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Biomedical subjects

C B Navarre

Publications and source records attributed to C B Navarre.

15 recordsLinked to original sources
PubMed2005

Normal calves produced after transfer of in vitro fertilized embryos cultured with an antiviral compound.

Bovine viral diarrhea virus (BVDV) replicates in embryo co-culture systems and remains associated with developing IVF bovine embryos, despite washing and trypsin treatment. Previous research demonstrated that 2-(4-[2-imidazolinyl]phenyl)-5-(4-methoxyphenyl)furan (DB606) inhibits replication of BVDV in cultured cells. The objective of this study was to evaluate the capability of IVF embryos to develop into normal, weaned calves after exposure to antiviral concentrations of DB606 during IVC. Oocytes were obtained from cows via transvaginal, ultrasound-guided follicular aspiration. Presumptive zygotes (n = 849) that resulted from fertilization of these oocytes were cultured for 7 d in medium supplemented with 0.4 microM DB606 or medium lacking antiviral agent. All blastocysts (n = 110) were transferred individually into the uterus of a synchronized recipient. The pregnancy status of recipients was determined using transrectal ultrasonography at 21-23 d after embryo transfer. Additional pregnancies as controls (n = 21) were initiated by natural breeding. Developing fetuses and resulting calves were evaluated every 27-34 d. Blastocyst development, pregnancies per transferred embryo, pregnancies maintained per pregnancies established, gestation length, gender ratio, birth weights, viability of neonates, complete blood counts, and serum chemistry profiles at 3 mo of age and adjusted 205 d weaning weights were compared for research treatments. Development to weaning after exposure to DB606 did not differ significantly from controls. In conclusion, bovine embryo cultures can be safely supplemented with antiviral concentrations of DB606; addition of DB606 agent might prevent viral transmission if BVDV were inadvertently introduced into the embryo culture system.

Animals↗
PubMed2004

Pharmacokinetics of ceftiofur in llamas and alpacas.

Pharmacokinetic studies of antibiotics in South American camelids are uncommon, therefore drugs are often administered to llamas and alpacas based on dosages established in other domestic species. The disposition of ceftiofur sodium was studied in llamas following intramuscular administration and in alpacas following intravenous and intramuscular administration. Eleven adult llamas were given ceftiofur sodium by intramuscular injection. Each animal received either a standard dose of 2.2 mg/kg or an allometrically scaled dose ranging from 2.62 to 2.99 mg/kg in a crossover design. Ten adult alpacas were given ceftiofur sodium by intravenous and intramuscular injections. Each animal received a standard dosage of 1 mg/kg or an allometrically scaled dose ranging from 1.27 to 1.44 mg/kg i.v., and 1.31-1.51 mg/kg i.m. Blood samples were collected at 0, 0.25, 0.5, 1, 2, 4, 8, 12, 24, 36, 48, and 72 h after administration of the ceftiofur. Pharmacokinetic parameters of ceftiofur in llamas and alpacas were similar following i.m. dosing at both dose levels. The only differences noted were in the total AUC between dose levels, but the AUC/dose values were not different. A sequence effect was noted in the alpaca data, which resulted in lower AUCs for the second dose when the i.v. dose was given first, and with higher AUCs for the second dose when the i.m. dose was given first. Overall, ceftiofur pharmacokinetics in llamas and alpacas are similar, and also very similar to reported parameters for sheep and goats.

Animals↗
PubMed2001

Internal parasite control strategies.

To maintain the general health of small ruminants, owners, managers, and clinicians should be familiar with the body condition-scoring [table: see text] methods, general health, and overall appearance of the animals in their care. Any changes in the overall health of individual animals or the flock should be noted immediately, the cause determined, and immediate measures should be taken to correct any problems. Parasite management in small ruminants is a difficult and arduous task. When a program that reduces parasite infestation is discovered, it should be carefully implemented, maintained with vigilance, and constantly "tweaked" to maximize its effectiveness.

Animals↗
PubMed2000

Differentiation of gastrointestinal diseases of calves.

With a complete history, careful physical examination, and targeted diagnostics, the practitioner can differentiate the causes of gastrointestinal diseases in calves. The authors hope that this article helps the practitioner in this regard. Armed with a diagnosis, he or she can then proceed with proper treatment and prevention, which is the ultimate goal.

Animals↗
PubMed2000

Differentiation of gastrointestinal diseases in adult cattle.

Many of the common gastrointestinal disorders of adult cattle may be diagnosed by a careful physical examination, whereas other disturbances require the use of diagnostic testing. It is important to differentiate the causes of gastrointestinal disturbances to make better treatment decisions and have a clearer prognosis for the specific animal or herd of cattle.

Animals↗
PubMed1999

Analysis of first gastric compartment fluid collected via percutaneous paracentesis from healthy llamas.

OBJECTIVE: To evaluate the safety and efficacy of percutaneous paracentesis for fluid collection from the first gastric compartment of healthy llamas and to describe characteristics of that fluid. DESIGN: Prospective study. ANIMALS: 10 healthy adult llamas. PROCEDURE: Physical examinations were performed prior to sample collection and for 14 days afterwards. A CBC was performed prior to sample collection and 5 days later. A 16-gauge, 7.5-cm stainless steel needle, positioned approximately 20 cm caudal to the costochondral junction of the last rib, was pointed in a dorsocraniomedial direction and pushed through the abdominal wall into the lumen of the first gastric compartment. Fluid was aspirated and analyzed immediately for color, odor, consistency, pH, methylene blue reduction (MBR) time, protozoa, and bacteria. RESULTS: Fluid samples were obtained from 9 of 10 llamas. Mean volume was 4.1 ml, mean pH was 6.67, and mean MBR time was 173 seconds. Odor was slightly acidic, color was light brown-green to light yellow-green, and consistency was moderate. Small protozoa with variable iodine staining and gram-negative bacteria were commonly detected. With few exceptions, results of physical examinations and CBC remained within reference ranges. CLINICAL IMPLICATIONS: Fluid samples from the first gastric compartment can be successfully obtained by percutaneous paracentesis. Fluid characteristics were similar to those of fluid collected via orogastric tube in llamas and cattle.

Animals↗
PubMed1999

Ceftiofur distribution in plasma and joint fluid following regional limb injection in cattle.

The objective of this study was to evaluate the efficacy of regional intravenous (i.v.) injection of ceftiofur in delivery of this drug to joint fluid and plasma in a limb distal to a tourniquet in five, healthy, adult, mixed breed beef cattle. A tourniquet was positioned in the mid-metacarpal region, and 500 mg of ceftiofur was administered through a catheter in the dorsal common digital vein (DCDV). Plasma samples were collected from the catheter at 15, 30 and 45 min postinjection, and from the abaxial proper palmar vein (APPV) at 15 min postinjection. Synovial fluid was collected from the metacarpal phalangeal joint at 45 min postinjection. Ceftiofur concentrations were estimated in plasma and synovial fluid using high-pressure liquid chromatography (HPLC) and a microbiological assay utilizing Pasteurella haemolytica as the test organism. Both assays indicated highest plasma concentrations of ceftiofur at 15 min, with the concentrations declining with time. Concentrations of ceftiofur in plasma obtained from the DCDV were not significantly different from APPV levels, indicating rapid distribution of ceftiofur within the limb. Microbiological assay always demonstrated higher concentrations of ceftiofur compared with HPLC assay, because the former probably also detected the active metabolites of ceftiofur as well as the parent compound. At 45 min, ceftiofur concentrations determined by HPLC were 251+/-97 and 15+/-5 microg/mL in plasma and synovial fluid, respectively. Regional intravenous injection appears to be a feasible technique to produce rapid distribution of ceftiofur within the limb well above therapeutic concentrations.

Animals↗
PubMed1999

Influence of pH and temperature on kinetics of ceftiofur degradation in aqueous solutions.

The objective of this study was to evaluate the stability of ceftiofur (1 mg mL(-1)) in aqueous solutions at various pH (1, 3, 5, 7.4 and 10) and temperature (0, 8, 25, 37 and 60 degrees C) conditions. The ionic strength of all these solutions was maintained at 0.5 M. Ceftiofur solutions at pH 5 and 7.4 and in distilled water (pH = 6.8) were tested at all the above temperatures. All other solutions were tested at 60 degrees C. Over a period of 84 h, the stability was evaluated by quantifying ceftiofur and its degradation product, desfuroylceftiofur, in the incubation solutions. HPLC was used to analyse these compounds. At 60 degrees C, the rate of degradation was significantly higher at pH 7.4 compared with pH 1, 3, 5 and distilled water. At both 60 degrees C and 25 degrees C, degradation in pH 10 buffer was rapid, with no detectable ceftiofur levels present at the end of 10 min incubation. Degradation rate constants of ceftiofur were 0.79+/-0.21, 0.61+/-0.03, 0.44+/-0.05, 1.27+/-0.04 and 0.39+/-0.01 day(-1) at pH 1, 3, 5, 74 and in distilled water, respectively. Formation of desfuroylceftiofur was the highest (65%) at pH 10. The rate of degradation increased in all aqueous solutions with an increase in the incubation temperature. At pH 7.4 the degradation rate constants were 0.06+/-0.01, 0.06+/-0.01, 0.65+/-0.17, and 1.27+/-0.05 day(-1) at 0, 8, 25, 37 and 67 degrees C, respectively. The energy of activation for ceftiofur degradation was 25, 42 and 28 kcal mol(-1) at pH 5, 7.4 and in distilled water, respectively. Desfurylceftiofur formation was the greatest at alkaline pH compared with acidic pH. Ceftiofur degradation accelerated the most at pH 7.4 and was most rapid at pH 10. The results of this study are consistent with rapid clearance of ceftiofur at physiological pH.

Cephalosporins↗
PubMed1998

Alterations in acid-base balance and serum electrolyte concentrations in cattle: 632 cases (1984-1994).

OBJECTIVE: To determine typical alterations in acid-base balance and serum electrolyte concentrations in cattle grouped on the basis of age, breed type, hydration status, clinical signs, and underlying disease. DESIGN: Retrospective study. ANIMALS: 632 cattle. PROCEDURE: Information on blood pH, PVO2, PVCO2, HCO3-concentration, and base excess (BE) as well as serum or plasma sodium, potassium, chloride, and total carbon dioxide concentrations was obtained. Values for calves (ie, cattle < 1 month old) were compared with values for cattle > or = 1 month old. Within each age-group, values were compared for cattle grouped on the basis of breed type, previous treatment, and hydration status. Proportions of cattle with various disorders for which values were within, greater than, or less than reference ranges were determined. RESULTS: BE, pH, and HCO3- concentration were significantly higher and PVCO2 and sodium, potassium, and chloride concentrations were significantly lower among cattle > or = 1 month old than calves. Base excess and HCO3- concentration were significantly lower among dairy than beef calves. Sodium and potassium concentrations were significantly lower among dairy than beef cattle > or = 1 month old. A higher proportion of cattle that did not survive had a high anion gap than cattle that did survive. Sodium, potassium, and chloride concentrations were significantly lower among dehydrated cattle than cattle that were not dehydrated. CLINICAL IMPLICATIONS: Because certain alterations were consistently found in some groups of cattle, it may be possible to make reasonable predictions of alterations in acid-base balance and serum electrolyte concentrations when laboratory evaluations are not available.

Acid-Base Equilibrium↗
PubMed1996

Catheterization of the auricular vein in cattle: 68 cases (1991-1994).

OBJECTIVE: To evaluate the use of auricular vein catheters (AVC) in cattle in a clinical setting. DESIGN: Case series. ANIMALS: 57 cattle. PROCEDURE: 68 AVC were placed in cattle for the administration of drugs or rehydration fluids. Catheter size, quantity of fluids administered, duration of administration, drugs administered, duration of catheter maintenance, and problems were recorded. RESULTS: The AVC ranged in size from 20 to 14 gauge, with the latter being the predominate size. A maximum flow rate of 7.7 L/h was achieved, and the flow rate was satisfactory in all but 1 case. The maximum duration of maintenance was > 96 hours. Problems occurred in 29 of 68 (43%) catheterizations; the most frequent problem was occlusion of the catheter, which occurred 16 times (24%). No serious complications occurred. CLINICAL IMPLICATIONS: Auricular vein catheters were a convenient, safe, and low-cost alternative to jugular vein catheters.

Animals↗
PubMedDate not supplied

Platelet function defect in a 5-day-old Simmental calf.

A 5-day-old Simmental Heifer was evaluated for excessive bleeding from the skin following horse fly bites. A coagulation profile and platelet numbers were normal. In vitro platelet function, measured by whole blood aggregometry, was found to be abnormal when compared with age-matched controls. Therefore, this defect in hemostasis was attributed to a qualitative defect in platelet function.

Animals↗
PubMedDate not supplied

Gastrointestinal motility and disease in large animals.

An understanding of the relationship between gastrointestinal (GI) motility and disease is imperative for the proper treatment of large animal patients, especially as new therapeutic agents become available. However, the abundance of information that has become available in the last 2 decades makes gaining this understanding a formidable task. This article summarizes the changes in GI motility caused by some common diseases and conditions encountered in large animal practice, such as GI obstruction, postoperative ileus, resection and anastomosis, diarrhea, endotoxemia, GI parasitism, hypocalcemia, and pregnancy.

Animal Diseases↗