A single-blind randomised study comparing the efficacy of fluconazole and itraconazole for the treatment of Malassezia dermatitis in client-owned dogs.

BACKGROUND: No reports have compared the clinical therapeutic efficacy of fluconazole and itraconazole in canine Malassezia dermatitis. OBJECTIVES: The study aimed to compare the clinical therapeutic efficacy of fluconazole and itraconazole and to evaluate the adverse effects of fluconazole in canine Malassezia dermatitis. ANIMALS: Sixty-one client-owned dogs with Malassezia dermatitis. MATERIALS AND METHODS: The enrolled animals were randomly divided into groups receiving 5 mg/kg fluconazole (5FZ), 10 mg/kg fluconazole (10FZ) or 5 mg/kg itraconazole (5IZ). The drugs were orally administered once daily for 28 days. Cytological examination, clinical index score (CIS), pruritus Visual Analog Scale (PVAS) evaluation and blood analysis (for 5FZ only) were performed on Day (D)0, D14 and D28. RESULTS: On D14, significant reductions in mean yeast count (MYC), CIS and PVAS were observed in the 5FZ (n = 20, p < 0.01), 10FZ (n = 17, p < 0.01) and 5IZ (n = 16, p < 0.05) groups. In all three groups, a significant reduction (p < 0.001) in MYC, CIS and PVAS expression was observed on D28. There was no significant difference in the percentage reduction of MYC, CIS and PVAS among the groups. Moreover, there was a significant difference (p < 0.05) in each group between D14 and D28, except for the percentage reduction in MYC in the 10FZ and 5IZ groups. No adverse effects of fluconazole were observed in the 5FZ or 10FZ groups. CONCLUSIONS AND CLINICAL RELEVANCE: This study indicates that 5FZ and 10FZ are as effective as itraconazole in canine Malassezia dermatitis.

Association between Hyperglycemia and Canine Serum Pancreatic Lipase Immunoreactivity Concentration in Diabetic Dogs.

It has been reported that hypertriglyceridemia can partially mediate between diabetes mellitus (DM) and pancreatitis in dogs, implying that another mediator, such as chronic hyperglycemia, might exist. Therefore, this study aimed to evaluate the relationship between hyperglycemia and serum canine pancreatic lipase immunoreactivity (cPLI) concentration in diabetic dogs. This retrospective cohort study included 26 client-owned diabetic dogs, divided according to their serum fructosamine levels (<500 µmol/L = well-controlled DM group; ≥500 µmol/L = untreated or poorly controlled DM group). Five of the 26 DM dogs (19.2%) had serum cPLI concentrations consistent with pancreatitis, among which two showed ultrasonographic evidence of pancreatitis without clinical signs. The serum cPLI concentrations (median [interquartile range]) were significantly higher in the untreated or poorly controlled group (520 µg/L [179.76-1000 µg/L]) than in the well-controlled group (77 µg/L [32.22-244.6 µg/L], P = 0.0147). The serum fructosamine concentration was positively correlated with the serum cPLI concentration (r = 0.4816; P = 0.0127). Multivariate analysis revealed serum triglyceride and fructosamine concentrations were associated with the serum cPLI concentration. In conclusion, this study suggests that chronic hyperglycemia may induce pancreatic inflammation in diabetic dogs; however, the clinical significance of increased cPLI concentration is unknown.

Heart failure in a cat due to hypertrophic cardiomyopathy phenotype caused by chronic uncontrolled hyperthyroidism.

A 16-year-old castrated male Persian cat was presented with weight loss, anorexia and dyspnoea. Tachycardia and tachypnoea were observed upon presentation. The cat was previously diagnosed with hyperthyroidism and left ventricular hypertrophy and received methimazole, but was subsequently not followed up and treated appropriately. Thoracic radiography revealed mild pleural effusion, interstitial lung pattern, moderate cardiomegaly and moderate-to-severe dilation of the pulmonary artery and pulmonary vein. On echocardiography, the left ventricular hypertrophy, identified earlier, shoed partial regression. Therefore, the previous myocardial hypertrophy was diagnosed as a hypertrophic cardiomyopathy phenotype related to hyperthyroidism. ST-segment elevation was identified on electrocardiography, and the thyroid profile examination revealed increased total thyroxine and free thyroxine and decreased thyroid-stimulating hormone levels, suggesting myocardial injury and uncontrolled hyperthyroidism, respectively. In addition, normal N-terminal pro-B-type natriuretic peptide and high cardiac troponin I levels were found. Based on these findings, the observed congestive heart failure was considered as a sequel of myocardial injury caused by uncontrolled hyperthyroidism. Clinical signs resolved after intravenous administration of furosemide and butorphanol, oxygen supply and thoracocentesis. Furosemide and pimobendan were additionally administered, and the cat was discharged. This case demonstrates that myocardial damage due to chronic uncontrolled hyperthyroidism may cause heart failure in cats.

18F-FDG PET/CT image findings of a dog with adrenocortical carcinoma.

BACKGROUND: In human medicine, 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) has been used to differentiate between benign and malignant adrenal tumors and to identify metastases. However, canine adrenocortical carcinomas identified by 18F-FDG PET/computed tomography (CT) have not been reported. CASE PRESENTATION: A 13-year-old, castrated male, Cocker Spaniel dog with severe systolic hypertension exhibited an adrenal mass approximately 3.6 cm in diameter on ultrasonography. There was no evidence of pulmonary metastasis or vascular invasion on thoracic radiography and abdominal ultrasonography, respectively. 18F-FDG PET/CT was performed to identify the characteristics of the adrenal mass and the state of metastasis. One hour after injection of 5.46 MBq/kg 18F-FDG intravenously, the peripheral region of the adrenal mass visually revealed an increased 18F-FDG uptake, which was higher than that of the liver, and the central region of the mass exhibited necrosis. The maximal standardized uptake value (SUV) of the adrenal mass was 3.24; and relative SUV, calculated by dividing the maximal SUV of the adrenal tumor by the mean SUV of the normal liver, was 5.23. Adrenocortical carcinoma was tentatively diagnosed and surgical adrenalectomy was performed. Histopathologic examination of the resected adrenal mass revealed the characteristics of an adrenocortical carcinoma. After adrenalectomy, systolic blood pressure reduced to below 150 mmHg without any medication. CONCLUSION: This is the first case report of 18F-FDG PET/CT findings in a dog with suspected adrenocortical carcinoma and may provide valuable diagnostic information for adrenocortical carcinoma in dogs.

Pharmacokinetics of fluconazole after oral administration to healthy beagle dogs.

BACKGROUND: Fluconazole can be effective in the treatment of superficial mycoses in dogs. However, the pharmacokinetics of fluconazole have not yet been evaluated to determine its optimal dosing regimen. OBJECTIVES: This study aimed to determine the plasma concentration of fluconazole after single and multiple administrations at two different dosages in dogs. METHODS AND MATERIALS: Eight healthy beagle dogs were divided into two groups, and each group received either 5 or 10 mg/kg of fluconazole per os. The pharmacokinetics of fluconazole was determined following single and multiple administrations p.o. Single- and multiple-dose treatment periods were separated by a washout period of seven days. Plasma concentrations of fluconazole were determined by established high-performance liquid chromatography coupled with tandem mass spectrometry system. RESULTS: In the 5 mg/kg group, the mean maximum concentrations (Cmax ) and the area under the plasma concentrations (AUC0-24h ) were 4.84 µg/mL and 85.56 µg*h/mL, respectively, after single administration and 6.58 µg/mL and 119.52 µg*h/mL, respectively, after multiple administrations. In the 10 mg/kg group, the Cmax and AUC0-24h were 5.67 µg/mL and 109.19 µg*h/mL, respectively, after single administration and 15.10 µg/mL and 291.51 µg*h/mL, respectively, after multiple administrations. The Cmax (p < 0.001) and AUC0-24h (p < 0.001) were significantly lower in the 5 mg/kg group than those in the 10 mg/kg group at multiple administrations. CONCLUSIONS AND CLINICAL RELEVANCE: Fluconazole accumulates in plasma and exhibits dose-proportional pharmacokinetics after multiple doses, and was safe and well tolerated at these doses for short-term administration.

Temporal and anatomical distribution of 18F-flutemetamol uptake in canine brain using positron emission tomography.

BACKGROUND: Positron emission tomography (PET) is increasingly being used as an imaging modality for clinical and research applications in veterinary medicine. Amyloid PET has become a useful tool for diagnosing Alzheimer's disease (AD) in humans, by accurately identifying amyloid-beta (Aß) plaques. Cognitive dysfunction syndrome in dogs shows cognitive and pathophysiologic characteristics similar to AD. Therefore, we assessed the physiologic characteristics of uptake of 18F-flutemetamol, an Aß protein-binding PET tracer in clinical development, in normal dog brains, for distinguishing an abnormal state. Static and dynamic PET images of six adult healthy dogs were acquired after 18F-flutemetamol was administered intravenously at approximately 3.083 MBq/kg. For static images, PET data were acquired at 30, 60, and 90 min after injection. One week later, dynamic images were acquired for 120 min, from the time of tracer injection. PET data were reconstructed using an iterative technique, and corrections for attenuation and scatter were applied. Regions of interest were manually drawn over the frontal, parietal, temporal, occipital, anterior cingulate, posterior cingulate, and cerebellar cortices, cerebral white matter, midbrain, pons, and medulla oblongata. After calculating standardized uptake values with an established formula, standardized uptake value ratios (SUVRs) were obtained, using the cerebellar cortex as a reference region. RESULTS: Among the six cerebral cortical regions, the cingulate cortices and frontal lobe showed the highest SUVRs. The lowest SUVR was observed in the occipital lobe. The average values of the cortical SUVRs were 1.25, 1.26, and 1.27 at 30, 60, and 90 min post-injection, respectively. Tracer uptake on dynamic scans was rapid, peaking within 4 min post-injection. After reaching this early maximum, cerebral cortical regions showed a curve with a steep descent, whereas cerebral white matter demonstrated a curve with a slow decline, resulting in a large gap between cerebral cortical regions and white matter. CONCLUSION: This study provides normal baseline data of 18F-flutemetamol PET that can facilitate an objective diagnosis of cognitive dysfunction syndrome in dogs in future.

Combination therapy with azathioprine, cyclosporine and ketoconazole in a dog with concurrent pemphigus foliaceus and hyperadrenocorticism - Case report.

A 10-year-old, spayed female Shih Tzu dog presented with a history of progressive erythema and multiple crusts developing 85 days previously. The dog had been diagnosed with hyperadrenocorticism (HAC) 55 days prior to presentation and was treated with oral trilostane (2.86 mg/kg, once daily) that was discontinued due to a poor response. In addition to generalised alopecia, erythematous plaques and crusts were noted on the trunk, head and footpads. Lesional impression smears revealed numerous acantholytic cells and non-degenerated neutrophils. Histopathological findings demonstrated subcorneal pustules with acantholytic cells and intact neutrophils. On the basis of these findings, we diagnosed pemphigus foliaceus (PF) with concurrent HAC. We wished to avoid glucocorticoids and, therefore, prescribed oral, once-daily azathioprine (2 mg/kg), modified cyclosporine (7 mg/kg) and ketoconazole (5 mg/kg). By day 71 post-treatment, the erythematous crusts had almost disappeared and the alopecia had improved considerably. However, by the subsequent follow-up examination on day 99, the clinical signs had reappeared due to the tapering of cyclosporine. To the best of our knowledge, this is the first case report describing concurrent PF and HAC in a dog. Combination therapy with azathioprine, modified cyclosporine and ketoconazole was effective, and should be considered for dogs diagnosed with concurrent autoimmune diseases and HAC.

High-resolution fluorodeoxyglucose positron emission tomography and magnetic resonance imaging findings of a pituitary microtumor in a dog.

A 16-year-old, castrated, male English cocker spaniel dog was presented due to generalized alopecia. Routine clinical pathology, endocrine and abdominal ultrasonography results were consistent with a diagnosis of pituitary-dependent hyperadrenocorticism. The adenohypophyseal lesion was clearly visualized on both 3 T and 7 T magnetic resonance imaging (MRI) of the pituitary gland. Although biochemical and MRI findings were consistent with a functional pituitary microtumor, a pituitary lesion was not detected using (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET). This report firstly describes the application of high-resolution FDG-PET to a spontaneous pituitary microtumor in a dog.

An evaluation of the physiological uptake range of 18F-fluoro-2-deoxy-D-glucose in normal ovaries of seven dogs using positron emission tomography/computed tomography.

Introduction: This study evaluated the physiological uptake range of 18F-fluoro-2-deoxy-D-glucose (18F-FDG) in the normal ovaries of seven dogs using positron emission tomography/computed tomography (PET/CT). Materials and methods: The dogs were subjected to general anesthesia and were positioned in ventral recumbency for PET/CT scans. The dosage of 18F-FDG ranged from 0.14 to 0.17 mCi/kg and was administered intravenously followed by 0.9% NaCl flushing; PET/CT images of each dog were obtained precisely 60 min after the injection of 18F-FDG. The regions of interest were drawn manually, and standardized uptake values (SUV) were calculated to evaluate the 18F-FDG uptake in each ovary. The maximum and mean SUVs (SUV max and SUV mean) for all the ovaries of the dogs were then computed. Results: The range of SUV max and SUV mean of the normal ovaries of the dogs were 1.28-1.62 and 1.07-1.31 (mean ± standard deviation), respectively. Conclusion: This is the first study to investigate the normal 18F-FDG uptake baseline data of normal canine ovaries using PET/CT scans. These data will help clinicians in identifying malignant tumors before anatomical changes in the ovary through PET/CT scans.

Serratia marcescens-associated subcutaneous abscess in a dog.

This report describes the clinical presentation and progression of a Serratia marcescens-associated subcutaneous abscess in a dog with hypothyroidism, hyperadrenocorticism and diabetes mellitus. The S. marcescens isolate was resistant to several antibiotics. Treatment with antibiotics and topical antiseptics was not successful.

Myxomatous mitral valve disease and associated pulmonary hypertension might increase serum angiopoietin-2 in dogs.

OBJECTIVE: To evaluate the relationships between the severity of myxomatous mitral valve disease (MMVD) and pulmonary hypertension (PH) and serum angiopoietin (Ang)-1 and Ang-2 concentrations in dogs with MMVD. ANIMALS: 74 dogs (control, n = 12; MMVD, n = 62) were included. METHODS: Serum Ang-1 and Ang-2 concentrations were estimated using the canine-specific ELISA kit. The concentrations were compared between dogs with MMVD and healthy dogs, and they were analyzed according to the severity of MMVD and PH. RESULTS: The median serum Ang-1 concentration did not differ among the study groups. The median serum Ang-2 concentration was higher in dogs with stage B2 MMVD (P = .041) and acute congestive heart failure (P = .002) than in control dogs. In addition, the median serum Ang-2 concentration was higher in MMVD dogs with PH than in those without PH (P = .031). Serum Ang-2 concentration was correlated with vertebral heart score (rs = 0.36, P = .004) and vertebral left atrial score (r = 0.50, P < .001) in dogs with MMVD, and correlated with vertebral heart score (r = 0.63, P = .01), maximum E wave amplitude of the diastolic transmitral flow (rs = 0.61, P = .018), ejection fraction (rs = -0.77, P < .001) and fractional shortening (rs = -0.56, P = .032) in dogs with acute congestive heart failure. CLINICAL RELEVANCE: Circulating Ang-2 levels increase in dogs with the severity of MMVD and the presence of PH.

Can neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios be used as markers for hypercortisolism in dogs?

Changes in neutrophil-to-lymphocite ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been identified in dogs with hypercortisolism (HC), but, no studies have investigated the changes in these inflammatory biomarkers as cost-effective and available parameters for the diagnosis and management of HC. This study was performed to evaluate whether NLR and PLR could be used as biomarkers for the diagnosis and treatment response in dogs with HC. This retrospective study included 67 dogs with HC, 58 dogs with non-adrenal illness (NAI), and 39 healthy dogs. NLR and PLR were compared among the three groups. Cut-off values of NLR and PLR for HC screening and percent change in biomarkers for assessing treatment response were evaluated. In addition, the NLR and PLR were compared before and after trilostane treatment. NLR and PLR were significantly higher in the HC group than in the NAI and healthy groups. The NLR cut-off value of 4.227 had a sensitivity of 67.16% and specificity of 65.52%, and the PLR cut-off value of 285.0 had a sensitivity of 56.72% and specificity of 70.69% for differentiating between dogs with HC and those with NAI, respectively. Furthermore, a significant decline in NLR was observed after treatment in the well-controlled HC group. The cutoff value of percent change in NLR to identify well-controlled HC was -7.570%; sensitivity and specificity were 100% and 63.64%, respectively. Therefore, NLR and PLR might be used cautiously as supportive biomarkers for HC diagnosis, and NLR could be a potential monitoring tool in assessing the treatment response of HC in dogs.

Remission of diabetes mellitus induced by prednisolone in combination with cyclosporine toxicity in a cat.

A 6-year-old spayed female domestic short-hair cat was presented for primary complaints of anorexia and lethargy. The cat was being treated with cyclosporine (25 mg/cat, PO q24h) and prednisolone (1 mg/kg, PO q12h) for feline hypersensitivity dermatitis and inflammatory bowel disease for 1 year, wherein prednisolone was withdrawn 2 weeks prior to presentation. At presentation, dehydration, hyperglycaemia, ketonaemia, increased fructosamine, glucosuria, ketonuria and metabolic acidosis were observed. The cat was diagnosed with diabetic ketoacidosis (DKA). Immediate treatments with insulin continuous-rate infusion and intravenous fluid therapy were initiated. A serum cyclosporine concentration was >2100 ng/mL, indicating cyclosporine toxicity. Cyclosporine was discontinued immediately. The cat's acidosis and ketonaemia were resolved within a week, allowing a switch from insulin continuous-rate infusion to subcutaneous glargine (1 IU/cat), which was eventually discontinued due to persistent normoglycaemia 12 days after initial presentation. Hyperglycaemia was not observed for 28 days thereafter without insulin, indicating remission of diabetes mellitus. This report suggests that using prednisolone, particularly immune suppressive doses, could be problematic in cats receiving long-term cyclosporine therapy. Additionally, diabetic cats receiving immune-suppressive agents can possibly achieve diabetic remission after surviving DKA through regular monitoring of blood glucose concentration, elimination of prednisolone and intensive blood glucose management.

Use of neurofilament light chain to identify structural brain diseases in dogs.

BACKGROUND: Neurofilament light chain (NfL) is released into the peripheral circulation by damaged axons. OBJECTIVES: To evaluate the diagnostic value of serum NfL concentration in dogs with intracranial diseases. ANIMALS: Study included 37 healthy dogs, 31 dogs with idiopathic epilepsy (IE), 45 dogs with meningoencephalitis of unknown etiology (MUE), 20 dogs with hydrocephalus, and 19 dogs with brain tumors. METHODS: Cohort study. Serum NfL concentrations were measured in all dogs using single-molecule array technology. RESULTS: Serum NfL concentration in dogs with each structural disease was significantly higher than in healthy dogs and dogs with IE (P = .01). The area under the receiver operating characteristic curve of NfL for differentiating between dogs with structural diseases and IE was 0.868. An optimal cutoff value of the NfL 27.10 pg/mL had a sensitivity of 86.67% and a specificity of 74.19% to differentiate the dogs with IE from those with structural brain diseases. There were significant correlations between NfL concentrations and lesion size: (1) MUE, P = .01, r = 0.429; (2) hydrocephalus, P = .01, r = 0.563. CONCLUSIONS AND CLINICAL IMPORTANCE: Serum NfL could be a useful biomarker for distinguishing IE from structural diseases in dogs and predicting the lesion sizes of MUE and hydrocephalus.

Case report: Sclerosing encapsulating peritonitis in a cat with disseminated pancreatic adenocarcinoma of presumed ductal origin.

A 9-year-old, neutered male, domestic short-haired cat was referred for recurrent ascites of unknown etiology over a week. Physical examination revealed abdominal distension and ultrasonography revealed a large volume of ascites throughout the abdominal cavity; this was interpreted as modified transudate. The mesentery and abdominal fat were hyperechoic and edematous. Fat tissue was assessed using fine-needle aspiration cytology, and adipocytes, fat-phagocytizing macrophages, and neutrophils were identified. Computed tomography revealed a pancreatic mass connected to the left pancreatic leg. Exploratory laparoscopy confirmed nodular masses and organ adhesions, leading to a tentative diagnosis of sclerosing encapsulating peritonitis. The cat was administered prednisolone, vitamin E, and tamoxifen but died 22 days after the initial therapy. Necropsy revealed a multi-lobulated pancreatic tumor (10 × 10 cm) tightly attached to the stomach and intestine, with a large amount of ascites. The peritoneum, stomach, intestine, and mesentery were covered with numerous disseminated nodules of various sizes (1-5 mm diameter). Microscopically, the tumor consisted of extensive adipose tissue, locally extensive inflammatory infiltrates, fibrous connective tissue, and small invasive proliferative glands. Well-defined small irregular glands composed of single-layered epithelial cells that appear to be of ductal origin were surrounded by an abundant desmoplastic stroma. Neoplastic nodules were widespread in the liver, stomach, peritoneum, mesentery, mesenteric lymph nodes, lungs, and urinary bladder. Immunohistochemistry revealed that the neoplastic glands were positive for pan-cytokeratin, confirming the pancreatic epithelial origin of the tumor. This is the first report of sclerosing encapsulating peritonitis accompanied by aggressive pancreatic adenocarcinoma of presumed ductal origin and extensive metastasis in a cat.

Oesophageal stricture in a cat with true pleuroperitoneal hernia.

A 2-year-old neutered male Bengal cat presented with solid food dysphagia and chronic regurgitation for >5 months. There were no clinical abnormalities on haematological or radiographic examinations. Thoracic radiography revealed a soft tissue opacity mass adjacent to the diaphragm in the caudoventral thorax. Ultrasonography revealed a protruding liver lobe surrounded by a hyperechoic lining from the diaphragm towards the thorax, and a pleuroperitoneal hernia was diagnosed. An endoscopy was performed to examine the cause of regurgitation, and an oesophageal stricture was observed. Endoscopic balloon dilation of the oesophageal stricture was performed, and the regurgitation was resolved immediately. However, regurgitation relapsed 2 months later, and computed tomography was performed to ascertain the cause. Computed tomography revealed oesophageal mural thickening and true pleuroperitoneal hernia with partial liver lobe herniation. A second endoscopy with balloon dilation was performed to treat the relapsing oesophageal stricture, and the clinical signs resolved without the need for herniorrhaphy. Nevertheless, oesophageal stricture could occur due to gastroesophageal reflux related to a pleuroperitoneal hernia; however, a definite link could not be elucidated in this case. This report describes a case of oesophageal stricture and concurrent true pleuroperitoneal hernia in a cat.

Serum concentrations of complement C3 and C4 in dogs with idiopathic epilepsy.

BACKGROUND: High concentrations of complement factors are presented in serum of animal epilepsy models and human patients with epilepsy. OBJECTIVES: To determine whether complement dysregulation occurs in dogs with idiopathic epilepsy (IE). ANIMALS: The study included 49 dogs with IE subgrouped into treatment (n = 19), and nontreatment (n = 30), and 29 healthy dogs. METHODS: In this case-control study, the serum concentrations of the third (C3) and fourth (C4) components of the complement system were measured using a canine-specific ELISA kit. RESULTS: Serum C3 and C4 concentrations were significantly higher in dogs with IE (C3, median; 4.901 [IQR; 3.915-6.673] mg/mL, P < .001; C4, 0.327 [0.134-0.557] mg/mL, P = .03) than in healthy control dogs (C3, 3.550 [3.075-4.191] mg/mL; C4, 0.267 [0.131-0.427] mg/mL). No significant differences were observed in serum C3 and C4 concentrations between dogs in the treatment (C3, median; 4.894 [IQR; 4.192-5.715] mg/mL; C4, 0.427 [0.143-0.586] mg/mL) and nontreatment groups (C3, 5.051 [3.702-7.132] mg/mL; C4, 0.258 [0.130-0.489] mg/mL). Dogs with a seizure frequency >3 times/month had significantly higher serum C3 (6.461 [4.695-8.735] mg/mL; P < .01) and C4 (0.451 [0.163-0.675] mg/mL; P = .01) concentrations than those with a seizure frequency ≤3 times/month (C3, 3.859 [3.464-5.142] mg/mL; C4, 0.161 [0.100-0.325] mg/mL). CONCLUSIONS AND CLINICAL IMPORTANCE: Dysregulation of classical complement pathway was identified in IE dogs. Serum C3 and C4 concentrations could be diagnostic biomarkers for IE in dogs with higher seizure frequency.

Expression of sphingosine-1-phosphate receptor 1 in neuroinflammation of canine brains.

Sphingosine-1-phosphate (S1P) is a signaling lipid mediator that is involved in multiple biological processes. The S1P/S1P receptor (S1PR) signaling pathway has an important role in the central nervous system. It contributes to physiologic cellular homeostasis and is also associated with neuroinflammation. Therefore, this study was performed to evaluate the expression of S1PR in dogs with meningoencephalitis of unknown etiology (MUE) and experimental autoimmune encephalomyelitis (EAE). The analysis used 12 brain samples from three neurologically normal dogs, seven dogs with MUE, and two canine EAE models. Anti-S1PR1 antibody was used for immunohistochemistry. In normal brain tissues, S1PR1s were expressed on neurons, astrocytes, oligodendrocytes, and endothelial cells. In MUE and EAE lesions, there was positive staining of S1PR1 on leukocytes. Furthermore, the expression of S1PR1 on neurons, astrocytes, oligodendrocytes, and endothelial cells was upregulated compared to normal brains. This study shows that S1PR1s are expressed in normal brain tissues and leukocytes in inflammatory lesions, and demonstrates the upregulation of S1PR1 expression on nervous system cells in inflammatory lesions of MUE and EAE. These findings indicate that S1P/S1PR signaling pathway might involve physiologic homeostasis and neuroinflammation and represent potential targets for S1PR modulators to treat MUE.

Preliminary study of neurofilament light chain as a biomarker for hypoxia-induced neuronal injury in dogs.

Neurofilament light chain (NfL) is a neuroaxonal protein in the nervous system. NfL has recently been demonstrated to be a biomarker for various neurological diseases. In this study, we investigated the potential role of NfL in hypoxia-induced neuronal injury in dogs. Serum NfL levels were determined using a single-molecule array. Serum NfL concentrations were significantly higher in hypoxemic dogs without neurological signs (n = 6, 175.5 pg/mL) than in healthy dogs (n = 15, 15.9 pg/mL; p < 0.0001). Therefore, neuronal injury should be considered in dogs with hypoxemia caused by cardiopulmonary diseases, even in the absence of neurological signs.