Pet owners often feed their cats wet food to increase their water intake and to maintain a balanced diet. The Consumer Council tested 22 models of canned or pouched wet food mainly intended for cats and found that the mineral or amino acid contents of 90% (20) of the models failed to fully comply with the recommended amounts stated in international guidelines on nutritional contents for complete pet food, while only 2 models fully met the relevant recommendations. The Council reminds cat owners to clearly differentiate “complete pet food” and “complementary pet food” before feeding, and to pay heed to the nutritional content listed on the product label, so as to ensure sufficient nutrients for their cats. The Council also urged pet food manufacturers to ensure complete pet food products do indeed have a complete and balanced nutrient profile with reference to the relevant international guidelines, and to include appropriate labelling on complementary pet food to prevent misfeeding by pet owners that may impose health risks to their cats.
Wet food for cats can be categorised as 2 main types — “complete” and “complementary” pet food, each with different amounts of nutrients. Complete pet food in theory should provide all the essential nutrients needed by a cat to sustain its daily energy and nutritional requirements, whereas complementary pet food must be fed in combination with other complete pet food. Pet owners should carefully read the labelling and understand what type the product belongs to, whether it is appropriate for the life stage of their cat, and be mindful of the serving size, in order to avoid possible serious health risks to cats due to long-term imbalanced nutrition.
The Council tested 22 models of canned or pouched wet food mainly intended for cats, including 12 models of complete pet food mostly labelled with “complete and balanced”, or which declared to meet the nutritional level for cat food established by the Association of American Feed Control Officials (AAFCO), plus 10 models of complementary pet food. The price ranged from $7 to $26 per can/pouch and with unit price from $8.7 to $30.6 per 100g, though the recommended daily serving sizes were found to vary notably between models. Based on the needs of a 4kg cat, the daily serving size of complete pet food ranged from 160g to 352g. If the 4kg cat is solely fed with the complete pet food model that fully meets the recommended nutrient content and with the highest retail price ($49/day), the estimated monthly cost (30 days) amounted to $1,470. On the other hand, 3 models of complementary pet food were not labelled with feeding guide, while the recommended daily serving size for the remaining models ranged from 42.5g to 170g. Excluding the expenses of complete pet food, the cost for feeding complementary pet food is approximately $150 to $1,014 per month, a difference of nearly 6 times. Test items included macronutrients and micronutrients, while the level of harmful substances was also evaluated.
The test results revealed that 90% (20) of the samples recorded problems in the mineral content, while only 2 models could fully comply with the relevant concentrations in cat food laid out by 3 pet food organisations including AAFCO, the European Pet Food Industry Federation (FEDIAF), and the National Research Council (NRC). Another 4 models had 1 type of mineral content that could not completely meet the recommended level, but the overall were relatively satisfactory. However, the remaining 16 models failed to comply with the recommended concentrations of all 3 organisations for 3 to 9 types of minerals, raising much concern.
Amongst the 12 models of complete cat food, the iron content (43.9mg/kg to 66.8mg/kg) of 4 models were lower than the minimum concentrations recommended by AAFCO and FEDIAF (80mg/kg to 107mg/kg), while the iron content (89.2mg/kg to 102.9mg/kg) of another 3 models, despite meeting the requirements of AAFCO, fell slightly below the minimum recommended level by FEDIAF. In addition, the zinc content (29.3mg/kg to 88.1mg/kg) of 5 models failed to meet the minimum concentration recommended by AAFCO and FEDIAF (75mg/kg to 100mg/kg), whereas 1 model’s zinc content (259mg/kg) exceeded the maximum concentration recommended by FEDIAF (227mg/kg). The test additionally revealed that 2 models were not detected with iodine, while 1 model contained 26.3mg/kg of iodine, well above the maximum recommended concentration in cat food suggested by AAFCO and FEDIAF (9mg/kg and 11mg/kg).
As for the complementary pet food, the tested models were generally found to have relatively low concentration in various minerals, including calcium, potassium, iron, copper, manganese, zinc and iodine. The Ca:P ratio was also comparatively low in general. Cat owners should never feed complementary pet food to cats as their staple diet.
The Council reminds pet owners that long-term consumption of complete pet food or complementary pet food with insufficient/excessive amounts of various minerals may lead to a number of health risks. For example, iron deficiency may cause iron deficiency anaemia, resulting in fatigue, increased heart rate and shortness of breath, and may also hinder the growth of kittens. Zinc deficiency may cause growth retardation in cats, while on the contrary, excessive intake may affect the absorption of copper and iron. Excessive or insufficient iodine intake may increase the chances of thyroid disorders in cats.
Sufficient intake of essential amino acids is also necessary to keep cats healthy. Deficiency in taurine may cause health problems for cats, such as central retinal degeneration and heart failure. The test found a significant variance in taurine content amongst the models, with the average taurine level in complementary pet food (0.38%) lower than that in complete pet food (0.58%). 1 model of complementary pet food was not found with taurine, while taurine content in 3 other complementary models were relatively low, ranging from 0.08% to 0.21%.
Furthermore, the test results showed that 2 models of complete pet food contained excessive levels of methionine, amongst which 1 model for kittens had a methionine concentration of 2.02%, exceeding the maximum recommended concentration suggested by both AAFCO and FEDIAF. Excessive intake of methionine could affect kittens’ appetite and their weight gain, affecting their growth and development, as well as adding the potential risk of haemolytic anaemia.
If cats are given a long-term diet with excessive mercury content, it could damage their nervous system and affect the physical coordination and balance in the long run. 13 out of the 22 models were detected with mercury content from 0.03mg/kg to 0.296mg/kg (with a moisture content of 12%). Amongst which, 9 models were labelled to contain tuna, or to have tuna as one of the major ingredients. The complementary pet food model with the highest concentration of mercury (0.296mg/kg) was close to the maximum limit in pet food (0.3mg/kg) laid out in EU regulations.
Protein has crucial functions such as maintaining the immune system and hormonal systems. The test revealed that 3 models of complete pet food had crude protein contents (from 32.3% to 32.9%) that were slightly below the FEDIAF’s minimum recommendation (33.3%) for the diets for low-activity level adult cats. In addition, 9 models of complementary pet food were found to contain crude fat content (from 4.1% to 8.5%) lower than the minimum concentrations (9%) recommended by AAFCO and FEDIAF.
Among the micronutrients, vitamin D supports the development of bones and bone health in cats. However, 2 models of complementary pet food were not detected with vitamin D3 or had a relatively low amount (323IU), which was below the minimum concentrations recommended for complete pet food of adult cats suggested by AAFCO and/or FEDIAF. Both models lacked clear labelling that indicated they were of complementary pet food, which might easily lead to misfeeding by pet owners.
Upon inspection of the labelling information of the tested modes, the Council found that 4 models of complementary pet food did not declare its product category as a complementary pet food on the packaging, and consumers might be misled into thinking that these models could provide complete and balanced nutrition for cats. The feeding instructions of some models were less user-friendly, requiring consumers to calculate the daily serving size based on the weight of their cats. 2 models only displayed product ingredients in Japanese, making it inaccessible for consumers to fully understand the ingredients of the product.
Consumers should pay heed to the following when feeding their cats wet food:
- Complementary pet food must be fed in combination with other complete pet food to provide complete and balanced nutrition for cats;
- Observe the suitable life stage as specified in the product description. If the product is not labelled as suitable for “all life stages”, or is only labelled as suitable for adult cats, then its nutrient level may not fulfil the nutritional requirements of kittens, pregnant or nursing cats;
- When reading the feeding guide on product labels, select the serving size based on the cat’s weight and make further adjustments based on the pet’s body condition and activity level;
- If considering switching to a different pet food, read the product labelling information carefully to avoid overfeeding and causing obesity or overweight issues, along with increased weight-related health risks, such as heart disease, arthritis and diabetes;
- Check the expiry date of wet food products before feeding. Once opened, it should be fed as soon as possible. Any wet food left at room temperature for several hours should be discarded;
- Owners should take their cats to the veterinary clinic for annual body checks, in particular conducting test on urine. If the cat’s urine is found to be alkaline, special attention should be paid to its diet, so as to prevent feline urologic syndrome.
The Consumer Council reserves all its right (including copyright) in respect of CHOICE magazine and Online CHOICE.