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Summary

The prevalence data of splenic diseases from 3 sources were studied. Group 1 consisted of a general diagnostic survey of accessions submitted from private veterinary hospitals in California during a period of approximately 4 years and included 1,372 submissions of canine splenic tissue. Group 2 consisted of surgical splenectomy specimens from 92 dogs; the specimens were submitted to the laboratory for gross and histologic evaluation prior to fixation, and a questionnaire was subsequently sent to determine the outcome of the disease. Group 3 was made up of specimens of 105 splenic lesions derived from a large colony of Beagles with complete medical records and records of pathologic findings.

In this study, splenic hematoma and hyperplastic nodule, not hemangiosarcoma, made up the bulk of splenic lesions. Hemangiosarcoma was the most frequent neoplasm of the canine spleen, but the combined prevalence of all other splenic neoplasms was similar to that of hemangiosarcoma alone. Splenic hematoma and hemangiosarcoma were grossly indistinguishable in most cases. Hyperplastic lymphoid nodules and hematomas of the spleen appeared to represent a continuum. If that finding was correlated with microscopic splenic blood flow, specific causal relationship could be suggested. Prognostically, the live/dead ratio and mean survival of dogs with various splenic lesions differed significantly.

Free access
in Journal of the American Veterinary Medical Association

SUMMARY

Akabane virus (akv) strain OBE-1 was inoculated IV into 17 pregnant sheep. Ten fetuses infected at 29 to 45 days of gestation and examined 29 to 30 days later had AKV antigen in the following groups of cells: neuroglial cells in the brain and spinal cord, ganglion cells in the cranial and abdominal ganglia, layer of ganglion cells in the retina, ganglion cells (Auerbach's plexus) in small intestine, hepatocytes, cells in the arterial wall of mesenteric membrane, and trophoblast cells in the placenta. Prior to detection of circulating virus-neutralizing antibody, immunoglobulin-containing cells were found initially at 59 days of gestation in the peripheral portion of white pulp tissue in the spleen. After that, numbers of immunoglobulin-containing cells gradually increased. These results indicated that akv may have strong affinity for neuronal and ganglional cells in infected fetuses and immunoglobulin-containing cells might be considered the earliest immunologic response to AKV replication in the fetus.

Free access
in American Journal of Veterinary Research

Summary

Polyclonal rabbit antiserum to human T-cell CD3 was used to study its reactivity in lymphoid tissues (lymph nodes, spleen, aggregated lymphoid follicles [Peyer's patches], thymus) of several animal species (cattle, sheep, goats, rats, and mice). Using a peroxidase-antiperoxidase technique on formalin-fixed and paraffin-embedded tissues, immunoreactive cells were detected in T cell-dependent areas of the lymphoid tissues. Reactivity was high in all species tested, but mouse tissues had reduced reactivity, compared with the other species. To obtain a reaction, it was necessary to digest tissues with pronase before application of the immunocytochemical technique. Our results indicate that CD3 antiserum may specifically recognize T-lymphoid cells as it does in human lymphoid tissues and can be used as a marker to study physiologic and pathologic conditions of the lymphoid system of these species.

Free access
in American Journal of Veterinary Research

Summary

Retrospective data on the type and prevalence of splenic disease in cats were evaluated in a large number of feline splenic tissues (n = 455) submitted as surgical and necropsy specimens from private veterinary hospitals in California during a period of approximately 5.5 years. Primary and metastatic neoplasia accounted for 37% of all feline splenic lesions. Mastocytoma, lymphosarcoma, myeloproliferative disease, and hemangiosarcoma, in that order, accounted for the bulk of neoplasia. Submission of accessory splenic tissue from either the omentum or pancreas accounted for 4% (17/455), whereas hyperplastic nodules, hematomas, and the combination of these changes in the spleen accounted for 4% (19/455). Splenitis was found in 2% (8/455) of submissions. Thromboembolism with regional splenic infarction accounted for 1% (4/455) of splenic lesions in cats. The remaining splenic lesions each accounted for < 1% of total splenic submissions, and as such, were considered incidental and of questionable clinical importance.

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective

To examine effects of virus exposure on embryonic lymphoid organ structure, apoptosis, and lymphoid cell subpopulations.

Animals

Eggs of specific pathogen free (SPF) White Leghorn chickens at embryonation day (ED) 17.

Procedures

Eggs were inoculated with 2,000 plaque-forming units (PFU) of serotype 1 herpesvirus (Marek’s disease virus [MDV 1]), 2,000 PFU of herpesvirus of turkeys (MDV 3), or 1,000 embryo infectious doses (EID50) of infectious bursal disease virus (IBDV). On post-inoculation days (PID) 3 and 5, lymphoid organ to body weight ratios were determined, and bursa of Fabricius, thymus, and spleen were evaluated for lesions and apoptosis. Proportions of lymphoid cell subpopulations of PID-3 chicken embryos and 7- to 10-day-old chicks were quantitated by flow cytometry.

Results

Lymphoid organ weights were similar in virus-free, MDV 1, and IBDV groups. Embryos inoculated with 2,000 PFU MDV 3/egg had lower bursal weights than virus-free controls. In a repeated trial, MDV 3 (1,000 PFU to 4,000 PFU) did not reduce bursal weights among groups. Histologic changes were seen in bursae after MDV 1 and IBDV inoculation. Apoptosis was greater in bursae of MDV 1-infected embryos than controls. Lymphoid cell subpopulations were similar among all groups with the exception of CD8+ and IgM+ cells in spleens of IBDV-infected 10-day-old chicks.

Conclusions and Clinical Relevance

Infection with pathogenic strains of MDV 1 and IBDV did not alter lymphocyte subpopulations in embryos or cause complete destruction of lymphoid organs. Changes in lymphoid cell subpopulations exposed as embryos to IBDV were seen only after hatching. (Am J Vet Res 1999;60:937–941)

Free access
in American Journal of Veterinary Research

Abstract

Objective

To determine the usefulness of a new method of measuring acoustic backscatter and attenuation in the liver of dogs with experimental steroid-induced hepatopathy.

Animals

10 clinically normal dogs.

Procedure

Steroid hepatopathy was induced by daily injections of prednisone (2 mg/kg of body weight, IM). Dogs were evaluated histologically and were sonographically imaged on days 0, 3, 7, 10, and 14. Acoustic backscatter and attenuation were measured from in vivo images of dogs, using a video signal method, and compared with results obtained from analysis of the unprocessed radio frequency signal.

Results

Histologic evaluation revealed midzonal, predominantly water-filled vacuoles in hepatocytes by day 7, which persisted for the remainder of the study and significantly (P = 0.0001) increased liver weight on day 14. Attenuation and backscatter increased during the experimental period. Mean effective attenuation difference was higher (P = 0.015) in the liver imaged through a left paraxyphoid window in experimental dogs by day 3. Significantly (P < 0.05) greater attenuation persisted in the liver of experimental dogs throughout the experimental period. Mean backscatter ratio was significantly increased (P = 0.02) by day 10. Uncorrected pixel intensity of the liver in 2 experimental dogs was approximately equal to that of the spleen on day 10 and greater than that of the spleen on day 14.

Conclusion

Administration of prednisone to dogs results in increased acoustic backscatter and attenuation in the liver.

Clinical Relevance

The video signal method is a sensitive technique for detecting subtle acoustic changes in the liver of dogs. (Am J Vet Res 1996;57:1690–1694)

Free access
in American Journal of Veterinary Research

SUMMARY

Two indirect elisa containing outer membrane protein (omp) and lipopolysaccharide (lps) antigens from a field isolate of Salmonella choleraesuis var kunzendorf developed and evaluated in experimentally infected and uninfected control pigs. Experimentally induced infection with S choleraesuis was successfully established in 10 pigs by oral inoculation with 108 organisms, and 3 pigs died of clinical salmonellosis at postinoculation (pi) weeks 1, 2, and 4. Swab specimens from tonsils, nostrils, and rectum of pigs were obtained for culture, and sera were evaluated at weekly intervals for 9 weeks after inoculation. The elisa containing omp and lps antigens with either anti-swine IgG or protein albumin-to-globulin ratio (antiglobulin) conjugates were standardized for serologic evaluation. All 4 elisa (2 omp and 2 lps) detected seroconversion by pi week 3 and had sensitivities and specificities of 97.8 and 88.8, 100 and 100, 95.6 and 88.8, and 93.3 and 72.5%, at their ideal cutoff points (negative mean optical density + 2 sd). There was excellent agreement between all 4 elisa systems as determined by kappa values. Cultures of fecal, tonsil, and nasal swab specimens were positive for S choleraesuis until the fourth week of infection. Fecal swab specimens from 1 pig were positive for S choleraesuis until pl week 7. Persistent infection after antemortem culture results were negative was detected by all 4 elisa, which indicated consistently high titers until the end of pi week 9. Conventional bacteriologic examination of intestines, mesenteric lymph nodes, bone marrow, lung, liver, spleen, and bile yielded positive results for S choleraesuis in the 3 pigs that died of clinical infection, whereas results were negative in the other 7 pigs infected by the end of pl week 9. Histologic examination of lung, liver, spleen, intestines, and mesenteric lymph nodes from the 3 pigs that died of S choleraesuis infection revealed severe ulceration and inflammatory cell infiltration in the lamina propria and submucosa of the intestine, whereas minimal changes were observed in other organs.

Free access
in American Journal of Veterinary Research

SUMMARY

Fetal infectivity of Ehrlichia risticii was investigated in 19 ponies that were E risticii negative on the basis of results of an indirect fluorescent antibody (ifa) test. Thirteen pregnant ponies were infected by iv administration of E risticii between 90 and 180 days of gestation. Six pregnant ponies served as noninfected controls. Each infected pony had clinical signs of equine monocytic ehrlichiosis, was confirmed to be ehrlichemic, and developed an ifa titer to E risticii. Two infected ponies became recumbent, were unresponsive to supportive care, and were euthanatized. After recovery from clinical illness, the remaining ponies were observed throughout gestation for reproductive abnormalities. On abortion, each fetus was necropsied and tissue specimens from the liver, bone marrow, spleen, colon, and mesenteric lymph nodes were inoculated into canine monocyte cell cultures. Six infected ponies aborted at a mean 217 days of gestation, which was between postinoculation days 65 and 111. Five fetuses were recovered for evaluation, and E risticii was isolated from 4 of them. All 5 fetuses recovered had similar histologic findings, including enterocolitis, periportal hepatitis, and lymphoid hyperplasia with necrosis of the mesenteric lymph nodes and spleen. All 5 fetuses tested negative for IgG to E risticii, although 3 had low IgM titer to E risticii. The remaining 5 infected ponies had normal parturition. Presuckle ifa titer to E risticii was measured in 4 of the term foals, and results for 3 were positive. Two foals from infected ponies were monitored for 6 months and daily gain in body weight was comparable to that of a control foal. None of the control ponies became ill or seroconverted during the clinical illness phase, and none aborted throughout gestation. Two control ponies seroconverted to E risticii 6 weeks before parturition. Results of this study indicate that E risticii is a primary abortifacient under experimental conditions.

Free access
in American Journal of Veterinary Research

ultrasonographic images (A and B) of the spleen of a 5-year-old spayed female Standard Poodle that underwent abdominal ultrasonography because of a 1-week history of intermittent vomiting, diarrhea, and listlessness. Diagnostic Imaging Findings and

Full access
in Journal of the American Veterinary Medical Association

. Abdominal palpation elicited signs of pain, and an abdominal fluid wave was detected. A large, firm, irregular mass was palpated in the area of the spleen, but detailed interpretation was not possible because of severe ascites. Serum biochemical analysis

Full access
in Journal of the American Veterinary Medical Association