Welcome back to another Foolish review of the hottest stocks as ranked by Motley Fool CAPS. We're looking at the three best-performing industries over the past 30 days and your favorite long and short candidates in each.

Has the cancellation crisis spread beyond American Airlines? I ask because the travel services sector, last week's champ is today's second-place finisher, with a 29.8% average return.

But that can't touch the returns diagnostic substances manufacturers are producing. Immucor (Nasdaq: BLUD), Human Genome Sciences (Nasdaq: HGSI), and their peers are up 67.2% as a group since mid-March.

Finally, stocks based in Cambridge, Mass., within spitting distance of Harvard Yard -- Akamai Technologies (Nasdaq: AKAM), for example -- are up 21.6% over the past month.

According to you, our Foolish readers, the best stocks in these industries to own now -- i.e., those with four or five of the maximum five stars in CAPS -- are:

Company

CAPS Stars

No. of CAPS Ratings

Percent Bulls

30-Day Price Change

IDEXX Laboratories (Nasdaq: IDXX)

*****

149

98.7%

(3.1%)

Meridian Bioscience (Nasdaq: VIVO)

*****

407

98.5%

11.8%

Neogen (Nasdaq: NEOG)

*****

206

98.1%

2%

Sources: Motley Fool CAPS, Yahoo! Finance (current as of 4/11).

And your favorite short candidates -- i.e., those rated with one or two stars in CAPS -- are:

Company

CAPS Stars

No. of CAPS Ratings

Percent Bears

30-Day Price Change

Nymox Pharmaceutical (Nasdaq: NYMX)

*

60

50%

(5.1%)

Sources: Motley Fool CAPS, Yahoo! Finance (current as of 4/11).

My favorite stock among today's contenders is pet medicine maker IDEXX Labs, for all the same reasons CAPS investor every1mustpay gave in this pitch from last month. Quoting:

IDEXX Labs is a one of a kind company in that it specializes in the one area where people spare no expense, their pets. Regardless of market and economic conditions people will continue to spend money on pets.

History bears witness to his thesis. Fool alamobull, a top scorer for IDEXX, explained it this way last January:

Mid cap growth, 10%+ rev growth [year-over-year] for last 10 years, + [free cash flow], +10% [earnings per share] growth [year-over-year] for last 10 years. ... Non-cyclical business (veterinary, food, agriculture)

Even so, with a 1.77 PEG ratio based on 2008 projected earnings, IDEXX isn't cheap. But that's to be expected -- high-growth, non-cyclical stocks are never easy to find, and this one, with its double-digit returns on equity and capital, appears worth the premium.

But that's my take. What would you do? Would you buy IDEXX at today's prices? Let us know what you think by signing up for CAPS today. It's 100% free to participate.

Cap off your day with related CAPS Foolishness:

Akamai Technologies is a Rule Breakers recommendation. Get free, unfettered access to the research and recommendations behind this market-beating service for 30 days. There's no obligation to subscribe.

Fool.com and Rule Breakers contributor Tim Beyers, who is ranked 16,816 out of more than 96,000 participants in CAPS, owned shares of Akamai at the time of publication. See Tim's portfolio and his latest blog entry. The Motley Fool's disclosure policy is hotter than city asphalt in the summer heat.