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Abstract

Objective—To characterize lysosomal storage body accumulation in the retina and brain of Tibetan Terriers with ceroid-lipofuscinosis and determine whether the disease in these dogs is accompanied by impaired retinal function and retinal degeneration.

Animals—Three 7- to 10-year-old Tibetan Terriers with ceroid-lipofuscinosis and 1 healthy 5-year-old Tibetan Terrier.

Procedure—Owners completed a questionnaire to identify behavioral and physical signs indicative of ceroid-lipofuscinosis. Neurologic, behavioral, and ophthalmologic evaluations, including full-field electroretinograms, were performed on each dog. Fluorescence, light, and electron microscopy were performed on specimens of retina, cerebral cortex, and cerebellum of all dogs postmortem.

Results—Behavioral assessments of the affected dogs revealed moderate visual impairment in lowlight conditions but good vision in bright light. On funduscopic evaluation of these dogs, abnormalities detected ranged from none to signs of moderately advanced retinal degeneration. Compared with findings in the control dog, electroretinography revealed depressed rod cell function with some impairment of cone cell function in the affected dogs. Morphologically, disease-specific storage bodies were detected in retinal Müller cells and neurons, particularly in ganglion cells, and in cells of the cerebral cortex and cerebellum in affected dogs. Substantial photoreceptor cell loss and disruption of photoreceptor outer segment morphology appeared to develop late in the disease.

Conclusions and Clinical Relevance—The similarities between ceroid-lipofuscinosis in Tibetan Terriers and some forms of ceroid-lipofuscinosis in humans suggest that the canine disease may have a genetic and biochemical basis similar to that of one of the ceroidlipofuscinosis disorders in humans. (Am J Vet Res 2005;66:67–76)

Full access
in American Journal of Veterinary Research

Objective

To develop an algorithm for predicting passive transfer status of lambs of various ages, using the lamb's age and serum ɣ-glutamyltransferase (GGT) activity.

Design

Prospective study.

Animals

51 Suffolk, Columbia, and crossbred lambs from 1 to 16 days old.

Procedure

Serum was obtained from all lambs. Serum GGT activity was measured, using a commercially available kit. Serum IgG concentration was determined by use of radial immunodiffusion. Day-1 serum IgG concentration was estimated from sample IgG concentration, lamb age, and the published 14-day half-life of IgG in lambs. Stepwise multivariate regression models were developed to estimate day-1 serum IgG concentration as a function of the natural logarithm of serum GGT activity (In[GGT]) and natural logarithm of lamb age (In[age]) at the time of sampling. These regression models were then used to calculate serum GGT activities that were equivalent to various day-1 IgG concentrations in lambs of various ages.

Results

In(GGT) and In(age) were significantly associated with estimated day-1 IgG concentration. Day-1 serum IgG concentration could be predicted using the formula: IgG = −7,686 + 1,366(In[GGT]) + 1,199(In[age]). The model was moderately accurate in predicting serum IgG concentration (R 2 = 0.52).

Clinical Implications

Serum GGT activity can be used to assess passive transfer status of lambs. (J Am Vet Med Assoc 1997;211:1163–1164)

Free access
in Journal of the American Veterinary Medical Association

Abstract

A study to determine and compare the sensitivity of the caudal fold tuberculin test (cft) and a commercial γ-interferon (γ-ifn) assay for diagnosis of bovine tuberculosis was conducted. A dairy herd with approximately a third of the cattle infected with Mycobacterium bovis was chosen for this study. All cattle from this herd were slaughtered, and tissue specimens for bacteriologic culturing and histologic examination were collected. Results of the cft and γ-ifn assay were compared with results of bacteriologic culturing and histologic examination to determine test sensitivity. Results were analyzed, using each of the following 4 standards to classify cattle as infected: positive test result by bacteriologic culturing only; histologic examination only; bacteriologic culturing and histologic examination; and bacteriologic culturing or histologic examination. Sensitivity of the cft ranged from 80.4 to 84.4%, depending on the standard of comparison. Sensitivity of the γ-ifn assay ranged from 55.4 to 97.1%, depending on the standard of comparison and on the method of interpretation. The cft was significantly (P < 0.001) more sensitive than the γ-ifn assay for diagnosis of bovine tuberculosis when the γ-ifn assay was conducted and interpreted as instructed by the manufacturer. Maximum overall sensitivity was achieved when results of the cft and γ-ifn assay were interpreted in parallel.

Free access
in American Journal of Veterinary Research