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Abstract

Objective—To identify demographic or signalment factors associated with calcium carbonate urolith formation in goats.

Design—Retrospective case series and case-control study.

Animals—354 goats with calcium carbonate uroliths (case animals) and 16,366 goats without urinary tract disease (control animals).

Procedures—Medical records of the Minnesota Urolith Center were reviewed to identify case goats for which samples were submitted between January 1, 1984, and December 31, 2012. Control goats evaluated at US veterinary teaching hospitals in the same time period were identified by searching Veterinary Medical Database records. Age, breed, sex, reproductive status, geographic location, season, and anatomic location of collected uroliths were analyzed to identify risk or protective factors associated with calcium carbonate urolithiasis.

Results—Nigerian dwarf goats had higher odds of developing calcium carbonate uroliths than did Pygmy goats (reference group). Several breeds had lower odds of this finding, compared with Pygmy goats; odds were lowest for mixed, Anglo-Nubian, and Toggenburg breeds. Breeds of African origin (Pygmy, Nigerian Dwarf, and Boer) comprised 146 of 275 (53%) case goats with data available. Goats of African descent had a higher risk of developing calcium carbonate uroliths than did goats of non-African descent (reference group). Males and neutered goats had higher odds of calcium carbonate urolithiasis, compared with females and sexually intact goats, respectively. Age category, geographic location, and season were associated with detection of calcium carbonate uroliths.

Conclusions and Clinical Relevance—Goats with calcium carbonate uroliths were typically neutered males, > 1 year of age, and of African descent. This study identified factors associated with calcium carbonate urolithiasis in goats; however, these associations do not allow conclusions regarding cause-and-effect relationships.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective

To evaluate the effects of dilution and alkalinization, separately and together, on the stability of uric acid in canine urine stored at −20 C.

Design

Prospective-controlled study.

Animals

5 dogs with confirmed ammonium urate uroliths, 6 Beagles, and 6 mixed-breed dogs.

Procedure

Dogs were fed a 31.4% protein (dry weight), meat-based diet for 21 days, and urine samples were collected on day 22. Urine samples were preserved, using combinations of dilution and alkalinization, and divided into 1-ml aliquots for storage at −20 C for 1 to 12 weeks. Urine uric acid concentrations were measured, using high-performance liquid chromatography, on day of collection (baseline), and after 1, 2, 4, 8, and 12 weeks.

Results

Alkalinization did not have a significant effect on reproducibility of measurements of uric acid concentrations in urine; however, dilution did have a significant effect. Compared with baseline, uric acid concentrations in urine samples collected from dogs with ammonium urate uroliths and Beagles and diluted 1:10 or 1:20 with deionized water were not different after storage for 1 to 12 weeks. Uric acid concentrations in urine samples collected from mixed-breed dogs did not differ from baseline values during the 12-week storage period whether samples were undiluted or were diluted 1:10 or 1:20 with deionized water.

Conclusions

Measurements of uric acid concentration are most reproducible in canine urine samples stored at −20 C for 1 to 12 weeks when samples are diluted 1:20 with deionized water.

Clinical Relevance

To ensure reproducibility of measurements of uric acid concentration in urine samples collected from dogs affected with urate uroliths, urine should be diluted 1:20 with deionized water. Alkalinization is not necessary, and is not recommended because of the additional step in processing and its potential to interfere with measurement of other urinary analytes. (Am J Vet Res 1996;57:787–790)

Free access
in American Journal of Veterinary Research

Abstract

Objectives—To compare serum concentrations of total thyroxine (TT4), free thyroxine (fT4), and thyroid- stimulating hormone (TSH), as well as measures of thyroid follicular colloid and epithelium, between groups of healthy dogs and severely sick dogs.

Design—Cross-sectional study.

Animals—61 healthy dogs and 66 severely sick dogs.

Procedure—Serum samples were obtained before euthanasia, and both thyroid lobes were removed immediately after euthanasia. Morphometric analyses were performed on each lobe, and serum TT4, fT4, and TSH concentrations were measured.

Results—In the sick group, serum TT4 and fT4 concentrations were less than reference range values in 39 (59%) and 21 (32%) dogs, respectively; only 5 (8%) dogs had high TSH concentrations. Mean serum TT4 and fT4 concentrations were significantly lower in the sick group, compared with the healthy group. In the healthy group, a significant negative correlation was found between volume percentage of colloid and TT4 or fT4 concentrations, and a significant positive correlation was found between volume percentage of follicular epithelium and TT4 or fT4 concentrations. A significant negative correlation was observed between volume percentages of colloid and follicular epithelium in both groups.

Conclusions and Clinical Relevance—TT4 and fT4 concentrations are frequently less than reference range values in severely sick dogs. Therefore, thyroid status should not be evaluated during severe illness. The absence of any significant differences in mean volume percentages of follicular epithelium between healthy and severely sick dogs suggests that these 2 groups had similar potential for synthesizing and secreting thyroid hormones. (J Am Vet Med Assoc 2003;222:1079–1085)

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine relative concentrations of selected major brain tissue metabolites and their ratios and lobar variations by use of 3-T proton (hydrogen 1 [1H]) magnetic resonance spectroscopy (MRS) of the brain of healthy dogs.

Animals—10 healthy Beagles.

Procedures—3-T 1H MRS at echo times of 144 and 35 milliseconds was performed on 5 transverse slices and 1 sagittal slice of representative brain lobe regions. Intravoxel parenchyma was classified as white matter, gray matter, or mixed (gray and white) and analyzed for relative concentrations (in arbitrary units) of N-acetylaspartate (NAA), choline, and creatine (ie, height at position of peak on MRS graph) as well as their ratios (NAA-to-choline, NAA-to-creatine, and choline-to-creatine ratios). Peak heights for metabolites were compared between echo times. Peak heights for metabolites and their ratios were correlated and evaluated among matter types. Yield was calculated as interpretable voxels divided by available lobar voxels.

Results—Reference ranges of the metabolite concentration ratios were determined at an echo time of 35 milliseconds (NAA-to-choline ratio, 1.055 to 2.224; NAA-to-creatine ratio, 1.103 to 2.161; choline-to-creatine ratio, 0.759 to 1.332) and 144 milliseconds (NAA-to-choline ratio, 0.687 to 1.788; NAA-to-creatine ratio, 0.984 to 2.044; choline-to-creatine ratio, 0.828 to 1.853). Metabolite concentration ratios were greater in white matter than in gray matter. Voxel yields ranged from 43% for the temporal lobe to 100% for the thalamus.

Conclusions and Clinical Relevance—Metabolite concentrations and concentration ratios determined with 3-T 1H MRS were not identical to those in humans and were determined for clinical and research investigations of canine brain disease.

Full access
in American Journal of Veterinary Research

Summary

In a prospective study, 141 cats with hematuria, dysuria, urethral obstruction, or combinations of these signs were evaluated by contemporary diagnostic methods and compared with 26 clinically normal cats (controls). Specific diagnosis was established in 45% (64/141) of cats affected with lower urinary tract disease (lutd). Crystalline matrix plug-induced urethral obstruction was diagnosed in 21% (30/141) of affected cats, uroliths were identified in 21% (30/141) of affected cats, uroliths with concomitant bacterial urinary tract infection (uti) were identified in < 2% (2/141) of affected cats, and bacterial uti alone was identified in < 2% (2/141) of cats with lutd. Viruses, mycoplasmas, and ureaplasmas were not isolated from urine samples collected from affected or control cats.

Bovine herpesvirus 4 (bhv-4)-neutralizing antibodies were not detected in any serum sample obtained from cats with lutd or from control cats. In contrast, bhv-4 antibodies were detected by an indirect immunofluorescent antibody (ifa) test in sera obtained from 31% (44/141) of cats with lutd and 23% (6/26) of control cats. The prevalence of positive bhv-4 ifa test results in affected cats was not significantly different from that observed in control cats. Significant association was not apparent between positive bhv-4 ifa test results and clinical diagnosis, abnormal laboratory findings, or cat age. However, the number of male cats with bhv-4 ifa titer was significantly (P < 0.02, χ2 test) greater than that of female cats. Detection of bhv-4 antibodies in approximately 30% of affected and control cats indicates prior virus exposure. Further investigations are warranted to clarify the specific role of bhv-4 in cats with naturally acquired lutd.

Free access
in Journal of the American Veterinary Medical Association