Salivary analysis to unveil the paradigma of stress of domestic horses reared in the wild.

Horse welfare is the product of multiple factors, including behavioral and physiological adjustments to cope with stressful situation regarding environment and housing condition. Collectively, it is supposed that a horse kept in the wild has a lower level of stress than other housing system, and the aim of the present study was to investigate the level of stress in domestic horses reared in the wild and then moved to human controlled housing, through saliva analysis. Twelve clinically healthy Catria (Italian local breed) mares, usually reared in the wild, were moved into collective paddocks for a folkloric event. Saliva samples were obtained before and after the change of housing condition to evaluate stress biomarkers including salivary cortisol, salivary alpha-amylase, and butyrylcholinesterase (BChol). The mares were also scored using the Welfare Aggregation and Guidance (WAG) Tool to highlight the presence of abnormal behaviors. Despite the absence of differences in behavioral scores between wild and paddocks, salivary cortisol and BChol were found to be higher in the wild and lower when mares were moved to paddocks. The highest concentrations in stress biomarkers like salivary cortisol and BChol in the wild was unexpected, but the need for managing hierarchical relationships, and the exposure to feral animals, predators, and weather changes, might explain these findings. The overall results of the present study may provide further knowledge toward stress response in domesticated horses living in the wild moved to human controlled housing system.

Colonic cyst in a cat presenting recurrent constipation and abdominal pain.

A 5-year-old domestic short-haired spayed female cat was presented for abdominal pain and suspended defecation. Abdominal radiographs confirmed constipation; abdominal ultrasonography showed a cystic oval structure attached to the colon. The structure exhibited a well-defined wall, composed of three layers. Its content was mildly echogenic and inhomogeneous. Laparotomy was performed and complete resection of the structure, and of part of the colon, was required (end-to-end anastomosis). Histopathology confirmed the structure to be a cystic formation of the colon with some areas of mucosal metaplasia. However the question whether the cystic structure was consistent with an intestinal duplication cyst - which is the most likely type of cyst in this particular case - a Meckel's diverticulum remnant, a vitelline duct cyst or a cystic diverticulum of the colon could not be resolved. Postoperatively, no further other episode of constipation occurred.

Clinical and epidemiological investigation of chronic upper respiratory diseases caused by beta-haemolytic Streptococci in horses.

An outbreak of strangle-like disease involving 26 horses farmed in central Italy was investigated by clinic examination, endoscopy, cytology, bacteriology and polymerase chain reaction (PCR). At weekly interval, a total of three nasal swabs and one guttural pouches lavage fluid (GPLF) were collected, and no Streptococcus equi subsp. equi carrier was found. Some horses showed upper airways disease and endoscopic signs of pharyngeal lymphoid hyperplasia of different grade and/or abnormal endoscopic appearance of guttural pouches. Streptococcus dysgalactiae subsp. equisimilis was isolated from 14 horses while S. equi subsp. zooepidemicus was isolated from six horses. PCR confirmed the biochemical and serological identification of all isolates and was positive in 10 bacteriological negative samples. The absence of S. equi and the frequent detection of S. equisimilis and S. zooepidemicus suggest that beta-haemolytic streptococci other than S. equi could be the causative agent of strangle-like disease.

Relationship between running speed, isoenzymes of serum creatine kinase and lactate dehydrogenase and left ventricular function in stallions.

The purpose of this study was to assess the possible relationship between maximal running speed, serum isoenzyme patterns of creatine kinase (CK) and lactate dehydrogenase (LDH) and echocardiographic indices of left ventricular function. A group of 15 healthy, 3-year-old Maremmano stallions were given a 100 day training programme. At the end of this the animals carried out a maximum speed test and were divided into 2 groups (A and B) according to whether or not they had attained a speed of 15 m/s. Venous blood samples were taken from each horse before exercise (T0), 2 min (T1) and 24 h (T2) after exercise. Total serum activity of CK and LDH was measured and their isoenzyme distribution pattern determined. The day before the speed test echocardiographic examination was carried out at rest to assess the left ventricular function by calculating telediastolic, telesystolic and stroke volume, ejection fraction and stroke index. Statistically significant differences were found for the CK isoenzyme pattern at T2, where Group A showed an increase in the MM fraction (P = 0.003) and a decrease in the MB fraction (P = 0.014). These changes were thought to be linked to an increased membrane leakage due to exercise and not to muscle fibre disruption because the CK and LDH total activities remained within the normal range. In Group A there was also greater left ventricular telediastolic volume (P = 0.044) and length (P = 0.033) at rest as well as a greater stroke index (P = 0.032). We concluded that the evaluation of CK pattern after exercise and of echocardiographic left ventricular function indices at rest made it possible to select for the fastest horses (Group A).

Physical exercise, oxidative stress and muscle damage in racehorses.

Since it has been suggested that lipid peroxidation following free radical overproduction may be one of the causes of physical exercise-induced myopathies and hemolysis in horses, we looked for the possible relationships between these phenomena and muscle fiber damage. We use a homogeneous group of Maremmana stallions which, after a 3-month training period, underwent a series of physical exercises of increasing intensity. We determined the contents of malondialdehyde (MDA), one of the main lipid peroxidation end-products, and glutathione the substrate of one of the most important free radical scavenger enzymes. We also measured creatine phosphokinase and serum lactate dehydrogenase isoenzyme activities whose modification may be indicative of muscle fiber damage. The results obtained indicated that the physical exercise we adopted was able to modify both MDA and glutathione contents in blood. However, its effect on some LDH isoenzyme activities suggested possible damage to tissues other than muscle.

Defence mechanisms against free radical-induced damage in sheep, cattle and dog erythrocytes.

1. Erythrocytes from sheep were to be found the least resistant to peroxidative stress induced in vitro as compared to those from cattle and dogs. 2. The differences found among species in alpha-tocopherol content and glutathione peroxidase activity were probably insufficient to explain the lowest resistance. 3. One of the main reasons of the lowest resistance may be found in the membrane composition and characteristics (membrane fluidity).