Q3 Premium Instrument Placements WW North

America Intl

Catalyst 1,700 608 1,092

New and competitive 1,163 303 860

Premium Hematology 978 358 620

SediVue® Dx 495 327 168

TOTAL 3,173 1,293 1,880

CAG Water LPD

Revenue $638M Revenue $33M Revenue $37MReported growth: +20% Reported growth: -5% Reported growth: +18%

Organic growth: +18% Organic growth: -4% Organic growth: +18%

For full financial data, non-GAAP reconciliations and cautionary language regarding forward-looking statements, please refer to IDEXX’s 2020 third quarter earnings release issued on October 29, 2020 available at https://www.idexx.com/investors. Amounts presented may not recalculate due to rounding.

IDEXX Q3 2020 Earnings Highlights (NASDAQ: IDXX)

Revenue OperatingProfit

Diluted Earnings Per Share

$722M $172M $1.69 Reported growth: of Revenue

Organic growth: YoY change in basis points: Reported growth:

CAG Diagnostics RecurringOrganic Growth:

Reported Constant currency

Comparable constant currency growth:

Net CAG Revenue Q3 Revenue

Reported Growth

year over year

Organic Growthyear over year

CAG Diagnostics Recurring $567M +23% +21%

IDEXX VetLab® Consumables $219M +23% +22%

Rapid Assay Products $71M +20% +20%

Reference Laboratory Dx and Consulting Services $254M +24% +21%

CAG Diagnostics Services and Accessories $24M +21% +20%

CAG Diagnostics Capital – Instruments $29M -10% -11%

Veterinary Software, Services and Diagnostic Imaging Systems $41M +4% +4%

2020 and 2021 Outlook

+19% +18%

24% +36%

+47% +70 bps +470 bps +21%

Strong global companion animal market trends supported high demand for CAG diagnostics products and services in the third quarter, following the V-shaped recovery seen in the second quarter. While these trends are encouraging, potential effects related to ongoing COVID-19 case management efforts and related economic impacts are challenging to predict and may pressure future revenues should enhanced social distancing policies and higher infection rates impact veterinary operations.

The company is maintaining suspension of 2020 guidance due to the unpredictability of potential future impacts related to the COVID-19 pandemic and is not providing preliminary 2021 guidance at this time.

© 2020 IDEXX Laboratories, Inc. All rights reserved. Contact: John Ravis, Investor Relations (207) 556-8155.

4.6%5.3% 5.5%

6.9%7.4% 7.6%

6.7%7.7% 8.0%

5.1% 5.4% 5.6% 5.9%

7.2%6.6% 6.2%

4.2%4.6% 5.0%

4.1%

5.8%5.1%

5.7%4.6%

4.2%

2.5%

10.9%

0.3%

1.5% 1.2%

2.5%

4.0%4.5%

3.4%

4.6% 5.0%

2.4% 2.5% 2.2% 2.4%3.5%

3.0%2.3%

0.4% 0.5% 0.6%-0.1%

1.5%1.0%

1.5%

0.1% 0.3%

-4.8%

1.3%

Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3-6%

-4%

-2%

0%

2%

4%

6%

8%

10%

12%

U.S. Companion Animal Practice Growth Update

© 2020 IDEXX Laboratories, Inc. All rights reserved. Contact: John Ravis, Investor Relations (207) 556-8155.

Practice Revenue Growth

2014 2015 2016 2017 2018

2.5% 2.1% 1.9% 1.6%2.5% 2.4% 3.0%

2.0%

-0.4%

-2.6%

6.4%

0.4% 0.5% 0.6%-0.1%

1.5% 1.0% 1.5%0.1% 0.3%

-4.8%

1.3%

Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3-6%

-4%

-2%

0%

2%

4%

6%

8%

2019

Total Visit Growth

2019

Total Practice Revenue and Visit GrowthWeighted Average Year-to-Year % Change Per Practice*

2018

Total and Clinical Patient Visit GrowthWeighted Average Year-to-Year % Change Per Practice*

Clinical Visit Growth

Total Visit Growth

Source: IDEXX Practice Intelligence data; sample of ~7,750 practices representing six different practice information management systems, weighted based on practice size and region to reflect market composition. ‘Clinical visits’ are those where the reason for visit involves an interaction between a clinician and a pet. *We estimate net new practice formation adds ~1% of incremental market growth per year beyond per practice growth. Growth rate estimate with margin of error of +/ - 0.4% at a 95% confidence level.

IDEXX Premium Instruments Installed Base

25.526.628.029.931.132.835.1

37.038.539.841.543.945.146.047.6

Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3

Catalyst Installed Base(in thousands)

2018 20192017

24.124.625.226.026.727.428.028.929.529.830.531.532.032.433.6

Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3

Premium Hematology Installed Base(in thousands)

2018 20192017

2.0 2.6 3.1 3.9 4.6 5.2 5.9 6.6 7.1 7.6 8.2 8.9 9.3 9.610.0

Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3

SediVue Installed Base(in thousands)

2018 20192017

2020

2020

2020 2020 2020

U.S. Companion Animal Market Trends UpdateAs of October 16, 2020

Total visits include clinical and non-clinical visits. In 2019, there were an estimated 315 million U.S. total visits. Approximately 70% of estimated U.S. companion animal diagnostic market revenue is from non-wellness visits.

Clinical visits are those where the reason for visit involves an interaction between a clinician and a pet. In 2019, there were an estimated 180million U.S. clinical visits.

Non-wellness visits include those for which the reason for visit is sickness, procedure or monitoring. In 2019, there were an estimated 105 million U.S. non-wellness visits.

Wellness visits include those visits for which the reason for visit is an annual exam, vaccination, or routine check-up. In 2019, there were an estimated 75 million U.S. wellness visits.

-45%

-35%

-25%

-15%

-5%

5%

15%

Jan 3 Feb 7 March 6 April 3 May 1 June 5 July 3 Aug 7 Sept 4 Oct 2Total Visits

ClinicalWellness

Non-wellness

U.S. Average Visits per Practice7-day Average Year-Over-Year Change (%)

1%

5%7%

5%

Month Total Clinical Non-wellness Wellness

January 3% 5% 5% 6%

February 2% 4% 3% 4%

March -4% -9% -4% -16%

April -15% -18% -10% -28%

May -2% 2% 2% 1%

June 2% 8% 5% 11%

July 1% 6% 2% 11%

August 1% 6% 3% 10%

September 2% 7% 4% 11%

Monthly Year-Over-Year % Growth Rates

* To smooth the volatility associated with holiday timing, the graph reflects 2-week average growth rates for the weeks ending 7/3, 7/10, and ending 9/4, 9/11.

Source: IDEXX Practice Intelligence data; sample of ~7,800 practices representing six different practice information management systems, weighted based on practice size and region to reflect market composition. Analysis reflects representative real-time trends on same practice year-over-year growth and does not include adjustments related to equivalent business days and may understate period activity due to latency at clinic level posting daily transactions. We update data for previously reported periods to include subsequent data reporting. Growth rates margin of error of +/ - 0.4% at a 95% confidence level.

© 2020 IDEXX Laboratories, Inc. All rights reserved. Contact: John Ravis, Investor Relations (207) 556-8155.

*

Average per Practice Q1 Q2 Q3October

(2 weeks ending October 16)

Total Practice Revenue 4% 2% 11% 11%

Total Visits 0.3% -5% 1% 1%

Clinical Visits -0.4% -3% 6% 5%

Non-Wellness Visits 1% -1% 3% 5%

Wellness Visits -3% -5% 11% 7%

2020 Year-Over-Year % Growth Rates

October Visit Growth (2 weeks ending Oct. 16)

*

U.S. Companion Animal Market Trends UpdateAs of October 16, 2020

Region Average Visits per Practice7-day Average Year-Over-Year Change (%)

© 2020 IDEXX Laboratories, Inc. All rights reserved. Contact: John Ravis, Investor Relations (207) 556-8155.

Total Visits

ClinicalWellness

Non-wellness

-50%

-40%

-30%

-20%

-10%

0%

10%

Jan 3 Feb 7 March 6 April 3 May 1 June 5 July 3 Aug 7 Sept 4 Oct 2

Northeast Region

16% of Total 2019 Clinical Visits

-45%

-35%

-25%

-15%

-5%

5%

15%

25%

Jan 3 Feb 7 March 6 April 3 May 1 June 5 July 3 Aug 7 Sept 4 Oct 2

Midwest Region

22% of Total 2019 Clinical Visits

-45%

-35%

-25%

-15%

-5%

5%

15%

Jan 3 Feb 7 March 6 April 3 May 1 June 5 July 3 Aug 7 Sept 4 Oct 2

West Region

22% of Total 2019 Clinical Visits

-45%

-35%

-25%

-15%

-5%

5%

15%

Jan 3 Feb 7 March 6 April 3 May 1 June 5 July 3 Aug 7 Sept 4 Oct 2

South Region

40% of Total 2019 Clinical Visits

1%

6%7%

5%

*

*

*

*

October Visit Growth (2 weeks ending Oct. 16)

*

*

*

*

0%

4%3%

6%

3%

7%6%

9%

-1%

3%0%

9%