SEGMENT REPORTING (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2015 USD ($) segment	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment									2
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenue									$ 104,597	$ 89,837	$ 78,339
Operating income (loss)	$ 3,565	$ 2,142	$ 1,829	$ 1,021	$ 1,754	$ 341	$ 917	$ (101)	8,557	2,911	(1,430)
Income before income taxes									8,427	2,950	(1,393)
Total assets	109,719				96,844				109,719	96,844	93,553
Net assets	63,528				53,132				63,528	53,132	47,116
Capital expenditures									3,773	2,337	1,930
Depreciation and amortization									4,187	3,712	2,497
United States
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenue									97,164	83,584	71,713
Total assets	106,780				93,977				106,780	93,977	90,572
Europe
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenue									2,086	2,264	2,738
Total assets	2,939				2,867				2,939	2,867	2,981
Other International
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenue									5,347	3,989	3,888
Total assets	0				0				0	0	0
Core Companion Animal Health
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenue									84,249	72,354	66,404
Operating income (loss)									4,911	1,198	(2,295)
Income before income taxes									4,836	1,290	(2,229)
Total assets	92,567				85,361				92,567	85,361	81,041
Net assets	48,175				41,286				48,175	41,286	36,933
Capital expenditures									1,177	1,864	512
Depreciation and amortization									3,478	2,954	1,691
Other Vaccines, Pharmaceuticals and Products
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total revenue									20,348	17,483	11,935
Operating income (loss)									3,646	1,713	865
Income before income taxes									3,591	1,660	836
Total assets	17,152				11,483				17,152	11,483	12,512
Net assets	$ 15,353				$ 11,846				15,353	11,846	10,183
Capital expenditures									2,596	473	1,418
Depreciation and amortization									$ 709	$ 758	$ 806