Toward laboratory blood test-comparable photometric assessments for anemia in veterinary hematology

Anemia associated with intestinal parasites and malnutrition is the leading cause of morbidity and mortality in small ruminants worldwide. Qualitative scoring of conjunctival redness has been developed so that farmers can gauge anemia in sheep and goats to identify animals that require treatment. For clinically relevant anemia diagnosis, complete blood count-comparable quantitative methods often rely on complicated and expensive optical instruments, requiring detailed spectral information of hemoglobin. We report experimental and numerical results for simple, yet reliable, noninvasive hemoglobin detection that can be correlated with laboratory-based blood hemoglobin testing for anemia diagnosis. In our pilot animal study using calves, we exploit the third eyelid (i.e., palpebral conjunctiva) as an effective sensing site. To further test spectrometer-free (or spectrometerless) hemoglobin assessments, we implement full spectral reconstruction from RGB data and partial least square regression. The unique combination of RGB-based spectral reconstruction and partial least square regression could potentially offer uncomplicated instrumentation and avoid the use of a spectrometer, which is vital for realizing a compact and inexpensive hematology device for quantitative anemia detection in the farm field

Endocrine system

The endocrine system is comprised of the glands and tissues that release hormones into the bloodstream, usually in response to a signal from the hypothalamus or pituitary gland. Hormones are synthesised, stored and secreted by the gland, and serve to regulate the function of distant organs or tissues. Hormone secretion occurs in response to a specific stimulus and is highly regulated, usually on several levels including the hypothalamus, the end organs and the gland itself. Hormones may have secondary effects that are not as tightly regulated, which at times may result in pathological states. For example, insulin is released in response to blood glucose concentration in a highly regulated manner, but the increased blood insulin needed to maintain euglycaemia in a horse with insulin dysregulation results in alterations in fat and protein metabolism. Thus, the result of chronic hyperinsulinaemia can be decreased fat mobilisation and increased adiposity

The short-term effect of ovariectomy on measures of insulin sensitivity and response to dexamethasone in mares

Objective-To evaluate the effect of ovariectomy on insulin sensitivity in horses and determine whether the effects of suppression of the hypothalamo-pituitary-adrenal axis differ before and after ovariectomy. Animals-6 healthy mares. Procedures-The horses underwent an IV glucose tolerance test (IVGTT), an insulin sensitivity test, and a dexamethasone suppression test before and 5 weeks after ovariectomy. Body weight, serum cortisol and plasma ACTH concentrations, serum insulin-to-blood glucose concentration ratios, and changes in blood glucose concentration with time after injection of glucose or insulin were compared before and after ovariectomy. Results-The dexamethasone injection resulted in a decrease in serum cortisol concentration before and after ovariectomy. In all horses, baseline plasma ACTH concentrations were within the reference range before and after ovariectomy. For each mare, results of an IVGTT before and after ovariectomy were considered normal. No significant differences in basal blood glucose concentration or time to reach baseline glucose concentration after an IVGTT were observed. Basal serum insulin concentration and serum insulin-to-blood glucose concentration ratios were not significantly different before or after ovariectomy, nor was the mean time to attain a 50% decrease in blood glucose concentration after insulin injection. Conclusions and Clinical Relevance-Results indicated that ovariectomy does not appear to modify dexamethasone response in horses and that it does not modify short-term measures of insulin sensitivity. Findings suggested that horses undergoing ovariectomy are not at higher risk of developing equine metabolic syndrome or hypothalamo-pituitary-adrenal axis dysfunction and associated morbidity

The Effect of Probiotics in a Milk Replacer on Leukocyte Differential Counts, Phenotype, and Function in Neonatal Dairy Calves

Probiotics have been investigated for many health benefits; however, few studies have been performed to determine the effects of oral probiotics on peripheral blood and respiratory immune cells in cattle. Our objectives were to determine changes in health and growth status, differential blood cell counts and function, and blood and lung cell function using flow cytometry and PCR in dairy calves fed a milk replacer with (PRO, N = 10) or without (CON, N = 10) the addition of probiotics to the milk replacer and dry rations from birth to weaning. Performance and clinical scores were not different between the treatment groups. Treatment-by-day interactions for peripheral blood leukocyte populations differed in cell number and percentages. A greater percentage of leukocytes expressed the cell surface markers CD3, CD4, CD8, CD11b, and CD205 on d 21 in CON animals. Lung lavages were performed on five animals from each treatment group on d 52. There were no differences between treatment groups for the expression of cytokines and Toll-Like Receptors as measured using Polymerase Chain Reaction, possibly due to the small sample size. Oral probiotics appear to affect peripheral blood immune cells and function. Their effect on overall calf health remains to be determined

Evaluation of a technique for percutaneous endoscopic gastrotomy tube placement in horses

Objective-To develop and assess the short-term feasibility, maintenance, and complications associated with percutaneous endoscopic gastrostomy (PEG) tube placement in standing horses. Animals-6 adult horses. Procedures-Feasibility of the technique was evaluated in 2 horses. In each of 4 other horses, a PEG tube was maintained for 14 days and used to provide fluid requirements during the latter 7 days, before removal. Following air inflation of the stomach, each PEG tube was placed via a left intercostal approach; proper tube location was ascertained by percutaneous ultrasonography and gastroscopy. The horses underwent physical examinations, CBCs, and peritoneal fluid analyses before and at intervals after tube placement. Seven days after tube removal, horses were euthanized and necropsied. Results-Placement of a PEG tube was feasible in all 6 horses. The 4 horses assessed long term tolerated water administration through the PEG tube and remained clinically stable throughout the 21-day experiment. However, during the period PEG tubes were in place, significant increases in some peritoneal and hematologic variables were detected. Postmortem evaluation revealed localized peritonitis in 1 horse and body wall inflammation along the PEG tube tracks in 3 additional horses. Conclusions and Clinical Relevance-Placement and maintenance of a PEG tube were tolerated well by the study horses, although peritoneal and systemic inflammation were detectable. Fluid requirements were adequately met with this technique, which could provide an alternative method for managing chronically dysphagic horses. Nevertheless, further research is warranted to evaluate the feasibility of enteral feeding by use of this approach in horses

Blood glucose and insulin concentrations after alpha-2-agonists administration in horses with and without insulin dysregulation

In metabolically stable horses, alpha-2-agonists suppress insulin secretion with transient hyperglycemia and rebound hyperinsulinemia. In horses with insulin dysregulation (ID), the effect of alpha-2-agonists has not been investigated; however, both the alpha-2-agonist-induced suppression of insulin secretion and rebound hyperinsulinemia could have clinical relevance.In horses with ID, alpha-2-agonists will alter insulin and glucose dynamics.Seven horses with ID and 7 control horses.In this randomized crossover study, xylazine hydrochloride (1.1 mg/kg) or detomidine hydrochloride (30 μg/kg) were administered IV, and blood was collected for glucose and insulin concentrations at 0, 15, 30, 45, 60, 90, 120, 150, 180, and 300 minutes after administration. Horses received each drug in a random order with a 24-hour washout period between drugs. Percent change in glucose and insulin concentrations was compared between groups, drugs, and over time with P