Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of blood analysis specialist Abaxis (Nasdaq: ABAX) crashed to the tune of 16.7% on very heavy trading volume.

So what: These first-quarter results were not what the doctor ordered. The company's 3% sales growth year over year produced 37% lower earnings, as rising operating costs cut into margins. Analysts had expected flat earnings and 10% higher revenue.

Now what: Abaxis normally boasts a much fatter operating margin than rivals Alere (NYSE: ALR) and Heska, fully in class with industry giant and five-star CAPS favorite IDEXX Laboratories (Nasdaq: IDXX). This quarter, the margin advantage all but evaporated. CEO Clint Severson explained that the margin hit came from heavy investment in future growth, including a new network of veterinary labs, and delays to some international orders contributed to the revenue slowdown.

But riddle me this, dear investor: Why would an investor in the medical sector take a chance on Abaxis turning these issues around, rather than banking on the proven growth of Intuitive Surgical (Nasdaq: ISRG) or the generous dividends of a Johnson & Johnson (NYSE: JNJ)? In my opinion, we shouldn't.

Interested in more info on Abaxis? Add it to your watchlist.

Fool contributor Anders Bylund owns shares of Intuitive Surgical, but he holds no other position in any company mentioned. Click here to see his holdings and a short bio. The Motley Fool owns shares of Johnson & Johnson. Motley Fool newsletter services have recommended buying shares of Johnson & Johnson and Intuitive Surgical. Motley Fool newsletter services have recommended creating a diagonal call position in Johnson & Johnson. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.