Segment Reporting - Information about Reportable Segments (Detail) - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2021	Jul. 25, 2020	Apr. 24, 2021
Segment Reporting Information [Line Items]
Net sales	$ 1,614,876	$ 1,245,837
Operating (loss) income	(39,529)	37,872
Total assets	2,750,849		$ 2,751,511
Consumable
Segment Reporting Information [Line Items]
Net sales	1,341,674	1,044,981
Equipment and software
Segment Reporting Information [Line Items]
Net sales	183,452	129,431
Value-added services and other
Segment Reporting Information [Line Items]
Net sales	89,750	71,425
Dental
Segment Reporting Information [Line Items]
Net sales	606,867	430,295
Dental | Operating Segments
Segment Reporting Information [Line Items]
Operating (loss) income	(1,086)	37,769
Total assets	852,723		863,718
Dental | Consumable
Segment Reporting Information [Line Items]
Net sales	376,576	256,603
Dental | Equipment and software
Segment Reporting Information [Line Items]
Net sales	156,966	113,017
Dental | Value-added services and other
Segment Reporting Information [Line Items]
Net sales	73,325	60,675
Animal Health
Segment Reporting Information [Line Items]
Net sales	1,002,790	812,153
Animal Health | Operating Segments
Segment Reporting Information [Line Items]
Operating (loss) income	23,805	17,399
Total assets	1,437,115		1,391,892
Animal Health | Consumable
Segment Reporting Information [Line Items]
Net sales	965,098	788,378
Animal Health | Equipment and software
Segment Reporting Information [Line Items]
Net sales	26,486	16,414
Animal Health | Value-added services and other
Segment Reporting Information [Line Items]
Net sales	11,206	7,361
Corporate
Segment Reporting Information [Line Items]
Net sales	5,219	3,389
Corporate | Operating Segments
Segment Reporting Information [Line Items]
Operating (loss) income	(62,248)	(17,296)
Total assets	461,011		$ 495,901
Corporate | Value-added services and other
Segment Reporting Information [Line Items]
Net sales	5,219	3,389
United States
Segment Reporting Information [Line Items]
Net sales	1,313,772	1,034,872
United States | Dental
Segment Reporting Information [Line Items]
Net sales	541,073	397,460
United States | Animal Health
Segment Reporting Information [Line Items]
Net sales	767,480	634,023
United States | Corporate
Segment Reporting Information [Line Items]
Net sales	5,219	3,389
United Kingdom
Segment Reporting Information [Line Items]
Net sales	192,747	149,392
United Kingdom | Animal Health
Segment Reporting Information [Line Items]
Net sales	192,747	149,392
Canada
Segment Reporting Information [Line Items]
Net sales	108,357	61,573
Canada | Dental
Segment Reporting Information [Line Items]
Net sales	65,794	32,835
Canada | Animal Health
Segment Reporting Information [Line Items]
Net sales	$ 42,563	$ 28,738