Search Results (44)

Background/Objectives: Human and canine leishmaniases are neglected diseases with limited therapeutic options. The nitrochalcone NAT22, a high-affinity inhibitor of the essential parasite enzyme tryparedoxin peroxidase (cTXNPx), has emerged as a promising antileishmanial candidate. Interestingly, NAT22 demonstrated superior efficacy when administered orally rather than intralesionally, suggesting a metabolism-driven activity enhancement. Since in vivo studies with chalcones have been conducted exclusively in mice, this study aimed to determine whether mice are suitable models for oral chalcone therapies for human and canine leishmaniases and to identify metabolites with potential antileishmanial activity. Methods: NAT22 hepatic metabolism was investigated using in silico prediction and in vitro liver microsomal assays from rats, mice, humans, and dogs. Metabolites were identified by LC-MS/MS and NMR, and docking studies were performed against cTXNPx. Results: In silico analysis predicted metabolism mainly by CYP1A2, CYP2A6, CYP2C8, and CYP3A4. Seven metabolites (M1–M7) were identified by LC-MS/MS and NMR in all species except mice, whose microsomes did not generate M6. Structural analyses indicated preservation of the α,β-enone system and nitro-substituted B ring in all metabolites. Docking studies showed that metabolites M2 and M4 displayed stronger predicted binding energies than NAT22. Conclusions: NAT22 undergoes hepatic phase I metabolism generating two metabolites with enhanced predicted interaction with cTXNPx. The similarity between human and canine metabolic profiles supports the translational relevance of oral NAT22 therapy in leishmaniasis, while metabolites M2 and M4 emerge as candidates for validation in local treatment of cutaneous leishmaniasis. Full article

(1) Background: Echinococcosis is a significant zoonotic disease that the World Health Organization (WHO) aims to eliminate by 2050. Current drug-based control faces challenges such as drug resistance, highlighting the urgent need to develop vaccines as a supplementary strategy. Although some progress has been made in the study of intermediate host vaccines using antigens such as Eg95, there is still no commercial vaccine available for the definitive host, canines—which are crucial for transmission—and it is not yet suitable for large-scale use. While vaccine studies targeting the key enzyme lactate dehydrogenase (LDH) in parasite energy metabolism remain scarce, they represent a promising area of potential. (2) Methods: The B cell antigen epitopes of LDH were analyzed, and prokaryotic (pET-28a-EgLDH) and eukaryotic (pVAX1-EgLDH) DNA vaccine expression vectors were constructed. After verifying expression and immunogenicity via qRT-PCR and WB, in vitro validation was performed in 293T cells. Mice were immunized with the vaccine and then challenged with the parasite; blood was collected from the orbital sinus, and IgG levels and cytokines were measured by ELISA. Protective effects were assessed through counting liver cysts and histopathological analysis. (3) Results: We constructed the pVAX1-EgLDH plasmid and immunized Kunming (KM) mice. Compared with the PBS control group, the vaccine group showed an 80.95% reduction in liver cysts (Quil-A group: 19.00%). Histopathological analysis indicated no significant liver damage, although the spleens in the vaccine group were smaller. ELISA results demonstrated an increase in total IgG (p < 0.05), and cytokine analysis showed elevated levels of IL-1 (p < 0.01), IL-4, and IL-10 (p < 0.001), whereas IL-5 and IFN-γ showed no significant changes (p > 0.05). (4) Conclusions: The EgLDH DNA vaccine can elicit a specific immune response and significantly reduce cyst burden, providing theoretical basis and data support for its use as a candidate vaccine for the prevention and control of Echinococcosis. Full article

A 14-year-old spayed female Jindo dog presented with a firm, non-painful right-sided cervical mass. Computed tomography identified three distinct, separate masses thought to be arising from the right thyroid lobe; the largest measured 66.6 mm × 42.0 mm × 37.6 mm with an estimated volume of 56 cm³ and showed invasion into the right internal jugular vein. Multiple hepatic nodules were detected without evidence of pulmonary metastasis and regional lymph node involvement. Right thyroidectomy with resection of the invaded vein and partial liver lobectomy were performed. The histologic results confirmed all three masses as follicular-compact thyroid carcinomas, and the hepatic lesion as metastatic thyroid carcinoma. The dog recovered uneventfully, remained euthyroid, and showed no local recurrence over a 5-month follow-up. In human medicine, multifocality is common in papillary thyroid carcinoma and is associated with a high rate of recurrence. This report documents the first canine case of multifocal thyroid carcinoma, featuring macroscopic vascular invasion and an uncommon metastatic pattern in which the liver was affected in the absence of detectable pulmonary lesion. The presence of multifocal disease within a single canine thyroid lobe necessitates comprehensive cross-sectional imaging, meticulous surgical planning with vascular considerations, and long-term monitoring to optimize the prognosis of this carcinoma. Full article

Gallbladder mucocele is a major cause of biliary disease in dogs, particularly affecting elderly and small-breed populations. Background: This study retrospectively evaluated 65 dogs that underwent cholecystectomy at a referral hospital in Seoul, Korea, (2022–2025) to characterize clinical features, bile culture results, antimicrobial susceptibility, and histopathologic findings. Methods: Signalment, ASA grade, preoperative laboratory data, bile culture and susceptibility results, and postoperative outcomes were reviewed. Results: Bile culture was positive in 21.3% (13/61) of cases, most frequently isolating Escherichia coli 38.5% (5/13) and Enterococcus spp. 30.8% (4/13). Approximately 18% of isolates were multidrug- or extensively drug-resistant, showing reduced susceptibility to β-lactams but retained sensitivity to imipenem and florfenicol. Preoperative increases in liver enzyme activities and C-reactive protein were common. Histopathology revealed gallbladder mucosal hyperplasia 90.4% (47/52) and inflammation 61.5% (35/52), often accompanied by hepatic inflammation or fibrosis. Toy Poodles were significantly over-represented (35.4%; OR = 3.1, p < 0.001). Antibiotic matching was not significantly associated with complications or the length of hospital stay (LOS). Conclusions: Although the bile-culture positivity rate was modest, the frequent detection of multidrug-resistant (MDR) and extensively drug-resistant (XDR) organisms highlights the clinical value of culture-guided antibiotic therapy. Routine bile culture with susceptibility testing, concurrent liver biopsy, and careful perioperative management may improve diagnostic accuracy and outcomes in canine gallbladder disease. Full article

Humans with chronic biliary tract disease (CBTD) have low serum liposoluble vitamins (A, D, E). Few studies have been performed in veterinary medicine to evaluate whether vitamins vary in canine CBTD. This study aimed to compare liposoluble vitamin between CBTD and healthy dogs. A total of 84 client-owned dogs with CBTD and 50 healthy dogs were included. CBTD diagnosis was based on clinical, blood biochemistry and abdominal ultrasound. Dogs with CBTD were divided into subgroups according to their cholestasis ultrasound severity. To measure vitamin concentrations, leftover serum samples were used. The 25-hydroxyvitamin D, α-tocopherol, and retinol, respectively, vitamin D, E, and A metabolites, were measured with HPLC. Both, 25-hydroxyvitamin D and α-tocopherol were significatively lower in CBTD than in healthy dogs. In contrast, retinol was higher in CBTD dogs. In CBTD dogs, no significant differences in vitamin concentrations considering ultrasound severity were found. Presence of biliary disease in dogs results in lower blood vitamins D and E, and higher vitamin A concentration. Lower vitamins D and E concentration could reflect a possible lipid malabsorption. The higher concentration of vitamin A could be in line with recent human studies, where retinol increases as an expression of dysregulated homeostasis during chronic liver disease. Full article

Canine hepatocellular carcinoma (HCC), the most common primary liver malignancy in dogs, shares many clinicopathological and molecular similarities with human HCC. However, its molecular characteristics remain insufficiently defined, and reliable diagnostic biomarkers are lacking. Elucidating dysregulated microRNAs (miRNAs) may aid in both disease characterization and comparative oncology research. Small RNA sequencing datasets from canine HCC were analyzed to identify significantly dysregulated miRNAs with high expression and biomarker potential. The top candidate was validated in clinical tissues, cell lines, patient’s plasma and plasma exosomes using RT-qPCR. Comparative analyses were conducted using human HCC datasets (TCGA and GEO), followed by target prediction and functional enrichment to identify conserved molecular pathways. Among the 59 differentially expressed miRNAs, cfa-miR-10a showed the highest average expression level and yet was significantly downregulated in canine HCC tissues. RT-qPCR confirmed reduced expression of cfa-miR-10a in canine HCC tissues, whereas plasma exosomes showed significant enrichment, demonstrating excellent diagnostic performance (AUC = 0.94). The mature sequence of cfa-miR-10a is highly conserved with hsa-miR-10a-5p. TCGA datasets confirmed downregulation of hsa-miR-10a-5p in HCC tissues, whereas a GEO dataset showed no significant change in serum exosome levels. Target prediction and functional annotation identified 59 overlapping genes, with the Proteoglycans in cancer pathways being conserved in both species, mediated by ACTG1, SDC1, FRS2, and WNT9B. Collectively, these findings demonstrate distinct intra-tumoral and exosomal expression pattern of miR-10a in canine HCC and support its potential as a non-invasive biomarker with translational relevance. Full article

Background: Water-soluble vitamin deficiencies are common in human chronic liver disease (CLD) due to impaired metabolic pathways. Vitamins B2 (riboflavin), B3 (niacin), and B5 (pantothenic acid) assume critical roles in hepatic and lipid metabolism and may exert hepatoprotective effects. In canine CLD, data beyond cobalamin are sparse, and no guidelines currently endorse B-vitamin supplementation. Methods: This case–control study analysed 66 stored serum samples from client-owned dogs with CLD and 50 from healthy blood-donor dogs. CLD diagnosis required persistent (>2 months) elevation of at least two liver enzymes (ALP, GGT, AST, ALT) and ultrasonographic evidence of CLD. Serum vitamin concentrations were quantified by LC-MS/MS (ng/mL). Results: Vitamin B2 was significantly lower in CLD dogs versus controls (median 48.4 vs. 85.5 ng/mL; p = 0.002). No significant difference was observed in B3 levels (p = 0.25). Vitamin B5 concentrations were significantly higher in the CLD group (median 176.5 vs. 116.1 ng/mL; p = 0.003). Conclusions: Reduced B2 may reflect impaired hepatic processing or absorption in canine CLD. The presence of normal or elevated B3 and B5 may relate to alternative metabolic pathways. This constitutes the first study assessing B2, B3, and B5 in canine CLD, underscoring riboflavin’s potential interest in CLD dogs. Full article

Although it is more than a century since it was first marketed, acetaminophen remains one of the most popular analgesic agents. In addition, acetaminophen has recently been applied to multimodal analgesia in combination with non-steroidal anti-inflammatory drugs, and its consumption significantly increased during the pandemic of coronavirus disease 2019 as well as diclofenac and ibuprofen. However, the detailed mode of analgesic action of acetaminophen is still unclear. In the present study, we comprehensively discuss conventional, recognized, and postulated mechanisms of analgesic acetaminophen and highlight the current mechanistic concepts while comparing with diclofenac and ibuprofen. Acetaminophen inhibits cyclooxygenase with selectivity for cyclooxygenase-2, which is higher than that of ibuprofen but lower than that of diclofenac. In contrast to diclofenac and ibuprofen, however, anti-inflammatory effects of acetaminophen depend on the extracellular conditions of inflamed tissues. Since the discovery of cyclooxygenase-3 in the canine brain, acetaminophen had been hypothesized to inhibit such a cyclooxygenase-1 variant selectively. However, this hypothesis was abandoned because cyclooxygenase-3 was revealed not to be physiologically and clinically relevant to humans. Recent studies suggest that acetaminophen is deacetylated to 4-aminophenol in the liver and after crossing the blood–brain barrier, it is metabolically converted into N-(4-hydroxyphenyl)arachidonoylamide. This metabolite exhibits bioactivities by targeting transient receptor potential vanilloid 1 channel, cannabinoid receptor 1, Cav3.2 calcium channel, anandamide, and cyclooxygenase, mediating acetaminophen analgesia. These targets may be partly associated with diclofenac and ibuprofen. The perspective of acetaminophen as a prodrug will be crucial for a future strategy to develop analgesics with higher tolerability and activity. Full article

Chronic liver diseases (CLDs) in dogs are progressive conditions that often lead to liver failure. Metabolic dysfunctions such as cholestasis, obesity, hyperlipidemia, and endocrine disorders play a key role in human liver diseases like MASLD (Metabolic Dysfunction Associated Steatotic Liver Disease) and MASH (Metabolic Dysfunction Associated Steatohepatitis), but their significance in canine CLDs is poorly understood. This study aims to evaluate the association between hepatic lipid accumulation and inflammation or fibrosis in canine CLDs and its potential association with metabolic dysfunctions. Sixteen client-owned dogs with CLDs were assessed for clinical data, histological features, and liver immunohistochemistry (IHC). Histological and IHC markers of inflammation (Iba-1, iNOS, NF-κB), fibrosis (CD206, α-SMA, Sirius Red), and lipid accumulation (adipophilin) were assessed to identify correlations with clinical conditions. The applied markers showed effectiveness in their use on canine liver tissue. Adipophilin-marked lipid accumulation correlated positively with inflammatory markers, indicating a link between steatosis and inflammation. Metabolic dysfunctions were linked to hepatic lipid accumulation and inflammation. These findings show a potential alignment of canine CLDs with human MASLD/MASH, where lipid-induced inflammation drives disease progression. IHC markers could effectively assess these processes, suggesting potential for guiding diagnostics and therapies, though further research is needed to clarify clinical associations. Full article

The concentrations of fecal and serum bile acids (BAs) are known to be altered in human patients with chronic liver diseases (CLDs), especially those with biliary tract involvement (BTD). Scarce literature is available regarding fecal BA modifications during canine CLDs. This study aimed to evaluate fecal BAs in canine CLDs according to different clinical and clinicopathological variables. Forty-six dogs were enrolled. Canine feces were analyzed by HPLC. Cholic Acid (CA), Chenodeoxycholic Acid (CDCA), Ursodeoxycholic Acid (UDCA), Deoxycholic Acid (DCA), and Lithocholic Acid (LCA) were measured, and primary BAs (CA + CDCA), secondary BAs (UDCA + DCA + LCA), and the primary/secondary (P/S) ratio were calculated. Primary BAs (p < 0.0001), CA (p = 0.0003), CDCA (p = 0.003), the P/S ratio (p = 0.002), and total BAs (p = 0.005) were significatively higher in BTD dogs (n = 18) compared to in non-BTD dogs (n = 28). Fecal secondary BAs did not statistically differ between BTD and non-BTD dogs. Gastrointestinal clinical signs (p = 0.028) and diarrhea (p = 0.03) were significantly more prevalent in BTD dogs compared to in non-BTD dogs, supporting the hypothesis of some pathological mechanisms assimilable to bile acid diarrhea (BAD). Our results could reflect imbalances of the fecal BA metabolism in dogs with CLDs. Further studies involving gut microbiome and metabolomic assessment are needed to better understand the possible clinical implications of BA metabolism disruption and their potential role in canine CLDs. Full article

Paraoxonase-1 (PON-1), a liver-synthesized enzyme, acts as a negative acute-phase reactant during systemic inflammation in dogs. Given the hepatic synthesis of this enzyme, the presence of liver diseases may influence PON-1, thus affecting its reliability as a biomarker for inflammatory/oxidative systemic diseases. The aim of this study is to investigate PON-1 activity variations among dogs suspected of liver injury or failure, evaluating the influence of hepatic diseases on PON-1 activity. A total of one-hundred-sixty dogs were retrospectively enrolled and categorized into three groups based on clinical presentation and laboratory results: control (C = 20), suspected liver injury (INJ = 114), and suspected liver failure (FAIL = 26). The INJ group was further divided into subgroups based on the severity of the alanine aminotransferase (ALT) increase. Both the INJ and FAIL groups were further divided based on serum macroscopic appearance. The PON-1 activity was quantified using a paraoxon-based method, which is already validated in dogs. No significant difference in PON-1 activity was observed between the C and INJ groups, despite a significant increase in the subgroups with moderate and severe elevations of ALT. The dogs with icteric serum exhibited decreased PON-1 activity, while lipemic serum was associated with an increased PON-1 activity. A significant reduction in PON-1 activity was noted in the FAIL group, compared to both C and INJ groups (p < 0.0001), regardless of serum appearance. Given the retrospective nature of this study, additional evaluations (e.g., histopathology, imaging) were not performed. The results obtained here suggest the importance of interpreting PON-1 activity cautiously in dogs with suspected liver disease. Full article

Human zoonotic visceral leishmaniasis (ZVL) and canine leishmaniasis (CanL) constitute a major public and veterinary health concern and are both caused by the infection with the protozoan parasite Leishmania infantum. One of the main target organs in CanL is the liver. This complex organ, composed of various highly specialized cell types, has garnered significant attention from the scientific community as a crucial player in innate immune functions. In the context of CanL, liver infection by parasites and the host immune response generated strongly influence the disease outcome. Thus, taking advantage of a co-culture system involving canine hepatocytes and L. infantum-infected autologous Kupffer cells (KCs), allowing cell-to-cell interaction, the current report aims to shed light on the hepatocyte-KCs immune interaction. The co-culture of infected KCs with hepatocytes revealed a vital role of these cells in the activation of a local immune response against L. infantum parasites. Although KCs alone can be immunologically silenced by L. infantum infection, the cell-to-cell interaction with hepatocytes in co-culture can lead to local immune activation. In co-culture it was observed gene expression increased the number of innate immune receptors, specifically cell membrane TLR2 and cytoplasmatic NOD1 along with high TNF-α generation. Altogether, these results suggest that the immune response generated in co-culture could induce the recruitment of other circulating cells to contain and contribute to the resolution of the infection in the liver. This work also enhances our understanding of the liver as a vital organ in innate immunity within the context of CanL. Full article

In both human and veterinary medicine, computed tomography (CT) volumetry provides a quantitative and accurate measure of liver volume. While CT volumetry is recognized as a useful method for assessing liver volume in dogs, a statistically significant reference interval for liver volume in dogs with no history of hepatic disease has not been reported. The purpose of the present study was to define a reference interval for liver volume with no history of hepatic disease using CT volumetry. Medical records from 2 June 2020 to 25 July 2022 were retrospectively reviewed, including 121 dogs that underwent abdominal CT scans and had no history of hepatic disease. Liver volumes were measured using CT volumetry and normalized by body weight. The median of normalized CT-based liver volume in 121 dogs was 22.2 cm³/kg. Based on these data, a weight-based reference interval lower limit of 11.1–15.5 (90% confidence interval [CI]) to an upper limit of 31.9–42.6 (90% CI) cm³/kg for CT-based liver volume was defined in dogs without hepatic disease. This study provides an accurate assessment of liver volume changes in dogs with various hepatic diseases. Full article

Alteration in the gut microbiome in human patients with chronic liver disease is a well-known pathophysiological mechanism. Therefore, it represents both a diagnostic and therapeutical target. Intestinal dysbiosis has also been identified in dogs with chronic liver disease, but clinical trials evaluating the effectiveness of synbiotic administration are lacking. Thirty-two dogs with chronic hepatobiliary disease were equally randomized into two groups: one treated with a synbiotic complex for 4–6 weeks (TG) and one untreated control group (CG). All dogs underwent clinical evaluation, complete anamnesis, bloodwork, abdominal ultrasound, fecal bile acids, and gut microbiome evaluation at T0–T1 (after 4–6 weeks). Treated dogs showed a significant reduction in ALT activity (p = 0.007) and clinical resolution of gastrointestinal signs (p = 0.026) compared to control dogs. The synbiotic treatment resulted in a lower increase in Enterobacteriaceae and Lachnospiraceae compared to the control group but did not affect the overall richness and number of bacterial species. No significant changes in fecal bile acids profile were detected with synbiotic administration. Further studies are needed to better evaluate the effectiveness of synbiotic administration in these patients and the metabolic pathways involved in determining the clinical and biochemical improvement. Full article

The assessment of liver size is usually performed using radiography in dogs. However, due to wide variations in patients’ sizes and body conformations, accurate diagnosis of hepatomegaly or microhepatia is difficult. Computed tomographic (CT) volumetry can quantitatively and accurately measure liver volume. However, a reliable method for the standardization or normalization of volume in dogs without hepatic disease using CT has not yet been established. The purpose of this study was to assess seven different anatomic measures for normalizing liver volume in dogs and determine the tentative range of liver volume in dogs without hepatic disease. We retrospectively searched medical records from 1 January 2017 through to 1 June 2020 and included dogs with abdominal computed tomography without hepatic disease. The liver volume, lengths of four vertebrae (T11, T12, L2, L3), diameter of the abdominal aorta, body weight, and body condition scores (BCSs) of the dogs were recorded. Forty-one client-owned dogs without evidence of hepatic disease were included. The CT-derived liver volume was 813.8 ± 326.5 cm³ (mean ± SD). Body weight was determined to be the most reliable single-variable method for normalizing liver volume, with a raw CT-derived liver-volume-to-body-weight ratio of 22.1 cm³/kg (95% CI: 12.9–31.3 cm³/kg) and regression prediction model of volume = 19 × BWkg + 97. However, a better normalizing factor would likely be provided by the fat-free mass if it can be accurately measured. Full article