Knee joint dysfunction in the patients immediately before arthroplasty was well reflected by locomotive syndrome, not physical frailty.

OBJECTIVES: We assessed physical function by three different methods in patients with knee osteoarthritis just before total knee arthroplasty (TKA) and investigated the relationship between impairment of mobility and preoperative factors. METHODS: All patients scheduled to undergo TKA at our hospital were assessed for basic attributes, clinical assessment, radiography, whole-body mode DXA, knee muscle strength. And frailty, sarcopenia, and locomotive syndrome (LS) were evaluated. RESULTS: Among 204 patients (213 knees),172 women, mean age 75.0 years, the overall distribution in frailty was ; in sarcopenia ; and in LS . Eighty-seven percent of the patients with frailty and 92% with LS stage 3 did not suffer from sarcopenia. Statistically significant relationships were observed between sarcopenia and frailty, while no relationship between LS and frailty or LS and sarcopenia. Multivariate analysis of related factors with severity level for frailty and LS revealed statistically significant correlations for frailty with gait speed and LS with KSS and muscle strength. CONCLUSION: In the patients with knee OA immediately before arthroplasty, physical frailty and LS was not related with by sarcopenia. Knee joint dysfunction without sarcopenia was well reflected by LS, not by physical frailty.

Comparative analysis of patient-reported outcomes in total knee arthroplasty and total hip arthroplasty: adjusting for demographic influences.

PURPOSE: Total knee arthroplasty (TKA) has consistently demonstrated lower patient satisfaction compared to total hip arthroplasty (THA). However, prior investigations failed to account for the patients' demographic characteristics. This study aimed to conduct a comparative analysis of patient-reported outcomes between TKA and THA while adjusting for patient background. METHODS: A total of 326 primary TKAs and 259 THAs conducted at a single center were assessed using Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores preoperatively and at 3 months, 1 year, and 2 years postoperatively. Notably, TKA patients exhibited advanced age and higher body mass index (BMI) than their THA counterparts. To mitigate the impact of these differences, we employed propensity score-matched data, adjusting for background characteristics such as age, gender, BMI, and diagnosis. RESULTS: THA consistently demonstrated significantly superior WOMAC total, pain, and stiffness scores compared to TKA at 3 months, 1 year, and 2 years postoperatively. Nevertheless, no statistically significant disparity in WOMAC physical function scores was observed between the two groups at 3 months and 1 year postoperatively in the matched data (3 months, p = 0.131; 1 year, p = 0.269). CONCLUSION: In contrast to earlier findings, our analysis of propensity score-matched data revealed no significant differences in WOMAC physical function scores between the TKA and THA groups at 3 months and 1 year postoperatively. The distinctive background factors observed in patients undergoing TKA and THA, notably advanced age and higher BMI, coupled with the delayed improvement timeline in TKA's WOMAC scores compared to that of THA, have the potential to impact patient-reported outcomes. Consequently, clinicians should be mindful of the potential impact of patient background on variations in patient-reported outcome measures following total joint arthroplasty.

Involvement of mitogen- and stress-activated protein kinase 1 in BMP-6-induced chondrocyte differentiation.

Bone morphogenetic proteins (BMPs) are involved in several cellular responsive actions, such as development, cell differentiation, and apoptosis, via their specific transmembrane receptors. In particular, BMPs promote the differentiation and maturation of bone and cartilage from mesenchymal stem cells. Based on comprehensive analyses performed with a large number of antibodies, mitogen- and stress-activated protein kinase (MSK)1 was found to be immediately phosphorylated in the mouse chondrocyte precursor cell line, ATDC5, upon BMP-6 stimulation. The overexpression and knockdown of MSK1 in ATDC5 cells also enhanced and suppressed BMP-6-induced chondrocyte differentiation, respectively. Similar to ATDC5 cells, an ex vivo organ culture system using mouse embryonic metatarsal bones also demonstrated that BMP-6-mediated MSK1 activation might play a role in chondrocyte differentiation. Using several inhibitors, the p38 kinase pathway was confirmed to be implicated in BMP-6-induced phosphorylation of MSK1. Furthermore, MSK1 mutants lacking kinase activities and those lacking serine/threonine residues targeted by p38 kinase severely impaired their ability to potentiate BMP-6-induced chondrogenic differentiation of ATDC5 cells. Interestingly, a loss-of-function study for Smad4 perturbed BMP-6-induced phosphorylation of p38 kinase to inhibit BMP-6-mediated chondrocyte differentiation via MSK1 activation. Overall, both Smad-dependent and independent pathways require BMP-6-induced chondrocyte differentiation via MSK1 activation in ATDC5 cells.

Zoledronate alleviates subchondral bone collapse and articular cartilage degeneration in a rat model of rotator cuff tear arthropathy.

OBJECTIVE: To evaluate the humeral head bone volume of patients with cuff tear arthropathy (CTA) and examine the therapeutic effect of zoledronate in a rat modified model of CTA (mCTA). DESIGN: The bone mass in patients with CTA was measured using Hounsfield units from CT images. The mCTA was induced by transecting the rotator cuff, biceps brachii tendon, and superior half of the joint capsule in adult rat shoulders. A single subcutaneous injection of zoledronate was followed by bone histomorphometry and immunohistochemistry of the humeral head, as well as the Murine Shoulder Arthritis Score (MSAS) assessment. RESULTS: The humeral head bone volume was decreased in patients with CTA. In the mCTA model, M1 macrophages were increased in the synovium and were decreased by zoledronate treatment. The increased expressions of TNF-α, IL-1ß and IL-6 in mCTA synovium and articular cartilage were suppressed in the zoledronate-treated mCTA group. The expression of catabolic enzymes in the articular cartilage and MSAS showed similar results. The zoledronate-treated mCTA group showed a decreased subchondral bone collapse with a decreased RANKL/OPG expression ratio and a suppressed number of osteoclasts compared with the control mCTA group. The enhanced expressions of HMGB1 and S100A9 in the mCTA shoulders were eliminated in the zoledronate-treated mCTA group. CONCLUSIONS: The humeral head subchondral bone was decreased in patients with CTA. In the mCTA model, the collapse and osteoarthritic changes were prevented by zoledronate administration. Zoledronate seemed to suppress the number of M1 macrophages in the synovium and osteoclasts in the subchondral bone.

Risk factors for vertebral fracture in rheumatoid arthritis patients using biological disease-modifying anti-rheumatic drugs (cases over 5 years): An observational study.

While biological disease-modifying anti-rheumatic drugs (bDMARDs) are considered beneficial for preventing osteoporosis and bone fracture, it is unclear whether bone loss is involved in the development of vertebral fracture, and few reports have examined the factors related to vertebral fracture in rheumatoid arthritis (RA) patients using bDMARDs. This study aims to identify factors influencing vertebral fracture in RA patients treated with bDMARDs. We retrospectively examined the records of 129 RA patients treated with bDMARDs for over 5 years. The lumbar spine and femoral bone mineral density, Disease Activity Score-28-C-Reactive Protein (DAS28-CRP) value, Simplified Disease Activity Index (SDAI), and modified Health Assessment Questionnaire (mHAQ) score were evaluated. The frequency of new vertebral fracture during the study and their risk factors were investigated. A comparison between the fracture group and the nonfracture group was performed. Multivariate analysis was performed using logistic regression analysis to detect risk factors for new vertebral fracture. The number of patients with new vertebral fracture during follow-up was 15 (11.6%) of the 129 patients in the study. Age and mHAQ score were significantly higher and lumbar spine and femoral neck bone mineral density were significantly lower in the fracture group than the nonfracture group. The risk factors for new vertebral fracture during the disease course were older age and higher mHAQ score indicating no remission over the 5 years of follow-up. In this study, there was no significant difference in disease indices such as the DAS28-CRP value and the SDAI between the fracture and nonfracture groups, suggesting an effective control of RA with bDMARDs. However, age and the mHAQ score, an index of RA dysfunction, were significantly higher in the fracture group. These results suggest that improving functional impairment may be important to prevent vertebral fracture in patients using bDMARDs.

Risk factors affecting delay of initiating adjuvant chemotherapy for stage III colorectal cancer.

PURPOSE: Delay in initiating adjuvant chemotherapy (AC) after curative resection of colorectal cancer (CRC) has been reported to lead to poor prognosis, but few studies have looked at associated factors. This study aimed to identify risk factors for delay in initiating AC. METHODS: Data from 200 consecutive patients who underwent curative resection and AC for stage III CRC between 2013 and 2018 were retrospectively collected and analyzed. RESULTS: AC was initiated more than 8 weeks after surgery in 12.5% of patients (the delay group). Compared to those with no delay (the non-delay group), patients in the delay group had significantly higher rates of synchronous double cancers (2.3% vs. 16.0%, p = 0.001), preoperative bowel obstruction (10.3% vs. 32.0%, p = 0.003), laparotomy (56.0% vs. 80.0%, p = 0.02), concomitant resection (2.9% vs. 24.0%, p < 0.001), and postoperative complications (32.0% vs. 56.0%, p = 0.02), and a significantly longer length of hospital stay (median 12 vs. 30 days, p < 0.001). In multivariate analysis, synchronous double cancers (odds ratio 10.2, p = 0.008), preoperative bowel obstruction (odds ratio 4.6, p = 0.01), concomitant resection (odds ratio 5.2, p = 0.03), and postoperative complications of Clavien-Dindo grade ≥ IIIa (odds ratio 4.0, p = 0.03) were identified as independent risk factors for delay in initiating AC. CONCLUSION: Careful preoperative treatment planning for CRC patients with synchronous double cancers, preoperative bowel obstruction, and concomitant resection, and management for postoperative complication are necessary to avoid delay in initiating AC.

Anti-tumour effects of lapatinib on HER2-positive canine prostatic carcinoma cell lines.

Background: Canine prostatic carcinoma (cPC) is a urogenital tumour with a poor prognosis, for which no effective treatment has been established. Recently, it has been shown that human epidermal growth factor receptor type 2 (HER2) is overexpressed in cPC cells; however, the efficacy of HER2-targeted therapy remains unclear. Aim: Investigate the anti-tumour effect of lapatinib on HER2-positive cPC cell lines. Methods: Two cell lines (muPC and bePC) were established from two dogs with cPC and the effects of lapatinib treatment on cell proliferation, apoptosis, and HER2 downstream signalling were investigated. Furthermore, muPC was used to generate tumour-bearing mice, and the anti-tumour effects of lapatinib were examined in vivo. Results: Lapatinib treatment inhibited the proliferation and phosphorylation of Erk1/2 and Akt, which are downstream signals of HER2. Furthermore, the TUNEL assay showed that lapatinib induced apoptosis in both cell lines. The muPC-engrafted nude mouse model showed that lapatinib significantly inhibited tumour growth and increased the area of necrotic tumour tissue compared to the vehicle-treated groups. Conclusion: Lapatinib exerts anti-tumour effects on cPC cells by inhibiting HER-2 signalling.

Oil blotting paper for formalin fixation increases endoscopic ultrasound-guided tissue acquisition-collected sample volumes on glass slides.

OBJECTIVES: Endoscopic ultrasound-guided tissue acquisition (EUS-TA) is used for pathological diagnosis and obtaining samples for molecular testing, facilitating the initiation of targeted therapies in patients with pancreatic cancer. However, samples obtained via EUS-TA are often insufficient, requiring more efforts to improve sampling adequacy for molecular testing. Therefore, this study investigated the use of oil blotting paper for formalin fixation of samples obtained via EUS-TA. METHODS: This prospective study enrolled 42 patients who underwent EUS-TA for pancreatic cancer between September 2020 and February 2022 at the Osaka International Cancer Institute. After a portion of each sample obtained via EUS-TA was separated for routine histological evaluation, the residual samples were divided into filter paper and oil blotting paper groups for analysis. Accordingly, filter paper and oil blotting paper were used for the formalin fixation process. The total tissue, nuclear, and cytoplasm areas of each sample were quantitatively evaluated using virtual slides, and the specimen volume and histological diagnosis of each sample were evaluated by an expert pathologist. RESULTS: All cases were cytologically diagnosed as adenocarcinoma. The area ratios of the total tissue, nuclear, and cytoplasmic portions were significantly larger in the oil blotting paper group than in the filter paper group. The frequency of cases with large amount of tumor cells was significantly higher in the oil blotting paper group (33.3%) than in the filter paper group (11.9%) (p = 0.035). CONCLUSIONS: Oil blotting paper can increase the sample volume obtained via EUS-TA on glass slides and improve sampling adequacy for molecular testing.

Protective role of protease-activated receptor-2 in anaphylaxis model mice.

Anaphylaxis is a severe life-threatening hypersensitivity reaction induced by mast cell degranulation. Among the various mediators of mast cells, little is known about the role of tryptase. Therefore, we aimed to elucidate the role of protease-activating receptor-2 (PAR-2), a receptor activated by tryptase, in murine anaphylactic models using PAR-2-deficient mice and newly generated tryptase-deficient mice. Anaphylaxis was induced by IgE-dependent and IgE-independent mast cell degranulation in mice. PAR-2 deficiency exacerbated the decrease in body temperature and hypotension during anaphylaxis; however, the number of skin mast cells, degree of mast cell degranulation, and systemic and local vascular hyperpermeability were comparable in PAR-2 knockout and wild-type mice. Nitric oxide, which is produced by endothelial nitric oxide synthase (eNOS), is an indispensable vasodilator in anaphylaxis. In the lungs of anaphylactic mice, PAR-2 deficiency promoted eNOS expression and phosphorylation, suggesting a protective effect of PAR-2 against anaphylaxis by downregulating eNOS activation and expression. Based on the hypothesis that the ligand for PAR-2 in anaphylaxis is mast cell tryptase, tryptase-deficient mice were generated using CRISPR-Cas9. In wild-type mice, the PAR-2 antagonist exacerbated the body temperature drop due to anaphylaxis; however, the effect of the PAR-2 antagonist was abolished in tryptase-deficient mice. These results suggest that tryptase is a possible ligand of PAR-2 in anaphylaxis and that the tryptase/PAR-2 pathway attenuates the anaphylactic response in mice.

[Tips and Outcomes of Safe Laparoscopic Rectal Resection with Adequate Lymph Node Dissection in Patients with Obesity].

BACKGROUND: This study aimed to describe the surgical procedures involved in laparoscopic rectal resection in patients with obesity and report the short-term outcomes. MATERIALS AND METHODS: A total of 194 consecutive patients who underwent laparoscopic rectal resection in our department from 2013 to 2018 were divided into non-obese(body mass index[BMI] <25 kg/m2; n=161)and obese groups(BMI≥25 kg/m2; n=33)and subsequently analyzed. RESULTS: The operative time was significantly longer in the obese group(225 vs 266 min; p=0.003)than in the non-obese group. No conversions to laparotomy occurred in either group, and no discernible differences in blood loss(1 vs 5 mL; p=0.582), number of harvested lymph nodes(20 vs 17; p=0.356), and postoperative complication rates(9.3 vs 6.1%; p=0.547)were observed. CONCLUSION: Establishing an appropriate operative field, clarifying landmarks, and standardizing the procedure are important to assure safe laparoscopic rectal resection with adequate lymph node dissection in patients with obesity.

Simple model for synchronization of two Belousov-Zhabotinsky gels interacting mechanically.

A Belousov-Zhabotinsky (BZ) gel is a unique biomimetic system that undergoes autonomous volume oscillations induced by the redox oscillation of the BZ reaction. In a previous study, researchers reported that the oscillations of two BZ gels coupled by compression were synchronized by a mechanical interaction. They mathematically explained the synchronization behavior using a phase oscillator model. As a different approach to the previous study, a physicochemical investigation of the phenomenon will lead to a better understanding of the functional biological rhythms essential for life. In this study, we construct a simple phenomenological model to understand the synchronization of BZ gels. The model consists of two parts. One is the dynamics of the chemical reactions in the BZ gels. We use a phenomenological model based on the Oregonator for the BZ reaction. The other is the dynamics of the mechanical deformation of the BZ gel. Using approximations, we extract the parameters essential for the synchronization of a mechanical interaction. Thus, we can derive a novel equation for the deformation dynamics of mechanically coupled BZ gels. By combining these two parts, we perform numerical calculations. This allows us to find that the synchronization of the two BZ gels is less likely to occur under stronger compression. We explain this trend through one physicochemical parameter in our model: the volume fraction of the BZ gel in the reduced state.

Flexible Electrohydrodynamic Fluid-Driven Valveless Water Pump via Immiscible Interface.

The conventional electrohydrodynamic (EHD) pump is limited to pumping functional and dielectric liquids, which restricts its applications in fields like microfluidics, food safety, and materials production. In this study, we present a flexible water pump driven by EHD fluid, achieved by integrating valveless elements into the fluidic channel. Our approach leverages the water-EHD interface to propel the immiscible aqueous liquid and reciprocate this process using the nozzle-diffuser system. All components of the water pump are digitally fabricated and assembled. The valveless parts are created using a laser cutting machine. Additionally, we develop a model for the EHD pump and nozzle-diffuser system to predict the generated flow rate, considering factors such as the asymmetrical performance of the EHD pump, pulse frequency, applied voltage, and structural parameters. Finally, we experimentally characterize the flow rates of both the EHD pump and water pump and apply the newly developed device to air bubble manipulation and droplet generation. This research broadens the range of specialized liquids pumped by EHD pumps to include other aqueous liquids or mixtures.

Ultraconformable Capacitive Strain Sensor Utilizing Network Structure of Single-Walled Carbon Nanotubes for Wireless Body Sensing.

Capture and real-time recording of precise body movements using strain sensors provide personal information for healthcare monitoring and management. To acquire this information, a sensor that conforms to curved irregular surfaces, including biological tissue, is desired to record complex body movements while acting like a second skin to avoid interference with the movements. In this study, we developed a thin-film-type capacitive strain sensor that is flexible and stretchable on the surface of a living body. We fabricated conductive polymeric ultrathin films ("nanosheets") comprising polystyrene-block-polybutadiene (SB) elastomers and single-walled carbon nanotubes (SWCNTs) (i.e., SWCNT-SB nanosheets) via gravure coating; the SWCNT-SB-coated nanosheets were used as the flexible electrode in a capacitive strain sensor. The dielectric (DE) layer was then prepared using the silicone elastomer Ecoflex 00-30 because its Young's modulus is comparable to that of the epidermis. The normalized capacitance changes (ΔC/C0) in the sensor increased with increasing tensile strain over a range from 0-100%, indicating that the proposed sensor can measure the strain of biological movements, including those of skin and blood vessels. To improve sensor conformability further, the effect of sensor thickness on the gauge factor (GF) was investigated using thinner DE layers by focusing on their flexural rigidity. As a result, the GF increased from 0.64 to 1.13 as the DE layer thickness decreased from 260 to 40 µm. Finally, we evaluated the fabricated sensor's signal stability and mechanical durability, including during wireless sensing when applied to human skin and a vascular model. The ΔC/C0 values varied in response to the bending motion of a finger, dilation of a blood vessel, and the swallowing movement of the throat. These results indicate that our capacitive strain sensor is conformable and functional on biological tissue to enable monitoring of dynamic biological movements (e.g., pulse rate and arterial dilation) without wearer discomfort.

Myeloid derived suppressor cells in peripheral blood can be a prognostic factor in canine transitional cell carcinoma.

Myeloid-derived suppressor cells (MDSCs) are immature cells with immunosuppressive properties found in the tumor microenvironment. MDSCs are divided into two major subsets: polymorphonuclear MDSCs (PMN-MDSCs) and monocytic MDSCs (M-MDSCs). Both MDSC subsets contribute to the creation of an immunosuppressive environment for tumor progression. In humans, patients with high levels of MDSCs show worse outcomes for several types of cancers. However, the association between MDSCs and clinical features has rarely been investigated in canine studies. In the present study, we measured the proportion of PMN-MDSCs and M-MDSCs in the peripheral blood and tumor tissue of dogs with hepatocellular carcinoma (HCC), prostate cancer (PC), transitional cell carcinoma (TCC), lymphoma, and pulmonary adenocarcinoma. Additionally, we examined immunosuppressive ability of PMN-MDSCs and M-MDSCs in peripheral blood mononuclear cells of TCC case on CD4+, CD8+ and interferon-γ+ cells and investigated the relationships of MDSCs with clinical features and outcomes. PMN-MDSCs increased in HCC, PC, TCC, and lymphoma. In contrast, M-MDSCs increased in the TCC. Both PMN-MDSCs and M-MDSCs exhibited immunosuppressive effects on CD8+, CD4+ and interferon-γ+ cells. In dogs with TCC, lymph node metastasis was associated with high level of PMN-MDSCs but not with M-MDSCs. High levels of both PMN-MDSCs and M-MDSCs were related to advanced tumor stage. Kaplan-Meier analysis revealed that high levels of both PMN-MDSCs and M-MDSCs were significantly associated with shorter overall survival. In addition, the Cox proportional hazard regression model showed that M-MDSCs and the tumor stage were independent prognostic factors for TCC. These results suggest that PMN-MDSCs and M-MDSCs may be involved in tumor progression and could be prognostic factors and promising therapeutic targets in dogs with TCC.

Effect of diazoxide on a cat with insulinoma.

Case summary: The patient was a castrated male American Shorthair cat, approximately 14 years old, weighing 3.4 kg. The patient had chronic kidney disease (CKD) (International Renal Interest Society stages 3-4) as an underlying disease. The cat was examined at a hospital for intermittent lethargy and seizures. Hypoglycaemia was repeatedly observed, and the insulin level was 1.78 ng/ml (reference interval 0.27-0.69) when the blood glucose was 49 mg/dl. Although the cat was tentatively diagnosed with insulinoma, surgery was not recommended because of the severe CKD. Although frequent feeding and prednisolone treatment were initially attempted, blood glucose decreased to 24-42 mg/dl. Diazoxide was additionally prescribed at a dose of 5.2 mg/kg q12h. The cat's clinical signs improved, and the blood glucose was in the range of 75-103 mg/dl during the first 2 months. It was maintained at >50 mg/dl until the patient died of renal failure 161 days after the start of diazoxide treatment. With regard to adverse events, vomiting once every 2-3 days without weight loss and non-regenerative anaemia were observed, which might have been at least partially caused by diazoxide treatment. An insulinoma was definitively diagnosed via pathological autopsy. Relevance and novel information: This is the first reported case of long-term treatment with diazoxide in a cat with insulinoma. Since it was effective in situations where conventional therapies were unsuccessful, diazoxide could be useful as a new therapeutic option for cats with insulinoma. Since adverse events, such as progression of vomiting frequency and non-regenerative anaemia, were observed, careful monitoring was required during administration.

Pocketable and Smart Electrohydrodynamic Pump for Clothes.

Seamlessly fusing fashion and functionality can redefine wearable technology and enhance the quality of life. We propose a pocketable and smart electrohydrodynamic pump (PSEP) with self-sensing capability for wearable thermal controls. Overcoming the constraints of traditional liquid-cooled wearables, PSEP with dimensions of 10 × 2 × 1.05 cm and a weight of 10 g is sufficiently compact to fit into a shirt pocket, providing stylish and unobtrusive thermal control. Silent operation coupled with the unique self-sensing ability to monitor the flow rate ensures system reliability without cumbersome additional components. The significant contribution of our study is the formulation and validation of a theoretical model for self-sensing in EHD pumps, thereby introducing an innovative functionality to EHD pump technology. PSEP can deliver temperature changes of up to 3 °C, considerably improving personal comfort. Additionally, the PSEP system features an intuitive, smartphone-compatible interface for seamless wireless control and monitoring, enhancing user interaction and convenience. Furthermore, the ability to detect and notify users of flow blockages, achieved by self-sensing, ensures an efficient and long-term operation. Through its blend of compact design, intelligent functionality, and stylish integration into daily wear, PSEP reshapes the landscape of wearable thermal control technology and offers a promising avenue for enhancing personal comfort in daily life.

[A case of total hip arthroplasty for femoral head necrosis while using satralizumab for neuromyelitis optica spectrum disorders].

A 47-year-old woman developed right femoral head necrosis during long-term steroid use for neuromyelitis optica spectrum disorder. She underwent a total hip arthroplasty because her right hip pain persisted after satralizumab treatment. There were no postoperative infections. Under oral administration of tacrolimus 3 mg, prednisolone 11 mg, and acetaminophen 2,275 mg, her postoperative body temperature was less than 38°C and normalized in about 2 days after the operation. No parameters indicating worsening of inflammation were observed in the blood test. In satralizumab-treated patients, infection cannot be ruled out even without inflammatory findings. In particular, if a slight fever of the 37°C-range or a mildly high white blood cell count persists, paying attention to signs of infection and actively investigating the presence or absence of infection using medical image diagnostic devices are necessary.

Effects of high-dose docosahexaenoic acid supplementation as an add-on therapy for canine idiopathic epilepsy: A pilot study.

Background: The anti-epileptic effects of docosahexaenoic acid (DHA) in dogs and humans remain controversial. The dosage and efficacy of DHA were various in the previous reports. Aim: The effects of high-dose DHA supplementation as add-on therapy for idiopathic epilepsy in dogs were evaluated. Methods: An open-label clinical trial was designed in this pilot study. Six dogs (median age: 6 years) with idiopathic epilepsy were included. All the patients were diagnosed with idiopathic epilepsy using magnetic MRI and cerebrospinal fluid examination (median: 2.0 years before the trial). They had 5-45 seizures and/or auras (median: 9.0) in the month before starting DHA supplementation. DHA was adjunctively administered at doses of 69-166 mg/kg/day without changing other prescriptions. Results: Four of the six patients completed the 6-month observation period. All the patients showed a decrease in seizure frequency of 50% or more within 2-3 months after the start of the administration, and three patients decreased to a frequency of 0-1 per month after 5-6 months. No clear adverse events were observed in the general condition or blood test results in any patients. Conclusion: Although the sample size was small and the study was not a randomized controlled trial, the data suggest that add-on supplementation of DHA could be useful in reducing the frequency of seizures in canine idiopathic epilepsy.