Ignacio Ayala

Cortisol, adrenocorticotropic hormone, serotonin, adrenaline and noradrenaline serum concentrations in relation to disease and stress in the horse

No detailed comparative data are available on the hormonal parameters of horses suffering from a number of diseases. The aim of our study was to measure concentrations of cortisol, adrenocorticotropic hormone (ACTH), serotonin, adrenaline and noradrenaline in horses with various diseases and following surgery, to assess the response of the HPA axis and adrenal medulla. Blood samples were obtained from six groups of horses comprising a total of 119 animals as follows: laminitis, acute abdominal syndrome (AAS), castration surgery, acute diseases, chronic diseases and healthy controls. Serum hormonal concentrations were determined for each group for comparison. Statistically significant differences between all groups and controls were found for cortisol, ACTH (except for castration), serotonin and adrenaline concentrations but only in horses with laminitis and AAS for noradrenaline. No statistically significant differences were found between males and females. The largest changes in the pituitary-adrenal axis activity occurred mainly in acute diseases, laminitis and in the AAS group.

Hyperlipidemic Chicken as a Model of Non-Alcoholic Steatohepatitis

Non-alcoholic steatohepatitis (NASH) is part of the spectrum of non-alcoholic fatty liver disease (NAFLD), currently the most common cause of abnormal liver tests. Given the difficulty of studying all the factors involved in it in human populations, studies in animal models might provide crucial insights in the pathogenesis of steatohepatitis. Several physiological features predispose birds to fat deposition in the liver. The present study was conceived to explore the possibilities of the chicken fed a cholesterol and fat enriched diet as a model for steatohepatitis. We used two different diets: a standard growing mash (control group) and a standard growing mash enriched with 2% cholesterol and 20% palm oil (hyperlipidemic group). We investigated the effect of feeding a cholesterol and fat enriched diet, on plasma lipid levels, liver enzymes and hepatic histopathology. Semiquantitative and quantitative assessment by image analysis was performed to determine changes in lipid deposits and inflammatory infiltration. Statistically significant increases were observed in all plasma lipid parameters, liver macroscopic features, fat deposits and cell-ballooning of hepatocytes between control and hyperlipidemic animals. Significant differences were also observed in the inflammatory infiltration parameters (number of foci, density, area and maximal diameter). Results show that diet-induced hypercholesterolemia and hypertriglyceridemia are associated with severe impairment of liver histology (fat accumulation, inflammation and cell-ballooning), reproducing histological features of human NAFLD. This model, which is easy and reproducible, offers economic and technical advantages. Furthermore, the reversibility of the pathologic changes makes it suitable for drug intervention studies of steatohepatitis.

Effect of atorvastatin and diet on non-alcoholic fatty liver disease activity score in hyperlipidemic chickens.

Non-alcoholic steatohepatitis (NASH) is part of the spectrum of non-alcoholic fatty liver disease (NAFLD), which includes from simple steatosis and steatohepatitis, to the most severe cirrhosis and carcinoma, which develops in the absence of excessive alcohol intake. NAFLD is the most common liver disorder in affluent societies. There is no proven treatment for NAFLD/NASH. One of the most frequent adverse effects of statins is an increase in hepatic aminotransferases. Studies that evaluate if the benefits of statins overcome the risks in NASH are lacking. The present study was conceived to explore the effect of both atorvastatin and diet on regression of steatohepatitis, using a chicken experimental model induced by a hyperlipidemic diet (HD). Plasma lipid levels, liver enzymes and hepatic histopathology, as well as image analysis were performed to determine changes in liver lipid deposits and inflammatory infiltration. Features of steatosis, cell-ballooning, and inflammation were scored to obtain the NAFLD activity score (NAS). A severe level of steatosis was found in animals fed on HD. Atorvastatin treated groups showed smaller size of lipid deposits and a lower level of inflammation than non-treated groups. Atorvastatin therapy induced a significant reduction of hepatocellular damage, even though in the animals which continuously received a hyperlipidemic diet. The combination of atorvastatin therapy and a standard diet produced the lowest decrease of NAS. Our results show that atorvastatin therapy not only decreased plasmatic levels of cholesterol and triglycerides, but also induced a reduction of liver steatosis, inflammation and hepatocellular damage, without increasing plasmatic aminotransferase levels.

Pharmacokinetics of danofloxacin in horses after intravenous, intramuscular and intragastric administration.

REASONS FOR PERFORMING STUDY Danofloxacin is a fluoroquinolone developed for veterinary medicine showing an excellent activity. However, danofloxacin pharmacokinetics profile have not been studied in horses previously. OBJECTIVE To study the pharmacokinetics following i.v., i.m. and intragastric (i.g.) administration of 1.25 mg/kg bwt danofloxacin to 6 healthy horses. METHODS A cross-over design was used in 3 phases (2 x 2 x 2), with 2 washout periods of 15 days (n = 6). Danofloxacin (18%) was administered by i.v. and i.m. routes at single doses of 1.25 mg/kg bwt. For i.g. administration an oral solution was prepared and administered via nasogastric tube. Danofloxacin concentrations were determined by HPLC assay with fluorescence detection. Tolerability at the the site of i.m. injection was monitored by creatine kinase (CK) activity. RESULTS Danofloxacin plasma concentration vs. time data after i.v. and i.g. administration could best be described by a 2-compartment open model. The disposition of i.m. administered danofloxacin was best described by a one-compartment model. The terminal half-lives for i.v., i.m. and i.g. routes were 6.31, 5.36 and 4.74 h, respectively. Clearance value after i.v. dosing was 0.34 l/kg bwt/h. After i.m. administration, absolute bioavailability was mean +/- s.d. 88.48 +/- 11.10% and Cmax was 0.35 +/- 0.05 mg/l. After i.g. administration, absolute bioavailability was 22.36 +/- 6.84% and Cmax 0.21 +/- 0.07 mg/l. CK activity following i.m. dosing increased 3-fold over pre-injection levels 12 h after dosing and subsequently approached (but did not reach) normal values at 72 h post dose. CONCLUSIONS Systemic danofloxacin exposure achieved in horses following i.m. administration was consistent with the predicted blood levels needed for a positive therapeutic outcome for many equine infections. Conversely, danofloxacin utility by the i.g. route was limited by low bioavailability. Tolerability associated with i.m. administration was high. POTENTIAL RELEVANCE Pharmacokinetics, blood levels and good tolerability of i.v. and i.m. administration of danofloxacin in horses indicates that it is likely to be effective for treating sensitive bacterial infections.

Electrocardiographic parameters in the clinically healthy Zamorano-leones donkey

Limited information exists regarding electrocardiographic parameters in clinically healthy donkeys. The study was carried out in 75 healthy adult animals (40 females and 35 males) using the Einthoven standard II and base-apex leads. The P wave showed usually a bifid shape deflection. The QRS complex of the donkeys appeared in several forms: QR and R were the most frequent in limb lead II, and QS and QR in the base-apex lead. Most T waves presented a simple negative configuration in lead II and biphasic shape in the base-apex one. Mean heart rate value was 52 beats per minute. The direction of the QRS vector in lead II had a mean value of 91.4 degrees. We observed a lack of detected arrhythmias. Statistically significant differences were observed between sexes for several parameters. The electrocardiogram of Zamorano-leones donkey differs in several duration, amplitude and morphologic parameters from that of several breeds of horses and donkeys. This fact justifies obtaining values for a specific breed against which to compare values for the same breed.

Intracellular retention of hepatic serpins caused by severe hyperlipidemia

Abstract: Background: High levels of circulating lipids contribute to both the development of non‐alcoholic liver steatosis (NALS) and peripheral arterial disease, leading to increased thrombotic risk. However, the effects of hyperlipidemia on hepatic proteins have barely been studied. Antithrombin is a hepatic serpin with anticoagulant and anti‐inflammatory roles. The conformational flexibility of antithrombin renders it susceptible to both, genetic and posttranslational modifications. Thus, mutations and environmental factors have been shown to alter this molecule.

Double-balloon enteroscopy in two dogs

It is difficult to insert a flexible endoscope deep into the small intestine. A new method, double-balloon enteroscopy, has been developed to improve access to the small intestine, and the aim of this study was to evaluate its usefulness for examination of the small intestine of dogs. The method uses two balloons, one attached to the tip of the endoscope and another attached to the tip of an overtube. The double-balloon endoscope is advanced through the intestine by being held alternately by the balloon on the endoscope and the balloon on the overtube. The technique was applied in two dogs of medium size, using both oral and anal approaches, and it was possible to examine the whole surface of the mucosa of their small intestines.

A Case of Lymphocytic-Plasmacytic Jejunitis Diagnosed by Double Balloon Enteroscopy in a Dog

A 3 yr old male English setter dog was presented for evaluation of a 6-wk history of intermittent diarrhea. After standard gastroduodenoscopy and colonoscopy showed normal mucosa, double-balloon endoscopy (DBE) was used via both oral and anal approaches. Gross changes consistent with inflammation in the jejunum were seen, and biopsy specimens were obtained. Histologic analysis confirmed a diagnosis of lymphocytic-plasmacytic jejunitis. Clinical remission of the disease occurred after 3 mo of therapy with prednisone, metronidazole, and a novel protein diet. Use of DBE has not been previously reported in dogs with inflammatory bowel disease, and isolated lymphocytic-plasmacytic jejunitis has not been described. The described cases of intestinal inflammatory disease diagnosed by conventional endoscopy were related to pathologic changes in the duodenum, ileum or colon, but not the jejunum. The main advantage of the DBE technique allowed examination of portions of the small intestine (jejunum) that were not commonly accessible by standard endoscopic techniques, and permitted a minimally invasive collection of biopsy samples compared with surgical biopsy. This case highlights the need to consider using DBE in animals with gastrointestinal disorders, whose symptoms are not readily explained by routine tests, conventional endoscopy, and dietary or therapeutic trials.

Effect of diet/atorvastatin on atherosclerotic lesions associated to nonalcoholic fatty liver disease in chickens

Comparative histological examination of both liver and the supra-aortic arteries have not previously examined the consequences of atherosclerosis and nonalcoholic fatty liver disease (NAFLD), and their response to diet and atorvastatin therapy. This study evaluates the effects of diet alone or in combination with atorvastatin therapy on the progression/regression of atherosclerosis and its correlation with NAFLD. This research was performed on a cohort of chickens on standard (SD) or hyperlipidemic diets (HD), either with or without atorvastatin therapy. The development of atherosclerotic lesions was assessed by histology, immunohistochemistry and quantitative image analysis and correlated with liver histology. The lowest levels of atherosclerotic lesions were found in animals on the HD for 3 months, followed by 3 months of SD in combination with oral atorvastatin. There was a strong association between the histologic findings of atherosclerosis and those of NAFLD. These studies show that standard diet and atorvastatin therapy can positively affect both arterial and hepatic lesions, influencing the regression of the changes. These results support the hypothesis that NAFLD and atherosclerosis may be actually two aspects of a shared disease and suggest the possibility of regression of both disorders with dietary and pharmacologic manipulations.

Neuromuscular disease associated with glycogen storage in a Spanish-bred filly

F. Gil, DVM, PhD, R. Latorre, DVM, PhD, Department of Anatomy, Veterinary Faculty, M. A. Carrion, DVM, C. Aguirre, DVM, I. Ruiz, DVM, I. Ayala, DVM, PhD, Large Animal Medicine and Surgery Service, Clinical Veterinary Hospital, University of Murcia, Spain M. Aleman, DVM, PhD, Department of Surgical and Radiological Sciences, University of California, Davis, USA M. A. Rivero, DVM, PhD, Department of Anatomy, Veterinary Faculty, University of Las Palmas de Gran Canaria, Spain Short Communications