Total selenium concentrations in canine and feline foods commercially available in New Zealand

Abstract

AIMS: To determine the total selenium concentrations in petfoods commercially available in New Zealand and to establish whether these meet the current minimum recommended requirements of selenium in foods for cats and dogs.

METHODS: Samples (n=89) from petfoods commercially available in New Zealand were analysed for total selenium concentration using a fluorometric method. Data, expressed on a dry matter (DM) basis, were analysed according to petfood type (dog or cat, and wet or dry), predominant flavour (chicken, seafood, chicken and seafood, beef, meat mix, other), manufacturer and country of manufacture.

RESULTS: Fifty percent of petfoods purchased for this study were manufactured in Australia, and the remainder were produced in the United States of America (USA), New Zealand or Thailand. Mean total selenium concentrations were similar (0.61–0.80 mg/kg DM) in petfoods produced in Australia, New Zealand and the USA, but higher (mean 3.77 mg/kg DM; p<0.05) in petfoods produced in Thailand. Petfoods produced in Australia, New Zealand and the USA contained a variety of predominant flavours, whereas petfoods from Thailand contained only seafood flavour. Seafood-based flavours had the highest selenium concentrations in both cat and dog foods. Wet and dry dog foods had similar concentrations of selenium to dry cat foods, but wet cat foods had higher and more variable concentrations of selenium than these others (p<0.05). The mean selenium concentrations in cat and dog foods were 1.14 and 0.40 mg/kg DM, respectively, and there were no significant differences between manufacturers.

CONCLUSIONS: Selenium concentrations in commercial petfoods sold in New Zealand appeared to meet recommended dietary requirements, although the range of concentrations was highly variable. Whether these recommendations are adequate for the maintenance of optimal health in cats and dogs has yet to be determined.

CLINICAL RELEVANCE: Overt selenium deficiency disorders are unlikely in dogs and cats in New Zealand fed commercial petfoods unless the bioavailability of selenium in particular petfoods is low.

KEY WORDS:

• Cat
• dog
• selenium
• requirements
• health
• petfoods
• fluorometric analysis

Acknowledgements

The corresponding author gratefully acknowledges the support of a fellowship from Alltech, USA. The authors also wish to thank Duncan Hedderly for his advice on statistical analysis.