Article Written By Juma Harrison, New Products & Business Development Manager – Unga Farm Care (EA) Limited
An emerging health risk in companion animal food is contamination with mycotoxins. These food preparations can be in the form of dry food (less than 11% moisture), semi-moist food (25-35% moisture) or canned food (60-87% moisture).
Mycotoxins are metabolites derived from different classes of fungi (mould growth) that are present in agricultural crops. These toxins are most times detected in nuts, cereals and cereal by-products used in companion animal food processing. The elevated temperatures and pressure used during food production do not fully inactivate or degrade the mycotoxins therefore, posing a huge health risk to the companion animals. Amongst the many, the important mycotoxins in dog and cat food are aflatoxins, fumonisins, deoxynivalenol (DON), zearalenone (ZEA), ochratoxin (OTA), HT-2, and T-2 as described in various studies1.
The main mycotoxin to cause havoc in pet food and therefore most regulated is aflatoxin B1. Cats are more sensitive to aflatoxin than dogs. The toxic effects in both can be acute, chronic, or secondary1.
Aflatoxicosis in Brief
Aflatoxicosis is an illness arising from the consumption of aflatoxins. This can be in acute, sub-acute or chronic forms. Aflatoxins are metabolized in the liver to form epoxide that binds nucleic acids1. These are carcinogenic, induce malformations in pregnancy, interferes with protein and enzymes synthesis, leading to immunosuppression. In dogs, clear clinical signs of aflatoxicosis are weakness, impaired liver function, jaundice, vomiting, depression, diarrhea, internal hemorrhage, and sudden death1. Susceptibility to aflatoxins toxicity varies with age, breed, dose, and length of exposure. Emerging outbreaks of aflatoxicosis are in dogs and rabbits. However, cat food, as reported in a recent study, has been found to contain fumonisins and DON mycotoxins1.
Symptoms of Aflatoxin Poisoning
Aflatoxicosis is chiefly a disease of the liver, causing gastro-intestinal symptoms, reproductive issues, anemia and jaundice. Certain types of aflatoxins are linked to cancer in animals.
If your dog or cat ingests food contaminated with aflatoxins, you can anticipate one or more of these symptoms: severe, persistent vomiting; bloody diarrhea; lack of appetite; fever; sluggishness; discolored urine; jaundice, especially around the whites of the eyes, gums and belly.
It is known that dogs can die suddenly or after a short illness after having eaten contaminated dog food2,3. The liver was most prominently affected in these acute cases as it was degenerating. Chronic poisoning and secondary effects are more subdued and severity of toxicity is on a sliding scale with level of aflatoxin B1 contamination. It is estimated that a daily dose of 5 µg per kilogram of dog body weight per day would induce adverse effects after three years4. In perspective, a daily dose of 1 µg per kilogram of dog body weight per day is estimated not to show adverse effects within the lifespan of the dog4.
If you think your pet has eaten potentially contaminated food, even if he/she is showing no symptoms of illness, get him/her to your veterinarian or an emergency veterinary clinic as soon as possible. And bring the food with you1.
We also recommend you talk with your holistic veterinarian about natural liver detox agents like milk thistle, SAMe, and chlorophyll.
Foods Most Likely to Be Contaminated with Aflatoxins
“Although we have no exact numbers, we can estimate that when half of the food is of vegetable origin, there will almost always be some degree of contamination. If the food is mainly of animal origins, the chances of contamination are greatly reduced1.”
Aflatoxins frequently contaminate agricultural crops before they are harvested. Conditions that promote pre-harvest contamination include high temperatures, prolonged periods of drought and insect activity.
Aflatoxins can also be a problem after harvesting if the crop stays wet for too long. Additionally, they can grow on stored crops if the moisture level is too high and mould develops.
The three crops with the highest rate of aflatoxin contamination are maize, peanuts and cottonseed. Other frequently contaminated agricultural products include:
- Sorghum, millets, rice and wheat cereals
- Soybean and sunflower oilseeds
- Chilli peppers, black pepper, coriander, turmeric and ginger spices
- Almonds, pistachios, walnuts, coconuts and brazil nuts
Preventing Contamination in Companion Animal Food
Since there does not appear to be an effective antidote to aflatoxin, the objective is to put measures in-place within the food production process to keep the mycotoxin level to a minimum and control this1.
- Scientific-based regulations on acceptable limits for mycotoxins in food for companion animals will ensure focus in meeting the nutritional needs of the animal rather than having to divert resources to manage health issues attributable to unnecessary outbreaks.
- Source food from reputable manufactures who have invested heavily on quality control checks and set up analytical detection capabilities to reduce the risk of onward transmission of the contaminant.
- Check the package label for expiry period and purchase smaller packed food bags to avoid longer storage duration
- Store the food in a cool, dry place and in an airtight container to discourage the growth of moulds.
- In the event that the companion animal develops strange behavior immediately after feeding, stop feeding, note the batch number on the food pack and consult with your local veterinarian.