Tumors frequently found in dogs include canine oral tumors, either cancerous or noncancerous. The bloodstream is an important route for tumor metastasis, particularly for late-stage oral melanoma (LOM) and late-stage oral squamous cell carcinoma (LOSCC). The present study aimed to investigate serum peptidome-based biomarkers of dogs with early-stage oral melanoma, LOM, LOSCC, benign oral tumors, chronic periodontitis and healthy controls, using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and liquid chromatography tandem mass spectrometry. A principal component analysis plot showed distinct clusters among all groups. Four peptides were identified, including peptidyl-prolyl cis-trans isomerase FKBP4 isoform X2 (FKBP4), steroid hormone receptor ERR1 (ESRRA or ERRA), immunoglobulin superfamily member 10 (IGSF10) and ATP-binding cassette subfamily B member 5 (ABCB5). FKBP4, ESRRA and ABCB5 were found to be overexpressed in both LOM and LOSCC, whereas IGSF10 expression was markedly increased in LOSCC only. These four proteins also played a crucial role in numerous pathways of cancer metastasis and showed a strong relationship with chemotherapy drugs. In conclusion, this study showed rapid screening of canine oral tumors using serum and MALDI-TOF MS. In addition, potential serum peptidome-based biomarker candidates for LOM and LOSCC were identified.

BPH is the most prevalent prostatic condition in aging dogs. Nevertheless, clinical diagnosis and management remain inconsistent. This study employed in-solution digestion coupled with nano-liquid chromatography tandem mass spectrometry to assess serum proteome profiling of dogs with BPH and those dogs after castration. Male dogs were divided into two groups; control and BPH groups. In the BPH group, each dog was evaluated at two time points: Day 0 (BF subgroup) and Day 30 after castration (AT subgroup). In the BF subgroup, three proteins were significantly upregulated and associated with dihydrotestosterone: solute carrier family 5 member 5, tyrosine-protein kinase, and FRAT regulator of WNT signaling pathway 1. Additionally, the overexpression of polymeric immunoglobulin receptors in the BF subgroup hints at its potential as a novel protein linked to the BPH development process. Conversely, alpha-1-B glycoprotein (A1BG) displayed significant downregulation in the BF subgroup, suggesting A1BG’s potential as a predictive protein for canine BPH. Finasteride was associated with increased proteins in the AT subgroup, including apolipoprotein C-I, apolipoprotein E, apolipoprotein A-II, TAO kinase 1, DnaJ homolog subfamily C member 16, PH domain and leucine-rich repeat protein phosphatase 1, neuregulin 1, and pseudopodium enriched atypical kinase 1. In conclusion, this pilot study highlighted alterations in various serum proteins in canine BPH, reflecting different pathological changes occurring in this condition. These proteins could be a source of potential non-invasive biomarkers for diagnosing this disease.

Background: Chronic gingivostomatitis in cats (FCGS) is a moderately to severely painful condition, potentially caused by inadequate immune response to oral antigenic stimulation. Salivary peptidome analysis can identify inflammatory protein mediators and pathways involved in oral mucosal immune activation and may indicate potential therapeutic options for FCGS. Objective: Evaluate the diversity and abundance of salivary peptides in cats with FCGS using matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) and nanoscale liquid chromatography-tandem mass spectrometry (nano LC-MS/MS). Animals: Thirty-two cats with FCGS and 18 healthy controls. Methods: Case-control cross-sectional study. We compared the salivary peptide profiles of diseased and healthy cats. The diagnosis of FCGS was confirmed by histopathology. Saliva samples were analyzed for viral infections using polymerase chain reaction (PCR), peptide mass fingerprint (PMF) using MALDI-TOF MS, and peptide identification using nano LC-MS/MS. Results: Distinct clusters of peptide profiles were observed between groups. In FCGS, 26 salivary peptides were altered, including apolipoprotein A1, nuclear receptor subfamily 1 group I member 3, fibrinogen alpha chain, interleukin 2 receptor gamma, interleukin 23 receptor, hemoglobin subunit alpha, and serpin peptidase inhibitor clade A (alpha-1 antiproteinase, antitrypsin) member 12, protein-tyrosine-phosphatase, and cholinergic receptor nicotinic alpha 10 subunit. Protein-anti-inflammatory drug interaction networks were observed. Conclusions and Clinical Importance: Peptide mass fingerprint and peptide profiles identified distinct clusters between FCGS and healthy cats. The 9 novel salivary peptide markers were associated with the JAK/STAT and PI3K/Akt pathways and immune responses. These potentially noninvasive biomarkers may facilitate understanding of FCGS pathophysiology and guide future therapeutic research.

Cannabidiol (CBD), a non-psychotropic cannabinoid derived from Cannabis plants, is increasingly explored for its potential therapeutic applications in veterinary medicine. This study aimed to evaluate the impact of CBD oil on the minimum alveolar concentration of isoflurane (MAC_iso) in cats. Sixteen healthy cats underwent isoflurane anesthesia, and the MAC_iso was determined using the tail-clamping technique both at baseline and 30 min after the administration of CBD oil (2 mg/kg) via a stomach tube. CBD administration resulted in a significant 11% reduction in the MAC_iso, from 1.77 ± 0.14% to 1.62 ± 0.21% (p < 0.001). Following CBD administration, heart and respiratory rates were elevated at the time of MAC_iso determination compared to baseline whereas other physiological parameters remained unchanged. Serum biochemical analysis conducted two weeks post administration revealed a significant decrease in blood urea nitrogen (BUN) levels while one cat exhibited a mild increase in alanine aminotransferase (ALT). Proteomic analysis identified 12 CBD-associated proteins in feline serum 30 min post administration, with CBDA and THCA synthases demonstrating significant upregulation. These findings indicate that CBD oil reduces anesthetic requirements in cats without inducing significant physiological disturbances. Further research is warranted to elucidate the underlying mechanisms of CBD’s anesthetic-sparing effects and its implications in veterinary anesthesia.

Background: Oral melanoma (OM) and oral squamous cell carcinoma (OSCC) are frequently diagnosed in dogs, presenting a challenge in distinguishing them from benign oral tumors (BN). Salivary metabolomic biomarkers offer a practical solution because of saliva's direct contact with tumors and the noninvasive nature of collection. Objective: Assess the diversity and abundance of the salivary metabolome in dogs with BN, OM, and OSCC using amine/phenol submetabolome analysis and high-performance chemical isotope labeling liquid chromatography–mass spectrometry (CIL LC-MS). Animals: Study included 11 BN, 24 OM, 10 OSCC, and 20 healthy control dogs. Methods: Case-control cross-sectional study was conducted to assess salivary submetabolic profiles in dogs with BN, OM, and OSCC and healthy dogs. Samples were labeled with 12C-dansyl chloride and analyzed using CIL LC-MS targeted to amine- and phenol-containing metabolites for amine/phenol submetabolome analysis. Results: Distinct clusters and significant differences in metabolite concentrations were observed among the oral cancer, BN, and control groups. A total of 154 and 66 metabolites showed significantly altered concentrations, particularly in OM and OSCC, respectively, when compared with BN (Padj < .05). Potential metabolic biomarkers were identified for each cancer, including decreased concentrations of seryl-arginine and sarcosine in OSCC. Moreover, high-confidence putative metabolites were identified, including an increase in tryptophyl-threonine and a decrease in 1,2-dihydroxynapthalene-6-sulfonic acid and hydroxyprolyl-hydroxyproline for OM. Conclusions and Clinical Importance: We identified high coverage of the amine/phenol submetabolome, including seryl-arginine, and sarcosine, in OSCC. Our findings emphasize the potential of these biomarkers for distinguishing between oral OSCC and BN in dogs.

Background: Tilapia Lake virus (TiLV) poses a significant threat to global tilapia aquaculture, causing high mortality rates and severe economic losses. However, the molecular mechanisms underlying TiLV-host interactions remain largely unexplored. Methodology: We investigated the proteomic and phosphoproteomic changes in two piscine cell lines, E-11 and RHTiB cells, following TiLV inoculation at different time points. Differential protein expressions at 10-min and 24-h post infection were selected for constructing protein-protein interactions and analyzing enriched pathways related to the viral entry and replication. Results: Our findings revealed significant alterations in protein expression and phosphorylation states, highlighting distinct responses between the cell lines. In E-11 cells, TiLV infection suppressed proteins involved in the Janus kinase-signal transducer and activator of transcription and Fas-associated death domain protein-tumor necrosis factor receptor-associated factor pathways, leading to activation of nucleotide oligomerization domain signaling and apoptosis. In RHTiB cells, TiLV suppressed host cellular metabolism by reducing protein phosphatase activity to facilitate early viral entry, while later stages of infection showed increased activity of myosin heavy chain 9 and enhanced host immune responses via phosphorylation of ribosomal protein L17 and GTPase immunity-associated protein 7 (GIMAP7). Conclusion: Our study suggested that TiLV employs different strategies to manipulate host cellular pathways depending on the cell type. Further studies are essential to validate these findings and ultimately facilitate the development of effective antiviral strategies.