For the three months ended March 31, 2014 and 2013, adjusted diluted earnings per share was $0.38 and $0.37, respectively. Adjusted diluted earnings per share for the three months ended March 31, 2013, excludes $3.8 million of charges related to vacated properties. The operations of two animal hospitals we vacated were consolidated into the newly constructed, VCA West Los Angeles Animal Hospital in the prior-year quarter.
Bob Antin, Chairman and CEO, stated, "While weather presented challenges of historical proportions, we were certainly excited by our ability to achieve revenue growth in both our core Animal Hospital and Laboratory business segments. In addition, we experienced improving results in the latter portion of the quarter and we remain optimistic with respect to our full year 2014 results.
"Animal Hospital revenue in the current quarter increased 3.2%, to $351.6 million, driven by acquisitions made during the past 12 months and same-store revenue growth of 0.5%. Our same-store gross profit margin increased to 14.4% from 13.6%, while our consolidated gross margin increased to 13.9% from 13.3%, in the prior-year quarter. Our adjusted same-store gross profit margin increased to 14.4% from 14.1%, in the prior-year quarter. Adjusted consolidated gross margin was flat at 13.9%. Adjusted operating margin decreased slightly to 11.2%, compared to 11.4%, in the prior-year quarter. During the quarter, we acquired four independent animal hospitals which had historical combined annual revenue of $16.0 million.
"Laboratory internal revenue in the first quarter increased 1.9%, to $88.4 million, driven by a 4.5% increase in the average revenue per requisition, offset by a 2.4% decrease in requisitions clearly affected by the significant number of weather-impacted pet care facilities throughout most of the country. Our Laboratory gross profit margin remained flat at 48.6%, and our operating margin was essentially flat at 39.6% from 39.5%.
"Revenue from our other operations reported in our All Other segment were essentially flat at $28.1 million in the 2014 quarter compared to $28.5 million in the prior-year quarter."
2014 Financial Guidance
We reaffirm the annual guidance provided on February 13, 2014.
Non-GAAP Financial Measures
We believe investors' understanding of our total performance is enhanced by disclosing adjusted net income, adjusted diluted earnings per common share and Adjusted EPS Excluding Amortization. We define these adjusted measures as the reported amounts, adjusted to exclude certain significant items and amortization of intangibles acquired in acquisitions.
Management believes these adjusted measures are useful to management and investors in evaluating the Company's operational performance and their use provides an additional tool for evaluating the Company's operating results and trends. As a result, these non-GAAP financial measures help to provide meaningful comparisons of our overall performance from one reporting period to another and meaningful assessments of related trends.
There is a material limitation associated with the use of these non-GAAP financial measures: our adjusted measures exclude the impact of these significant items, and as a result, our computation of adjusted diluted earnings per common share does not depict diluted earnings per common share in accordance with GAAP.
To compensate for the limitations in the non-GAAP financial measures discussed above, our disclosures provide a complete understanding of all adjustments found in non-GAAP financial measures, and we reconcile the non-GAAP financial measures to the GAAP financial measures in the attached financial schedules titled "Supplemental Operating Data."
We will discuss our first quarter 2014 financial results during a conference call today, April 24th, at 4:30 p.m. Eastern Time. A live broadcast of the call may be accessed by visiting our website at investor.vcaantech.com. The call may also be accessed by dialing (877) 293-5492. Interested parties should call at least ten minutes prior to the start of the call to register. Replay of the webcast will be available for ninety days by visiting the company's website.
This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Among the forward looking statements in this press release are statements addressing our 2014 guidance and plans, expectations, future financial position and results of operation. These forward-looking statements are not historical facts and are inherently uncertain and out of our control. Any or all of our forward-looking statements in this press release may turn out to be wrong. They can be affected by inaccurate assumptions we might make or by known or unknown risks and uncertainties. Actual future results may vary materially. Among other factors that could cause our actual results to differ from this forward-looking information are: the continued effects of the economic uncertainty prevailing in regions in which we operate; our ability to execute on our growth strategy and to manage acquired operations; changes in demand for our products and services; fluctuations in our revenue adversely affecting our gross profit, operating income and margins; and the effects of the other factors discussed in our Annual Report on Form 10-K, Reports on Form 10-Q and our other filings with the SEC.
About VCA Antech
We own, operate and manage the largest networks of freestanding veterinary hospitals and veterinary-exclusive clinical laboratories in the country, additionally we are the largest provider of online communication, professional education and marketing solutions to the veterinary community. We also supply diagnostic imaging equipment to the veterinary industry.
Chief Financial Officer