Goodwill and Other Intangible Assets (Tables)

9 Months Ended

Sep. 30, 2012

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill

	Animal Hospital			Laboratory		All Other			Total
Balance as of December 31, 2011	$	1,035,401		$	96,810	$	105,396		$	1,237,607
Goodwill acquired	120,505			34		11,194			131,733
Foreign translation adjustment	2,053			23		—			2,076
Other (1)	(4,271		)	—		(1,028		)	(5,299		)
Balance as of September 30, 2012 (2)	$	1,153,688		$	96,867	$	115,562		$	1,366,117

 ____________________________

⁽¹⁾  Other includes acquisition-price adjustments, which consist primarily of an adjustment related to capital leases and buy-outs.

⁽²⁾  Net of accumulated impairment losses of $21.3 million recorded in 2011, all related to our medical technology business, included in "All Other" in the above table.

Other Intangible Assets

	As of September 30, 2012							As of December 31, 2011
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Non-contractual customer relationships	$	113,689	$	(33,011	)	$	80,678	$	82,891	$	(21,147	)	$	61,744
Covenants not-to-compete	12,262		(7,225		)	5,037		13,035		(8,067		)	4,968
Favorable lease assets	7,163		(3,717		)	3,446		5,571		(3,210		)	2,361
Trademarks	14,017		(2,667		)	11,350		7,405		(1,686		)	5,719
Contracts	3,500		(519		)	2,981		3,500		(185		)	3,315
Technology	17,161		(3,919		)	13,242		16,589		(2,342		)	14,247
Client lists	85		(57		)	28		84		(35		)	49
Total	$	167,877	$	(51,115	)	$	116,762	$	129,075	$	(36,672	)	$	92,403

Aggregate amortization expense

	Three Months Ended September 30,				Nine Months Ended September 30,
	2012		2011		2012		2011
Aggregate amortization expense	$	6,612	$	3,883	$	16,830	$	9,092

Estimated amortization expense related to intangible assets

Remainder of 2012	$	6,040
2013	22,377
2014	19,935
2015	17,837
2016	14,586
Thereafter	35,987
Total	$	116,762