High-performance liquid chromatographic assay of (+/-)-lactic acid and its enantiomers in calf serum

Two high-performance liquid chromatographic methods are described for the determination of lactic acid and its enantiomers in calf serum. A 300x8.0 mm I.D. column packed with sulfonated styrene-divinylbenzene copolymer and a 50x4.6 mm ODS column with N,N-dioctyl-L-alanine were used. UV detection was at 205 and 236 nm for the non-chiral and chiral assays, respectively. Both assays demonstrated excellent linear relationships between peak area ratios and serum concentrations over a range of 0.5 to 20 mM, based on 100 microl bovine serum. Recovery was complete. Inter- and within-batch bias and relative standard deviation were <15%.

Examination of metabolism of viscera drained by the portal vein in neonatal calves, using short-term intravenous infusions of glutamine and other nutrients

OBJECTIVE

To quantify glutamine use in viscera drained by the portal vein in neonatal calves and to assess the relative nutritional importance of glutamine, glucose, and acetate for enterocytes.

ANIMALS

5 healthy neonatal calves.

PROCEDURE

A femoral artery, jugular vein, and the portal vein were surgically cannulated in each calf. Blood flow in the portal vein was measured by use of an ultrasonographic transit-time flow probe. A series of solutions was infused on 4 days for each calf. On the infusion days, acetate, glucose, glutamine, and saline (0.9% NaCl; control) solutions were administered IV during 1-hour periods via the jugular vein. Venous and arterial blood samples were collected during the last 15 minutes of each 1-hour infusion.

RESULTS

Uptake of glutamine and glucose by viscera drained by the portal vein was 0.3+/-1.1 and 1.9+/-3.1 micromol/kg0.75/min, respectively, during saline infusion. During acetate, glucose, and saline infusions, glucose was a greater source of energy for the intestines than was glutamine. However, during glutamine infusion, uptake of glutamine by viscera drained by the portal vein increased significantly (29.9+/-11.2 micromol/kg0.75/min), which was associated with an increase in ammonia production (7.0+/-0.5 micromol/kg0.75/min). Toxicosis was not associated with IV administration of glutamine.

CONCLUSION

Glutamine infusion resulted in an increase in glutamine uptake by viscera drained by the portal vein, which was associated with an increase in ammonia production and a slight increase in oxygen consumption.

CLINICAL RELEVANCE

These solutions may be used to develop treatments that enhance healing of intestines of diarrheic calves.

Nutrient uptake by viscera drained by the portal vein in neonatal calves during intravenous infusion of glutamine

OBJECTIVE

To quantify glutamine use by viscera drained by the portal vein in neonatal calves and to determine whether uptake could be stimulated by long-term IV infusion or long-term use of oral supplements.

ANIMALS

4 healthy neonatal calves.

PROCEDURE

A femoral artery, jugular vein, and the portal vein were surgically cannulated in each calf. Blood flow in the portal vein was measured, using an ultrasonic transit-time flow probe. Calves were given an IV infusion of glutamine on days 6, 8, and 10 after surgery. Before the first infusion, calves were fed a diet of milk only. The diet was supplemented with glutamine for the second and third infusions. Glutamine was administered via the jugular vein during a 5-hour period. Venous and arterial blood samples were collected every hour for 5 hours.

RESULTS

During glutamine infusion, uptake of glutamine by viscera drained by the portal vein increased in association with increased production of ammonia. Glutamine supplementation of the diet did not alter glutamine uptake. Glutamine infusion did not increase viscera uptake of indispensable amino acids. Long-term use of glutamine supplements or infusion of glutamine for periods of more than 1 hour increased glutamine uptake by viscera. Arterial leucine concentration and uptake of leucine by the viscera decreased during glutamine infusion, indicating that leucine became the limiting factor.

CONCLUSION

Glutamine administration (supplements or infusions) to calves may require that a mixture of amino acids be provided to improve effectiveness.

CLINICAL RELEVANCE

Glutamine may be beneficial in treatments designed to promote intestinal healing in diarrheic calves.

Hyperkalaemic periodic paralysis in homozygous and heterozygous horses: a co-dominant genetic condition

Historical, clinical and experimental data were collected from 9 horses homozygous for HYPP (H/H). All showed episodes of respiratory stertor, described as a rattling or honking sound, usually within the first week post partum. Five horses had one or more episodes of dysphagia, in 3 horses this was accompanied by drooling and in 3 by weight loss. In comparison, only one of 35 contemporaneous half siblings (of which approximately half would be expected to be of the H/N genotype and half N/N) was observed to have respiratory stertor prior to weaning and none had problems with dysphagia. One mature homozygous stallion was infertile secondary to urospermia. Six homozygous horses died or were subjected to euthanasia; 4 age less than a year, one age 20 months and one age 5 years. The remaining 3 cases were still alive at the end of the study. A comparison of homozygous and heterozygous horses using standardised potassium chloride challenge testing indicated that during attacks homozygotes showed significantly more frequent signs of drooling, prolapse of the third eyelid, respiratory stridor and weakness than heterozygous horses. Homozygotes also had significantly more total abnormalities (including myotonic discharges, high frequency repetitive discharges, and spontaneous activity) on electromyographic examination than heterozygotes. These data imply that HYPP is inherited as a codominant genetic defect, because the homozygotes showed more severe clinical signs of disease than heterozygotes. Homozygous foals would be expected to be produced in 25% of matings in which both parents are heterozygous. Owners and veterinarians should be aware of the risks of this mating.

Long-term surgical preparation of portal vein-drained viscera for determination of their nutritional requirements in preruminant calves

OBJECTIVE

To develop a surgical preparation to study the nutrient concentration difference across the portal vein-drained viscera of preruminant calves over a 2-week period.

ANIMALS

9 healthy preruminant male Holstein calves.

PROCEDURE

A bilateral subcostal approach was used to reach the portal area to provide access for proper placement of an ultrasonic transit time flow probe around the portal vein. The umbilical vein was used as an entry point for the portal vein catheter. The femoral artery was also catheterized. Calves were observed daily, and food intake was recorded. Body weight was recorded weekly. The calves were euthanatized, and necropsy was performed 2 weeks after surgery.

RESULTS

Of the 9 calves, 7 recovered without surgical complications. Within 24 hours of surgery, 1 calf developed an intestinal hernia at the flank incision that was surgically repaired without further complications. One calf was euthanatized a week after surgery because it developed septicemia secondary to catheter-related infection.

CONCLUSION

The bilateral subcostal approach provided access to the portal area, and the umbilical vein was useful as an entry point. Application of an ultrasonic flow probe provided consistent measurements of blood flow over a 2-week period.

CLINICAL RELEVANCE

These results may have implications for development of treatment to promote gastrointestinal tract healing in calves with diarrhea.

Hyperkalemic periodic paralysis

Hyperkalemic periodic paralysis is an autosomal codominant genetic disease of horses who are descendants of the quarter horse sire Impressive. It produces a muscular phenotype that has been selected by show judges, which has resulted in the rapid dissemination of this disease. Clinical attacks are characterized by muscle fasciculation and spasm, and they respond to treatments for the concurrent hyperkalemia.

Effect of glutamine or glycine containing oral electrolyte solutions on mucosal morphology, clinical and biochemical findings, in calves with viral induced diarrhea

Twenty-one diarrheic calves were randomly assigned to 1 of 3 oral electrolyte treatments. The treatments were either a conventional oral electrolyte containing glycine (40 mmol/L) as the amino acid, an oral electrolyte in which glutamine (40 mmol/L) replaced glycine or an electrolyte in which high concentrations of glutamine (400 mmol/L) replaced glycine. The calves were monitored while on trial and at the end of the treatment they were euthanized and a necropsy was immediately performed. Calves fed the high glutamine electrolyte had more treatment failures (2/7 versus 0/7 for each of the other 2 treatments). There was a significant effect of type of electrolyte on fecal consistency. Calves fed the glycine containing electrolyte had the most solid feces. Duodenal villus height was significantly affected by the type of electrolyte: values (mean +/- 1 SEM) were 0.61 +/- 0.09, 0.46 +/- 0.05, and 0.59 +/- 0.07 mm for high glutamine, low glutamine and glycine electrolytes respectively. There was no significant difference in small intestinal surface area between groups. High glutamine treated calves had the greatest capacity to absorb xylose from the small intestine but this difference was not statistically significant. Overall, this trial does not suggest that substituting glutamine for glycine in oral electrolyte solutions improves treatment of diarrheic calves or speeds mucosal healing.

cDNA cloning, expression, and chromosomal localization of a human UDP-GalNAc:polypeptide, N-acetylgalactosaminyltransferase

Oligonucleotide primers derived from the cDNA encoding a full-length bovine UDP-GalNAc:polypeptide, N-acetylgalactosaminyltransferase (GalNAc-transferase) [Homa, F. L., Hollander, T., Lehman, D. J., Thomsen, D. R., and Elhammer, A. P. (1993) J. Biol. Chem. 268, 12609-12616], were used for PCR to isolate sequences encoding a homologous enzyme from human salivary gland cDNA. Comparison of the human and bovine nucleotide sequences reveals 94.8% sequence identity in their coding regions and 87% identity in their 3-untranslated regions. The translation of the human GalNAc-transferase coding region predicts an amino acid sequence which is nearly identical (99.6%) to that of the bovine counterpart; there are five conservative and one non-conservative amino acid substitutions between the two enzymes. Expression of the bovine and human cDNAs in the insect cell line, Sf9, resulted in the synthesis of proteins which appeared identical on SDS-PAGE and which had similar enzymatic properties. Screening of a somatic cell human/rodent hybrid panel with a probe derived from the human GaLNAc-transferase cDNA sequence indicated that the human GalNAc-transferase gene is localized to chromosome 18.

Effect of psyllium on plasma concentration of glucose, breath hydrogen concentration, and fecal composition in calves with diarrhea treated orally with electrolyte solutions

We investigated the effect of adding psyllium to a standard electrolyte solution in 10 calves with diarrhea. The calves were tested with the standard solution on one day and standard solution plus psyllium on the alternate day. The order of treatments was randomized. Psyllium converted the solution into mucilage, but did not affect fecal consistency. Mean +/- SEM area under the glucose absorption curve was lower for mucilaginous than for nonmucilaginous solutions, 2.1 +/- 0.62 vs 3.75 +/- 1.18 mmol.h, respectively, but the difference was not significant. The area under the breath hydrogen curve was marginally lower for mucilaginous than nonmucilaginous solutions, 102 +/- 20 and 209 +/- 60 ppm.h, respectively. The usefulness of such decreased bacterial fermentation is doubtful.

Equine hyperkalemic periodic paralysis: review and implications

The purpose of this review is to present an up-to-date summary of the signs, diagnosis, treatment, and implications of equine hyperkalemic periodic paralysis. The review encompasses all original articles published between 1986 and early 1993. Hyperkalemic periodic paralysis is the result of a genetic mutation in the skeletal muscle sodium channel gene. It is inherited as an autosomal dominant trait; most affected horses are heterozygotes. The classical signs are muscle fasciculation, spasm, and weakness associated with hyperkalemia. However, these signs are only rarely observed in affected horses. Potential sequelae to attacks are abrasions and involuntary recumbency; these problems are not specific for hyperkalemic periodic paralysis, but they occur more frequently in hyperkalemic periodic paralysis-affected horses. It is also likely that hyperkalemic periodic paralysis results in greater muscle mass. There are suggestions that homozygotes may be more severely affected and show signs of upper respiratory obstruction as foals. The practitioner needs to be aware of the tests for hyperkalemic periodic paralysis, and their limitations, so that he can properly diagnose this condition. The industry has the difficult problem of deciding whether or not testing should be mandatory and the fate of positive horses.

Selection of quarter horses affected with hyperkalemic periodic paralysis by show judges

Thirty offspring of a Quarter Horse sire, affected by hyperkalemic periodic paralysis (HPP), were examined electromyographically. On the basis of the detection of or lack of spontaneous activity with high frequency myotonic or pseudomyotonic discharges, the horses were diagnosed as being affected (14 horses) or unaffected (16 horses) with HPP. The show performance of these horses was evaluated for the first 3 to 9 years of their life by use of American Quarter Horse Association records. Horses affected with HPP performed significantly (P < 0.01) better in halter classes than did unaffected horses; mean halter points for the 2 groups were 11.9 and 0.4, respectively. The mean total performance points were not significantly different. None of the offspring had a successful racing record.

Determination of lactose and xylose malabsorption in preruminant diarrheic calves

In preliminary studies feeding the poorly absorbed carbohydrate sorbitol at 2.3 g/kg body weight as an indication of maximal fermentative capacity failed to produce the expected large increase in breath hydrogen excretion but did produce a transient diarrhea in five out of six control calves. Twelve healthy control and eighteen diarrheic calves were fed lactose or D-xylose on consecutive days at 1.15 g/kg body weight and a concentration of 46 g/L. Breath and blood samples were collected at 1 h intervals from 0 to 7 h. After administration of lactose, there was a significant increase in breath hydrogen excretion in diarrheic versus control calves. The increase in plasma glucose concentrations was delayed in diarrheic calves but the area under the absorption curve was similar in control and diarrheic calves. After administration of D-xylose, breath hydrogen excretion did not increase significantly but plasma D-xylose concentrations were significantly reduced in diarrheic calves. The pathogens commonly isolated from the feces were Cryptosporidium species, rotavirus and coronavirus. The number of pathogens and the severity of the calves' acid-base deficit were not related to the severity of carbohydrate malabsorption. Decreased absorption of lactose and D-xylose may be the result of intestinal villous atrophy caused by viral or parasite infection. It was concluded that carbohydrate malabsorption rather than a specific lactose maldigestion is a significant problem in diarrheic calves. Diarrheic calves appear to digest and absorb lactose when fed in small amounts.

Clinical syndrome and diagnosis of hyperkalaemic periodic paralysis in quarter horses

Of the 16 horses studied, 14 belonged to a family previously shown to be susceptible to hyperkalaemic periodic paralysis (HPP), and 8 were shown to have HPP. Diagnosis of HPP by electromyographic detection of myotonic discharges or by oral administration of KCl to induce clinical signs and hyperkalaemia had similar reliability and gave the same result in 80% of cases. KCl had to be administered at doses up to 0.2 g/kg bodyweight to produce signs in some horses. KCl challenge testing was more time consuming than EMG and resulted in one fatality. Overall, electromyography and potassium challenge testing together gave the most accurate diagnosis. Horses were more likely to manifest signs of HPP if they were immature. There was no sex predisposition. The most frequent sign of HPP was muscle fasciculation. Other signs were sweating, muscle spasm, and weakness. Respiratory rate increased greatly during some attacks. Attacks of muscle fasciculation without hyperkalaemia were observed in 2 HPP-affected horses. Affected horses had a greater frequency of spontaneous clinical abnormalities, due mainly to trailering problems, traumatic abrasions and episodes of continuous muscle fasciculation. Hyperkalaemia was confirmed in only one of these instances.

Effects of electrolyte solutions for oral administration on clotting of milk

The effect of electrolyte solutions commercially formulated for oral administration on clotting of milk was investigated in vitro. Rennet or abomasal fluid was used as the clotting agent. Electrolyte solutions that contained large amounts of bicarbonate or citrate (greater than 40 mEq/L) had marked adverse effects on milk clotting, probably because bicarbonate increased pH and because citrate chelated calcium. Addition of solutions that did not contain alkalinizing agents resulted in normal or enhanced clotting, and enhancement was associated with the presence of acid phosphate salts. Electrolyte solutions that included acetate as the alkalinizing agent did not interfere with milk clotting as long as pH of the final solution was acidic and minimal amounts of citric acid salts were present (less than 10 mEq/L). Acetate-containing electrolyte solutions can be used for oral administration in calves in which alkalinization of blood without interference with milk clotting is desired.

Chronic obstructive pulmonary disease: Usefulness of clinical signs, bronchoalveolar lavage, and lung biopsy as diagnostic and prognostic aids

We examined 18 horses with clinical signs of chronic obstructive pulmonary disease (COPD) using physical examination, cytological and bacteriological evaluation of bronchoalveolar fluid, and percutaneous lung biopsy. In 16 cases, histological examination of lung tissue confirmed the diagnosis of COPD. Two horses were excluded: one had uncomplicated bacterial pneumonia and in the other a satisfactory lung biopsy could not be obtained. In horses with COPD, the most common historical complaint was coughing, which was reported in 88%. The most frequently detected abnormal finding on physical examination was abnormal lung sounds; these were detected in 69% of horses at rest and in 88% of horses breathing deeply into a bag. A novel finding was that 29% of horses had lung sounds that were quieter than would be expected for the degree of respiratory effort. Horses with COPD had increased percentages of neutrophils and decreased percentages of lymphocytes and macrophages in their bronchoalveolar lavage fluid. Bronchiolar neutrophil infiltration and peribronchiolar mast cell accumulation in lung biopsy tissue had the highest correlation with clinical condition. The severity of pathological changes in biopsies of lung did not predict whether the horse would die in the two to four year follow-up period. Horses that died in the follow-up period were more severely affected clinically at initial presentation than horses that were alive at the end of the follow-up period.

Familial incidence of hyperkalemic periodic paralysis in quarter horses

The pedigrees of 17 horses with hyperkalemic paralysis were studied. All were first-, second-, or third-generation offspring of a common sire, 16 were registered Quarter Horses. Analysis indicated that it was unlikely that the concentration of hyperkalemic periodic paralysis in the offspring of this sire was attributable to chance. The familial nature of this condition should help veterinarians diagnostically. It also suggests that it is possible to reduce the incidence of this condition by breeding from non-affected lines of horses and reinforces the need for studies to determine whether the disease is genetic in origin. Although more affected horses were second-generation offspring, the proportion of horses affected was largest in the first generation and decreased progressively with each generation. This is probably because horses in the earlier generations have been observed for longer periods and thus clinical signs are more likely to have been noticed in these horses.

Inheritance of myotonic discharges in American quarter horses and the relationship to hyperkalemic periodic paralysis

Electromyography (EMG) was used to detect myotonic discharges in Quarter Horse breeding stock and to follow the results of mating horses with hyperkalemic periodic paralysis (HPP). The studies were performed on two brood mare farms. A total of six breeding stock showed myotonic discharges and 15 were nonmyotonic. Myotonic discharges were seen in five of six horses belonging to the blood line previously implicated as being predisposed to HPP. Two of these horses had shown clinical signs of HPP. Only one of 15 breeding horses unrelated to the HPP predisposed blood line showed myotonic discharges. When both parents were non-myotonic on EMG than the F1 generation (n = 6) were also nonmyotonic. When a stallion with HPP and myotonic discharges was mated to eight nonmyotonic mares over a six year period half the animals of the F1 generation (n = 25) showed myotonic discharges. When both parents showed myotonic discharges four F1 offspring were myotonic and two were nonmyotonic on EMG testing. There was no evidence of sex linkage. The results are consistent with an autosomal dominant mode of inheritance. Hyperkalemic periodic paralysis and myotonic discharges on EMG may be different manifestations of the same underlying defect.

A comparison of three oral electrolyte solutions in the treatment of diarrheic calves

Thirty-six diarrheic calves infected with rota- and coronaviruses were randomly allocated to one of three oral electrolyte treatments: Ion-Aid (Syntex Agribusiness), Life-Guard (Norden Inc), or Revibe (Langford Inc). The calves were also allowed voluntary access to milk which was offered at the rate of 5% of body weight per feeding in two feedings daily. There were significant differences in recovery rate among calves treated with the different electrolytes. Only 33% of Ion-Aid-treated calves recovered; Revibe- and Life-Guard-treated calves had high recovery rates of 92% and 83%, respectively. The much higher recovery rates with Life-Guard and Revibe were attributed to the presence of an alkalizing agent in these preparations. Life-Guard uses bicarbonate to counteract acidosis and there was some evidence that this may have interfered with milk digestion. Revibe uses acetate; this was effectively metabolized within the calves' tissues and produced alkalization without interference with milk digestion.

Use of electromyography for the diagnosis of equine hyperkalemic periodic paresis

The use of electromyography (EMG) as a diagnostic aid for equine hyperkalemic periodic paresis (EHPP) was investigated in seven affected and seven control horses. Affected horses were confirmed positive for EHPP either by elevated serum potassium concentration with clinical signs of myotonia, or by inducing hyperkalemia and clinical signs using oral potassium chloride challenge. All horses were asymptomatic at the time EMG was performed, using bipolar fine wire needle electrodes. The myopotentials were recorded on magnetic tape and displayed on paper charts for analysis. Insertional and resting activity were recorded from the right supraspinatus, triceps, extensor carpi radialis and gluteal muscles in standing horses. Myotonic discharges were seen in six of seven affected horses but not in any of the controls. All seven affected horses and two control horses had prolonged insertional activity. Five out of seven affected horses and one control horse displayed spontaneous motor unit discharges unrelated to recording electrode movement. Myoelectrical potentials containing closely timed muscle potentials, i.e. doublets, were found in all affected horses, with four of seven affected horses also showing triplets. These potentials were not observed in any of the controls. No obvious difference in activity was observed among the four muscle sites tested. It is concluded that EMG is a safe and useful tool for diagnosing EHPP in horses not currently displaying clinical signs. Myotonic discharges and doublets appear to be the most diagnostically significant electromyographic abnormalities in EHPP affected horses.

Risk factors for mortality from diarrhea in beef calves in Alberta

A case-study involving 56 randomly selected beef herds in Alberta was conducted to assess the association of a number of suspected risk factors upon the odds of a high mortality from diarrhea among calves less than 30 days of age. Using stepwise logistic regression it was found that an increased percentage of heifers calving in the herd, poor drainage in the nursing area, providing limited shelter in the nursing area, a large calving area, and wintering cows and heifers on the same ground were conditionally associated with an increase in the odds of high mortality from neonatal diarrhea.

Oral fluid therapy in neonatal ruminants and swine

Definitive recommendations regarding the best method to treat the diarrheic calf cannot be made at this time. The exact recommendation will probably depend on the situation. At the present time, I do not believe it is detrimental to withdraw milk from the diet for periods up to 24 to 36 hours, as long as the calf is in good condition and is returned to a full ration (maintenance plus) of milk within 3 to 5 days from the start of milk withdrawal. Milk withdrawal is most likely to be beneficial in those situations in which the calf is depressed and has lost its sucking reflex. Oral electrolyte solutions should be fed at the rate of 4-6 L/day if diarrhea is profuse or if the calf is depressed. As the calf feels better and the severity of diarrhea decreases, the amount of oral electrolyte solution can be reduced. It is sensible to continue feeding oral electrolyte solution, perhaps at the rate of 2 L/day, as long as the calf scours. Products containing 40-80 mEq/L of alkalizing agent give the best results. The higher concentrations may be more effective in older calves. Products containing bicarbonate or metabolizable base can be used when the calf is held off milk, whereas only solutions that contain a metabolizable base should be used if the calf is fed milk that day. Milk withdrawal may only be beneficial in calves that are losing their interest in sucking. Early reintroduction to milk and avoidance of milk deprivation in bright calves will help maintain condition and may boost immune function and mucosal repair. Calves that are held off milk for more than 2 days and calves that are deprived of milk while in poor condition should be fed a high-energy electrolyte solution. Beef calves tend to be treated while they are still on the dam, and if they are separated from the cow, it is usually only for a short period. This maintains the cow's lactation and maternal instincts. Cow's milk is better digested than many milk replacers and is available at a steady rate because calves suck frequently. Calves maintained on cow's milk should be fed an oral electrolyte solution containing a metabolizable base. Gastric fill from the electrolyte solution will tend to reduce milk consumption. It is important to prevent the calf from gorging on milk, which sometimes happens when a calf that is depressed and not sucking regains its appetite and has access to a very full udder. Cows that have been separated from their calf or that have distended udders should be milked out.

The effects of feeding milk to diarrheic calves supplemented with oral electrolytes

The effects of feeding different levels of milk to diarrheic calves (n = 19) supplemented with oral electrolytes were investigated. In the early stages of the disease the calves were fed either enough milk to maintain normal growth in a healthy calf, one half that volume or no milk. The three groups were further subdivided according to whether or not the electrolyte solution contained bicarbonate. A full milk ration allowed uninterrupted weight gains of 1% body weight/day (p = 0.003), but caused greater inappetence (p = 0.003 to 0.037) at the beginning of the trial than lower levels of milk intake. Electrolyte solutions with bicarbonate reduced growth rates in milk fed calves (p = 0.014). The density of fat stores increased with the level of milk feeding (p = 0.04 to 0.053). The mitotic index of the duodenal mucosa increased with milk feeding (p = 0.08), indicating a superior mucosal regeneration potential. Thymic atrophy was pronounced in those calves fed no milk (p = 0.001). It was concluded that the continued feeding of milk to diarrheic calves was beneficial. Electrolyte solutions containing bicarbonate should be avoided when milk is fed to diarrheic calves.

Coronavirus-associated diarrhea (winter dysentery) in adult cattle

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A retrospective study of the relationship between clinical signs and severity of acidosis in diarrheic calves

A retrospective study of 123 calves under two months of age with signs of diarrhea was performed to investigate the relationships among the calf's demeanor, dehydration, rectal temperature, and base deficit. The severity of dehydration, hypothermia, and metabolic acidosis were associated with level of depression. Clinical signs and age of calf could be used to predict the severity of acidosis. Acidosis was more severe in calves over eight days of age and also increased in severity with the degree of depression. The most severe metabolic acidosis was seen in calves over eight days of age presented in sternal or lateral recumbency; the base deficit in these groups was 16.3 +/- 8.3 (means +/- 1SD) and 20.3 +/- 10.1 mmol/L respectively, and on average these calves require 2.4 and 3.0 L respectively of 1.3% sodium bicarbonate solution to correct the acidosis.

Diagnosis of copper deficiency and effects of supplementation in beef cows

The effects of feeding supplementary dietary copper to a herd of 400 beef cows, were studied over a two year period. In the first year of the trial, the calves showed clinical signs of copper deficiency. There was improved growth following subcutaneous injection of copper ethylenediamine tetraacetate, and the treated calves had a 2.8% increase in adjusted weaning weights. In the second year of the trial pregnant cows were fed a basal ration of bromegrass silage, barley and minerals over the winter feeding period. The feed was supplemented with copper so that half received 5.5 mg/kg of copper on a dry matter basis and half 40 mg/kg. Calving occurred in the spring and half the calves were treated with injectable copper at birth and again at 12 weeks of age. There was no evidence of copper deficiency in the calves and there was no effect of high level copper supplementation on calf birth weight, or neutrophil candidacidal activity. Susceptibility to diarrhea varied in a complex fashion; morbidity was lowest in calves born to dams fed supplementary copper and highest in calves born to supplemented dams and injected with copper at birth. The cows and calves grazed the same copper deficient pasture over the summer. The average daily gain for calves born to supplemented cows was 0.999 +/- 0.010 kg/day (x +/- SEM) which was significantly greater than the 0.972 +/- 0.009 kg/day for calves from nonsupplemented dams (p = 0.044). The benefit of copper supplementation on 200 day weaning weight was estimated at 4.8 kg. Evidence of copper deficiency was seen when a herd test showed mean serum levels below 9 mumol/L and liver values below 0.09 mmol/kg wet matter.

Clinical and pathological effects of flunixin meglumine administration to neonatal foals

The effects of daily intravenous administration of flunixin meglumine at dosages of 0.55, 1.1, 2.2 and 6.6 mg/kg for five days were examined in neonatal foals. Six two day old foals were used to evaluate the effect of each dosage. Foals were examined every day and blood samples collected on days 1, 3 and 6. All foals were euthanized after six days, necropsied and examined for lesions. The major clinical abnormality was diarrhea, but the incidence was not related to the dosage of flunixin meglumine administered. The foals receiving 6.6 mg/kg of flunixin meglumine had significantly more gastrointestinal ulceration and greater cecal pathology and cecal petechiation scores than those foals treated with saline. The foals in the 6.6 mg/kg treatment group had a greater loss of total protein during the study, but the difference was not significant. There were no statistically significant blood cellular or biochemical alterations associated with the administration of flunixin meglumine. There were no significant clinicopathological differences between healthy foals treated with the recommended dosage of flunixin meglumine and those treated with physiological saline.

Bioassay techniques and high-performance liquid chromatography for detection of oxytetracycline residues in tissues from calves

Tissue specimens from muscle, liver, kidney, and injection sites were collected, and serum was obtained from 3 calves euthanatized on each of posttreatment days 5 and 22. Calves were treated with 6.7, 13.4, or 20 mg of oxytetracycline (OTC)/kg of body weight, IM, once daily for 3 days; these dosages are 1, 2, and 3 times the label dose, respectively. One control calf was euthanatized on each of posttreatment days 5 and 22. In treated male calves killed 2 days after the last injection, OTC residues were detected in all tissues and serum, using high-performance liquid chromatography. Tissues from all injection sites also were considered positive for antimicrobial residues, using the swab test on premises (STOP), microbial inhibition test (MIT), and thin-layer chromatography-bioautography (TLCB) test. Kidney tissues from a calf given 13.4 mg of OTC/kg and kidney and liver tissues from a calf given 20 mg of OTC/kg also were considered positive, using the MIT and TLCB. Results of the STOP only were considered positive for the liver and kidney of a calf given 20 mg of OTC/kg, but substitution of Saskatoon antibiotic medium-3 for the original medium (antibiotic medium-5) allowed the STOP to detect residues in these tissues from all treated calves. In female calves killed 19 days after the last injection, the STOP, MIT, and TLCB procedures revealed positive results for tissues from some injection sites, but revealed negative results for other tissues.(ABSTRACT TRUNCATED AT 250 WORDS)

A retrospective study of 51 cases of abdominal problems in the calf: etiology, diagnosis and prognosis

A retrospective study of 51 calves less than two months of age showing signs of abdominal pain or presented because of abdominal distension was carried out to evaluate the relationship between etiological, diagnostic, and prognostic characteristics. We found that the age of the calf differed with the type of lesion present. Calves under eight days of age had a 73% incidence of lesions which required surgical therapy. Atresia of part of the intestinal tract was the most frequently diagnosed problem, In eight-day to two-month-old calves, medical causes of colic were more common; only 26% of cases had lesions that required surgical correction. Gaseous distension of the abomasum and intestine was the most frequent cause of colic in older calves. Other abdominal problems observed in this study included abomasal ulceration and abomasal torsion.Mortality was more common in calves with surgical problems. Of the 21 calves with surgical problems, 76% died compared with a 20% mortality rate in the 30 calves with medical problems. Because of the high incidence of surgical problems in young calves, mortality was 69% in calves under eight days of age and only 33% in older calves. The chance of recovery decreased with the severity of hypothermia and dehydration. Most calves (75%) which were recumbent at presentation died, whereas only 29% of calves which were alert and able to stand at presentation died. Hematological findings indicative of severe inflammation were poor prognostic signs. Heart rate and the apparent severity of abdominal pain were not useful prognostic indicators.

Persistence of chloramphenicol residues in calf tissues

Twenty-one 5 to 18 day old calves were administered 11 mg chloramphenicol in propylene glycol per kg body weight intramuscularly twice daily for three days. Groups of calves were euthanized with a barbiturate overdose at 5, 21, 42 and 70 days after the last dose was administered. Serum, kidney, analyzed for the drug using a quantitative gas chromatographic method with a detection limit of five parts per billion. After five days of withdrawal, chloramphenicol was detected in all the injection sites and in 6 out of 16 of the other samples. After 21 days of withdrawal, chloramphenicol was detected in all the injection sites and in one each of the serum, liver and muscle samples. After 42 days of withdrawal, chloramphenicol was detected in the injection sites only, and after 70 days of withdrawal it was not detected in any of the samples.

Correction of metabolic acidosis in diarrheal calves by oral administration of electrolyte solutions with or without bicarbonate

Acid-base balance was evaluated in calves with experimentally induced viral diarrhea. When blood pH decreased to less than 7.200, calves were assigned to treatment groups and fed milk replacer, electrolyte solution without bicarbonate, or electrolyte solution containing bicarbonate. Calves in the electrolyte treatment groups had lower mortality (P less than 0.05), were better hydrated (P less than 0.05), and were less acidotic (P less than 0.05) than calves fed milk replacer. Bicarbonate-containing electrolyte solution restored acid-base balance (P less than 0.05) and corrected depression better (P less than 0.05) than electrolyte solution that did not contain bicarbonate. Both electrolyte solutions were equally good at correcting dehydration.

Severity and nature of acidosis in diarrheic calves over and under one week of age

A prospective study of the severity of dehydration and acidosis was carried out in 42 calves under 35 days of age presented for treatment of neonatal diarrhea. Clinically the mean level of dehydration was 8 to 10%. The plasma volume was 65% of that in the hydrated calf but the calves only gained 6.5% in weight during therapy.Calves under eight days of age often had a lactic acidosis. Blood pH was 7.118+/-0.026 (mean +/- 1 standard error), bicarbonate concentration 18.8+/-1.3 mmol/L, base deficit 11.4+/-1.7 mmol/L and lactate of 3.6+/- 0.06 mmol/L. Calves over eight days usually had a nonlactic acidosis. Blood pH was 7.042+/-0.021, bicarbonate 10.8+/-1.0 mmol/L, base deficit 19.5+/-1.2 mmol/L and lactate 1.2+/-0.3 mmol/L. These values were all significantly different from those in younger calves.Over all calves there was a poor correlation between the severity of acidosis and dehydration(r=0.05). The severity of lactic acidosis was related to the severity of dehydration. Mean bicarbonate requirements to correct acidosis were calculated to be 200 mmol(17 g of sodium bicarbonate)and 450 mmol(37 g of sodium bicarbonate)in calves under and over eight days of age respectively. Both groups of calves required a mean volume of 4L of fluid to correct dehydration.

Evaluation of the Total Carbon Dioxide Apparatus and pH Meter for the Determination of Acid-Base Status in Diarrheic and Healthy Calves

Three simple tests of acid-base status were evaluated for field use. Blood samples were collected from 20 diarrheic and 24 healthy calves less than six weeks of age. One sample was collected anaerobically and immediately analyzed on a blood gas analyzer. The other samples were used for measurement of blood and serum pH using a pH meter and pH paper, and for serum total carbon dioxide (TCO(2)) using a TCO(2) apparatus. The TCO(2) apparatus gave the best results and would be useful in the field. TCO(2) apparatus measurements had a high correlation, r=0.91, with blood gas analyzer blood bicarbonate values. Healthy calves have a serum TCO(2) content of 30 mmol/L and bicarbonate requirements for correcting metabolic acidosis in diarrheic calves can be calculated:Bicarbonate required (mmol) = (30-TCO(2)) x Body Weight x 0.6 This can be converted to grams of sodium bicarbonate by dividing by 12.

Further studies on the clinical features and clinicopathological findings of a syndrome of metabolic acidosis with minimal dehydration in neonatal calves

A syndrome of metabolic acidosis of unknown etiology was diagnosed in twelve beef calves 7 to 31 days old. Principal clinical signs were unconsciousness or depression concomitant with weakness and ataxia. Other signs included weak or absent suckle and menace reflexes, succussable nontympanic fluid sounds in the anterior abdomen, and a slow, deep thoracic and abdominal pattern of respiration. The variation in clinical signs between calves was highly correlated (r = 0.87, P less than 0.001) with their acid-base (base deficit) status. Abnormal laboratory findings included reduced venous blood pH, pCO2 and bicarbonate ion concentration as well as hyperchloremia, elevated blood urea nitrogen, increased anion gap and neutrophilic leukocytosis with a left shift. Sodium bicarbonate solution administered intravenously effectively raised blood pH and improved demeanor, ambulation and appetite. All calves did well following a return to a normal acid-base status.

The alkalinizing effects of metabolizable bases in the healthy calf

The alkalinizing effect of citrate, acetate, propionate, gluconate, L and DL-lactate were compared in healthy neonatal calves. The calves were infused for a 3.5 hour period with 150 mmol/L solutions of the sodium salts of the various bases. Blood pH, base excess, and metabolite concentrations were measured and the responses compared with sodium bicarbonate and sodium chloride infusion. D-gluconate and D-lactate had poor alkalinizing abilities and accumulated in blood during infusion suggesting that they are poorly metabolized by the calf. Acetate, L-lactate and propionate had alkalinizing effects similar to bicarbonate, although those of acetate had a slightly better alkalinizing effect than L-lactate. Acetate was more effectively metabolized because blood acetate concentrations were lower than L-lactate concentrations. There was a tendency for a small improvement in metabolism of acetate and lactate with age. Sodium citrate infusion produced signs of hypocalcemia, presumably because it removed ionized calcium from the circulation. D-gluconate, D-lactate and citrate are unsuitable for use as alkalinizing agents in intravenous fluids. Propionate, acetate and L-lactate are all good alkalinizing agents in healthy calves but will not be as effective in situations where tissue metabolism is impaired.

Protein energy malnutrition and fat mobilization in neonatal calves

Fat stores and organ weights were assessed in calves at birth (n=5) and after seven days of milk (n=5) or electrolyte (n=5) feeding.Compared to newborn calves, milk-fed calves had a significant (p < 0.05) redistribution of fat from perirenal area to bone marrow. The thymus also involuted during milk feeding.In electrolyte-fed calves there was a significant loss of perirenal and bone marrow fat. The visible omental, mesenteric and subcutaneous fat stores were depleted. Epicardial fat stores were not visibly affected.There was a high correlation between bone marrow crude fat and bone marrow dry matter (R=0.92). This suggests that dry matter estimations can be used to assess bone marrow fat stores. Perirenal fat may be intermediate in type between brown and white adipose tissue because it is mobilized in response to fasting, and formalin fixed perirenal fat did not contain detectable levels of thermogenin.

Episodic muscle tremors in a quarter horse: resemblance to hyperkalemic periodic paralysis

A three year old Quarter Horse stallion was presented with a one year history of episodes of generalized muscle tremors and stiffness, and spasm of the muscles of facial expression, lasting 10-15 minutes. Between attacks, the horse was either normal or had a localized muscle tremor in the flank region. Episodes appeared unrelated to exercise. The major abnormal findings included 1) a rise in plasma potassium from a resting level of 4.4 to 7.9 mmol/L during an attack and 2) electromyographic findings of generalized increased insertion activity and myotonic discharges. The horse was treated with hydrochlorothiazide tablets for nine months, during which time no further attacks were noted. However, four months after the drug was stopped, sporadic focal muscle tremors reappeared; two months later, generalized attacks were seen. Despite reinstitution of the diuretic, a focal flank tremor persisted. Two related horses in the same stable also were reported by the owner to exhibit sporadic generalized muscle twitching. The abnormal findings of the present case differ from clinical syndromes previously reported in horses. Some similarities to hyperkalemic periodic paralysis in humans are noted.

Relationships between metabolic changes and clinical signs in pregnant sheep given endotoxin

Groups of four pregnant ewes were allocated to the following feeding and intravenous endotoxin treatments: fed, Escherichia coli endotoxin (50 micrograms/kg X 75), fed, saline, fasted, E. coli endotoxin (50 micrograms/kg X 75) and fasted, saline. Endotoxin administration resulted in depression, fever, hypoglycemia, hypocalcemia and a reduction in nonesterified fatty acid and ketone body concentrations. Depression correlated best with body temperature (r = 0.76), fasted sheep showed smaller increases in body temperature and were less depressed following endotoxin. Three of eight endotoxin treated sheep died, mortality was not related to rectal temperature but was associated with lactic acidosis. Hypoglycemia was not associated with either death or depression. Fed sheep that were unable to stand had lower serum calcium concentrations than standing sheep.

Clinical evaluation of sodium bicarbonate, sodium L-lactate, and sodium acetate for the treatment of acidosis in diarrheic calves

Thirty-six dehydrated diarrheic neonatal calves were used to study the effects of various alkalinizing compounds on acid-base status, the changes in central venous pressure (CVP) in response to rapid IV infusion of large volumes of fluid, and the correlation of acid-base (base deficit) status, using a depression scoring system with physical determinants related to cardiovascular and neurologic function. Calves were allotted randomly to 4 groups (9 calves/group). Over a 4-hour period, each calf was given two 3.6-L volumes (the first 3.6 L given in the first hour) of a polyionic fluid alone (control group) or were given the polyionic fluid with sodium bicarbonate, sodium L-lactate, or sodium acetate added (50 mmol/L). Acid-base status, hematologic examination, and biochemical evaluations were made immediately before infusion of each fluid (at entry) and after 3.6, 4.8, and 7.2 L of fluid had been given. Compared with control values, bicarbonate, lactate, and acetate had significantly greater alkalinizing effects on pH (P less than 0.01) and base deficit (P less than 0.01) after 3.6, 4.8, and 7.2 L of fluid were given. Bicarbonate had the most rapid alkalinizing effect and induced greater changes in base deficit (P less than 0.01) than did acetate or lactate at each of the 3 administered fluid volumes evaluated. Acetate and lactate had similar alkalinizing effects on blood. Rehydration alone did not improve acid-base status. The CVP was elevated in 10 (28%) of the 36 calves after 1 hour of fluid (3.6 L) administration, but significant differences in body weight, PCV, and clinical condition or depression score at entry were not found between calves with elevated CVP and those with normal CVP.(ABSTRACT TRUNCATED AT 250 WORDS)

Raising the orphan foal

Orphan foals are best reared by fostering them onto a brood mare of appropriate size. If no foster mother is available, they can be reared on 2 per cent fat skimmed cow's milk fortified with dextrose at the rate of 20 gm per L. This should be slowly increased from 10 per cent of body weight at 1 day of age to 25 per cent of body weight at 10 days of age. The amount should then be held constant until weaning. Alternatively, foals can be reared on milk replacers. Manufacturers' feeding instructions rarely mimic the milk intake obtained by a foal nursing her dam, and problems have been observed in milk replacer fed foals. It may be better to feed milk replacers at 1- to 2-hour intervals as a 12.5 per cent solution. The volume fed can be slowly increased from 5 per cent of body weight at day 1 to 20 per cent of body weight at day 10. Fresh water, hay, and good-quality creep feed with at least an 18 per cent crude protein should be offered from 2 weeks of age. Foals can be weaned at 8 to 12 weeks of age.

In vivo studies of hypoglycemia and lactic acidosis in endotoxic shock

Sheep were prepared with catheters in an artery and mesenteric, portal, and hepatic veins. Blood flows and metabolite concentration differences were measured across liver and gut. Net organ production rates were calculated for liver, portal drained viscera, and extrasplanchnic regions. Arterial glucose concentration rose for 2 h after endotoxin administration. The hyperglycemia was associated with increased hepatic glucose production. Hypoglycemia developed between 3 and 8 h when hepatic glucose production decreased closer to control values. Arterial glucagon concentrations rose to high levels during the hypoglycemic period. Neither hepatic blood flow or oxygen delivery limited glucose production; uptake of the gluconeogenic substrate lactate was reduced on some occasions. Glucose utilization was increased in shock. Portal glucose utilization accounted for 14.5% of nonhepatic glucose utilization. Increased portal glucose utilization was not related to plasma insulin concentrations or insufficient oxygen supply to the gut. Hyperglycemia drove glucose utilization. Although plasma insulin concentrations rose significantly in endotoxemia, the increase in pancreatic insulin output was much smaller and failed to attain statistical significance.

Arteriovenous fistula in the orbit of a calf

An Ayrshire calf with a protruding left eye and a fluctuant swelling dorsal to the orbit was examined. A diagnosis of arteriovenous fistula was made based on the findings of pulsation, a palpable thrill and a machinery-like bruit on auscultation over the swelling. Arteriography failed to outline the full extent of the fistula. The calf was euthanized and the fistula dissected. An enlarged superficial temporal artery communicated with a branch of the maxillary vein by way of a tortuous mass of vessels. The frontal bone was eroded by this plexus.

Measurement of portal and hepatic blood flows using a modified method for surgical placement of catheters in the major splanchnic vessels of sheep

A modified catheterization and para-aminohippurate dye dilution technique was used to measure portal and hepatic blood flows in sheep. Blood flows (mean +/- 1SD) for 7 healthy sheep were 1.54 +/- 0.71 L/min and 1.98 +/- 0.75 L/min for portal and hepatic flows, respectively. Blood flow measurement was facilitated when dye injection rates produced blood para-aminohippurate acid concentrations greater than 15 mg/L. Uniform mixing of dye with blood was confirmed in 1 sheep with 2 portal vein catheters. Surgery to place the catheters was facilitated by using a ventral para-costal approach. Blood gas analysis was useful in confirming the placement of the catheters. Useful catheter life in this experiment was 41 days, which was longer than in previous reports. Treating the catheters with an organo-silane preparation, protecting the catheters against dislodgement, and use of a belly bandage to minimize damage to the external parts of the catheter may have prolonged catheter life in this experiment.