Objective—To compare seroprevalence of antibodies
against equine arteritis virus (EAV) in horses residing
in the United States with that of imported horses.
Sample Population—Serum samples from 364 horses
on 44 equine operations in California and 226 horses
imported from various countries.
Procedure—Serum samples were collected from
each imported horse and from up to 20 horses on
each operation. For resident horses, the number of
sampled horses on each operation was determined
on the basis of the number of horses on the operation.
Samples were tested for antibodies against EAV
by use of a serum neutralization test.
Results—1.9% of resident horses and 18.6% of
imported horses were seropositive to EAV, including
16.1% of imported stallions.
Conclusions and Clinical Relevance—Results indicate
that the EAV seroprevalence of horses residing
in California is considerably lower than that of imported
horses, including imported stallions. (J Am Vet
Med Assoc 2001;219:946–949)
Objective—To estimate risk of exposure and age at
first exposure to Sarcocystis neurona and Neospora
hughesi and time to maternal antibody decay in foals.
Animals—484 Thoroughbred and Warmblood foals
from 4 farms in California.
Procedure—Serum was collected before and after
colostrum ingestion and at 3-month intervals thereafter.
Samples were tested by use of the indirect fluorescent
antibody test; cutoff titers were ≥ 40 and
≥ 160 for S neurona and N hughesi, respectively.
Results—Risk of exposure to S neurona and N hughesi
during the study were 8.2% and 3.1%, respectively.
Annual rate of exposure was 3.1% for S neurona and
1.7% for N hughesi. There was a significant
difference in the risk of exposure to S neurona among
farms but not in the risk of exposure to N hughesi.
Median age at first exposure was 1.2 years for S neurona and
0.8 years for N hughesi. Highest prevalence
of antibodies against S neurona and N hughesi was
6% and 2.1%, respectively, at a mean age of 1.7 and
1.4 years, respectively. Median time to maternal antibody
decay was 96 days for S neurona and 91 days for
N hughesi. There were no clinical cases of equine protozoal
Conclusions and Clinical Relevance—Exposure to
S neurona and N hughesi was low in foals between birth
and 2.5 years of age. Maternally acquired antibodies
may cause false-positive results for 3 or 4 months after
birth, and EPM was a rare clinical disease in horses ≤ 2.5
years of age. (Am J Vet Res 2004;65:1047–1052)
Objective—To optimize the isolation and culture of mesenchymal stem cells (MSCs) from umbilical-cord blood (UCB), identify variables that predicted successful MSC isolation, and determine whether shipping, processing, and cryopreservation altered MSC viability, recovery rates, and expansion kinetics.
Sample Population—UCB samples from 79 Thoroughbred and Quarter Horse mares.
Procedures—UCB samples were processed to reduce volume and remove RBCs. Nucleated cells (NCs) were cryopreserved or grown in various culture conditions to optimize MSC monolayer expansion and proliferation. Donor and UCB-sample factors were analyzed to determine their influence on the success of MSC isolation and monolayer expansion.
Results—MSCs capable of multilineage in vitro differentiation were expanded from > 80% of UCB samples. Automated UCB processing and temperature-controlled shipping facilitated sterile and standardized RBC reduction and NC enrichment from UCB samples. The number of NCs after UCB samples were processed was the sole variable that predicted successful MSC expansion. The UCB-derived MSCs and NCs were successfully cryopreserved and thawed with no decrease in cell recovery, viability, or MSC proliferation. The use of fibronectin-coated culture plates and reduction of incubator oxygen tension from 20% to 5% improved the MSC isolation rate. Some UCB-derived MSC clones proliferated for > 20 passages before senescence. Onset of senescence was associated with specific immunocytochemical changes.
Conclusions and Clinical Relevance—Equine UCB samples appeared to be a rich source of readily obtainable, highly proliferative MSCs that could be banked for therapeutic use.
Objective—To determine the optimal osteogenic source of equine mesenchymal stem cells (eMSCs) and optimize collection of and expansion conditions for those cells.
Animals—10 adult Quarter Horses and 8 newborn Thoroughbred foals.
Procedures—eMSCs were isolated from bone marrow (BM), adipose tissue, and umbilical cord blood and tissue, and the osteogenic potential of each type was assessed. Effects of anatomic site, aspiration volume, and serum type on eMSC yield from BM were investigated.
Results—BM-eMSCs had the highest overall expression of the osteogenic genes Cbfa1, Osx, and Omd and staining for ALP activity and calcium deposition. There was no significant difference in BM-eMSC yield from the tuber coxae or sternum, but yield was significantly greater from the first 60-mL aspirate than from subsequent aspirates. The BM-eMSC expansion rate was significantly higher when cells were cultured in fetal bovine serum instead of autologous serum (AS).
Conclusions and Clinical Relevance—eMSCs from BM possessed the highest in vitro osteogenic potential; eMSCs from adipose tissue also had robust osteogenic potential. The tuber coxae and the sternum were viable sources of BM-eMSCs in yearlings, and 60 mL of BM aspirate was sufficient for culture and expansion. Expanding BM-eMSCs in AS to avoid potential immunologic reactions decreased the total yield because BM-eMSCs grew significantly slower in AS than in fetal bovine serum. Additional studies are needed to determine optimal ex vivo eMSC culture and expansion conditions, including the timing and use of growth factor—supplemented AS. (Am J Vet Res 2010;71:1237-1245)