderate CB₁ receptor and TRPV1 immunoreactivity, while all of them were CB₂-positive and nearly 40% also expressed GPR55 immunolabeling. Schwann cells, blood vessel smooth muscle cells, and pericyte-like cells all expressed CB₂ receptor immunoreactivity, endothelial cell being also PPARα-positive. All the satellite glial cells (SGCs) displayed bright GPR55 receptor immunoreactivity. In half of the study dogs, SGCs were also PPARα-positive, and limited to older dogs displayed TRPV1 immunoreactivity. The present study may represent a morphological substrate to consider in order to develop therapeutic strategies against chronic pain.

Aquaculture is the fastest-growing food-producing sector, with a global production of 122.6 million tonnes in 2020. Nonetheless, aquatic animal production can be hampered by the occurrence of viral diseases. Furthermore, intensive farming conditions and an increasing number of reared fish species have boosted the number of aquatic animals’ pathogens that researchers have to deal with, requiring the quick development of new detection and study methods for novel unknown pathogens. In this respect, the molecular tools have significantly contributed to investigating thoroughly the structural constituents of fish viruses and providing efficient detection methods. For instance, next-generation sequencing has been crucial in reassignment to the correct taxonomic family, the sturgeon nucleo-cytoplasmic large DNA viruses, a group of viruses historically known, but mistakenly considered as iridoviruses. Further methods such as in situ hybridisation allowed objectifying the role played by the pathogen in the determinism of disease, as the cyprinid herpesvirus 2, ostreid herpesvirus 1 and betanodaviruses. Often, a combination of molecular techniques is crucial to understanding the viral role, especially when the virus is detected in a new aquatic animal species. With this paper, the authors would critically revise the scientific literature, dealing with the molecular techniques employed hitherto to study the most relevant finfish and shellfish viral pathogens.

A spontaneous seminoma in a 3 yr old male koi carp Cyprinus carpio L. is described. The animal, presenting a symmetric abdominal enlargement, showed a celomatic multinodular, white-yellowish and firm mass that infiltrated the liver and the intestine wall. Histologically, the neoplasm was non-encapsulated and poorly demarcated, showed invasive growth and was characterized by a lobular architecture, subdivided by abundant fibro-connective septa. Large necrotic and calcified areas together with small aggregates of residual spermatids were present. We diagnosed a classical seminoma with a diffuse pattern. Neoplastic cells cross-reacted with vimentin, placental alkaline phosphatase, and c-KIT. An immunohistochemical phenotypization of the tumor was performed to exclude other celomatic neoplasms and to compare this seminoma with those reported in mammals and humans.