Table 5.

Individually administered antimicrobial use by antimicrobial class^a for bovine respiratory disease (BRD) in total number of animal daily doses (nADD), stratified by reason for exposure, and risk category for BRD with relative risk of antimicrobial exposure for cattle assessed to be high risk (HR) or low risk (LR) for BRD.

		Reason for Exposure		Assessed risk category for BRD
		Metaphylaxisb	Treatmentc	HR	LR
	AMD Class	nADD (% of total for column)
I	FQ	0	44,192	34,713	9,479
		(0)	(7.9)	(1.0)	(0.5)
	CEPH	0	51,498	22,911	28,587
		(0)	(9.2)	(0.7)	(1.4)
II	MAC	1,975,173	143,019	2,049,808	68,384
		(40.7)	(25.6)	(60.9)	(3.3)
	PEN	0	13	13	0
		(0)	(<0.01)	(<0.01)	(0)
	TMS	0	659	131	528
		(0)	(<0.01)	(<0.01)	(<0.01)
III	TET	2,876,561	81,634	1,060,891	1,897,304
		(59.3)	(14.6)	(31.5)	(92.8)
	PHEN	584	238,256	198,043	40,797
		(0)	(42.6)	(5.9)	(2.0)
	SULF	0	20	16	4
		(0)	(<0.01)	(<0.01)	(<0.01)
	ALL	4,852,318	559,291	3,366,526	2,045,083
		(100)	(100)	(100)	(100)

The nADD is presented in the top of the cell, and the % of the total nADD by reason or assessed risk category for BRD that this number represents is presented in parentheses in the bottom of the cell. Percentages of use may not add to 100% due to rounding.

^aFQ, fluoroquinolones; CEPH, 3rd generation cephalosporins; MAC, macrolides; PEN, penicillin; TMS, trimethoprim-sulfamethoxazole; TET, tetracyclines; PHEN, phenicols; SULF, sulfonamides. Roman numerals I to III signify category of importance to human medicine as designated by the Canadian Veterinary Drugs Directorate.

^bMetaphylaxis is the group administration of an antimicrobial to a population at risk for disease before overt clinical disease is apparent in the entire group.

^cTreatment is the administration of an antimicrobial to an individual animal diagnosed with clinical disease.