Endometrial Population of Oestrogen Receptors Alpha and Beta and Progesterone Receptors A and B During the Different Phases of the Follicular Wave of Llamas (Lama glama)

The aim of this study was to characterize the distribution of oestrogen receptor (ER)α and ERβ as well as both progesterone receptors isoforms progesterone receptor (PR) A and PRB in the luminal and glandular epithelia and stroma of the endometrium during the different phases of the follicular wave in llamas. Six llamas were examined by transrectal ultrasonography, and a transcervical biopsy was obtained when a follicle at the growing, plateau and regressing phase was recorded. Blood samples were collected at the time of biopsy for hormone determinations. An immunohistochemical technique was used to study receptor populations. Total positive area was evaluated in the different cell types by Image Analysis. Mean diameter measurements of the largest follicle were 6.9, 8.5 and 5.1 mm (p < 0.001) and mean plasma oestradiol‐17β concentrations were 27.9 ± 3.26; 30.0 ± 2.79 and 24.0 ± 1.78 pmol/l (p = 0.32) during the growing, plateau and regressing phases, respectively. Immunostaining of ERα was higher in the luminal epithelium during the plateau and regressing phases (p < 0.05) than during the growing phase. More positive cells to ERβ were observed in the glandular epithelium of the growing and plateau phases (p < 0.05) than during the regressing phase. A higher percentage of cells positive to PRB was recorded in the luminal and glandular epithelia during the plateau phase (p < 0.05), while the PRA immunostaining was similar among phases. In brief, this study showed an increased population of ERα and PRB in the luminal epithelium, and only of PRB in the glandular epithelium at the time when an ovulatory follicle is present. The physiological importance of these changes in llamas remains to be elucidated.     

Chloride Ion in Small Animal Practice: The Forgotten Ion

The Physiology of chioride ion and its relationship to clinical disorders in small animall practice is reviewed. Chioride is the major anion in the extracellular fluid and is important in the metabolic regulation of acid-base balance. A new clinical approach is used to assess chloride ion changes after accounting for changes in free water. Using this approach chloride disorders can be divided into corrected and artifactual. Changes in free water are solely responsible for the chioride ion changes in artifactual disorders, whereas in corrected chloride disorders, chloride ion itself changes. Corrected hypochioremia is associated with increases in the strong ion differece (SID) and metabolic alkalosis and is caused by administration of solution containing a high concentration of sodium relative to chioride (e.g., Sodium bicarbonate) or the excessive loss chioride relative to sodium (e.g., vomiting of stomach contents). Administration of chioride is correction of hypochioremic metabolic alkalosis. Corrected hyperchioremia is associated with a decreased SID and metabolic acidosis and is usually the result of excessive loss of sodium relative to chloride (e.g., diarrhea), chioride retention (e.g., renal tubular acidosis), or therapy with solutions containing a high concentration of chioride relative to sodium (e.g.,0.9% sodium chloride;3–24% hypertonic saline). Treatment with sodium bicarbonate should be attempted in patients with corrected hyperchioremia and a plasma pH beiow 7.2.     

Effect of dietary supplementation with flaxseed oil or vitamin E on sheep experimentally infected with Fasciola hepatica

The effects of two diets supplemented with flaxseed oil (FO) or vitamin E (VE) were studied in sheep infected with Fasciola hepatica. The control group (CO), not supplemented, had higher weight gain and faecal egg count (P < 0.05) at the end of the study. At necropsy, the number (71.2 ± 26.5) and size of flukes were lower in the FO group (P < 0.01), probably due to the higher levels of white blood cells and lymphocytes (P < 0.01). This group also had higher red blood cell and haematocrit values (P < 0.01). The CO group had more severe hypoproteinaemia and hypoalbuminaemia, due to having the highest fluke burden (123.0 ± 35.2), and also the highest IgG1 titre (P < 0.01). The diet did not affect production or gene expression levels of IFN-γ and IL-4. On the other hand, the supplementation with VE led to a reduction in adult fluke burden (97.7 ± 39.9) and lower lipid oxidation in the liver (P < 0.001).     

Placental thrombosis in acute phase abortions during experimental Toxoplasma gondii infection in sheep

After oral administration of ewes during mid gestation with 2000 freshly prepared sporulated oocysts of T. gondii isolate M4, abortions occurred between days 7 and 11 in 91.6% of pregnant and infected ewes. Afterwards, a further infection was carried out at late gestation in another group of sheep with 500 sporulated oocysts. Abortions happened again between days 9 and 11 post infection (pi) in 58.3% of the infected ewes. Classically, abortions in natural and experimental ovine toxoplasmosis usually occur one month after infection. Few experimental studies have reported the so-called acute phase abortions as early as 7 to 14 days after oral inoculation of oocysts, and pyrexia was proposed to be responsible for abortion, although the underline mechanism was not elucidated. In the present study, all placentas analysed from ewes suffering acute phase abortions showed infarcts and thrombosis in the caruncullar villi of the placentomes and ischemic lesions (periventricular leukomalacia) in the brain of some foetuses. The parasite was identified by PCR in samples from some placentomes of only one sheep, and no antigen was detected by immunohistochemical labelling. These findings suggest that the vascular lesions found in the placenta, and the consequent hypoxic damage to the foetus, could be associated to the occurrence of acute phase abortions. Although the pathogenesis of these lesions remains to be determined, the infectious dose or virulence of the isolate may play a role in their development.     

Expression of transforming growth factor-beta 1 (TGF-beta1) in different types of granulomatous lesions in bovine and ovine paratuberculosis

Paratuberculosis, caused by Mycobacterium avium subsp. paratuberculosis (Map), is manifested by a broad spectrum of clinical and lesional presentations. We have evaluated the expression of transforming growth factor-beta1 (TGF-beta1), a cytokine known to have immunosuppressor effects, by immunohistochemistry, in different paratuberculosis lesions in the intestine and lymph nodes from 20 sheep and 25 cattle. Peripheral immune responses were assessed by interferon-gamma (IFN-gamma) test and the presence of antibodies. Expression of TGF-beta1, observed in macrophages and giant cells forming the lesions, was closely related to the amount of Map. In focal and multifocal forms, usually positive to IFN-gamma test, bacilli were difficult to detect and TGF-beta1 expression was low or absent. Diffuse multibacillary lesions, negative to IFN-gamma, show large numbers of Map and the highest percentage of immunolabelled cells. Diffuse paucibacillary forms, positive to IFN-gamma, have low numbers of AFB and scant or no cells positive to TGF-beta1. The high expression of TGF-beta1 would be related to the inability of macrophages to limit the multiplication of Map.     

Survey of Feeding Practices, Supplement Use, and Knowledge of Equine Nutrition among a Subpopulation of Horse Owners in New England

Nutrition is a critical component of equine health. Horse owners' knowledge of nutrition is likely to affect their feeding practices. The aim of this study was to survey feeding practices, dietary supplement use, and knowledge about equine nutrition in New England by surveying a subpopulation of horse owners (67/337 or 19.8%) who brought their horses to the Large Animal Hospital at the Cummings School of Veterinary Medicine at Tufts University between July and September 2008. All owners reported feeding hay, with the majority feeding grass or timothy hay. Most owners (96%) reported feeding a concentrate in addition to hay. Approximately 84% of owners reported including at least one dietary supplement in their horse's daily feeding. The most commonly used supplements were chondroprotectives, electrolytes, and multivitamins. Survey questions designed to assess the owner's knowledge of nutrition suggested that many owners may not have a basic understanding of principles of equine nutrition; less than 50% knew the daily water and hay requirements for a horse, and 69% lacked knowledge about the proper use of concentrates in a diet. Most of the surveyed owners consulted multiple sources of information concerning equine nutrition, including veterinarians (n = 36), trainers (n = 27), feed stores (n = 10), and the internet (n = 7). Although the major source of information was the veterinarian, it appears that the communication between horse owners and their veterinarian about optimal feeding practices could be enhanced. This survey demonstrated areas in the veterinarian–client dialog that need to be addressed when evaluating the health and well-being of the horse.