Ouabain, a cardiac glycoside, binds to the Na+-K+i-adenosine triphosphatase (Na+ pump) and prevents active transport of Na+ and K+ across cell membranes. We used [3H]ouabain to quantify the number and affinity of Na+ pumps in skeletal muscle from Quarter Horses with the muscular disorder hyperkalemic periodic paralysis (HYPP). [3H]Ouabain-binding properties of gluteal muscle from clinically normal and affected horses were used to determine whether altered Na+ pump number or affinity could contribute to the pathologic features of muscle in affected horses. Foals and adult horses with HYPP were compared with age-matched clinically normal horses. The number of [3H]ouabain-binding sites in adult gluteal muscle was not different between the 2 types of horses (85.7 +/- 8.9 pmol of [3H]ouabain-binding sites/g [wet muscle weight] in horses with HYPP vs 100.2 +/- 8.8 pmol/g in clinically normal adult horses). Gluteal muscles in HYPP-affected and clinically normal foals also contained a similar number of [3H]ouabain-binding sites (222.3 +/- 21.0 pmol/g vs 225.3 +/- 24.2 pmol/g, respectively). The affinity of these binding sites for ouabain was not different, between adults or foals, in clinically normal or affected horses. Our results indicate that membrane events underlying the periodic episodes of paralysis in horses with HYPP are not attributable to quantitative changes in Na+ pump number or affinity. Our data cannot exclude the possibility that the specific activity of the Na+ pump is altered in muscle from HYPP-affected horses.

L-lactic acid and D,L-lactic acid infusion in ponies resulted in metabolic acidosis with high anion gap (AG). Increased AG was explained entirely by increased blood L- and D-lactate concentrations. Hydrochloric acid infusion caused metabolic acidosis with decreased AG. Saline (NaCl) infusion caused mild metabolic acidosis, with no significant change in AG. Plasma K+ concentration was decreased by all types of infusions, with a maximum of 0.50, 0.25, 0.40, 0.50 mmol/L below baseline at the end of infusion in the L-lactic acid-, D,L-lactic acid-, HCl-, and NaCl-infused ponies, respectively. Only hydrochloric acid had a tendency to increase plasma K+ concentration. Hypophosphatemia developed in NaCl- and HCl-infused ponies, but not in the D,L-lactic acid-infused ponies. Serum inorganic phosphate concentration in L-lactic acid-infused ponies increased initially, but was significantly (P < 0.05) lower than values in the other ponies at 4 hours after onset of infusion. In ponies, the effect of acidemia on plasma K+ and serum inorganic phosphate concentrations was similar to that reported for other species. Changes were small in magnitude and depended on the nature of the acid anion. Results indicate that large changes in plasma K+ and serum inorganic phosphate concentrations during acidosis are probably not a direct result of acidemia.

Urinary protein-to-creatinine ratios and serum albumin concentrations were measured in 8 adult male dogs experimentally inoculated with Ehrlichia canis. Urinary protein concentration increased significantly, but transiently, during the acute phase of infection. Urinary protein-to-creatinine ratios were highest (mean, 8.6) during the third and fourth weeks after infection, and decreased to < 0.5 by 6 weeks after infection. Correspondingly, albumin concentration decreased significantly during the acute phase. Serum albumin concentrations were lowest (mean, 2.1 g/dl) the fourth week after infection and increased to > 3.0 g/dl by 11 weeks after infection. There was an inverse linear correlation between urinary protein-to-creatinine ratio and serum albumin concentration. The magnitude of proteinuria and its inverse relationship with serum albumin concentration suggested that hypoalbuminemia associated with acute E canis infection may be attributable primarily to increased renal loss of protein, rather than decreased hepatic synthesis as previously suggested. Another dog was subsequently inoculated with E canis from 1 of the experimentally infected dogs and a renal biopsy was performed during peak proteinuria (urinary protein-to-creatinine ratio = 22 and serum albumin = 1.1 g/dl). Immunofluorescent staining revealed mild to moderate deposits of anti-canine IgM, and to a lesser extent, anti-canine IgG and complement factor C3 in the glomerular tufts and mesangium. Ultrastructural evaluation revealed distortion and fusion of podocyte foot processes and increased microvilli on podocytes. These morphologic changes were consistent with transient glomerular leakage of protein of a magnitude that would significantly contribute to hypoalbuminemia during acute E canis infection. An underlying immunologic mechanism was suggested by positive glomerular immunofluorescence and previously described histologic findings.

Concentrations of total, free, and esterified carnitine were determined in plasma, liver, and skeletal muscle from cats with idiopathic hepatic lipidosis and compared with values from healthy cats. The mean concentrations of plasma, liver, and skeletal muscle total carnitine; plasma and skeletal muscle free carnitine; and plasma and liver esterified carnitine were greater (P < 0.05) in cats with idiopathic hepatic lipidosis than in control cats. The mean for the ratio of free/total carnitine in plasma and liver was lower (P < 0.05) in cats with idiopathic hepatic lipidosis than in control cats. These data suggest that carnitine deficiency does not contribute to the pathogenesis of feline idiopathic hepatic lipidosis.

Minimising health problems and increasing yield have always been the objectives in livestock agriculture. Hence, increases in incidences of reproductive conditions in cattle farming pose a great threat to productivity and impose undesirable economic implications. This study aimed to examine the concentrations of different biochemical compounds in cows with reproductive conditions. Seventy-seven blood samples were collected from cows at different rural areas around Mafikeng, following cases of downer cow syndrome, dystocia, retained placenta, vaginal prolapse and abortion. Means of serum metabolites across the different reproductive conditions were statistically compared using Pearson's chi-square test to determine variations of serum metabolites in cows of different breeds. In mixed breed cows, higher than normal calcium concentrations were observed in downer cow syndrome (25.25 ± 8.47) and dystocia (85.50 ± 8.46) cases. It was also observed that cholesterol concentrations were significantly low in abortion (2.52 ± 0.79), retained placenta (3.18 ± 0.61) and vaginal prolapse (2.37 ± 0.97) cases in Afrikaner cows. The study showed that Brahman (43.1%) and Afrikaner (43.1%) breeds were mostly affected by downer cow syndrome. Additionally, the occurrences of downer cow syndrome (53.9%) and abortions (60%) were mostly observed in cows of 1-3 years, in second and first parities, respectively. This study proves that concentrations of calcium, urea or blood urea nitrogen (BUN), magnesium and cholesterol are significantly altered in incidences of reproductive conditions in cows of different breeds. It is also shown that serum biochemistry is affected by reproductive conditions in cows of different ages and parity. This data serves as a tool that could be used to enhance research in animal production and reproduction.

Minimising health problems and increasing yield have always been the objectives in livestock agriculture. Hence, increases in incidences of reproductive conditions in cattle farming pose a great threat to productivity and impose undesirable economic implications. This study aimed to examine the concentrations of different biochemical compounds in cows with reproductive conditions. Seventy-seven blood samples were collected from cows at different rural areas around Mafikeng, following cases of downer cow syndrome, dystocia, retained placenta, vaginal prolapse and abortion. Means of serum metabolites across the different reproductive conditions were statistically compared using Pearson’s chi-square test to determine variations of serum metabolites in cows of different breeds. In mixed breed cows, higher than normal calcium concentrations were observed in downer cow syndrome (25.25 ± 8.47) and dystocia (85.50 ± 8.46) cases. It was also observed that cholesterol concentrations were significantly low in abortion (2.52 ± 0.79), retained placenta (3.18 ± 0.61) and vaginal prolapse (2.37 ± 0.97) cases in Afrikaner cows. The study showed that Brahman (43.1%) and Afrikaner (43.1%) breeds were mostly affected by downer cow syndrome. Additionally, the occurrences of downer cow syndrome (53.9%) and abortions (60%) were mostly observed in cows of 1–3 years, in second and first parities, respectively. This study proves that concentrations of calcium, urea or blood urea nitrogen (BUN), magnesium and cholesterol are significantly altered in incidences of reproductive conditions in cows of different breeds. It is also shown that serum biochemistry is affected by reproductive conditions in cows of different ages and parity. This data serves as a tool that could be used to enhance research in animal production and reproduction.

This study was carried out to investigate the prevalence of equine&#xD;lameness and metabolic disorders in endurance horses during an endurance race. Out of 67 horses that participated in the race, 19 horses completed the race successfully without any derangement while 48 horses were eliminated from the race for various disorders. Fifty-three (53.73%) percent of these horses had metabolic disorders and&#xD;17.91% were eliminated due to lameness. The study showed that the highest number of endurance horses that were eliminated were due to metabolic disorders followed by lameness. These findings may assist veterinarians in designing laudable measures in the management and&#xD;conditioning protocols of endurance horses during training and further prevent the morbidity and mortality during endurance races.

The study was carried out to investigate the effect of prolong&#xD;submaximal exercise on heart rate reflecting the performance of endurance horses after covering distances of 40 and 80 km races. This study was conducted in Malaysia to determine the post-race&#xD;heart rates of endurance horses based on distances for the eliminated horses and those that completed the races with good&#xD;performance. Heart rates of competing endurance horses were examined at pre and post-race. Thirty-four endurance horses were sampled; N = 9 (40 km) and N = 9 (80 km) were the good performance horses while, N = 3 (40 km) and N = 13 (80 km) were the poor performance horses&#xD;eliminated from the race. The mean heart rate of the good performance horses in the 40 km category was 53 ± 8 bpm and that of&#xD;the 80 km in the good performance category was 56 ± 7 bpm, while the eliminated horses of the 40 km group had 74 ± 17 bpm and those in the 80 km group had 78 ± 7 bpm. The study showed that eliminated&#xD;horses in the 40 and 80 km categories both exhibited high heart rates compared to the good performance horses that were in the same racing category. Thus, the heart rates of horses during training may be used to predict performance based on distances covered in endurance races.

Exercise-induced changes of pro-oxidant generating substances and muscle fibre damaging enzymes are the possible causes of reduced performance in endurance horses. Therefore, this study aims to investigate on the performance of different age and gender using biochemical profile of endurance horses during 120 km endurance race. One hundred and eighty four Arabian endurance horses were physically examined and blood samples were collected post-race.&#xD;After physical examination, the MD (F, n= 44; G, n = 86) and SC (F, n = 20; G, n = 34) were identified. T-test and pairwise correlation were used for the analysis. There were significant differences in&#xD;CK, uric acid, lactate and age (P<0.0001) respectively between the gender in the MD and SC. There were significant differences in AST (P<0.0029) and GGT (P<0.0039) respectively between the gender in the&#xD;MD and SC. In conclusion age and gender significantly affect performance of endurance horses in relation to biochemical profile during 120 km endurance race. Therefore, further studies are required to determine if age, gender and biochemical profile could be used to assess performance in endurance horses.