DIAGNOSTIC LAB NEWS (CONT.)
needed during transportation, cold packs or other refrigerant blocks that are self-contained should be used instead of ice. Note that one ice pack will only keep a specimen cold for 24 hours. Several biomed- ical suppliers offer packing solutions for transporta- tion of biological specimens that can facilitate and simplify this part of the process.
ABORTION STORM IN A DAIRY HERD Nathan. D. Helgert, VMD, DACVP
Assistant Professor, Veterinary Pathology Murray State University Breathitt Veterinary Center
History A dairy herd of approximately 45 milking cows kept in a tie-stall barn with occasional access to pasture experienced an increased number of abortions over a three-week period. During this time, approximately 15 cattle delivered dead premature calves. An entire abortus and maternal serum were submitted to the Breathitt Veterinary Center for evaluation.
Figure 1. Brain, cerebellar white matter. Multifocally, the neuroparenchyma is necrotic and rarefied with infiltration by mononuclear cells, including microglia, lymphocytes, and plasma cells. Infectious agents were not identified; however, these lesions are characteristic for infection with Neospora caninum.
Gross Examination Te fetus measured 69cm from crown to rump, correlating with a gestational age of 224 days (approximately 46 days from full-term).11 Te tissues were diffusely red and expanded by clear red fluid (autolysis). Sig- nificant gross lesions were not identified. Samples of all major organs, including liver, lung, kidney, heart, intestine, and brain were collected and fixed in 10% neutral buffered formalin. Fresh tissues were submitted for ancillary diagnostics.
Histologic Examination Troughout the brain were multiple areas of necrosis with rarefaction of the neuroparenchyma and mild infiltration by mononuclear cells; infectious organisms were not identified. (Figure 1). Pulmonary alveoli occasionally contained meconium. No other significant histologic changes were identified.
Ancillary Testing Examination of fresh liver, lung, thymus, and spleen for bovine herpes virus (infectious bovine rhinotra- cheitis virus) and bovine viral diarrhea virus via fluorescent antibody testing did not demonstrate either agent within the tissues. Aerobic and anaerobic culture of abomasal fluid yielded no growth. Examination of fresh liver, kidney, and spleen by qualitative polymerase chain reaction (qPCR) for Leptospira interrogans was negative; PCR of formalin-fixed, paraffin-embedded brain tissue was positive for Neospora caninum.
Maternal Serology
Anaplasma spp. (cELISA) Bluetongue (AGID)
Result
Negative -4.1% (% inhibition>30 is positive) Negative
Epizootic Hemorrhagic Disease (AGID) Negative Neospora caninum (cELISA) Leptospira canicola (MAT)
Leptospira grippotyphosa (MAT) Leptospira hardjo (MAT)
Leptospira icterohemorrhagiae (MAT) Leptospira Pomona (MAT)
Continued on pg. 10
Positive 35.8% (% inhibition>30 is positive) Negative 1:100 Negative 1:100 Positive 1:100 Positive 1:100 Positive 1:200
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