Objective—To determine herd characteristics and
management practices associated with milk production
in dairy herds enrolled in official Dairy Herd
Improvement Association (DHIA) programs in Ohio.
Sample Population—186 dairy farms in Ohio.
Procedure—All herds in official DHIA programs in 9
counties were invited to participate. Information
regarding herd characteristics and management practices
was obtained, using a standardized questionnaire.
Bulk-tank milk samples were obtained for bacteriologic
culture. Official DHIA test-day records were
obtained, and associations were identified, using multivariable
Results—Of 479 eligible producers, 186 (39%) participated,
and consecutive bulk-tank milk samples
were available for culture from 172 (36%). Streptococcus
agalactiae and Mycoplasma spp were not
recovered from bulk-tank milk samples, but
Staphylococcus aureuswas recovered from 64 (37%)
herds. Mean (± SD) number of lactating cows in participating
herds was 97 ± 66, with 123 (66%) herds
milking < 100 cows. The RHA was significantly associated
with number of cows in milk, estimated percentage
of herd detected in estrus, reported annual
percentage of heifer calves born alive that died before
8 weeks old, percentage days in milk, use of bovine
somatotropin during the preceding 2 years, and sex of
the person completing the questionnaire.
Conclusions and Clinical Relevance—In this study,
the strongest indicator of milk production was number
of cows in milk. However, merely adding cows to a
herd should not be considered to guarantee increased
milk production, because other management traits
could be confounded with increased number of cows
in a herd. (Am J Vet Res 2001;62:1262–1266)
Objective—To determine plasma disposition after
dermal application of a liposome-encapsulated formulation
of lidocaine in cats.
Animals—6 healthy adult cats with a mean (± SD)
body weight of 4.1 ± 0.44 kg.
Procedure—CBC determination and biochemical
analysis of blood samples were performed for all cats.
Cats were anesthetized by use of isoflurane, and
catheters were placed IV in a central vein. The next
day, blood samples were obtained from the catheters
before and 1, 2, 3, 4, 6, 8, 10, 12, and 24 hours after
applying a 4% liposome-encapsulated lidocaine
cream (15 mg/kg) to a clipped area over the cephalic
vein. Plasma concentrations of lidocaine were analyzed
with a high-performance liquid chromatography
Results—Two cats had minimal transdermal absorption
of lidocaine, with lidocaine concentrations below
the sensitivity of the assay at all but 1 or 2 time
points. In the other 4 cats, the median maximum plasma
concentration was 149.5 ng/ml, the median time
to maximum plasma concentration was 2 hours, and
the median area under the concentration versus time
curve from zero to infinity was 1014.5 ng·h/ml.
Conclusions and Clinical Relevance—Maximum
plasma concentrations of lidocaine remained substantially
below toxic plasma concentrations for cats.
On the basis of these data, topical administration of a
liposome-encapsulated lidocaine formulation at a
dose of 15 mg/kg appears to be safe for use in healthy
adult cats. (Am J Vet Res 2002;63:1309–1312)