Goodwill and Other Intangible Assets (Tables)

3 Months Ended

Mar. 31, 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	92,264			8		10,075		102,347
Other (1)	(1,565		)	13		167		(1,385		)
Balance as of March 31, 2012 (2)	$	1,126,100		$	96,831	$	115,638	$	1,338,569

 ____________________________

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

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

Other Intangible Assets

	As of March 31, 2012							As of December 31, 2011
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Noncontractual customer relationships	$	100,723	$	(24,444	)	$	76,279	$	82,891	$	(21,147	)	$	61,744
Covenants not-to-compete	13,350		(7,191		)	6,159		13,035		(8,067		)	4,968
Favorable lease asset	5,571		(1,823		)	3,748		5,571		(3,210		)	2,361
Trademarks	8,162		(1,954		)	6,208		7,405		(1,686		)	5,719
Contracts	4,061		(296		)	3,765		3,500		(185		)	3,315
Technology	18,957		(2,872		)	16,085		16,589		(2,342		)	14,247
Client lists	84		(43		)	41		84		(35		)	49
Total	$	150,908	$	(38,623	)	$	112,285	$	129,075	$	(36,672	)	$	92,403

Aggregate amortization expense

	Three Months Ended March 31,
	2012		2011
Aggregate amortization expense	$	4,876	$	2,655

Estimated amortization expense related to intangible assets

Remainder of 2012	$	16,198
2013	19,348
2014	17,022
2015	15,157
2016	11,933
Thereafter	32,627
Total	$	112,285