Hypernatremia in Calves

Hypernatremia (sodium chloride intoxication) is described in two calves due to presumed mixing errors of oral electrolyte solutions while undergoing therapy for neonatal diarrhea. The experimental induction of hypernatremia in two clinically normal calves is also reported. Physical findings in diarrheic calves included depression, weakness, dehydration, and diarrhea. Serum sodium concentrations were found to be 171.6 mEq/l and 208.0 mEq/l, respectively. Treatment with intravenous fluids was attempted in both cases, but one calf died after 6 hours and the other calf died after 2 days and exhibited periodic convulsions before death. Experimental induction with oral administration of 1 l of electrolyte concentrate, which contained approximately 2750 mEq sodium revealed that the normal calves would willingly consume the solution as mixed with milk and develop clinical signs of hypernatremia within 6 hours of administration. Serum sodium concentrations of 176.0 and 179.8 were found in the experimental calves and coincided with the onset of overt depression and weakness, at which time they were euthanatized. Cerebrospinal fluid electrolyte analysis paralleled the serum electrolyte alterations.     

Ascaris suum Infection in Calves III. Pathology

Gross changes in the lungs of Ascaris suum- infected calves consisted of atelectasis and hemorrhagic foci, edema and emphysema, frequently with bullae. Prominent microscopic lung lesions were edema and emphysema of the interlobular septa with large numbers of eosinophils within and around lymphatics, peribronchiolar lymphoid nodules and parasitic granulomas. Many of the microscopic features were consistent with those found in atypical interstitial pneumonia. Changes in the alveoli were atelectasis, the exudation of plasma proteins, mononuclear cells and eosinophils, and alveolar wall thickening. Lesions found later included fibrosis and fetalization of the alveolar walls. Plasma cells and neutrophils were not common. Challenge with Toxocara canis after sensitization with A. suum resulted in the lungs developing a few areas of atelectasis. Migration of T. canis to lungs of calves is slower than A. suum. A. suum larvae were always found in bronchi, bronchioles and alveoli of calves that died. Lesions were observed in the liver but not the kidney of A. suum infected calves; both lung and liver lesions tended to resolve with time.     

Marine Fat Fed to Young Calves: II. Experiments With Re-Entrant Duodenal Fistulated Calves

In two calves fed milk replacers containing hydrogenated marine fat, collection of the duodenal chyme was carried out over a 24 hr. period, when the calves were about one and a half weeks old. The fat was partly broken down to free fatty acids (F.F.A.) before entering the duodenum. Hydrolysis was probably due to pregastric esterase. No hydrogenation of the unsaturated fatty acids was observed.     

Ascaris suum Infection in Calves I. Clinical Signs

Clinical signs consistent with those of atypical interstitial pneumonia (AIP) were induced in calves sensitized with infective Ascaris suum eggs at seven to 20 weeks of age and challenged at three-week intervals one or more times. These signs usually appeared on the sixth or seventh day postinfection and reached maximum severity between the tenth and 13th days following infection. Prominent signs were: dyspnea, often with expiratory grunt, coughing, mouth breathing and emphysema as well as increased respiration and heart rates. In general, the intensity of signs was dependent upon dose size, although a single small dose resulted in acute signs and death in one calf. Intermittent coughing and vesicular sounds were induced in calves given A. suum eggs continually over prolonged periods. No respiratory abnormalities resulted from challenge with Toxocara canis after sensitization with A. suum. Antihistamine therapy did not alter the clinical signs in A. suum infected calves.     

Plasma Atrial Natriuretic Peptide in Healthy Calves and Calves with Congenital Heart Disease

Background: The basic and clinical implications of evaluating plasma atrial natriuretic peptide (ANP) concentration in calves are unknown.
Objective: To investigate the relationship between the plasma ANP concentration and left ventricular end-diastolic pressure (LVEDP) in healthy calves subjected to volume overload (Study 1), and to compare the plasma ANP concentration in calves with or without heart disease (Study 2).
Animals: Six healthy calves were used in Study 1; disease calves and sick calves with (n = 9) and without congenital heart disease (CHD) (n = 9) were used in Study 2.
Methods: In Study 1, LVEDP in anesthetized calves was manipulated by IV administration of acetated Ringer's solution (rate of 100 mL/kg/h for 20 minutes) and furosemide. In Study 2, disease calves were identified by blood examination and echocardiography or pathological examination. The plasma ANP concentration was determined by a chemiluminescence enzyme immunoassay for human α-ANP.
Results: In Study 1, preloading significantly increased the plasma ANP concentration (36 ± 20–185 ± 156, P < .01) and LVEDP (−11 ± 7–2 ± 12, P < .01) from the baseline. Furthermore, plasma ANP concentrations were strongly correlated with LVEDP ( r = 0.61). In Study 2, the plasma ANP concentration was significantly higher in the calves with CHD than in the calves without heart disease (220 [67–970] versus 31 [10–86]; mean [range], P < .001).
Conclusions and Clinical Importance: Measurement of plasma ANP concentrations in calves can provide additional information useful for predicting hemodynamic abnormalities.     

Experimental Adenovirus Infection in Calves

Twenty-four dairy calves ranging in age from six to 15 weeks were divided so that 10 were inoculated with bovine adenovirus serotype 1 (BA-1), eight were inoculated with bovine adenovirus serotype 3 (BA-3), and six were inoculated with control tissue culture and fluids.

Post-inoculation serum samples from most of the calves presented evidence of adenovirus infection, but none of the animals exhibited signs of respiratory or enteric disease. Histopathological examination of lung tissue was not considered to be specific for adenovirus pneumonia, but was characterized by peribronchial cuffing and slight aspiration pneumonia. BA-1 was not isolated from any of the inoculated calves, and BA-3 was only recovered from the feces of two animals.

Reasons for the discrepancy between these results and those of other workers are considered, and the etiology of peribronchial cuffing is briefly discussed.

     

Vertebral Fractures in Newborn Calves

A prospective study on vertebral fractures in newborn calves is described. Vertebral fractures were found in 7.0% of necropsied calves of the Danish Holstein-Friesian (SDM) and Red Danish Dairy (RDM) breeds. Cases were not found in submitted calves of the Jersey breed or beef breeds. At least in beef breeds this was probably due to the low number necropsied. The rate of vertebral fractures in SDM and RDM breeds and between males and females were similar. Most cases occurred in calves born by heifers, and manual traction force had been applied in all cases. All fractures which in most cases consisted of a simple epiphysiolysis were located at the thoraco-lumbar area, and especially the posterior epiphysis of T13 was afflicted.