Mycotoxicosis-Aflatoxin Toxicity in Dogs
Mycotoxicosis-aflatoxin toxicity is the medical term used for a condition resulting from a fungal toxin that affects the liver of dogs. The fungi Aspergillus flavus, A. parasiticus, and Penicillium puberulum are the known transmitters of aflatoxin. It is known to develop in humid climates, where grain-based foods are more likely to be exposed to moisture. The condition may also develop if contaminated grains (such as grains that are improperly stored and thereby exposed to moisture) are used in the production of feeds. It is known that occasional outbreaks have occurred due to contaminated grains being used in the production of commercial dog foods.
This condition is known only to occur in dogs – no cases have been reported in cats – and is rarely reported. It is believed that young male dogs and pregnant females may be more susceptible. Outdoor dogs are also believed to be at higher risk.
Symptoms and Types
The clinical symptoms of mycotoxicosis-aflatoxin are dependent on the dose and time of ingestion. Acute symptoms (those symptoms that develop suddenly) include anorexia and accompanying weight loss, hemorrhage, and ascites, a condition in which fluid accumulates in the peritoneal cavity in the abdomen. Acute symptoms may be so severe as to lead to sudden death.
Chronic (long-term) symptoms include anorexia, weight loss, depression, liver failure, and coagulopathy, a blood-clotting disorder in which the blood fails to clot normally.
Mycotoxicosis-aflatoxin is a serious condition that if left untreated can lead to persistent liver dysfunction. Even with treatment, the prognosis is poor for dogs diagnosed with this condition.
The condition mycotoxicosis-aflatoxin is caused by the ingestion of grain-based foods contaminated by the fungi known as Aspergillus flavus, A. parasiticus, or Penicillium puberulum. When contaminated grain-based feeds are ingested, they may react with an enzyme in the liver (specifically the P450 enzyme), leading to a toxic reaction. Foods that show obvious signs of mold and spoiling are an obvious indication that your dog may have ingested a toxic fungus. Dogs that spend a lot of time outdoors are at increased risk.
Your veterinarian will perform a thorough physical exam on your dog, taking into account the background history of symptoms and possible incidents that might have led to this condition. Your doctor will need to differentiate mycotoxicosis-aflatoxin toxicity from other conditions that show symptoms of liver disease and coagulopathy. To this end, a liver biopsy may help eliminate other possible diagnoses, such as liver disease, and a coagulation profile will be performed.
The primary test that can be used to diagnose mycotoxicosis-aflatoxin toxicity is a urine analysis for the aflatoxin metabolite (Aflatoxin M1). An analysis of possibly contaminated food samples for aflatoxin traces may also be useful if you have samples of food that your dog has eaten recently.
Treatment for mycotoxicosis-aflatoxin toxicity is aimed at reducing stress on the liver. A high-quality protein diet, including a source of dietary glucose, such as corn syrup, is recommended. Follow your veterinarian's guidelines closely regarding diet recommendations. The administration of intravenous (IV) fluids may also be necessary if your dog is suffering from anorexia and weight loss. In some cases, medication may be prescribed to treat the coagulation disorder, such as heparin, but any type of drug that needs to be metabolized by the liver will be avoided in order to prevent any further stress on the liver's ability to function.
Living and Management
Administer any prescribed medications regularly, and stick to your veterinarian's dietary recommendations. As previously mentioned, a high-quality protein and dietary glucose supplements are both recommended.
Do not feed your dog foods that are obviously moldy, as they may be contaminated with one of these toxic fungi. Store feed dishes in a clean dry area to avoid moisture from accumulating, and clean feed dispensers regularly to avoid moisture and contamination. Prevention is important, since even with treatment the prognosis is poor for dogs affected by mycotoxicosis-aflatoxin.
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