High sulfide concentrations in rumen fluid associated with nutritionally induced polioencephalomalacia in calves

Nine 115- to 180-kg, hay-adapted, Holstein steers were fed an experimental diet with added sodium sulfate that induces polioencephalomalacia (PEM). Five calves developed the disease. Thiamine concentrations in blood, CSF, brain, and liver were not indicative of thiamine deficiency. The odor of hydrogen sulfide in eructated rumen gas was associated with the onset of PEM. Sulfide concentrations in rumen fluid were measured 1 or 2 times a week by 2 techniques. Sulfide concentrations progressively increased in all 9 calves after the feeding of the PEM-inducing diet commenced. The highest concentrations coincided with the onset of clinical signs of PEM and were significantly higher in the calves that developed PEM than in those that did not. This suggests that PEM can result from sulfide toxicosis following excess production of sulfide in the rumen.     

Clinical, haematological and biochemical findings in milk-fed calves with chronic indigestion

The principal clinical signs in 59 milk-fed calves with chronic indigestion were general malaise and depression, poor appetite, poor body condition, dehydration, a dull and scaly hair coat, alopecia and clay-like faeces. All the calves had metabolic acidosis, which was associated with an inability to stand up in more than half of them. There were significant differences in the severity of acidosis between the calves that could stand and those that could not. Other signs in some of the calves were dehydration, leucocytosis, and increased activities of liver enzymes.     

Sulfur-induced polioencephalomalacia in sheep: some biochemical changes.

The effect of high dietary sulfur (S) supplementation on blood thiamine (B1) concentration, biochemical indices of liver, muscle and kidney damage and selected plasma electrolytes was studied in six sheep. Three of these sheep received an additional 230 mg thiamine/kg diet (Group 2). After approximately 2.5-3 weeks on this diet, all three sheep in the non-B1-supplemented group (Group 1) showed loss of appetite and developed mild neurological signs: depression, intermittent signs of excitation and head pressing. Increases in blood B1 concentration and plasma creatine kinase (CK) and aspartate aminotransferase (AST) were observed during this time in all affected animals. Clinical signs lasted only for two to five days. Sheep in group 2 were clinically normal throughout the experiment, but all of these animals also had elevated blood B1 concentrations and plasma CK activity at the 3 wk sampling. Plasma magnesium concentrations of group 1 sheep were elevated at the 2.5-3 wk and 6 wk samplings but they declined significantly (p less than 0.05) to low normal levels thereafter. Magnesium concentrations of group 2 sheep were low at the beginning but progressively increased during the course of the experiment. At necropsy, brain lesions suggestive of polioencephalomalacia (PEM) were observed in all sheep but were most marked in group 1. It is speculated that PEM may be caused by a direct toxic effect of S, S metabolites or B1 antimetabolites in the brain rather than by an in vivo B1 deficiency per se.     

Evaluation of structural and functional alterations of circulating neutrophils in calves with experimentally induced pneumonic pasteurellosis

OBJECTIVES: To determine the structural and functional alterations in circulating neutrophils that may lead to sequestration in lung microvasculature and endothelial injury in calves with experimentally induced pneumonic pasteurellosis. ANIMALS: 10 healthy, 2- to 4-week-old male Holstein calves. PROCEDURES: Holstein calves were anesthetized and inoculated intrabronchially with Dulbecco phosphate buffered saline (0.9% NaCl) solution (DPBSS; 5 control calves) or 1 x 10(9) Pasteurella haemolytica organisms (5 infected calves). Blood samples were collected before and 1, 2, 4, and 6 hours after inoculation. Total and differential WBC count, dilute whole blood leukocyte deformability, neutrophil size distribution, and neutrophil surface CD11b expression were measured in blood samples. RESULTS: A progressive decrease in leukocyte deformability and increase in neutrophil size was detected 1, 2, 4, and 6 hours after inoculation of P haemolytica. Neutrophil surface CD11b expression was greater than baseline values at 6 hours after inoculation of P haemolytica. Two populations of neutrophils with an increase in size were detected in P haemolytica-infected calves. Both subpopulations had increased CD11b expression, compared with neutrophils that were typical in size. CONCLUSIONS AND CLINICAL RELEVANCE: Neutrophils circulate in an activated and nondeformable state in calves with experimentally induced pneumonic pasteurellosis. A decrease in neutrophil deformability and neutrophil aggregation may contribute to neutrophil trapping in the lung microvasculature during pneumonic pasteurellosis in calves.     

Epinephrine induced hyperglycemia in bulls and its relationship to polioencephalomalacia.

Data on blood glucose concentration in bulls affected with molasses associated polioencephalomalacia are controversial. It has been suggested that the brain lesions are related to a "hypoglycemic state" during the development of polioencephalomalacia. This paper reports the mobilization of glucose by means of the epinephrine test in three bulls fed two diets, one forage based and the other molasses based. The results showed significantly greater hyperglycemic responses in the animals during the molasses diet than during the forage one. This probably means that glucose stores (as glycogen) are higher in cattle consuming molasses than those consuming forage. Such hepatic glucose output is in disagreement with the hypoglycemia theory as the cause of the early stages of brain lesions and focuses the probable cause as being related to glucose utilization.     

Clinical signs and biochemical changes in calves caused by injection of ivermectin

Eight-month-old Jersey bull calves given ivermectin intravenously or subcutaneously showed signs of depression, ataxia, difficulty in breathing, tachycardia, salivation, diarrhoea, miosis, and an increase in pseudocholinesterase activity. The clinical signs were severe in calves given the drug intravenously. The findings suggest that the cholinergic nervous system may be involved in some of the adverse effects of ivermectin observed in calves.     

Serum biochemical changes in calves with Johne's disease

SUMMARY Calves clinically affected with experimentally induced Johne's disease exhibited elevation of caeruloplasmin oxidase activity, and marked depression of α-mannosidase activity during the period when clinical signs of the disease were most prominent. Changes in serum copper levels and alkaline phosphatase activity were closely correlated with the elevation of caeruloplasmin oxidase activity, and depression of α-mannosidase activity. The pattern of these changes was similar to nutritional and metabolic changes described previously in acute infectious conditions in man and animals.     

Cardiac isoenzymes in healthy Holstein calves and calves with experimentally induced endotoxemia

This paper describes a controlled study designed to establish normal values for cardiac troponins I and T (cTnI and cTnT) and CK-MB mass in healthy newborn Holstein calves, and to compare values for cTnI, cTnT, CK-MB and total creatine kinase (CK) with age-matched calves experiencing experimentally induced endotoxemia. Nineteen healthy Holstein bull calves, 48 to 72 h of age were used. Baseline cTnI, cTnT, CK-MB and total CK measurements were obtained from control (n = 9) and experimental (n = 10) calves. Controls then received physiological saline and experimental calves received endotoxin (O55:B5 Escherichia coli LPS) intravenously after which cardiac biomarkers and total CK were measured at 3 h, 6 h, 12 h, and 24 h post-initiation of infusion. Measured values were analyzed and compared using analysis of variance (ANOVA) by repeated measure design, with statistical significance set at P < 0.05. The cardiac biomarker cTnT was not detected in any calf at any time point, and CK-MB was only detected in 5 of 95 samples. The cTnI was significantly increased compared to baseline and controls, 3 h post lipopolysaccharide (LPS) infusion. Total CK was significantly increased in LPS administered calves at 18 and 24 h post infusion. The mean, standard deviation, and range for cTnI in healthy controls were 0.023 ng/mL (s = 0.01), and 0.01 to 0.05 ng/mL, respectively. In conclusion, LPS administration was associated with rapid and significant increases in cTnI but CK-MB and cTnT were not detected in the plasma of healthy calves. Total CK values increased significantly following LPS administration. Biochemical evidence of myocardial injury occurs within 3 h following LPS administration to neonatal Holstein calves.     

Role of thiamine status in sulphur induced polioencephalomalacia in sheep.

The effects of excess dietary sulphur were studied in sheep supplemented and unsupplemented with thiamine. The diets contained either 0.19 per cent sulphur (LS) or 0.63 per cent sulphur (HS) in combinations with 14 mg kg-1 thiamine (LB1) or 243 mg kg-1 thiamine (HB1). A total of 56 two-month-old lambs were used. Groups consisting of nine, nine, 22 and 16 lambs were fed LS-LB1, LS-HB1, HS-LB1 and HS-HB1 diets, respectively for 14 weeks. Out of 22 lambs fed the HS-LB1 diet, seven lambs developed neurological signs between the third and eighth week of the trial. Two of these lambs died, three that were in extremis were euthanased, and two recovered completely. All clinically affected animals had extensive malacic lesions in the cerebral cortex, midbrain and brainstem. None of the lambs from the LS groups or HS-HB1 group developed clinical signs. Several clinically normal lambs from the HS-LB1 group had necrotic lesions in their brains at gross and microscopic examination. Supplementation with dietary thiamine prevented development of clinical signs, but did not totally prevent development of microscopic brain lesions. Brain thiamine concentration, transketolase activity and thiamine pyrophosphate (TPP) effect were not different (P greater than 0.05) among groups. There was a strong effect (P less than 0.0001) of dietary thiamine supplementation on blood thiamine concentration and TPP effect. Blood thiamine concentration was higher whereas TPP effect was lower in the thiamine supplemented sheep. Blood and tissue thiamine concentrations in sheep exposed to high dietary sulphur did not indicate either systemic or local thiamine deficiency per se. Increased TPP effect in sheep fed the HS-LB1 diet indicated mild to moderate metabolic thiamine deficiency. Thiamine inadequacy may be an effect of an increased requirement for thiamine in animals exposed to excess dietary sulphur.     

Clinical aspects of experimentally induced chloride deficiency in Holstein calves

A severe total body chloride deficit was induced in Holstein calves by feeding a low-chloride ration (0.063% Cl) and removing digesta daily from the abomasum through a surgically implanted cannula. Clinical signs of the deficit observed included polydipsia, polyuria, dehydration, anorexia, scleral injection, decreased respiratory rate, and blood and mucus in the feces. Necropsy findings included dehydration, blood in the lumen of the small intestine, and renal lesions. The most extensive histopathologic changes occurred in the renal tubular epithelium of the outer medulla where mineralization of the tubular epithelium and basement membranes was frequently seen.     

Lymphocyte alterations in zinc-deficient calves with lethal trait A46

Lymphocyte numbers and activities were evaluated at 2, 4, 8 and 12 weeks of age in two calves with lethal trait A46 (A46), a genetic disorder affecting intestinal zinc absorption. Plasma zinc concentrations declined to subnormal by 3 weeks of age, after which anorexia, diarrhea, alopecia and hyperkeratosis occurred. Lymphocyte response to phytohemagglutinin-P (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM) stimulation was variably reduced. CD4+ T-lymphocytes were subnormal on at least one observation period following onset of zinc deficiency, and relative numbers of B lymphocytes were decreased at 8 weeks. Secondary antibody responses to bacteriophage phi X 174 were significantly reduced. The results demonstrate that calves homozygous for the A46 trait have normal numbers of functional lymphocyte subpopulations at birth, and that the activity of their lymphocytes is altered once the calves become zinc deficient.     

Clinical and pathologic studies of experimentally induced Pasteurella haemolytica pneumonia in calves

Pasteurella haemolytica pneumonia of the right caudal lung lobe was experimentally induced in 2-week-old Holstein calves (n = 11) by endobronchial inoculation of 7.9 x 10(10) colony-forming units of 6-hour log-phase bacteria. Calves were studied for 72 hours after inoculation. The challenge procedure consistently induced a lesion in the right caudal lung lobe, which was consistent radiographically with results of pathologic examination and a similar volume of bronchography contrast medium. Clinically, the calves developed a significant increase in rectal temperature within 24 hours after inoculation. Seventy-two hours after inoculation, the total WBC counts, absolute band neutrophil counts, monocyte counts, and blood fibrinogen concentrations were significantly higher than normal and albumin concentration was significantly decreased. Necropsy revealed a circular to oblong lesion that was congested, edematous, and firm and occupied 20 to 40% of the right caudal lung lobe. Histologic examination revealed a severe acute inflammatory reaction characterized by cellular exudate and proteinaceous fluid in the alveoli, interlobular septa, and pleura.     

Morphologic alterations of Anaplasma marginale in calves after treatment with oxytetracycline.

The morphologic features of Anaplasma marginale were determined after treatment of infected calves with oxytetracycline. By light microscopy, anaplasma bodies in erythrocytes of treated calves were enlarged and vacuolated, small and dense, or comma shaped. Several degenerated forms of anaplasma bodies were observed by electron microscopy. There was a blending of the 2 membranes surrounding initial bodies, aggregation of nucleoprotein at the periphery of the subunit, and vacuolation. A 2nd form of degeneration was coalescence of subunits in marginal bodies. A 3rd form of degeneration was unification of subunits of anaplasma bodies and clumping of nucleoprotein. A 4th form of degeneration was the persistence of an anaplasma body as a solitary, irregularly shaped mass containing electron-opaque clumps.     

Haematological and biochemical changes in buffalo calves inoculated with Sarcocystis fusiformis from cats

Two groups of buffalo calves were infected with Sarcocystis fusiformis sporocysts. Animals of the first group received each 5 X 10(5) sporocysts, those of the second group 5 million sporocysts. All calves were clinically normal during 6 weeks after infection. Minor changes were observed in the blood cytology, serum alkaline phosphatase, glutamic oxalacetic transaminase, glutamic pyruvic transaminase, total proteins, urea and glucose of infected buffalo calves.     

Changes in the blood biochemical and haematological profile of neonatal calves with age

Fourteen calves were used to investigate the changes from birth to 83 days of age in the concentrations of serum albumin, alkaline phosphatase, beta-hydroxybutyrate, plasma cortisol, serum creatine kinase, creatinine, iron, plasma fibrinogen, serum gamma-glutamyl transferase, plasma glucose, haptoglobin, serum non-esterified fatty acids, total protein, transferrin, triglycerides, urea and gamma globulin; the haematological variables measured were: basophils, eosinophils, haematocrit, haemoglobin, lymphocytes, mean cell haemoglobin, mean cell haemoglobin concentration, mean cell volume, monocytes, band neutrophils, neutrophils, platelets, red blood cells and white blood cells. The changes are presented as a series of graphs and the values are discussed in relation to the published reference ranges for adult cattle. Two populations of calves were identified which gave rise to a bimodal distribution for some of the variables. Differences in haematocrit, haemoglobin and red blood cell counts were apparent at birth, with raised values for these measurements being associated with an increased white blood cell and neutrophil count between three and 27 days of age.     

Hematologic and serum biochemical changes in Salmonella ser Typhimurium-infected calves

OBJECTIVE: To evaluate hematologic and serum biochemical changes in Salmonella ser Typhimurium-infected calves. ANIMALS: 16 male 3- to 4-week-old dairy calves. PROCEDURE: 13 calves were experimentally infected with S Typhimurium (strains IR715 and CS401, which are derivatives of ATCC 14028), and 3 calves were uninfected controls. Several hematologic and serum biochemical parameters were measured. RESULTS: Hematologic changes included increases in PCV, RBC count, and hemoglobin concentration, associated with a transitory leukopenia characterized by neutropenia and lymphopenia. Biochemical findings included hypoglycemia, increased BUN, creatinine, and fibrinogen concentrations, and decreased sodium, total CO2, calcium, total protein, and albumin concentrations. Increased total bilirubin concentration associated with decreased conjugated bilirubin concentration was also observed. No significant changes in aspartate aminotransferase, gamma-glutamyltranspeptidase, alkaline phosphatase, and creatinine kinase activities were detected. CONCLUSIONS AND CLINICAL RELEVANCE: Experimental salmonellosis of calves results in marked to severe dehydration, accompanied by metabolic acidosis, hypoglycemia, and an acute inflammatory response associated with increased fibrinogen concentrations and severe neutropenia immediately after inoculation.