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  • Author or Editor: Robert V. English x
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Summary

Limbal squamous cell carcinoma in 4 horses was treated successfully, using carbon dioxide laser ablation. Tumors were removed, with minimal to no postoperative inflammation or discomfort to the horses. Carbon dioxide laser ablation represents a promising new option in the treatment of limbal squamous cell carcinoma in horses.

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in Journal of the American Veterinary Medical Association

Summary

Feline leukemia virus and feline immunodeficiency virus (fiv) are lymphotropic retroviruses that cause a wide range of diseases in domestic cats. Although it is known that both viruses are capable of infecting T lymphocytes and that infected cats are lymphopenic, it was not known how infection with either virus might alter specific lymphocyte subpopulations. Using a panel of monoclonal antibodies to feline lymphocyte subpopulations, we examined, by use of flow cytometric analysis, lymphocyte changes in cats naturally infected with FeLV or fiv and explored the early stages in the immunopathogenesis of experimentally induced infection with these viruses. Both groups of naturally infected cats had T-cell lymphopenia. In the fiv-infected cats, the T-cell decrease was principally attributable to loss of CD4+ cells, whereas CD8+ and B-cell numbers remained normal. This led to inversion of the CD4+ to CD8+ ratio in these cats. In contrast, the T-cell lymphopenia in FeLV-infected cats resulted from decrease in CD4+ and CD8+ cells, which led to a CD4+ to CD8+ ratio within normal limits. Experimentally induced infection with these 2 viruses supported these findings. Infection with FIV induced early (10 weeks after infection), chronic inversion of the CD4+ to CD8+ ratio. In contrast, infection with FeLV did not alter CD4+ to CD8+ ratio in the first 20 weeks after infection.

Free access
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association

Abstract

Objective—To compare prevalence of organisms and histologic changes in eyes from dogs with blastomycosis that were either untreated or undergoing treatment with itraconazole.

Design—Retrospective study.

Animals—36 dogs with endophthalmitis associated with blastomycosis.

Procedure—Signalment, results of ophthalmic examination, and duration of treatment with itraconazole were extracted from medical records. Histologic sections from eyes were examined for prevalence and viability (ie, budding) of fungal organisms. A scoring system was devised to assess the degree of inflammation.

Results—Clinically, all eyes were blind and had signs of severe endophthalmitis. Histologically, the type and degree of inflammation and prevalence of Blastomyces dermatitidis were not significantly different between dogs treated with itraconazole and untreated dogs or among groups of dogs treated for different time periods (4 to 14, 15 to 28, or 29 to 72 days). Replication of the organisms in vascular tissues as well as avascular spaces in the eyes was similar in treated and untreated dogs. Lens rupture was seen in 12 of 29 (41%) eyes.

Conclusions and Clinical Relevance—Persistence of inflammation in eyes of dogs with naturally occurring blastomycosis is likely attributable to the continued presence of B dermatitidis, regardless of the duration of treatment with itraconazole. Lens capsule rupture, a common and previously unreported histologic finding, may contribute to cataract formation and continued inflammation. (J Am Vet Med Assoc 2004; 224:1317–1322)

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in Journal of the American Veterinary Medical Association

SUMMARY

Sequential histologic, immunologic, and virologic features of herpesvirus-induced keratitis were studied in 18 experimentally infected cats. Histologic changes were assessed by use of light microscopy, and the presence of viral antigen, B lymphocytes, and T lymphocytes was verified immunohistochemically. Flow cytometry was used to monitor changes in blood T lymphocytes (CD4 and CD8 homologues) and B lymphocytes. Cellular immunity was assessed by use of the lymphocyte proliferation assay. Development of stromal keratitis was preceded by prolonged absence of corneal epithelium, decreased numbers of circulating lymphocyte subsets, decreased mitogen responses, and acquisition of viral antigen by the corneal stroma. Return to normal of circulating lymphocyte numbers and function was temporally associated with the arrival of neutrophils and B and T lymphocytes in the corneal stroma. Sequelae to stromal inflammation were fibrosis and scarring. Findings suggest that suppression of local immune responses allows virus access to the corneal stroma, and that subsequent keratitis is mediated by an immune response to viral antigen.

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in American Journal of Veterinary Research

Summary

Clinical findings and laboratory test results from 91 cats with chronic conjunctivitis were studied to determine the causes of the disease and the sensitivity of diagnostic procedures used, and to identify correlations between results of various diagnostic procedures and clinical or signalment variations. Mean age of affected cats was 2.9 ± 2.7 years (± sd), with a range from 1 month to 11 years. Conjunctivitis was more likely to be bilateral (56 cats) than unilateral (35 cats). In cats tested for FeLV or feline immunodeficiency virus infection, 15 and 8.5%, respectively, of the results were positive, compared with 4 and 2.6% for the general hospital population. Culturing or immunofluorescent assay (ifa) for feline herpesvirus 1 (fhv-1) and Chlamydia psittaci ifa resulted identification of pathogens (positive test results) in 19% (fhv-1) and 18% (C psittaci) of tested cats. For fhv-1, culturing was more sensitive than was ifa, yielding positive results in 19 vs 8.8% of cases. In only 1 cat were fhv-1 and chlamydiae recovered. The probability of positive test results for fhv-1 or chlamydiae was unrelated to concurrent corneal disease, unilateral vs bilateral involvement, or age. Cause of conjunctivitis could not be definitively determined in the remaining 35 cases tested for both agents. Bacterial species considered to be potentially pathogenic were isolated from conjunctival sac specimens in only 1 of 38 attempts. Cytologic changes considered compatible with chlamydial or fhv-1 infection (intracytoplasmic inclusions or multinucleated epithelial cells, respectively) were found in 8 and 5 cases, respectively. In only 4 of these cases, however, was the cytologic impression supported by a concurrently positive result on antigen-detection testing. This study revealed that routinely used diagnostic procedures were not able to confirm an etiologic diagnosis in most cats with chronic conjunctivitis.

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in Journal of the American Veterinary Medical Association

Summary

Keratoconjunctivitis sicca (kcs) is a prevalent and often vision-threatening condition in dogs. In several reports, 2% cyclosporine (cyclosporin A, CsA) was described as effective in modulating the clinical signs of kcs. This study was designed to compare the efficacy of 1% CsA vs a placebo, using a randomized double-blind clinical trial. Topical administration of 1% CsA significantly improved Schirmer wetting values and subjective markers of corneal health as compared with the placebo. In the dogs treated with topical administration of 1% CsA, the clinical signs of kcs were improved in 81.8% of cases.

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in Journal of the American Veterinary Medical Association

Summary

Neodymium:yttrium aluminum garnet (Nd:yag) laser energy was transsclerally applied to the ciliary body of 56 eyes of 37 dogs for treatment of glaucoma. Forty-four eyes were glaucomatous at the time of treatment, and 12 normotensive eyes with ciliary cleft closure were treated prophylactically. Glaucoma was primary in 35 dogs and secondary in 2 dogs (1 eye in each dog). Energy was delivered by a general surgical Nd:yag laser via a hand-held, 600-µc-diameter flexible quartz fiber. The mean (±sd) number of spots treated per eye was 35 (±9.7), with mean energy per burst of 7.1 (±2.6) J; mean total energy delivered to the eyes was 228 (±81) J.

Follow-up evaluation was available for 42 eyes from 2 to 4 weeks after treatment, and for 32 eyes from 12 to 24 weeks after treatment. Treatment success, defined as maintenance of intraocular pressure <25 mm of Hg, was achieved in 83% (20/24) of glaucomatous eyes evaluated between 12 and 24 weeks of treatment. Of 4 treatment failures, 3 were eyes devoid of uveal pigment. The consistent acute effects of treatment were conjunctival vascular congestion and blood-aqueous barrier disruption, recognized clinically by the presence of aqueous flare. Hyphema developed in 16% (9/56) of eyes; hyphema resolved without complication in all but 2 eyes. A common long-term complication of treatment was cataract formation, recognized in 37% (12/32) of eyes evaluated at 12 to 24 weeks. Cataracts were sufficiently dense to obstruct vision in 4 eyes. Phthisis bulbi was observed in 1 eye. Results of this study indicate that Nd:yag laser cyclocoagulation is an effective means of controlling intraocular pressure in dogs with glaucoma. Cataract formation is a potential complication of treatment.

Free access
in Journal of the American Veterinary Medical Association