Medicine and Pharmacology

Abstract: The first detection of the Shamonda virus in Central Europe occurred in mid-June 2026. Direct detection of the virus in blood or cerebrospinal fluid from living horses has not yet been reliably achieved. Serological examinations could therefore be crucial for future diagnostics. This study aimed to determine whether clinically healthy horses develop antibodies against viruses of the simbu serogroup and at what point the first positive antibody titers can be detected. To this end, blood sera from eleven clinically healthy horses based in southern Germany were examined retrospectively at three different time points between June and September 2026. Serological testing was performed using the ID Screen® Schmallenberg virus Multi-species ELISA kit; Innovative Diagnostics, Grabels, France. The results showed that all horses were seronegative or doubtful (one horse) in June (time point 1) and seronegative in July 2026 (time point 2). All eleven horses tested positive for antibodies in August or September (time point 3). There was a significant increase in antibody titers between time point 1 and time point 3, as well as between time point 2 and time point 3. The study found that even clinically healthy horses had been exposed to the pathogen and developed antibodies. Therefore, a positive antibody titer is not necessarily associated with clinical disease.

Abstract: The objective was to compare the linear, spatial, and temporal variables of the Marcha Batida (MB) and Marcha Picada (MP) gaits, aiming to characterize and identify their differences. 135 ridden Mangalarga Marchador horses were evaluated. The following variables were measured: speed, length, frequency, and duration of strides; distribution of stride time in each type of support; time and position of the diagonal dissociation; type and distance of the lateral limb footprints. At the same speed (3.88 m/s), MB and MP presented the same frequency, duration, and length of strides. MB showed a predominance of diagonal supports, followed by thoracic tripedal, pelvic tripedal, lateral bipedal, quadrupedal and pelvic monopedal supports, while MP showed a predominance of lateral supports, followed by diagonal supports, thoracic and pelvic tripedal supports, and pelvic unipedal support. All MP animals showed dissociation starting with the thoracic limb and were more dissociated than the MB. Most MB horses showed overstepping, while in the MP, the predominance was of animals with overstepping and an average distance of 17.68 centimeters. It is concluded that MB and MP presented differences in the kinematic variables analyzed, and the values found showed divergence from the description of the current breed standard.

Abstract: Staphylococci are the major pathogens associated with bovine mastitis, and the antimicrobial resistance, biofilm formation, and virulence factors may promote infection persistence. Forty-two Staphylococcus spp. isolates ob-tained from the milk of cows with clinical and subclinical mastitis were analyzed from farms in the Almaty, Zhetysu, and Kyzylorda regions of the Republic of Kazakhstan. The isolates were identified using MALDI-TOF MS, after which their hemolytic and DNase activities, ability to form biofilms, and susceptibility to antimicrobial agents were determined. PCR was used to detect the presence of antibiotic resistance genes (blaZ, mecA, tetM, tetK, ermB, aac(6′)/aph(2″)), as well as genes associated with adhesion and biofilm formation (clfA, icaA, icaD, aap, fnbpA) and virulence (hla, hlb, sea, seb, tst). S. aureus was detected in 17 (40.5%) cases, and S. epidermidis in 12 (28.6%). Bio-film formation was detected in 22 (52.4%) isolates. Resistance to penicillin G and ampicillin was detected in 41 (97.6%) isolates, and the most common genetic determinants were clfA (73.8%), blaZ (47.6%), and mecA (35.7%). Overall, these findings show that resistance- and persistence-related traits are common among Staphylococcus spp. isolates associated with bovine mastitis.

Abstract:

Sepsis is characterized by a dysregulated host response to infection; this can lead to multiorgan dysfunction where liver and kidneys play a key role. This study evaluated whether long-term oral administration of A12C modulates hepatic and renal homeostasis under basal conditions and during polymicrobial sepsis. Forty-five male Sprague–Dawley rats were allocated to healthy control (SAN), healthy A12C-treated (STO), septic control (IC), or septic A12C-treated (IA) groups. A12C was administered in drinking water at 6×10⁸ CFU/mL for 30 days, and sepsis was induced by caecal ligation and puncture (CLP). Gene expression, protein abundance, antioxidant enzyme activities, and histopathological alterations were evaluated in liver and kidney. Under basal conditions, A12C reduced hepatic Tlr4 and Tgfb1 expression and TLR4, ICAM-1, and SOD2 protein abundance, whereas renal Tnf and Icam1 expression and SOD and GRd activities increased. During sepsis, A12C-treated rats showed lower hepatic expression of Tnf, Il6, Ccl2, Icam1, and Nos2, together with increased SOD1 protein abundance. In kidney, A12C reduced Tlr4, Il6 and Icam1 expression and increase CAT, GPx, and GRd activities. Reduced expression of several inflammatory and endothelial mediators was detected in both organs and a marked enhancement of renal antioxidant defences during sepsis. The present results support the potential of A12C to improve the host response to sepsis and limit sepsis-associated organ dysfunction, possibly through a preconditioning-like mechanism.

Abstract: Environmental contamination in veterinary healthcare facilities may contribute to the persistence and potential dissemination of multidrug-resistant (MDR) bacteria, thereby creating challenges for infection control and clinical management. A structured litera-ture search was conducted in PubMed, Scopus, and Google Scholar for studies published between 2010 and 2025 that investigated the bacterial contamination of small-animal veterinary environments, equipment, and/or veterinary personnel. A total of 96 studies met the inclusion criteria. Swabbing was the predominant sampling method, used ex-clusively in 56 studies (58.3%). Resistance-targeted selective and/or chromogenic culture media were used in 41 studies (42.7%). Among the clinical areas, intensive care units showed the highest proportion of studies reporting MDR bacteria (13/20, 65.0%). Re-garding individual sampling sites, MDR bacteria were reported in 27 of 44 studies sam-pling cages (61.4%). High proportions of MDR detection were also reported for scales (8/11, 72.7%), ultrasound equipment (10/15, 66.7%), sinks (13/21, 61.9%), and computer keyboards (19/32, 59.4%). Staphylococcus was the predominant reported genus (58 studies, 60.4%), while MDR S. pseudintermedius and S. aureus were reported in 27 (28.1%) and 25 (26.0%) studies, respectively. Among resistance determinants, mecA was the most fre-quently reported gene. These findings highlight the widespread detection of MDR bac-teria across veterinary clinical environments and support the need for systematic envi-ronmental surveillance and strengthened infection prevention measures.

Abstract: Bovine mastitis caused by Escherichia coli and Staphylococcus aureus remains a major driver of antimicrobial use in dairy herds, and the evaluation of plant extracts as possible complementary agents is hampered by poorly standardised extraction protocols that make published results difficult to compare. This preliminary in vitro study examined whether maceration time, a process variable rarely controlled in studies of Taraxacum officinale, modifies the antibacterial activity of ethanolic extracts against clinical mastitis isolates. Leaves and flowers were macerated in 96% ethanol for 1, 2, 4 and 6 days under otherwise constant conditions, and the extracts were screened by disc diffusion against one E. coli and one S. aureus isolate in a randomised complete block design (nine treatments, six replicate discs each, n = 54). Net inhibition diameter differed markedly among treatments (F = 262.43; p < 0.0001), and maceration time, microorganism and their interaction were significant in the block-adjusted factorial model (p < 0.0001). Extracts macerated for 1 to 4 days produced net zones of 1.33 to 5.67 mm, whereas the six-day extract produced 20.50 mm against E. coli and 9.50 mm against S. aureus. Because all extracts shared the same solvent, volume and application procedure, the time-dependent increase indicates that the activity of the six-day extract cannot be explained by the ethanol vehicle alone. GC–MS tentatively assigned 21 constituents in the six-day extract, dominated by linolenic acid (37.46%), linoleic acid (10.61%), palmitic acid (9.26%) and ethyl palmitate (8.94%). The novelty of the work lies in showing, within a single constant protocol, that extraction time alone can shift a dandelion extract from negligible to substantial in vitro activity, which identifies maceration time as an uncontrolled source of heterogeneity among published studies. These results establish the six-day macerate as the priority extract for quantitative evaluation by broth microdilution, bioguided fractionation and chemical comparison across maceration times.

Abstract: Feline infectious peritonitis (FIP) remains diagnostically challenging, and rapid antemortem confirmation is increasingly important in the era of effective antiviral therapy. This pilot diagnostic accuracy study assessed agreement between effusion RT-qPCR and cell tube block immunohistochemistry (CTB-IHC) in 40 cats with suspected FIP and developed an exploratory effusion-based predictive score using CTB-IHC as the reference standard. RT-qPCR and CTB-IHC showed almost perfect agreement (κ = 0.86): 30 cats were positive by both methods, eight were negative by both, and two were CTB-IHC-positive/RT-qPCR-negative. RT-qPCR showed 93.8% sensitivity (95% CI: 79.2–99.2%), 100% specificity (63.1–100%), and 95.0% accuracy (83.1–99.4%). The three-parameter FIP Predictive Score, combining globulin concentration, FIP Effusion Index, and A:G ratio, achieved an apparent AUC of 0.916 (95% CI: 0.842–0.990), with 78.1% sensitivity (60.0–90.7%) and 100% specificity (63.1–100%) at ≥ 2 points. Given that the score was derived and evaluated within the same small cohort, independent external validation is essential before clinical implementation. Nevertheless, neither a low score nor a negative molecular result should independently close investigation when FIP remains clinically suspected. These findings provide a foundation for a structured, multimodal effusion-based diagnostic approach integrating molecular, antigen, biochemical, and cytometric evidence.

Abstract: Shamonda virus (SHAV), which has recently emerged in Central Europe, was detected in brain tissue from two horses that showed clinical signs including neurological disorder and underwent pathological examination. The horses reportedly exhibited seizure-like episodes (Horse A) as well as fever and ataxia (Horse B). In both horses, severe lymphohistiocytic meningoencephalitis with hemorrhages were observed in various parts of the central nervous system (CNS), while outside the CNS no abnormalities were found. The virus genome could be detected by RT-qPCR in all examined parts of the CNS of both horses. In a postmortem cerebrospinal fluid sample of one horse, the virus could only be detected with a very low genome load; however, postmortem contamination cannot be completely ruled out. Consistent with the histological findings, no SHAV genome was detected in either the blood or organs outside the CNS. Postmortem, CNS material - especially brainstem tissue – is suitable for detection of histological lesions and virus genome via PT-qPCR, while intra vitam diagnostics of a SHAV infection in horses exhibiting neurological signs is at the moment only possible to a very limited extent.

Abstract: Feline infectious peritonitis (FIP) can be overlooked in older cats with competing causes of effusion. An older female domestic shorthair cat with hyperthyroidism and a hypertrophic cardiomyopathy phenotype developed abdominal effusion in December 2023. Initial effusion total protein was 5.46 g/dL, the albumin-to-globulin ratio was 0.48 and delta total nucleated cell count ratio (ΔTNC) was 60.58, yielding an FIP Effusion Index of 126.2. Coronavirus RT-PCR detected FCoV RNA, with M1058L mutation positivity, and cell tube block immunohistochemistry (CTB-IHC) demonstrated viral antigen within macrophages. A second effusion sample collected 9 days after the first had ΔTNC of 2.15 and a FIP Effusion Index of 7.17, despite higher total protein and a lower albumin-to-globulin ratio. GS-441524 treatment began on 20 December 2023 and ended on 22 March 2024. Abdominal fluid was no longer detected at the assessment on 25 January. No confirmed FIP relapse was documented before death during cardiopulmonary decompensation in January 2026. This case illustrates complementary contributions of the FIP Effusion Index and CTB-IHC, with an exploratory observation of serial FIP Effusion Index change. Threshold comparison is retrospective, and the serial measurements do not establish a validated marker of treatment response.

Abstract: Yellow fever virus (YFV) causes a systemic, frequently fatal infection in susceptible nonhuman primates (NHPs), which serve as important hosts and sentinels of viral circulation. However, susceptibility and pathological outcomes differ markedly between New World and Old World species. This narrative review comparatively examines the hepatic and extrahepatic histopathological spectrum of lesions associated with YFV infection in NHPs and explores their implications for pathogenesis, surveillance, conservation, and outbreak preparedness. The liver is the principal target organ, with characteristic findings including midzonal hepatocellular necrosis, Councilman bodies, microvesicular steatosis, sinusoidal congestion, hemorrhage, and relatively limited inflammatory infiltration. Extrahepatic lesions commonly involve the spleen, lymph nodes, kidneys, lungs, heart, and central nervous system, reflecting the systemic nature of severe infection. Highly susceptible Neotropical primates, particularly Alouatta spp., generally develop high viral burdens, extensive multiorgan damage, and high mortality. In contrast, many African Old World primates experience subclinical or milder infections with more limited tissue injury, possibly reflecting long-term host–virus coevolution and enhanced mechanisms of viral tolerance or control. Histopathology remains essential for investigating primate epizootics, although diagnostic accuracy improves with integration of immunohistochemistry, reverse-transcription polymerase chain reaction, in situ hybridization, and genomic methods. Standardized protocols for necropsy, sampling, lesion scoring, and reporting are needed to improve interspecies and interregional comparisons. Comparative primate pathology can strengthen early-warning surveillance, guide human vaccination strategies, support wildlife conservation, and advance integrated One Health preparedness.

Abstract: The dissemination of antibiotic resistance genes (ARGs) via conjugative plasmids is a major driver of the antimicrobial resistance crisis. The optrA gene, which confers cross-resistance to linezolid and florfenicol, is frequently detected in Enterococcus isolates and disseminated via plasmids. This study investigated the inhibitory effect of carvacrol on horizontal transfer of an optrA-carrying plasmid in porcine Enterococcus faecalis. In vitro conjugation assays showed that subinhibitory carvacrol (1/32 MIC, 16 µg/mL) significantly reduced conjugation efficiency in a dose- and time-dependent manner. In vivo (mouse model) treatment with 32 μg/mL carvacrol decreased transconjugant recovery by 62.8%. Mechanistically, carvacrol disrupted membrane integrity, depleted intracellular ATP, sup-pressed ROS production, reduced biofilm formation, and downregulated conjugation-associated genes (type VI secretion protein, conjugal transfer protein, prgB, asa1) as shown by transcriptomics and RT-qPCR. Collectively, carvacrol inhibits optrA plasmid transfer via multi-target mechanisms involving membrane damage, energy metabolism interference, and suppression of conjugation gene expression. This study highlights carvacrol as a natural agent to control the transfer of ARGs.

Abstract: Raccoon dog and fox amdoparvovirus (RFAV), classified as Amdoparvovirus carnivoran3, was recently identified in domestic dogs, though its clinical significance remains unclear. This study describes RFAV detection in a 4-year-old female Doberman Pinscher with multisystemic disease, including progressive weight loss, poor coat condition, ocular lesions, hyperkeratosis of the nasal planum and footpads, and marked icterus. Clinical progression and laboratory parameters were monitored during hospitalisation, followed by postmortem pathological assessment. Antemortem and postmortem specimens were tested for amdoparvovirus DNA. PCR products were sequenced and subjected to phylogenetic analysis. Amdoparvovirus DNA was detected in nasal, conjunctival, and rectal swabs, whole blood, urine, and multiple postmortem tissues. Sequencing confirmed the virus as Amdoparvovirus carnivoran3, with the Croatian sequence closely related to a strain recently reported in clinically affected Doberman Pinschers in Serbia. Additionally, 60 archived canine rectal swab samples collected earlier in 2026 were screened for amdoparvoviruses. All retrospectively screened samples tested negative. This study documents the first detection of an amdoparvovirus in Croatia and provides new clinical and histopathological data on RFAV in domestic dogs.

Abstract: Bovine mastitis remains one of the most economically significant and biologically complex diseases in dairy production, with major implications for animal welfare, antimicrobial use, milk quality and food safety. Conventional diagnostic approaches, including somatic cell count and microbiological culture, are widely used but present limitations in sensitivity, specificity and timeliness, particularly for subclinical infections. In this context, acute phase proteins (APPs) have emerged as promising host-response biomarkers that provide a direct and biologically relevant measure of mammary inflammation. This review critically evaluates the role of key APPs, along with emerging markers such as cathelicidins, lactoferrin and lipopolysaccharide-binding proteins, in identifying and monitoring bovine mastitis. Evidence indicates that APPs, particularly when measured in milk, offer superior sensitivity for early and subclinical disease compared to somatic cell count and can provide additional insights into disease severity, pathogen class, and local immune responses. Importantly, the review extends beyond diagnostics to examine the underexplored relationship between mastitis-associated inflammation, antimicrobial pharmacokinetics and the risk of drug residues in milk. Inflammatory disruption of the blood–milk barrier, altered transporter activity and changes in milk composition can significantly influence drug distribution and persistence, potentially leading to regulatory exceedances. Future perspectives highlight the integration of APPs into multi-marker diagnostic platforms, biosensor technologies, precision dairy systems and “One Health” frameworks.

Abstract: Tick-borne diseases represent a challenge to both human and animal health, but the strength of the available evidence varies among Ehrlichia species. This critical narrative review analyzed the diversity, geographic distribution, vectors, hosts, zoonotic potential, diagnosis, and surveillance of ehrlichioses. The synthesis distinguished among seroreactivity, molecular detection, isolation, clinical association, vector competence, and reservoir competence. Ehrlichia chaffeensis, E. ewingii, and E. muris subsp. eauclairensis are established human pathogens. Ehrlichia canis causes a widely distributed veterinary disease and has been molecularly confirmed in human infections; however, its frequency and population-level relevance remain uncertain. For E. minasensis, E. japonica, and provisional taxa, detection in animals or ticks alone is insufficient to demonstrate zoonotic transmission. In Latin America, particularly in Brazil, evidence of human infection remains limited, is often based on serology, and contrasts with negative molecular investigations. The absence of a specific nationwide mandatory notification system, low clinical suspicion, and limited access to PCR contribute to underdiagnosis and underreporting. Integrated surveillance is therefore recommended, based on the early collection of human samples, investigation of animals and ticks linked to exposure, molecular characterization, and joint spatial and environmental analysis.

Abstract: Canine hip osteoarthritis (OA) is a common musculoskeletal disorder requiring mul-tidimensional assessment. This randomized, double-blind, placebo-controlled trial evaluated 4-week treatment with meloxicam, two marine-based fatty acid com-pounds, combination treatment, or placebo in 203 client-owned dogs with naturally occurring hip OA. The principal outcome was peak vertical force (PVF) of the index hindlimb measured by force-plate gait analysis. Secondary outcomes included PVF responder status, orthopedic assessment score (OAS), Liverpool Osteoarthritis in Dogs (LOAD), Canine Brief Pain Inventory (CBPI), adverse events, and laboratory safety variables. Baseline-adjusted mean PVF did not differ significantly among treatment groups, although within-group PVF increased in the meloxicam group be-tween weeks 2 and 4. Using a predefined >5% of body weight PVF responder thresh-old, meloxicam-treated dogs were more likely than placebo-treated dogs to respond at week 4 (relative risk = 4.000; 95% confidence interval, 1.223 to 13.079; p = 0.022). Combination treatment was associated with improvements in LOAD and CBPI pain interference, PCSO-524 showed within-group improvement mainly in LOAD score, and EAB-277 showed within-group improvement in CBPI pain interference. OAS did not change significantly, and no consistent group-level laboratory safety concern was detected. These findings support multidimensional assessment of short-term treat-ment response in canine hip OA.

Abstract:

Background: The inflammation of the mammary gland, known as bovine mastitis, is a major challenge for the dairy cattle industry globally. The main organisms responsible for mastitis are bacteria, classified as either contagious, such as Staphylococcus aureus, Streptococcus dysgalactiae, and Streptococcus agalactiae; or environmental, primarily Streptococcus spp. (e.g. Streptococcus uberis) and coliform species. Even though the emergence of antibiotic-resistant strains of pathogens poses a serious threat, antibiotics are still the primary treatment for mastitis. It is therefore necessary to explore alternative therapies, such as essential oils (EOs). This in vitro research intended to evaluate the efficacy of EOs against etiological agents of bovine mastitis, as an alternative or complementary treatment to conventional antibiotics. Methods: The bactericidal activity of eleven essential oils and two blends was tested on five strains causing bovine mastitis: Str. agalactiae, Str. dysgalactiae, Str. uberis, Sta. aureus, and Staphylococcus epidermidis. An assessment was carried out of both the reduction of biofilm formation and the inhibition of pre-formed biofilm against biofilm-formative strains of Sta. aureus and Sta. epidermitis. Results: Origanum vulgare and Cinnamomum zeylanicum resulted to be the EOs with the highest activity against the above-mentioned bacteria, inhibiting both bacterial growth and biofilm formation. Conclusions: This study emphasises the relevance of investigating natural products and supports the hypothesis of safe use of EOs to reduce bacterial infections and provide an effective alternative to antibiotics in complementary therapy. Moreover, to avoid treatment failure, the combined use of available antibiotics and natural compounds should also be considered.

Abstract: Reliable molecular detection of foot-and-mouth disease virus (FMDV) depends on RT-qPCR performance and pre-analytical factors, including sample matrix, RNA extraction method, carrier RNA supplementation, and storage conditions. This study compared silica membrane- and magnetic bead-based RNA extraction for detection of FMDV serotypes O, A, and SAT2 in serum, swab suspensions, and tissue homogenates at three virus dilutions, with and without carrier RNA. FMDV RNA stability in serum stored at room temperature or −20 °C for up to 60 days and following five freeze–thaw cycles was also evaluated using serotype O. Extraction performance was matrix-dependent. In serum, silica-based extraction yielded significantly lower Ct values than magnetic bead-based extraction. In tissue homogenates, magnetic bead extraction performed better with carrier RNA, whereas carrier RNA impaired silica-based extraction. No significant differences were observed for swabs. FMDV RNA detectability remained stable at −20 °C for 60 days, whereas room-temperature storage caused progressive signal loss, which was reduced by carrier RNA. Five freeze–thaw cycles did not progressively affect RNA detectability. These findings demonstrate that FMDV RNA detectability depends on interactions between extraction method, sample matrix, and carrier RNA, highlighting the importance of matrix-specific extraction optimization and appropriate frozen storage for reliable RT-qPCR diagnosis.

Abstract: Image-guided surgery has become an integral component of modern veterinary surgery using advanced imaging modalities, as computed tomography, magnetic resonance imaging, ultrasonography, and fluoroscopy. Recently, extended reality (XR) technologies have emerged as promising tools to enhance image-guided surgical procedures by improving three-dimensional anatomical understanding, surgical navigation, and intraoperative decision-making. Although XR has gained considerable attention in human surgery, its application in veterinary surgery remains at an early stage. This narrative review aimed to provide a comprehensive overview of the current evidence regarding XR technologies in small animal surgery, with particular emphasis on their integration with preoperative and intraoperative imaging modalities. The available literature was reviewed to evaluate current clinical applications, technological developments and future perspectives. Although several studies have explored the use of XR technologies for veterinary education, anatomical training, and diagnostic imaging instruction, relatively few investigations have assessed their direct application in clinical surgical practice. Potential applications have been described in orthopedic, oncologic, neurologic, cardiovascular, and minimally invasive procedures. Current evidence suggests that XR has considerable potential to improve image-guided veterinary surgery by enhancing surgical planning, anatomical understanding, and procedural guidance. Further prospective clinical studies are required to establish its clinical effectiveness, cost-effectiveness, and impact on surgical outcomes.

Abstract:

Continuous renal replacement therapy (CRRT) can precipitate anemia in critically ill patients, but temporal hematologic trends and anemia management strategies in cats remain poorly characterized. Medical records of three client-owned cats treated with CRRT for severe acute kidney injury with evidence of pre-existing chronic kidney disease at a single referral center were retrospectively reviewed. Hematologic variables (hematocrit, hemoglobin concentration, absolute reticulocyte count) and renal parameters (blood urea nitrogen, creatinine, phosphorus) were evaluated before, during, and after CRRT, along with the timing of CRRT sessions, whole blood transfusions, erythropoiesis-stimulating agent administration, and adjunctive molidustat use. All three cats demonstrated a progressive decline in hematocrit during the CRRT period despite repeated whole blood transfusions, with only transient post-transfusion improvement. Blood urea nitrogen and creatinine concentrations decreased promptly following CRRT initiation but showed variable rebound patterns during follow-up. Absolute reticulocyte counts increased after CRRT discontinuation in two cats, indicating preserved or recovering erythropoietic activity, while one cat with concurrent systemic inflammation showed a minimal response. Progressive anemia occurred consistently despite transfusion support, highlighting the multifactorial nature of anemia during feline CRRT. These descriptive findings provide clinically relevant insight into anemia progression during feline CRRT and may inform the design of future prospective studies.

Abstract: Canine urothelial carcinoma (UC) is commonly managed with NSAIDs alone or in combination with cytotoxic chemotherapy. Clinical evidence for subcutaneous KLH-based immunotherapy in canine UC is lacking. We describe two client-owned dogs with clinically diagnosed lower urinary tract UC managed with NSAIDs, Immucothel®, and selenium supplementation after their owners declined cytotoxic chemotherapy. Case 1 was an 11-year-7-month-old castrated male Maltese with a bladder-neck/proximal-urethral lesion. A presumptive diagnosis was based on a positive veterinary bladder tumor antigen test, cytologic urothelial proliferation with dysplasia, compatible serial imaging, and exclusion of metastatic disease; CADET® BRAF and BRAF-PLUS assays were negative. Piroxicam (0.3 mg/kg PO q24h) was administered from 22 February 2023 through December 2024. The dog received Immucothel® (1 mg SC near the right inguinal lymph node) with intravenous selenium (200 µg/kg diluted 1:1 in saline over approximately 40 min), followed by oral selenium. Serial CT and ultrasonography during follow-up showed persistent localized mural thickening without detectable regional or distant metastasis. Case 2 was an 11-year-old neutered male Poodle with a BRAF V595E-positive urethrovesical-junction lesion managed with firocoxib and the same multimodal protocol. Serial ultrasonographic measurements fluctuated during approximately two years of follow-up, including during changes in NSAID administration and booster interval, without documented metastatic progression. No treatment-associated adverse event required permanent discontinuation in either dog. Because both dogs received concurrent therapies, response assessment was not standardized, histopathologic confirmation was unavailable, and no comparator was included, the contribution of KLH-based immunotherapy cannot be determined. These cases should be interpreted as descriptive clinical observations rather than evidence of efficacy.