In 2007, three different pet foods were withdrawn from the market in four months. The scandal was extensively covered in all the media, but to get the last word on what happened, Health24 spoke to the professionals.
This image will tell you what's in dog food:
Image: Courtesy Die Burger.
What Health24’s CyberVet had to say:
At the end of 2006 a few cases of dogs suffering from acute (sudden onset) renal failure were reported in the Western Cape. The accused brand was dry pet food from Aquanutro, distributed by Woolworths, which withdrew it in February 2007. The ‘outbreak’ of acute renal disease came to an end. On analysis, the finger was pointed at some ingredients that had originated in China.
Ethylene glycol (antifreeze) was suspected, but a few months later Aquanutro reported that the level of ethylene glycol found in the disputed pet food range was much lower than levels expected to cause disease.
China the culprit?
Early in March 2007 in the US, an "outbreak" of acute renal disease was seen in pets eating predominantly wet food containing wheat gluten sourced in China. Soon thereafter, pets fed food containing rice protein developed kidney failure – the rice protein was also sourced in China.
Back in SA, a new ingredient was included in a Royal Canin brand, Vets Choice, from early March 2007. Within weeks, acute kidney failure was linked to this brand. Royal Canin SA immediately recalled all suspected products and about a week later, announced that melamine had been found in corn gluten used in the product.
Melamine in the gluten
How did the melamine get into the gluten? Melamine has a high nitrogen content and is manufactured from urea. It is used in the manufacture of melamine resin used in among others, plastics and adhesives. Kitchen cupboards and worktops are made from these.
It has been suggested that melamine (and excess urea from the manufacturing process) could have been used as a crop fertiliser and may have become incorporated into the cornfields destined for pet food manufacture. However this would not explain the crystalline substance found in samples of the wheat and corn gluten. If it had been taken up by the plants and deposited in the gluten, the gluten added as a food ingredient would resemble pure organic gluten and not contain crystalline material.
Foul play has been suggested: some tests to determine the protein content of substances measure the nitrogen content (because of the high nitrogen content of protein). The question has been posed; is it possible that these disputed substances were added to the gluten and rice protein to artificially boost the apparent protein content?
At the time, Chinese suppliers denied exporting anything but pure gluten.
Dog food ingredients given the all clear
Media releases by Royal Canin SA have since reported that all ingredients now incorporated in their diets (Vets Choice and Royal Canin) have been tested, and are free of melamine. The company also stated that they would refund pet owners who returned the suspect food, and would pay for the renal screening of pets that consumed their products. They also offered to investigate compensating owners who have lost pets on a case-by-case basis.
Treating kidney failure
At this stage there is no simple treatment for renal disease caused by the melamine-containing crystals found in the bladder.
Pets that have been diagnosed with melamine-associated renal disease are treated with intravenous fluid infusions and diuretics in an attempt to flush the offending material out of the kidney.
This treatment is given over a few days during which the animals are hospitalised.
It is not known at this stage if there will be lasting damage in the kidneys of those pets that recover from this illness.
Huge advances in pet food industry
These events have been distressing, and it’s unfortunate that such a toxicosis could have occurred. Dr Malan van Zyl, specialist veterinarian, confirms that there have been huge advances in the manufacture of pet foods.
"The pet food industry has become very specialised in catering to specific needs of animals," he said. "Research is ongoing and products are being improved constantly."
Until recently the benefits were mainly improved nutrition, but today there are many diets formulated for specific conditions. For example there are diets formulated for different-sized (and sometime different breed) puppies, diets for sensitive digestive systems, skin complaints, to keep teeth cleaner reducing gum disease, prescription diets formulated for animals with specific diseases, and more.
Premium brand food companies spend heavily on research and development of pet foods and – distressing though the series of incidences has been – one should not dismiss the industry on the basis of these recent events.
We at Health24 feel that these unfortunate occurrences should be a wake-up call for the industry – it should lead to more rigorous testing of the ingredients being used in products destined for the pet food market.
(Susan Erasmus and Dr Cedric Tutt, Health24, updated October 2007)
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