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Abstract

Objective

To determine whether quantification of myeloperoxidase (MPO) activity could be a useful laboratory technique to detect granulocyte infiltration in equine intestinal tissues.

Sample Population

Intestinal tissue (inflamed or healthy) collected from 16 age- and sex-matched Shetland Ponies.

Procedure

Intestinal tissue MPO activity was determined, and histologic assessment of adjacent specimens from healthy and inflamed intestine was done.

Results

Intestinal tissue MPO activity and histopathologic score increased with time after castor oil challenge and peaked at 16 hours in an equine diarrhea model in which individual ponies provided their own control tissues.

Conclusions

Intestinal tissue inflammation scores correlated positively with tissue MPO activity in adjacent specimens.

Clinical Relevance

Tissue MPO assay may be a useful laboratory tool to quantify intestinal mucosal inflammation in ponies. (Am J Vet Res 1999;60:807–813)

Free access
in American Journal of Veterinary Research

Abstract

Objective—To develop a method for percutaneous collection of fetal fluid from cattle in the late stages of gestation and determine whether bovine viral diarrhea virus (BVDV) can be isolated from such fluids.

Design—Case series.

Animals—169 pregnant beef cattle.

Procedure—Animals were restrained in a squeeze chute, and hair was clipped from a region of the right flank. Pregnancy was confirmed, and fetal fluids were identified by means of abdominal ultrasonography. Fetal fluid was collected with a spinal needle. Virus isolation was performed on fetal fluids, WBC lysates from 160 live calves, and tissues from 12 calves that died or were aborted. Blood samples collected from adult cattle were assayed with an immunoperoxidase monolayer assay.

Results—Fourteen animals aborted or delivered premature calves within 3 weeks after fetal fluid collection; however, it could not be determined whether this was a complication of the procedure or attributable to other factors. Results of BVDV isolation from fetal fluid samples were negative for 168 animals. However, a noncytopathic BVDV was isolated from fetal fluid obtained from a 2-year-old heifer; results of the immunoperoxidase assay of serum from this heifer were also positive, and a noncytopathic BVDV was isolated from tissue specimens from a stillborn calf produced by this heifer.

Conclusions and Clinical Relevance—Results suggest that fetal fluids can be collected percutaneously from cattle in the late stages of gestation and that virus isolation performed on fetal fluids can be used to identify fetuses infected with BVDV in utero. However, safety of the procedure could not be evaluated. (J Am Vet Med Assoc 2002;220:1348–1352).

Full access
in Journal of the American Veterinary Medical Association

Objective

To compare cutaneous reactivity to insect and arachnid allergens in clinically normal (control) and allergic dogs in the southeastern United States.

Design

Prospective, controlled study.

Animals

26 clinically normal dogs and 82 allergic dogs from the southeastern United States.

Procedure

Intradermal skin testing with various dilutions of 13 insect and arachnid allergens was performed on control dogs to establish skin threshold concentrations (ie, concentrations to which < 25% of the dogs had positive reactions). These established threshold concentrations were then used to test allergic dogs for reactivity. Prevalence of single and multiple insect and arachnid reactions were determined.

Results

Flea allergen was the only allergen that caused a significantly higher prevalence of positive reactions in allergic dogs than in control dogs.

Clinical Implications

Flea hypersensitivity is the most important arthropod hypersensitivity in dogs. The importance of reactivity to insect and arachnid allergens other than flea allergen can be determined only when prevalence of positive reactivity has been determined in an appropriate regional control group of dogs. (J Am Vet Med Assoc 1996;209:1431–1434)

Free access
in Journal of the American Veterinary Medical Association

Summary

A commercially available automated enzyme-multiplied immunoassay technique (emit) was used to determine serum caffeine concentration after oral and iv administrations of caffeine at dosage of 5 mg/kg of body weight to 12 clinically normal dogs. Dogs were allotted to 2 groups of 6 dogs each; 1 group initially received caffeine orally and the other received caffeine iv. After 72 hours, caffeine administration was repeated in all dogs in the alternate manner. Serum samples were obtained at multiple intervals over 24 hours to determine distribution and elimination kinetics. Analysis of the drug concentration-time data indicated iv elimination half-life (t½) of 6.39 ± 1.87 hours, volume of distribution at steady state of 685.3 ± 132.2 ml/kg, total body clearance of 1.31 ± 0.38 ml/min/kg, absorption t½ of 1.02 ± 0.68 hour, oral elimination t½ of 6.53 ± 2.72 hours, lag time after oral administration of 0.0614 ± 0.0661 hour, highest measured concentration of 5.29 ± 1.17 μg/ml, time to peak concentration of 2.74 ± 1.30 hours, and bioavailability of 99.4 ± 19.4%. Data from 6 dogs best fit a 1-compartment open model and those from 6 other dogs best fit a 2-compartment open model. On the basis of data from the 6 dogs that best fit a 2-compartment model, t½ of distribution was 0.58 ± 0.72 hour. Data for oral administration best fit a single absorption phase and a single elimination phase.

The increased availability and simplicity of the emit offers an opportunity to study the application of caffeine elimination for clinical evaluation of dogs with liver disease. Data obtained from this study allow determination of t½ and clearance to be simplified by obtaining samples 4 and 8 hours after oral or iv administrations and establishes canine reference values for elimination kinetics of caffeine administered at dosage of 5 mg/kg and assayed by use of the emit.

Free access
in American Journal of Veterinary Research

Abstract

OBJECTIVE To evaluate whether anti-inflammatory doses of cyclosporine activate Toxoplasma gondii in chronically infected cats or potentiate infection in cats exposed for the first time.

ANIMALS 30 T gondii–negative cats.

PROCEDURES Cats were assigned to 1 of 3 groups (10 cats/group). Group 1 (control) cats were administered a placebo for 126 days; group 2 cats were administered a placebo for 84 days, followed by cyclosporine at 7.5 mg/kg/d, PO, for 42 days; and group 3 cats were administered cyclosporine at 7.5 mg/kg/d, PO, for 126 days. Cats were orally inoculated with T gondii on day 42. Results for fecal flotations, PCR assays, and histologic examinations and IgM and IgG titers were analyzed. Cyclosporine concentrations were measured on selected days.

RESULTS All cats were infected by T gondii and developed signs of self-limiting gastrointestinal tract infection. Group 3 had the highest incidence and severity of CNS and pulmonary histopathologic findings typical of toxoplasmosis. One cat in group 3 died of systemic toxoplasmosis; that cat had a cyclosporine concentration of 1,690 ng/mL. Group 2 cats infected with T gondii before cyclosporine administration did not have repeated oocyst shedding. Group 3 cats shed fewer oocysts for a shorter time than did control cats of group 1.

CONCLUSIONS AND CLINICAL RELEVANCE Oral administration of cyclosporine in accordance with the protocol for this study did not potentiate the enteroepithelial phase of T gondii infection. Cats with high cyclosporine blood concentrations at the time of primary T gondii infection may be at risk of developing systemic toxoplasmosis.

Full access
in American Journal of Veterinary Research

Abstract

Objective

To determine the effect of craniectomy and durotomy on intracranial pressure (ICP) in clinically normal dogs.

Design

Two-part study (experiments A and B) involving craniectomy and durotomy, with and without treatments to lower ICP.

Animals

Six (experiment A) and 7 (experiment B) healthy dogs.

Procedure

In experiment A, craniectomy was performed in combination with durotomy, diuretic administration, methylprednisolone sodium succinate administration, and hyperventilation, and effect of these manipulations on ICP was determined. In experiment B, dogs had only craniectomy and durotomy without associated ICP-lowering treatments. During both experiments, ICP was monitored throughout the surgical procedure with a fiber optic ICP monitoring device.

Results

Intracranial pressure decreased after the combination of craniectomy, durotomy, and other ICP-lowering treatments in dogs of experiment A. Similar magnitude of decrease in ICP was observed in dogs of experiment B after craniectomy and durotomy.

Conclusions

Comparison of these experiments indicate that surgical removal of overlying skull and incision of the dura mater can significantly decrease ICP in clinically normal dogs.

Clinical Relevance

Craniectomy and durotomy may be useful as an adjunct treatment for increased ICP. (Am J Vet Res 1996;57:116-119)

Free access
in American Journal of Veterinary Research

Abstract

Objective—To determine whether serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentration is useful in discriminating between cardiac and noncardiac (ie, primary respiratory tract disease) causes of respiratory signs (ie, coughing, stertor, stridor, excessive panting, increased respiratory effort, tachypnea, or overt respiratory distress) in dogs.

Design—Multicenter cross-sectional study.

Animals—115 dogs with respiratory signs.

Procedures—Dogs with respiratory signs were solicited for study. Physical examination, thoracic radiography, and echocardiography were used to determine whether respiratory signs were the result of cardiac (ie, congestive heart failure) or noncardiac (ie, primary respiratory tract disease) causes. Serum samples for NT-proBNP assay were obtained at time of admission for each dog. Receiver-operating characteristic curves were constructed to determine the ability of serum NT-proBNP concentration to discriminate between cardiac and noncardiac causes of respiratory signs.

Results—Serum NT-proBNP concentration was significantly higher in dogs with cardiac versus noncardiac causes of respiratory signs. In dogs with primary respiratory tract disease, serum NT-proBNP concentration was significantly higher in those with concurrent pulmonary hypertension than in those without. A serum NT-proBNP cutoff concentration > 1,158 pmol/L discriminated between dogs with congestive heart failure and dogs with primary respiratory tract disease with a sensitivity of 85.5% and a specificity of 81.3%.

Conclusions and Clinical Relevance—Measuring serum NT-proBNP concentration in dogs with respiratory signs helps to differentiate between congestive heart failure and primary respiratory tract disease as an underlying cause.

Full access
in Journal of the American Veterinary Medical Association