Relative Flow-Time Relationships in Single Breaths Recorded After Treadmill Exercise in Thoroughbred Horses

Analysis of individual breaths after exercise has potential for pulmonary function testing. The aims of this study were to investigate the dependence of measurements of pulmonary function in single breaths on time postexercise and tidal volume (V_T) after treadmill exercise. Five Thoroughbred horses without evidence of airway disease were used. Horses had been previously acclimated to treadmill exercise and to wearing a face mask. A Quadflow spirometer recorded airflow rates continuously during 90 seconds after intense treadmill exercise to fatigue. Indices of function were based on ratios of times within each breath and analyses of the shape of relative flow–time curves within inspiration and expiration. Restricted maximum likelihood, general linear regression, repeated-measures one-way analysis of variance (ANOVA), and two sample t-tests were used, with statistical significance at P < .05. Time postexercise had no effect on several ratios based on time for inspiration (T_I) and expiration (T_E), and times to peak flows (T_I/T_T, T_E/T_T, T_E/T_I, Tpef [peak expiratory flow]/T_E, and Tpif [peak inspiratory flow]/T_I). Many variables were significantly dependent on V_T. Occasional big respiratory cycles with V_T more than 10% greater than in the previous breath had significantly different means for relative flow (Rf)/(T_E/T_I), epz_50% (50% of the time from Tpef to end of expiration), epz_75% (75% of the time from Tpef to end of expiration), and ipz_75% (75% of the time from Tpif to end of inspiration). Predicted means for these variables differed by 10–20%. This study establishes guidelines for the selection of breaths after exercise, and describes a new approach to measurement of relative flow and time relationships. It was concluded that several time-based ratios have potential for measuring pulmonary function. However, care is needed when selecting breaths for calculation of most of the new relative flow–time variables.     

Gross Anatomy of the Pancreatic Lobes and Ducts in Six Breeds of Domestic Ducks and Six Species of Wild Ducks in China

A previously unreported pancreatic duct was found by Liu (1989) in Pekin ducks. This duct has now been consistently found in six breeds of domestic ducks and six species of wild ducks in China. For purposes of Nomina Anatomica Avium it is hereby called the ‘first pancreatic duct’(Ducius pancreaticus primus) since it enters the duodenum at or near the flexure where the descending duodenum becomes the ascending duodenum. All other pancreatic ducts enter the duodenum later, closer to where it joins the jejunum. This first pancreatic duct drains the caudal extremity of the dorsal lobe of the pancreas and can be easily exteriorized for experimental purposes. Within the parenchyma of the dorsal lobe of the pancreas this duct communicates with the dorsal pancreatic duct. In the present study of the gross anatomy of the pancreatic lobes of domestic and wild Chinese ducks we describe and illustrate variations in position and number of all biliary and pancreatic ducts.     

Growth and feed utilization by yearling horses fed added dietary fat

Twenty-four yearlings were used to evaluate the efficacy of feeding feed-grade fat to growing horses. All horses were started on trial at 13-months-of-age and were fed for 112 days. The experimental diets, containing similar nutrient-to-calorie ratios, were: 1) control (no added fat; 2) 5% added fat and; 3) 10% added fat. There was a trend for yearlings fed the 10% added fat diet to grow faster and eat less feed than those on the control diet. Data from this study indicate that feed-grade fat can be safely fed to growing horses. Feeding fat to yearlings stimulated growth and efficiency of feed utilization initially, but these effects were not maintained as the yearlings grew toward maturity.     

Additive genetic relationships between heifer pregnancy and scrotal circumference in Nellore cattle

To estimate heritability (h2) for yearling heifer pregnancy and to estimate the genetic correlation between heifer pregnancy and scrotal circumference, 18,145 records of Nellore heifers exposed to breeding at an age of approximately 14 mo and 25,466 records of contemporary young bulls were analyzed. Heifer pregnancy was considered as a categorical trait, with the value 1 (success) assigned to heifers that were pregnant after rectal palpation approximately 60 d after the end of a 90-d breeding season and the value 0 (failure) otherwise. A single-trait animal model for heifer pregnancy and a two-trait animal model including heifer pregnancy and scrotal circumference were used. Contemporary groups were defined in two ways: including (CG2) or not including (CG1) weaning management of the heifer. Heritability estimates obtained by Method R in single-trait analyses were 0.68 +/- 0.09 and 0.61 +/- 0.10 using CG1 and CG2 definitions, respectively. Heritability estimates for two-trait analyses were 0.69 +/- 0.09 (CG1) and 0.63 +/- 0.08 (CG2) for heifer pregnancy and 0.57 +/- 0.03 (both CG) for scrotal circumference. The genetic correlation estimates between the two traits were 0.20 +/- 0.12 (CG1) and 0.20 +/- 0.13 (CG2). Based on the results of this study, EPD for heifer pregnancy can be used to select bulls for the production of precocious daughters and will be more effective than selecting on scrotal circumference EPD in Nellore cattle. However, scrotal circumference can be incorporated in a two-trait analysis to increase the accuracy of prediction for heifer pregnancy EPD for young bulls. Using contemporary group without heifer weaning management gave higher h2 and, for two-trait analysis, converged more quickly.     

Effect of metoclopramide on gastro-esophageal reflux in anesthetized dogs

Administration of morphine before anesthesia leads to gastro-esophageal reflux (GER) in over 50% of dogs during the subsequent anesthetic. This GER is clinically silent but can lead to aspiration pneumonitis, esophagitis and esophageal stricture. In this prospective clinical study we aimed to determine the effect of metoclopramide on gastro-esophageal reflux (GER) in dogs undergoing elective orthopedic surgery. Dogs were admitted to the study if they were healthy, and had no history of vomiting or dysphagia. Dogs were fasted for an average of 18.2 ± 4.3 (mean ± SD) hours prior to induction of anesthesia. Anesthesia in all dogs included acepromazine, morphine, thiopental and isoflurane in oxygen. By random allocation, half the dogs received metoclopramide (M) as an IV bolus (0.4 mg kg^–1) and then infusion (0.3 mg kg^–1hour^–1), the others received equivalent volumes of saline (S). To measure esophageal pH a sensor-tipped catheter was placed with the tip 5–7 cm cranial to the lower esophageal sphincter, and connected to a computer for continual data collection. The pH of any fluid running from the mouth or nose was measured. Gastro-esophageal reflux was defined as a decrease in esophageal pH below 4 or an increase above 7.5. Fisher's Exact test was used to test significance of differences in incidence between groups. Separate multivariable logistic regression models were created for each outcome to assess the effects of risk factors on outcome. There were seven cases of GER in 16 dogs receiving M and 8/14 in those receiving S. There were no significant differences between M and S treated dogs in age, weight, duration of anesthesia and fasting, thiopental dose or incidence of vomiting. The administration of metoclopramide at this dose did not significantly reduce the incidence of GER in these anesthetized dogs.     

Intracranial fusariosis: a novel cause of fungal meningoencephalitis in a dog

The Fusarium species are a group of saprophytic fungal organisms that are occasionally the cause of opportunistic infections in humans and animals. Central nervous system disease associated with a Fusarium species is most commonly described in horse, resulting in equine leukoencephalomalacia. This report describes a 2-year-old, spayed, female German Shepherd Dog with meningoencephalitis secondary to infection with Fusarium spp. Meningoencephalitis in dogs secondary to a species of Fusarium has not been previously reported. The diagnosis was made based on the histopathologic examination of brain tissues postmortem and special immunohistochemical stains specific for Fusarium solani. The clinical signs in this dog were indicative of multifocal brain disease and included seizures and a paradoxical vestibular syndrome. The clinical findings, diagnostic and histopathologic test results, and the comparative characterizations of other disseminated fungal diseases, especially aspergillosis, are described.     

The prevalence and clinical relevance of hyperkalaemia in calves with neonatal diarrhoea

One hundred and twenty-four calves with neonatal diarrhoea were investigated in order to assess the prevalence of hyperkalaemia and the associated clinical signs. Hyperkalaemia (potassium concentration >5.8 mmol/L) was recognized in 42 (34%) calves and was more closely associated with dehydration than with decreases in base excess or venous blood pH. In 75 calves with normal blood concentrations of D-lactate (i.e. ?3.96 mmol/L), K concentrations were moderately correlated with base excess values (r = ?0.48, P < 0.001). In contrast, no significant correlation was observed in 49 calves with elevated D-lactate. Only three hyperkalaemic calves had bradycardia and a weak positive correlation was found between heart rate and K concentrations (r = 0.22, P = 0.014). Ten of the 124 calves had cardiac arrhythmia and of these seven had hyperkalaemia indicating that cardiac arrhythmia had a low sensitivity (17%) but a high specificity (96%) as a predictor of hyperkalaemia.In a subset of 34 calves with base excess values ??5 mmol/L and D-lactate concentrations <5 mmol/L (of which 22 had hyperkalaemia), changes in posture/ability to stand could be mainly explained by elevations of K concentrations (P < 0.001) and to a lesser extent by increases in L-lactate concentrations (P = 0.024). Skeletal muscle weakness due to hyperkalaemia alongside hypovolaemia may produce a clinical picture that is similar to that in calves with marked D-lactic acidosis. However, since reductions in the strength of the palpebral reflex are closely correlated with D-lactate concentrations, a prompt palpebral reflex can assist the clinical prediction of hyperkalaemia in calves presenting with a distinct impairment in their ability to stand (specificity 99%, sensitivity 29%).