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  • Author or Editor: Robert M. Miller x
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Abstract

Objective—To estimate the analytic sensitivity of microscopic detection of Toxoplasma gondii oocysts and the environmental loading of T gondii oocysts on the basis of prevalence of shedding by owned and unowned cats.

Design—Cross-sectional survey.

Sample Population—326 fecal samples from cats.

Procedures—Fecal samples were collected from cat shelters, veterinary clinics, cat-owning households, and outdoor locations and tested via ZnSO4 fecal flotation.

Results—Only 3 (0.9%) samples of feces from 326 cats in the Morro Bay area of California contained T gondii–like oocysts. On the basis of the estimated tonnage of cat feces deposited outdoors in this area, the annual burden in the environment was estimated to be 94 to 4,671 oocysts/m2 (9 to 434 oocysts/ft2).

Conclusions and Clinical Relevance—Despite the low prevalence and short duration of T gondii oocyst shedding by cats detected in the present and former surveys, the sheer numbers of oocysts shed by cats during initial infection could lead to substantial environmental contamination. Veterinarians may wish to make cat owners aware of the potential threats to human and wildlife health posed by cats permitted to defecate outdoors.

Restricted access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To compare ocular structures of Quarter Horses homozygous for hereditary equine regional dermal asthenia (HERDA) with those of Quarter Horses not affected by HERDA (control horses) and to determine the frequency of new corneal ulcers for horses with and without HERDA during a 4-year period.

Design—Cohort study of ocular structures and retrospective case series of horses with and without HERDA.

Animals—The cohort portion of the study involved 10 Quarter Horses with HERDA and 10 Quarter Horses without HERDA; the retrospective case series involved 28 horses with HERDA and 291 horses without HERDA.

Procedures—Ophthalmic examinations, Schirmer tear tests, tonometry, corneal pachymetry, histologic examinations, and scanning electron microscopy (SEM) were performed in cohorts of Quarter Horses with and without HERDA. Records were reviewed to determine the incidence of corneal ulcers in horses with and without HERDA during a 4-year period.

Results—Corneal thickness of horses with HERDA was significantly less than that of control horses, but tear production of horses with HERDA was significantly greater than that of control horses. Results of SEM revealed zones of disorganized, haphazardly arranged collagen fibrils in corneas of horses with HERDA that were not evident in corneas of control horses. The incidence of corneal ulcers was significantly greater for horses with HERDA than for horses without HERDA during the 4-year period.

Conclusions and Clinical Relevance—Alterations in corneal thickness, arrangement of collagen fibers, and incidence of corneal ulcers indicated that abnormalities in horses with HERDA were not limited to the skin.

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To estimate prevalence of and identify risk factors for fecal Salmonella shedding among hospitalized horses with signs of gastrointestinal tract disease.

Design—Cross-sectional study.

Animals—465 hospitalized horses with gastrointestinal tract disease.

Procedure—Horses were classified as positive or negative for fecal Salmonella shedding during hospitalization by means of standard aerobic bacteriologic methods. The relationship between investigated exposure factors and fecal Salmonella shedding was examined by means of logistic regression.

Results—The overall prevalence of fecal Salmonella shedding was 13%. Salmonella serotype Newport was the most commonly isolated serotype (12/60 [20%]), followed by Anatum (8/60 [13%]), Java (13%), and Saint-paul (13%). Foals with gastrointestinal tract disease were 3.27 times as likely to be shedding Salmonella organisms as were adult horses with gastrointestinal tract disease. Adult horses that had been treated with antimicrobial drugs prior to hospitalization were 3.09 times as likely to be shedding Salmonella organisms as were adult horses that had not been treated with antimicrobial drugs prior to hospitalization. Adult horses that underwent abdominal surgery were 2.09 times as likely to be shedding Salmonella organisms as were adult horses that did not undergo abdominal surgery.

Conclusions and Clinical Relevance—Results suggest that a history of exposure to antimicrobial drugs prior to hospitalization and abdominal surgery during hospitalization were associated with Salmonella shedding in adult horses with gastrointestinal tract disease. Foals with gastrointestinal tract disease were more likely to shed Salmonella organisms than were adult horses with gastrointestinal tract disease. (J Am Vet Med Assoc 2004;225:275–281)

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate the effect of 4 antiarrhythmic treatment protocols on number of ventricular premature complexes (VPC), severity of arrhythmia, heart rate (HR), and number of syncopal episodes in Boxers with ventricular tachyarrhythmias.

Design—Randomized controlled clinical trial.

Animals—49 Boxers.

Procedure—Dogs with > 500 VPC/24 h via 24-hour ambulatory ECG (AECG) were treated with atenolol (n = 11), procainamide (11), sotalol (16), or mexiletine and atenolol (11) for 21 to 28 days. Results of pre- and posttreatment AECG were compared with regard to number of VPC/24 h; maximum, mean, and minimum HR; severity of arrhythmia; and occurrence of syncope.

Results—Significant differences between pre- and posttreatment number of VPC, severity of arrhythmia, HR variables, or occurrence of syncope were not observed in dogs treated with atenolol or procainamide. Significant reductions in number of VPC, severity of arrythmia, and maximum and mean HR were observed in dogs treated with mexiletineatenolol or sotalol; occurrence of syncope was not significantly different between these 2 treatment groups.

Conclusions and Clinical Relevance—Treatment with sotalol or mexiletine-atenolol was well tolerated and efficacious. Treatment with procainamide or atenolol was not effective. (J Am Vet Med Assoc 2002;221:522–527)

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine whether renal crystals can be experimentally induced in animals fed melamine or the related triazine compound cyanuric acid, separately or in combination, and to compare experimentally induced crystals with those from a cat with triazine-related renal failure.

Animals—75 fish (21 tilapia, 24 rainbow trout, 15 channel catfish, and 15 Atlantic salmon), 4 pigs, and 1 cat that was euthanatized because of renal failure.

Procedures—Fish and pigs were fed a target dosage of melamine (400 mg/kg), cyanuric acid (400 mg/kg), or melamine and cyanuric acid (400 mg of each compound/kg) daily for 3 days and were euthanatized 1, 3, 6, 10, or 14 days after administration ceased. Fresh, frozen, and formalin-fixed kidneys were examined for crystals. Edible tissues were collected for residue analysis. Crystals were examined for composition via Raman spectroscopy and hydrophilic-interaction liquid chromatography–tandem mass spectrometry.

Results—All animals fed the combination of melamine and cyanuric acid developed goldbrown renal crystals arranged in radial spheres (spherulites), similar to those detected in the cat. Spectral analyses of crystals from the cat, pigs, and fish were consistent with melamine-cyanurate complex crystals. Melamine and cyanuric acid residues were identified in edible tissues of fish.

Conclusions and Clinical Relevance—Although melamine and cyanuric acid appeared to have low toxicity when administered separately, they induced extensive renal crystal formation when administered together. The subsequent renal failure may be similar to acute uric acid nephropathy in humans, in which crystal spherulites obstruct renal tubules.

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVE

To determine the outcome in dogs diagnosed with congenital extrahepatic portosystemic shunts (EHPSS) at ≥ 5 years of age treated with medical management only (M) or with surgical attenuation (S). The hypothesis was that dogs undergoing surgical attenuation would have a longer survival time than dogs undergoing medical management only.

ANIMALS

351 dogs definitively diagnosed with EHPSS at ≥ 5 years of age.

PROCEDURES

Medical records from 2009 to 2019 at 16 veterinary teaching hospitals were evaluated. Data collected included signalment, clinical signs at diagnosis, clinicopathologic data, surgical and medical treatments, shunt morphology, clinical signs and medical treatments at 6 to 12 months after diagnosis, and survival time.

RESULTS

351 dogs (M, 119 [33.9%]; S, 232 [66.1%]) were included in the study. Survival time was longer with surgery than medical management (hazard ratio, 4.2; M, 3.4 years; S, 10.9 years). Continued clinical signs at 6 to 12 months after diagnosis were more common with medical management (M, 40% [33/88]; S, 14% [21/155]). Continued medical treatments at 6 to 12 months after diagnosis were more common in the medical management group (M, 78% [69/88]; S, 34% [53/155]). Perioperative mortality rate was 7.3%.

CLINICAL RELEVANCE

Dogs diagnosed at ≥ 5 years of age with EHPSS have significantly better survival times and fewer clinical signs with surgical attenuation, compared with medical management. Older dogs have similar surgical mortality rates to dogs of all ages after surgical EHPSS attenuation.

Restricted access
in Journal of the American Veterinary Medical Association