Brian McKeon
Chief Financial Officer at IDEXX Laboratories
Good morning, and welcome to our second quarter earnings call. Today, I'll take you through our Q2 results and review our updated financial outlook for 2024.
IDEXX delivered solid organic revenue growth and strong comparable profit gains in the second quarter. In terms of highlights, overall revenues increased 7% organically, supported by 7% organic growth in CAG diagnostic recurring revenues and 10% organic gains in our water business. Solid CAG revenue growth was driven by global benefits from IDEXX execution drivers, reflected in sustained solid new business gains, record second quarter premium instrument placements, and double-digit growth in recurring veterinary software and diagnostic imaging revenues. Partially offsetting these benefits, CAG diagnostic recurring revenue growth in Q2 was constrained by impacts from near-term macro and sector headwinds, which contributed to a 2% decline in U.S. same-store clinical visit growth levels in the quarter. IDEXX's operating performance reflected in solid comparable operating profit gains continued to be strong in Q2. EPS in the quarter was $2.44, down 9% as reported, including a $0.56 per share impact from a $62 million discrete expense accrual related to an ongoing litigation matter. Comparable EPS growth was 15% in the quarter, ahead of our expectations, supported by solid gross margin gains and benefits from lower net interest costs and shares outstanding.
IDEXX continues to make progress expanding our business, advancing our innovation agenda, and delivering strong comparable profit gains as we work through near-term macro and sector headwinds that continue to pressure clinic visit levels. We've updated our 2024 financial outlook to incorporate recent sector trends, which we estimate at midpoint will constrain overall organic revenue growth to the lower end of our original organic growth guidance for 2024. Our updated P&L guidance maintains our outlook for solid comparable operating margin gains this year and incorporates favorable adjustments for updated foreign exchange, net interest expense, and effective tax rate estimates.
We'll review our updated guidance detail later in my comments. Let's begin with a review of our second quarter results.
Second quarter organic revenue growth of 7% reflected 7% organic CAD gains, 10% organic growth in water, and improved 3% organic growth in our LPD business. CAG organic revenue growth was supported by 8% organic gains in veterinary software and diagnostic imaging revenues, driven by 12% organic growth in recurring revenues. CAG instrument revenue increased 5% organically, building on high prior year placement levels. CAG diagnostic recurring revenue increased 7% organically in Q2, supported by average global net price improvement of 5% to 5.5%, with U.S. net price realization at the lower end of this range. CAG diagnostic recurring revenue growth in Q2 was supported by 10% international organic gains, including approximately 1% of growth benefit from equivalent days effects in international regions. Strong international growth reflects benefits from net price realization and continued solid volume gains. International growth continues to be driven by IDEXX execution, reflected in strong new business gains and high premium instrument placements, which supported a double-digit year-on-year expansion of our global premium instrument install base.
U.S. CAG diagnostic recurring revenue growth was 5.2% in Q2, net of a 0.5% U.S. equivalent day growth headwind in the quarter. IDEXX growth was supported by solid new business gains, sustained high customer retention levels, and benefits from net price realization. IDEXX growth continues to expand at a high premium to U.S. same-store clinical visit growth levels, which declined 1.8% in Q2. In the U.S., diagnostic utilization per clinical visit continues to expand solidly at the clinic level. This is reflected in a 7.5% year-on-year increase in diagnostic revenue dollars per clinical visit, including diagnostics. While diagnostic frequency per clinical visit declined modestly in Q2, diagnostic frequency per wellness visit expanded 100 basis points.
This partially offset lower diagnostic frequency per non-wellness visit. The decline in diagnostic frequency for non-wellness visits may reflect recent growth in fall clinical visits for pain management drug treatment, which may not include diagnostics. Adjusting for these effects would imply relatively softer comparable U.S. clinical visit trends and a relatively higher IDEXX growth premium.
Overall, IDEXX continues to achieve solid organic revenue growth in CAG diagnostic revenues as we work through headwinds from broader cumulative macro impacts on consumers, which are likely pressuring near-term U.S. clinical visit growth levels. While we remain highly confident in the positive long-term drivers of demand for diagnostics, including the future benefits that will flow from IDEXX innovation, we factored in expectations for continued pressure from lower U.S. clinical visits in the second half of 2024 and our updated full year organic growth outlook. IDEXX execution drivers supported solid organic revenue growth across our modalities in Q2.
At IDEXX VetLab, consumable revenues increased 8% organically, reflecting solid gains in the U.S. and double-digit growth in international regions. Consumable gains were supported by 11% year-on-year growth at our global premium instrument install base, reflecting strong gains across our catalyst, premium hematology, and SediVue platforms. We achieved a Q2 record 4,952 CAG premium instrument placements, an increase of 4% year-on-year compared to high prior year levels. These results were supported by continued strong growth in premium hematology and SediVue placements. ProCyte One momentum continues, with the global ProCyte One installed base increasing to over 17,000 instruments. Global catalyst placements decreased year-on-year in the quarter, reflecting comparisons to high prior year placement levels and placement mix in international regions.
Global rapid assay revenues expanded 6% organically in Q2, driven by solid gains in the U.S., including benefits from higher net price utilization. Global lab revenues also increased 6% organically, reflecting solid U.S. gains and high single-digit growth in international regions. Veterinary software and diagnostic imaging revenues increased 12% as reported, including benefits from our recent Greenline software and data platform acquisition. 8% overall organic revenue gains were driven by 12% organic growth in recurring revenues, reflecting benefits from ongoing momentum in cloud-based software placements.
Water revenues increased 10% organically in Q2, driven by double-digit gains in the U.S. and continued solid growth in Europe. Livestock, Poultry and Dairy revenues increased 3% organically. Continued solid gains in the U.S. and Europe offset lower Asia-Pacific revenues, including impacts from reduced Swine testing in China and lower herd health screening revenues.
Turning to the P&L, Q2 profit results were supported by gross margin gains. Gross profit increased 8% in the quarter as reported and 9% on a comparable basis. Gross margins were 61.7% of 90 basis points on a comparable basis. Gross margin gains reflect benefits from net price utilization, offsetting inflationary cost impacts, software service margin gains, and favorable business mix. On a recorded basis, operating expenses increased 28% year-on-year, including 22% of growth impact related to the $62 million discrete litigation expense accrual recorded in G&A.
Excluding this impact, Q2 Opex growth was in line with overall revenue growth, driven by increases in R&D spending aligned with advancing our innovation agenda, including new platform development. On a reported basis, operating margins were 26.3% in the quarter, including a 610 basis point impact from the discrete litigation expense accrual. On a comparable basis, excluding this impact, operating margins increased approximately 110 basis points year-on-year in the quarter. EPS was $2.44 per share in the quarter, a decrease of 9% as reported, including the $0.56 per share impact related to the discrete litigation expense accrual. EPS increased 15% on a comparable basis. Foreign exchange produced revenues by approximately $7 million, operating profit by approximately $3 million, and EPS by approximately $0.02 per share in the quarter, net of a $2 million hedge gain. Free cash flow was $215 million in Q2. On a trailing 12-month basis, our net income to free cash flow conversion ratio was 99%. For the full year, we're maintaining our outlook for free cash flow conversion of 90% to 95%, reflecting estimated capital spending of approximately $180 million.
Our balance sheet remains in a strong position. We ended the quarter with leverage ratios of 0.7 times gross and 0.4 times net of cash, as we continue to manage our balance sheet conservatively. We allocated $208 million in capital to share repurchases in the second quarter, supporting a 0.7% year-on-year reduction in diluted shares outstanding.
Turning to our 2024 guidance, we've updated our full year organic growth outlook to reflect expectations for continued pressure on U.S. clinical visit trends in the second half of 2024. Our P&L outlook reinforces our full year goals for solid, comparable operating margin improvement and incorporates favorable adjustments to estimates for foreign exchange impacts, net interest expense, and our effective tax rate. Our updated full year guidance for reported revenues is $3,885 million to $3,945 million, a reduction of $15 million at midpoint.
Our updated reported revenue outlook includes a favorable $15 million adjustment related to more recent foreign exchange estimates. We've updated our full year guidance for overall organic revenue growth and CAG diagnostic organic recurring revenue growth to 6.2% to 7.8%, or approximately 7% at midpoint. Our outlook for overall organic revenue growth continues to reflect expectations for solid CAG diagnostics recurring revenue gains supported by IDEXX execution.
This includes consistent expectations for full year global net price improvement of approximately 5%. Our updated organic growth outlook at midpoint assumes IDEXX execution growth benefits will be partially offset by continued pressure on U.S. clinical visit levels in the second half of this year, similar to first-half trends. We expect our H2 organic revenue growth results will benefit by approximately 0.5% overall from equivalent days effects, reflecting 1% to 1.5% organic growth rate benefits in Q3.
In terms of our profit guidance, our updated outlook incorporates impacts from the discrete litigation expense accrual, which we estimate will reduce full year recorded operating margins by approximately 160 basis points and EPS by $0.56 per share. We will normalize for the effects of this accrual in setting our 2025 financial performance goals. Incorporating these impacts, our updated reported operating margin outlook is 28.7% to 29.0%. This reflects a consistent 40 basis point improvement in comparable operating margins at midpoint, net of a negative 40 basis point impact related to lapping of the Q1 2023 customer contract resolution payment.
Our updated full year EPS outlook at $10.31 to $10.59 per share is down $0.56 per share at midpoint, reflecting the impact from the discrete litigation expense accrual. Adjustments to our organic revenue growth outlook reduce our operational EPS estimates by approximately $.08 per share at midpoint, which is offset by approximately $0.4 in favorable foreign exchange adjustments and positive below-the-line benefits from refinements to our net interest expense and effective tax rate outlook.
We now estimate foreign exchange will reduce full year revenue growth by approximately 0.5% and EPS by approximately $0.5 per share. In terms of our outlook for Q3, we're planning for reported revenue growth of 6% to 8% in net of an estimated 1% growth headwind from foreign exchange and incorporating approximately 0.5% in growth benefits from our recent software acquisition. This outlook aligns with an organic revenue growth range of approximately 6.5% to 8.5%, including approximately 1% to 1.5% of growth benefit from equivalent day's effects. We're planning for reported operating margins of 29.5% to 30.0% in Q3, down moderately on a comparable basis. This factors in year-on-year comparisons to relatively lower prior sales and marketing expense levels and projections for continued high year-on-year growth in R&D spending, including support of new platform advancement.
That concludes our financial review. I'll now turn the call over to Jay for his comments.