The US pet supplies chain PetSmart increased its net sales in the first quarter of the year by 9.5 per cent compared with the same period last year to $ 1.3 bn. Comparable store sales grew 3.9 per cent in the first quarter, the company reported. Net income was $ 46.3 million in the first quarter of 2009, compared to net income of $ 41.2 million in the first quarter of 2008. Senior vice president and chief financial officer Chip Molloy expects comparable store sales in the low-single digits in the second quarter.