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80% of Complete Canned Dog Food Failed to Meet Internationally Recommended Levels for Micronutrients and Amino Acids Negligence of Labelling and Misfeeding May Cause Health Risks

  • 2021.04.15

Pet owners often give wet food to their “furry kids” as a special treat, or even as a complete substitute to dry pet food. The Consumer Council tested 20 models of canned or boxed wet dog food and found that the mineral contents of 80% of the models failed to fully comply with the recommended amounts stated in international guidelines on nutritional contents for complete pet food, while only 3 models fully met the relevant recommendations. Besides, some models of complete pet food were found to contain nutrient contents lower than the recommended minimum concentrations by American and EU standards, including the vitamin D content for 2 models and the amino acids content for 1 model. Feeding your dogs exclusively with the products of concern for long term might impair the health of dogs. As for complementary pet food, the various tested models showed a considerable variance in their protein and fat content. Over-consumption by dogs may cause obesity or increase the burden on kidneys for dogs with kidney diseases.

The Council reminds consumers that “complete pet food” should contain all the essential nutrients needed by a dog to sustain its daily energy and nutritional requirements when being fed alone, whereas “complementary pet food” must be fed in combination with other complete pet foods to provide complete and sufficient nutrients for dogs. When purchasing and feeding wet food, consumers should carefully read the labelling and understand whether the product is complete or complementary pet food, its nutritional content, whether it is appropriate for the life stage of your pet, in addition to the feeding guideline, in order to ensure a balanced diet for their dogs. A prolonged unbalanced diet that contains, for example, insufficient or excessive nutrients, or an unbalanced mineral content, may impact the health of dogs.

The Council tested 20 models of canned or boxed wet food for dogs, including 15 models of complete pet food labelled with “complete and balanced”, or which declared to meet the nutritional levels for dog food established by the Association of American Feed Control Officials (AAFCO) Dog Food Nutrient Profiles, plus 5 models of complementary pet food. The various models vastly varied in price, ranging from $7 to $47.5 per can/box and with unit price from $1.9 to $20 per 100g, a difference of 9.5 times. Furthermore, the estimated monthly cost (30 days) for feeding a 25kg dog solely with complete pet food ($330/day) that fully meets the recommended nutrient content and with the highest retail price amounted to $9,960 per month. Consumers should keep their budget in check when purchasing wet food for their pets.

Test items included macronutrients and micronutrients, while the level of harmful substances was also evaluated. The results revealed that 1 complementary model contained a crude fat amount (5.3%) slightly lower than the 5.5% minimum concentration recommended by AAFCO and the European Pet Food Industry Federation (FEDIAF) for complete pet food for adult dogs, while all the remaining models met the relevant recommended minimum concentration. However, dog owners should note that an appropriate amount of protein and fat can help support the healthy growth for dogs, yet the 5 models of complementary pet food showed a greater variance in crude protein (27.5% to 97%) and crude fat (5.3% to 34.5%), a variance of up to 2.5 times and 5.5 times respectively. The 2 models with the highest crude protein content contained 78% and 97% respectively, but were not labelled with the recommended daily serving size. The model with the highest crude fat content (34.5%) showed a distinctly higher fat percentage. Should pet owners overlook the difference in fat content among different products and overfeed their pet, it may result in overconsumption of fat and overweight issues, along with increased health risks related to obesity.

Besides, the test revealed that amongst the 20 models of wet dog food, over 80% recorded problems in the amount of micronutrients, such as the mineral contents, while only 4 models could fully comply with the recommended concentrations in pet food laid out by 3 pet food organisations, namely the AAFCO, FEDIAF, and the National Research Council (NRC). Another 4 models had 1 type of mineral content that could not completely meet the recommended level, while the 12 remaining models failed to fully meet the recommended concentrations of all 3 organisations for 2 to 8 types of minerals.

Amongst the tested models, 3 complementary pet food models proved of more concern in terms of their mineral contents. In general, their calcium, iron, copper, manganese, zinc and iodine contents were relatively low, while the calcium to phosphorus ratio was also quite low. Dog owners should not feed complementary pet food as the major diet for their dogs, but instead feed in combination with other complete pet foods to provide complete and balanced nutrition for their dogs.

For complete dog food, 2 models failed to meet the nutritional concentrations recommended by the 3 organisations for 4 to 5 types of mineral. For 1 model for adult dogs, its magnesium, copper, manganese, zinc and iodine content all failed to meet the minimum recommended concentrations suggested by AAFCO and FEDIAF, meaning that it might be unable to provide complete and balanced minerals for adult dogs if used as a long-term staple diet. The Council reminds consumers that the tested pet food models were generally found to contain insufficient or excessive levels of copper and zinc. If their diet contain an excessive amount of copper or zinc, it may affect absorption of the other minerals. If dogs fail to obtain a sufficient amount of zinc, it may cause hair loss and affect their skin condition. On the contrary, copper deficiency may cause anaemia in the long run.

Another type of micronutrient, vitamin D, helps maintain healthy bones and teeth for dogs. However, the test results showed that amongst the 15 models of complete pet food, the amounts of vitamin D3 in 2 models (303IU/kg and 483IU/kg, on dry matter basis) fell short of the relevant minimum recommended level for complete pet food for adult dogs. Besides, vitamin D3 was not found in 1 model of complementary pet food. As dogs mainly obtain vitamin D through their daily diet, long-term deficiency of vitamin D may upset the balance of calcium and phosphorus in their blood and affect the immune system. In the long run, this might even cause rickets or affect the bone growth of puppies, as well as other potential problems such as osteoporosis for adult dogs.

Furthermore, 3 models of complete pet food had a relatively low concentration of amino acids, with the lowest model only containing 0.29% (on dry matter basis) methionine which did not meet the minimum concentration recommended by AAFCO and FEDIAF. Although the total methionine and cystine content of all 3 models (0.69% to 0.79%) met AAFCO’s minimum recommended concentrations, they failed to fully comply with the relevant minimum level (0.76% to 0.88%) recommended by FEDIAF. Sufficient intake of methionine and cystine is essential for supporting the production of taurine in dogs to maintain their body’s needs. Deficiency of essential amino acids may result in diseases and even impact cardiac health in the long run.

Lead could accumulate in animals’ bodies. Excessive intake of lead could affect the brain and nervous system of dogs. The test found that 4 models contained lead, including 1 model of complementary pet food with a lead content of 11.2mg/kg (with a moisture content of 12%), which exceeded the maximum limit permitted by EU legislation for complementary pet food (10mg/kg). The Council urges providers to observe the lead content in pet food products. In addition, 9 models were found to contain arsenic or cadmium, amongst which 2 models were found to contain trace amount of melamine, though the levels did not exceed the stipulated maximum limit of the EU standard (2.5mg/kg) and presumably would not cause health risks to dogs.

Upon inspection of the labelling information of the tested models, 1 model of complementary pet food did not declare its product nature to be a complementary pet food on the packaging, potentially misleading consumers into thinking said model could provide complete and balanced nutrition for dogs. The feeding instructions of 8 models were less user-friendly, and consumers had to calculate the daily serving size based on the weight of their dog, making it less convenient for pet owners. 1 model only displayed product ingredients in Japanese, while another model only claimed to contain 50% boar meat in its description, making it difficult for consumers to fully understand the detailed ingredients of the product based on the labelling information.

Consumers should pay heed to the following when feeding their dogs wet food:

  • Complementary pet food should not be treated as the main diet and must be fed in combination with other complete pet food to provide complete and balanced nutrition to dogs;
  • If considering switching to a different brand, remember to carefully read the product labelling information. If the new product contains a higher calorie and fat content, the serving size should be smaller than the previous brand, and vice versa;
  • When consulting the feeding guide on product labels, select the serving size based on the dog’s bodyweight and make further adjustments based on the pet’s body condition and activity level;
  • Observe the suitable life stage and dog breed as specified in the product description. If the product is not labelled as suitable for “all life stages”, or is only labelled as for adult dogs, then its nutrient level may not fulfil the nutritional requirements of puppies, pregnant or nursing dogs;
  • 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;
  • Wet food that has been opened but not consumed should be wrapped up promptly. For example, place the whole can/box of wet food inside a food storage bag and store it in the fridge. Do not keep it near foods for human consumption (especially raw meat). 

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