Medicine and Pharmacology

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.

Abstract: Background: Haemonchus spp. is one of the most pathogenic nematodes in sheep production due to the health and economic losses it causes. Aim: This study determined the prevalence and associated risk factors in sheep from the Guanujo parish, Ecuador. Methods: A quantitative, descriptive, cross-sectional study was conducted between November 2025 and March 2026. Seventy fecal samples were collected individually from sheep via rectal sampling. These samples were then analyzed using coproparasitological techniques, and the modified McMaster method was applied to quantify eggs per gram (EPG). Results: Thirty-eight animals tested positive for the pathogen, representing a prevalence of 54.3% (95% CI: 42.6–65.5%). Parasite counts ranged from 200 to 3500 EPG, with an average of 1150 EPG. Mild infestation was observed in 42% of the animals, moderate infestation in 34%, and severe infestation in 24%. Infection was higher in young animals, lactating ewes, those in poor body condition, and those raised in extensive systems with irregular deworming. A significant association was identified with age, physiological state, deworming frequency, animal density, and production system (p<0.05). Conclusion: These findings confirm that Haemonchus represents a significant production and health challenge in local sheep farming systems, suggesting the need for integrated parasite control strategies.

Abstract: This study evaluated the performance of the Mindray BC-60 R differential WBC count (AD) in comparison with manual method (MD) in rabbits. Diagnostic blood samples were analyzed within 1 h of collection, and MD was performed by counting 100 leukocytes. Leukocyte scatterplots were visually inspected and samples showing overlapping cell populations or the presence of abnormal cell clusters were removed. After their exclusion, the Spearman’s rank correlation between AD and MD was excellent for heterophils (r=0.93, p<0.0001), lymphocytes (r=0.92, p<0.0001), moderate for monocytes (r=0.74, p<0.0001) and basophils (r=0.72, p<0.0001), but not significant for eosinophils, due to insufficient spread of values. Passing–Bablok regression revealed no statistically significant constant or proportional bias for heterophils, lymphocytes, or monocytes, whereas basophils showed both. The Bland–Altman analysis showed a significant underestimation of heterophils and overestimation of lymphocytes and basophils, while monocyte and eosinophil biases were not significant. Abnormal scattergram patterns were indicative of morphologically abnormal leukocytes. The Mindray BC-60R analyzer showed good-to-excellent overall accuracy for leukocyte differentiation in rabbits, except in cases with severe toxic changes in heterophils or blasts. Evaluation of blood smear in rabbits is required to identify the atypical cell population on scatterplot.

Abstract: Alzheimer’s disease (AD) in humans shares several features with canine cognitive dysfunction (CCD), a disease that affects older dogs. Therefore, CCD serves as a natural model for the study of AD. Several studies have documented early pathological changes in both AD and CCD, including widespread damage to the cerebral cortex and hippocampus, with this pathology attributed to the deposition of neurotoxic proteins such as beta-amyloid. Magnetic resonance imaging (MRI) is currently the only advanced imaging modality routinely used to support the diagnosis and prognosis of CCD. However, it is not commonly applied for the diagnosis or longitudinal monitoring of aging dogs with cognitive dysfunction. MRI can detect brain atrophy, hippocampal atrophy, ventricular enlargement, widening of the cerebral sulci, lesions in the temporal lobes of the cerebral cortex, and progressive thinning of the interthalamic adhesion in dogs undergoing natural or pathological aging. Accordingly, this imaging modality may serve as a valuable diagnostic marker for CCD in both early and advanced stages.

Abstract: Raccoon dog and fox amdoparvovirus (RFAV) has been reported in raccoon dogs and foxes, but natural infection in domestic dogs has not previously been documented. During March-April 2026, samples from affected Dobermann dogs from a kennel near Novi Sad, Serbia, were submitted for laboratory investigation. After negative testing for canine adenovirus, canine coronavirus, herpesvirus, parvovirus, distemper virus, influenza A virus, and leptospirosis, metagenomic sequencing was performed on selected tissues, followed by bioinformatic analysis and targeted RFAV PCR screening of additional outbreak-associated samples. Affected dogs had prolonged illness characterized by conjunctivitis with ocular and nasal discharge, occasional blue eye appearance, progressive weight loss, poor coat quality, biochemical evidence of hepatic injury, and neurologic signs including paraplegia in advanced cases. Sequencing generated 434,220 reads and identified multiple RFAV hits; pooled assembly produced a 4,799-bp consensus genome with approximately 97% similarity to known RFAV strains and genome organization consistent with the genus Amdoparvovirus. RFAV DNA was subsequently detected by virus-specific PCR in a epidemiologically linked dog and across diverse specimen types including blood, urine, kidney, spleen, brain, lung, testicle, ileocecal lymph node, and throat swabs, whereas clinically healthy unrelated dogs were PCR-negative.

Abstract: Foot-and-mouth disease (FMD) is one of the most infectious viral diseases of coven-hoofed animals. The crucial strategy for FMD control is the combination of animal quarantine and rapid onsite diagnostic assay capable of differential infected from vaccinated animals (DIVA). Herein, we have developed a lateral flow immunoassay to detect specific antibodies against FMDV non-structural protein (NSP), based on recombinant mu3ABC produced by E. coli as an antibody detector, so called mu3ABC strip test. Performance of mu3ABC strip test was examined using 566 field serum samples from cattle, pigs, and goats and compared with the commercial ELISA kit, resulting in the diagnostic sensitivity (DSn) and specificity (DSp) of 88.18% and 92.56%, respectively. Additionally, efficacies of the mu3ABC strip test and commercial ELISA were determined using 200 reference bovine sera (100 positives, 100 negatives) classified by the Regional Reference Laboratory for Foot and Mouth Disease in South East Asia (RRL). The result reveals that DSn and DSp of mu3ABC strip test were 78% and of 91%, respectively while the commercial ELISA kit had DSn of 69%and DSp of 100%. The developed mu3ABC strip tests are effective and can be used to differentiate the infected animals in parallel with the sero-surveillance ELISA test.

Abstract: This retrospective study evaluated clinical and radiographic outcomes in dogs wei-ghing < 10 kg undergoing surgical stabilization of radius–ulna fractures using either the Vitcone® internal fixator system (Group A) or Veterinary Instrumentation locking plates (Group B) between January 2021 and December 2025. Dogs were included if they presented with complete diaphyseal or metaphyseal fractures without concurrent orthopedic or neurological disease. Preoperative radiographs were assessed by two independent observers, and fractures were managed with open reduction and internal fixation using craniomedial or craniolateral approach. Postoperative care included re-stricted activity for six weeks and standardized lameness scoring at the eight week re-check. Radiographic healing was evaluated using a Visual Assessment Scale (VAS), and interobserver agreement was quantified using the intraclass correlation coefficient (ICC). Ninety three dogs met inclusion criteria (59 in Group A, 34 in Group B). Most fractures resulted from low energy trauma and involved the distal metaphysis or diaphysis. In Group A 52/59 dogs showed a lameness score of 0/4 at eight weeks. Group B showed similar recovery in 26/34 dogs, although 5/34 exhibited ROM re-duction. Radiographic healing was comparable between groups, with cortical brid-ging typically observed within eight weeks and excellent interobserver agreement (ICC > 0.75). Major complications occurred in 5/59 (8.4%) dogs in Group A, 4/5 re-fractures after early implant removal in young, small dogs and 1/5 implant breakage. Group B showed a significantly similar major complication rates including refractures in 3/34 (8%). No differences were statistically observed (p > 0.05). Owner follow up confirmed complete weight bearing in all contacted cases. These findings suggest that small breed dogs with radial fractures treated with Vitcone® fixation, have similar cli-nical outcome of those achieved with Veterinary Instrumentation system.

Abstract:

Acute lead intoxication is rarely reported in bottlenose dolphins (Tursiops truncatus) in human care, and information on tissue distribution during acute exposure is limited. This study describes the clinical presentation, management, and tissue distribution of lead (Pb) following accidental ingestion of Pb pellets in a group of six dolphins (two lactating adult females, their male calves, one juvenile female, and one adult male). The adult male did not develop clinical signs nor evidence of pellet ingestion and was therefore not included among the clinically affected cases. Clinical evaluation, hematology, serum biochemistry, heavy metal analysis, diagnostic imaging, and endoscopy were performed. Elevated blood Pb levels were detected in all clinically affected animals. Pellets were identified in the stomach of the three females and one of the calves. The calf without detectable pellets had the highest blood Pb concentration, suggesting lactational transfer. Despite intensive supportive and chelation therapy, the three adult females died, and complete necropsies were conducted. Pb concentrations were measured in liver, kidney, brain (three cerebral regions), blubber, muscle, and skin. Post-mortem analyses demonstrated high Pb concentrations in liver (1.14 mg/kg), kidney (0.814 mg/kg), and brain (0.554 mg/kg), as well as detectable levels in blubber (1.166 mg/kg). Skin Pb concentrations (1.254 mg/kg) were comparable to those of liver and kidney. Histopathology revealed intranuclear inclusion bodies in renal and hepatic cells. These findings characterize systemic Pb distribution in acute intoxication and identify skin as a potential diagnostic matrix in dolphins.

Abstract: Adhesive tape strip cytology at 1,000× magnification is the recommended method for the presumptive diagnosis of canine Malassezia overgrowth and/or dermatitis. This study aimed to determine the minimum number of microscopic fields required to achieve optimal intraobserver repeatability and interobserver reproducibility. Two groups of cytology slides were evaluated: 12 slides paired with photographs of pruritic dogs, in which a presumptive diagnosis of Malassezia dermatitis was defined by the detection of at least one yeast organism, and eight slides paired with photographs of non-pruritic dogs, in which a presumptive diagnosis of Malassezia overgrowth and dermatitis was defined by the detection of an average of at least one yeast organism per microscopic field. Twelve investigators examined each slide twice, and results from the first 10, 20, 30, 40, and 50 oil immersion fields were recorded and used for statistical analysis. Regardless of the number of microscopic fields examined, overall intraobserver repeatability and interobserver reproducibility were poor for both slide groups. Consequently, negative adhesive tape strip cytology results do not exclude Malassezia overgrowth and/or dermatitis in dogs with compatible clinical signs.

Abstract: Quality of life (QoL) assessment in companion animals has received increasing attention in veterinary medicine; however, companion rabbits have been systematically excluded from validated instrument development despite being the third most common companion species in several countries. The objective of this study was to develop and preliminarily validate a QoL questionnaire specifically designed for domestic rabbits (Oryctolagus cuniculus). Twenty-eight items were generated across three theoretical domains (behavioral, physical, and nutritional) through literature review and expert panel evaluation, and administered online to 192 owners of rabbits considered healthy. Exploratory factor analysis (EFA) identified a three-factor solution partially congruent with the proposed domains. Confirmatory factor analysis of the full 28-item model showed insufficient fit (CFI = 0.613; RMSEA = 0.056). Behavioral block sub-analysis revealed that the reactivity-to-owner subfactor achieved acceptable internal consistency (α = 0.709), the only domain to surpass the conventional 0.70 threshold. Significant overestimation of QoL by owners was observed relative to structured questionnaire scores (global: +0.62 points, p < .001; physical health: +0.57 points, p < .001). These results establish a preliminary psychometric profile for the first QoL instrument developed for companion rabbits, identifying a clinically viable reactivity subscale and delineating the modifications required for future validation cycles.

Abstract: Chronic synovial inflammation is a hallmark of osteoarthritis progression and is tightly regulated by synovial macrophages. Voltage-gated sodium channels (NaV) have emerged as modulators of macrophages-driven inflammation, positioning them as novel therapeutic targets. Neosaxitoxin, a highly selective NaV channel blocker, has anesthetic and immunomodulatory properties; however, its intra-articular effects on joint inflammation remain unexplored. Using a bilateral equine carpal osteoarthritis model, this study evaluated the immunomodulatory and tissue-preserving effects of intra-articular neosaxitoxin. Sixteen horses were randomized into two experimental groups (n=8/each): Neosaxitoxin in one joint and triamcinolone (+control) in the contralateral joint; or neosaxitoxin in one joint and saline (-control) in the contralateral joint. Clinical parameters, synovial fluid cytology and cytokine profiles, and histological changes in synovium and cartilage were assessed over 30 days. Neosaxitoxin reduced synovial inflammation, evidenced by decreased synovial effusion and surface temperature, along with improved joint flexion. Further, synovial fluid from neosaxitoxin-treated joints exhibited lower counts of erythrocytes, neutrophils, mononuclear cells, total protein, and key pro-inflammatory mediators (IL-1β, IL-6 and TNF-α). Histologically, neosaxitoxin-treated joints exhibited few synovium inflammatory infiltrate and cartilage integrity preservation. In contrast, control joints exhibited synovial hyperplasia, fibrovascular proliferation, and cartilage degeneration. Intra-articular neosaxitoxin better conserved joint homeostasis by limiting synovial inflammation and preserving cartilage integrity. These results warrant further investigation on NaV channel blockage as a novel disease-modifying strategy for osteoarthritis.

Abstract: Distal radial and ulnar fractures in miniature and toy-breed dogs are associated with high rates of delayed union, non-union, and refracture. This retrospective observational study evaluated the outcomes of simple distal radial and ulnar fractures treated by open reduction and internal fixation using a locking plate in a non-rigid configuration. Ten fractures in eight dogs weighing less than 5 kg were included. Cases were selected according to predefined biomechanical construct criteria, including a plate bridge ratio > 0.7, plate span ratio > 10, plate working length > 40% of plate length, and screw density < 0.6. Median radiographic follow-up was 224 days (range, 46–408 days). Radiographic bone healing was achieved in all cases, with a mean time to union of 53 days (range, 28–113 days) and healing occurred faster in skeletally immature dogs. Indirect bone healing with callus formation was observed in 7 of 10 fractures. Minor postoperative complications occurred in three cases and resolved with local treatment. No implant failures or refractures associated with previous screw holes were observed. A reduction in ulnar thickness was identified in evaluable cases, although this finding remained stable during follow-up and did not appear clinically relevant. These findings suggest that locking plate fixation in a non-rigid configuration provides reliable bone healing with a low complication rate in simple distal radial and ulnar fractures of miniature- and toy-breed dogs.

Abstract: Levetiracetam, a second-generation antiepileptic drug, is effective in therapy of various types of seizures. Its pharmacological properties are increasingly used in diversified clinical conditions such as anxiety and neuropathic pain. Levetiracetam has unique mechanism of action - it selectively binds to the synaptic vesicle protein 2A (SV2A), which stabilizes synaptic function and reduces neurotransmitter release, distinguishing it from traditional antiepileptics. The aim of the present paper was to investigate whether levetiracetam (31.25; 62.5 mg/kg, ip) may also be effective drug in reducing of symptoms in morphine dependence in mice. It was studied in three paradigms: 1) morphine tolerance to antinociceptive effect measured in the hot plate test; 2) naloxone-induced (2 mg/kg, ip) morphine withdrawal signs (manifested as jumpings); 3) morphine-induced behavioral sensitization to the locomotor activity of mice. Levetiracetam, at least in one of the doses used, was effective drug in reduction of all measured parameters. The study highlights the need for further research on levetiracetam properties, because it seems to be an innovative target in morphine dependence.

Abstract: Primary hepatic masses in dogs represent a heterogeneous group of lesions with variable biological behavior and challenging preoperative characterization. The objective of this retrospective study was to describe the clinical presentation, diagnostic findings, surgical management, and outcome of dogs with primary hepatic masses treated surgically. Ten dogs with resectable hepatic lesions and no evidence of extrahepatic metastasis were included. Clinical records, imaging findings, histopathological diagnoses, treatment, and follow-up data were reviewed. Histopathological diagnoses included hepatocellular carcinoma (n=3), nodular hyperplasia (n=2), lobular hyperplasia (n=1), hepatocellular adenoma (n=1), undifferentiated sarcoma (n=1), osteosarcoma (n=1), and one case without definitive histological diagnosis. Tumor size ranged from 3.3 to 18 cm and was not associated with biological behavior. Preoperative cytology showed poor concordance with final histopathological diagnosis in all sampled cases. Abdominal ultrasound identified solitary lesions in all evaluated dogs, although surgery revealed previously undetected multifocal disease in two cases. Most lesions were located in the right hepatic lobes, differing from the predominance of left-sided lesions commonly reported in the literature. All dogs underwent surgical resection. Two perioperative deaths occurred secondary to postoperative renal failure. In the remaining dogs, surgery resulted in complete remission of clinical signs and prolonged survival, including dogs with malignant tumors. Four dogs remained alive and disease-free at the end of the follow-up period (>730 days). These findings highlight the limitations of preoperative diagnostic techniques for predicting the biological behavior and extent of canine hepatic masses. Surgical resection provided substantial clinical benefit and prolonged survival in most cases, supporting its consideration whenever complete excision is technically feasible.

Abstract: This prospective case series evaluated the short-term outcomes following percutaneous cementoplasty as the sole palliative treatment for appendicular osteosarcoma in 10 dogs. Synthetic self-hardening calcium-phosphate bone substitute was injected into the osseous defect under fluoroscopic guidance after curettage of the bone tumor. Clinician assessment included a numerical rating score for lameness, offloading, and ease of lifting the contra-lateral limb as well as the 4A-VET post-operative pain scale. Owner assessment was obtained using three descriptive questionnaires, the Helsinki Chronic Pain Index (HCPI), the Canine Brief Pain Inventory (CBPI) and the Canine Symptom Assessment Scale (CSAS). Measures were recorded preoperatively and at 2-, 4-, 8-, and 12-weeks following surgery. Early improvement in the 4A-Vet score was noted at the 2-, 4-, 8-, and 12-week time points for all major pain and function metrics. Similarly, the CBPI pain severity and interference scores demonstrated early postoperative improvement during the 2- and 4-week time points with partial attenuation by 8- and 12-weeks. Panting, difficulty sleeping, whining/moaning, and lack of appetite were significantly reduced when assessed via the CSAS. Cementoplasty as a monotherapy, affording early pain relief and improved structural integrity, supports its role as a limb-sparing option for dogs unable to undergo amputation.

Abstract: This study characterized the cultivable oral microbiota of domestic dogs and evaluated antimicrobial susceptibility patterns and resistance accumulation in a veterinary context. A cross-sectional analytical design was conducted including 100 domestic dogs attended in urban veterinary clinics in southern Ecuador, from which 139 bacterial isolates were obtained through oral swabbing and conventional microbiological identification. Antimicrobial susceptibility was assessed using the disk diffusion method according to CLSI guidelines. Resistance accumulation was defined as the number of antimicrobial classes to which each isolate exhibited resistance, and multidrug resistance as resistance to three or more classes. A predominance of Gram-negative bacteria was observed (65.5%), with Pseudomonas (27.3%), Klebsiella (20.9%), and Enterobacter (7.9%) as the most frequent genera, while Staphylococcus aureus represented 34.5% of isolates. Resistance to at least one antimicrobial was detected in 71.2% of isolates, and multidrug resistance in 9.4% of the total dataset, exclusively among Gram-negative bacteria, corresponding to 14.3% within this group. Resistance to two or more antimicrobial classes was observed in 42.9% of Gram-negative isolates. Multivariable logistic regression showed that bacterial genus was the only factor significantly associated with resistance accumulation, with Enterobacter presenting a higher odds ratio compared to Pseudomonas (adjusted OR = 16.30; 95% CI: 1.69–157.14; p = 0.016), while host-related variables were not significant (p > 0.05). These results indicate that antimicrobial resistance in the canine oral microbiota is primarily structured by bacterial identity rather than host factors, highlighting the role of the oral cavity as a reservoir of resistant bacteria with implications for veterinary clinical practice and epidemiological surveillance.

Abstract: Feline gingivostomatitis is an inflammatory syndrome of the oral mucosa characterized by chronic pain. Its multifactorial etiology and debilitating consequences are associated with difficult clinical management and high relapse rates even after invasive interventions, potentially severely compromising the animals’ quality of life. Cannabidiol (CBD) has been investigated for its anti-inflammatory, antioxidant, analgesic, and immunomodulatory effects and is considered a potential therapeutic alternative for chronic inflammatory diseases. The present report aims to describe a significant clinical improvement in a 5-year-old mixed-breed male cat affected by feline gingivostomatitis, presenting with hyporexia and sialorrhea. A broad-spectrum Cannabis oil rich in CBD was prescribed at doses ranging from 0.5 to 1.0 mg/kg, administered twice daily for two months. Early clinical improvement was observed from the first day of administration, with a dose-dependent response, ultimately resulting in an overall satisfactory clinical outcome. Therefore, it can be concluded that the clinical application of a broad-spectrum Cannabis oil rich in CBD may represent a promising therapeutic alternative for cats affected by feline gingivostomatitis, especially in refractory cases or those with limitations to conventional therapies.

Abstract: Feline Infectious Peritonitis (FIP) has been transformed from a fatal disease to a treatable condition following the introduction of GS-441524, a nucleoside analogue targeting feline coronavirus replication. However, the widespread use of unregulated compounded formulations and the absence of validated analytical tools for therapeutic drug monitoring (TDM) represent critical gaps in clinical FIP management. This study describes the development and full ICH M10-compliant validation of a high-throughput LC-MS/MS method for the quantification of GS-441524 in feline serum, incorporating an automated protein precipitation protocol and a PBS-BSA surrogate matrix in accordance with 3Rs principles. The method met all acceptance criteria across validated parameters, including linearity (0.1–50 µg/mL), accuracy (bias within ±12.5%), precision (CV ≤10.9%), selectivity, extraction recovery (87.5–107.9%), and stability under clinically relevant storage conditions. Matrix equivalence between PBS-BSA and authentic feline serum was confirmed, enabling routine calibration without animal-derived materials. The validated method was applied to clinical TDM in cats undergoing GS-441524 treatment for FIP, providing preliminary evidence of inter-individual pharmacokinetic variability. The compounded formulations administered to the TDM cohort were independently verified by LC-MS/MS, confirming drug content within ±15% of labelled claims and excluding pharmaceutical quality as a confounding factor in the interpretation of serum drug concentrations.

Abstract: Cranial cruciate ligament (CrCL) rupture in cats is less common than in dogs, and its optimal treatment remains a subject of debate. The aim of this study was to evaluate the application of cranial tibial wedge osteotomy technique (CTWO) as a dynamic stabilization technique in cats with CrCL rupture, describing the technical aspects and clinical outcomes obtained. Five cases with a confirmed diagnosis of CrCL rupture between 2020 and 2024 were included in this study. All patients were treated with CTWO using specific osteosynthesis locking plates for this technique in dogs and a complementary cerclage wire. Radiographic rechecks were performed at 8 and 12 weeks postoperatively and clinical evaluations were performed 24 hours, 8 weeks, 12 weeks and six months postoperatively in every patient. Successful and complete bone healing of the tibial osteotomy was observed in every case. No intraoperative or postoperative complications related to implants or soft tissues were recorded. All cats achieved a complete functional recovery without lameness at the last recheck six months after surgery. The technique was performed without significant technical difficulties, providing adequate stability and favorable clinical outcomes in all cases. Although the use of a cranial tibial wedge osteotomy in combination with a tibial plateau leveling osteotomy (TPLO) was reported by Hoot et al to treat a cruciate ligament rupture in a cat presenting a deformity of the proximal tibia (Hoot et al), to the authors´ knowledge the use of the cranial tibial wedge osteotomy as single technique to treat the CrCL rupture in cats has not been previously reported in the literature. These preliminary results support the use of CTWO as an effective surgical alternative for the treatment of CrCL rupture in cats. However, further studies with a larger number of cases and a longer follow-up are required to evaluate better its clinical application, outcomes and influence on osteoarthritis progression in the long term.

Abstract: Osteoarthritis (OA) in companion animals is a progressive and debilitating condition for which current treatments primarily provide symptomatic relief without modifying disease progression. Cell-free regenerative approaches have recently emerged as promising alternatives. This study evaluated the clinical effectiveness of membrane-free stem cell extract (MF-STEM) in canine and feline osteoarthritis in comparison with intra-articular hyaluronic acid in a real-world clinical setting. A total of 271 animals were enrolled, including an MF-STEM group (n = 210) and a control group (n = 61), with treatment allocation based on owner preference. Clinical outcomes were assessed using the Joint Evaluation Index (JEI), along with recovery and recurrence rates. MF-STEM treatment resulted in a marked reduction in JEI scores (12.3 → 2.2), compared with a more limited decrease in the control group (11.3 → 7.0). The recovery rate was significantly higher in the MF-STEM group (93.3% vs. 32.8%), while the recurrence rate within one year was substantially lower (2.4% vs. 60.6%). No treatment-related adverse events were observed (0%). Although the non-randomized design limits causal interpretation, key baseline characteristics were generally comparable between groups, and consistent improvements were observed across multiple outcome measures in a relatively large real-world cohort. In conclusion, MF-STEM demonstrated clinically meaningful improvements in canine and feline osteoarthritis and may suggest a potential to influence disease progression with sustained therapeutic benefits. Further randomized controlled and mechanistic studies are required to confirm these findings.