Abbott Laboratories (NYSE:ABT) has been one of the best investments to hold over the long term. Had you invested $1,000 in the company 30 years ago, your purchase, without dividends reinvested, would be worth $24,497.27 today. This equates to a 2,349.73% cumulative gain on your original $1,000 investment.Of course, investors need to be more concerned with where a company is going rather than where it came from. When we are looking for an investment, we want to own shares of companies that are not only doing well now, but also have the potential for future growth as well.In my view, Abbott Laboratories has plenty of growth ahead. The percentage of the population over the age of 65 is expected to grow from ~9% today to 16.7% over the next three decades. This gives Abbott Laboratories, and its portfolio of leading healthcare products, an increasing pool of people who will need the company’s offerings to maintain and improve their quality of life in the years to come.Company background and recent earnings resultsAbbott Laboratories was founded in the late 1880s. From humble beginnings, the company has grown into a global leader in the healthcare sector and has a market capitalization of nearly $159 billion today. The company sells medical devices, nutritional products, generic pharmaceuticals and diagnostic equipment. Abbott Laboratories spun off AbbVie (NYSE:ABBV) in 2013, which is another recent purchase of ours.We added to our Abbott Laboratories position on Feb. 4, 2020, paying $88.91 for this lot of shares. Abbott Laboratories is now one of the larger holdings in our portfolio.The company released earnings results for the fourth quarter and full year 2020 on Jan. 22, 2020. EPS of $0.95 was in-line with estimates, up 17.3% from the previous year. Revenue grew 7.1% to $8.3 billion, which was nearly $60 million higher than expected.For full-year 2019, EPS increased 12.5% to $3.24, which matched Abbott Laboratories’ guidance for the year. Revenue increased more than 4% to $31.9 billion.Organic growth was 8.5% for the quarter and 7.7% for the year. Currency exchange reduced results by 1.4% for the quarter and 3.4% for 2019.Medical Devices, which accounted for almost 39% of total sales, had 11.3% organic growth in the quarter and 10.5% for the year. This segment had several product areas show high rates of growth. Structural Heart was up 17%, led by growth in sales for MitraClip, which is a minimally invasive treatment for a leaky mitral heart valve. This product grew nearly 29% year-over-year. The Heart Failure business improved 12.5% for the quarter and 20% for the year due to the company’s HeartMate 3, a device that has proven successful at reducing death rates for those with advanced heart failure.Diabetes Care grew 35% in the fourth quarter as the company’s FreeStyle Libre product continues to see high rates of growth. The FreeStyle Libre allows those with diabetes to monitor their glucose levels without requiring the use of finger sticks. The device can be worn up to 14 days, making it the longest lasting wearable glucose sensor on the market. These technological innovations have caused an increase in demand for the FreeStyle Libre, with sales growing 70% to nearly $2 billion for 2019.Sales for the Nutrition segment were up 5.8% in the fourth quarter and 5.3% in 2018. Adult Nutrition was the main driver of growth during the quarter, with sales growing almost 10% organically. The Ensure and Glucerna product lines were the primary contributors to growth. Results were also aided by improved sales for PediaSure and Pedialyte.Diagnostics improved 6.4% and 5.9% in the quarter and full year, respectively. A 10% increase in Core Laboratory sales more than offset weakness in Molecular and Point of Care sales during the fourth quarter. Abbott Laboratories’ Alinity diagnostic instruments are seeing high uptake rates in both the U.S. and international markets.Established Pharmaceuticals, which are sold in just international markets, was higher by 10% for the quarter and 7.3% for the year. Abbott Laboratories is seeing high rates of growth in key emerging markets. The company has focused on the BRIC countries (Brazil, Russia, India and China) and results have shown that this focus has been successful. These countries, especially in Asia and Latin America, are seeing the emergence of a middle class and increasing access to healthcare. These populations are also beginning to age, meaning that Abbott Laboratories is well-positioned with its generic pharmaceutical business in key markets.Story continuesCompanywide, Abbott Laboratories had a strong fourth quarter and full year 2019. Growth for the company is likely to continue as the world’s population continues to age. This can be seen in the company’s guidance for 2020. Abbott Laboratories expects organic growth of 7% to 8% for the current year, led by a double-digit increase for Medical Devices. Every other segment expects at least mid-single-digit organic revenue growth. Abbott Laboratories expects adjusted EPS of $3.55 to $3.65 for 2020, which would be an improvement of 9.6% to 12.7% from last year.Dividend and valuation analysisIncluding the years that AbbVie was part of the company, Abbott Laboratories has paid and increased its dividend for 48 consecutive years. The company has paid an uninterrupted dividend since 1924.Shares yielded 1.6% at the time of our purchase, which may not catch the eye of those looking for a source of high income. On the other hand, those looking for a high dividend growth rate and a low payout ratio should be impressed by Abbott Laboratories.The company increased its dividend by 12.5% for the Feb. 14 2020 payment, which is above its five-year average growth rate of 7.8%.The annualized dividend of $1.44 would represent just 40% of expected adjusted EPS for 2020, matching the decade-long average EPS payout ratio of 40%.Abbott Laboratories hasn’t released a cash flow statement for the full year, but over the previous four quarters, the company distributed $2.2 billion in dividends while generating $5.5 billion in free cash flow. This means that just 40% of the company’s free cash flow during this period of time was used to cover the dividend. This is below the average free cash flow payout ratio of 47% for 2016 through 2018.With a very low EPS and free cash flow payout ratio, Abbott Laboratories looks well-positioned to continue paying and increasing its dividend for many years into the future.With the EPS and organic growth rates that the company is experiencing and expects to see in the future, you’d expect the valuation of Abbott Laboratories to be quite high – and you’d be right.Using our purchase price of $88.91 and the midpoint for adjusted EPS for 2020, Abbott Laboratories has a price-earnings ratio of 24.7. This is above the five-year average price-earnings ratio of 21.1 and 10-year average price-earnings ratio of 17.7. The multiple we paid is near the highest valuation for the stock in the last 10 years.Given Abbott Laboratories’ recent performance, organic growth projections, a large pool of future customers and its dividend track record, we were comfortable adding shares of the company at the current valuation.Final thoughtsAbbott Laboratories has been a remarkable investment for a long period of time. Shares are not cheap, but the company continues to produce organic growth at a high clip. Aging demographics are likely to be a significant tailwind to future results. The company has also been very successful at bringing products to market, such as the FreeStyle Libre, that can quickly become very profitable. This is why shares of Abbott Laboratories trade with an elevated price-earnings ratio today.That said, Abbott Laboratories is a classic dividend growth story. The company has paid an uninterrupted dividend for almost a century and has nearly five decades of dividend growth.We believe that Abbott Laboratories, despite the valuation, has plenty of growth in its future, which will only lead to many more years of dividend growth. For these reasons, buying more of the healthcare giant was a decision that made sense to us.Disclosure: Author is long Abbott Laboratories and AbbVie.Read more here:Not a Premium Member of GuruFocus? Sign up for a free 7-day trial here.This article first appeared on GuruFocus.