Aflatoxicosis
By By Dr Mackie Hobson BSc(Agric),BVSc

Aspergillus- Aflatoxins

A potential but rare occurrence in Angora goats. In the case of Angora goat, mycotoxicosis would usually be due to Aspergillus flavus and parasiticus contaminated maize (also cottonseed and peanuts, sorghum, and sunflower seeds). Goats are considered resistant, so the acute, rare and chronic forms are more likely to be seen.

What do the toxins do?

The toxic effects include mutagenesis, carcinogenesis, teratogenesis, reduced protein synthesis, and immunosuppression.

High dosages of aflatoxins result in hepatocellular necrosis.

Prolonged low dosages result in reduced growth rate(reduced protein synthesis), immunosuppression, and liver enlargement.

Clinical signs

Goats are relatively resistant to the acute form of the disease but are susceptible if toxic diets are fed over long periods.

• Poor appetite
• Poor growth rate,
• Unthriftiness,
• Depression,
• Haemorrhage,
• Icterus,
• Death,
• Terminal signs reported of grinding teeth, abdominal pain, tenesmus, rectal prolapse and diarrhoea
• Photosensitivity is rare

Diagnosis:

Diagnosis is based on clinical signs, liver lesions, and laboratory detection of aflatoxins in the feed.

Treatment:

• No specific antidote is available
• Remove contaminated feed and replace it with a good quality diet.
• If immunosuppressed, antimicrobial therapy for infectious processes should be considered.
• Liver support (vit B)

Prevention:

• Avoiding aflatoxin-contaminated feed ( analytical testing for aflatoxins in feed batches)
• Use of mycotoxin binders in feed

Does sunlight affect the mycotoxin?

Aflatoxins are resistant to heat but are degraded to a certain extent by sunlight.

Post Mortem:

In acute cases:

• widespread haemorrhages
• icterus,
• The liver is enlarged, and fatty accumulations and massive centrilobular necrosis and hemorrhage.

In subacute cases:

• the hepatic changes are not so pronounced;
• the liver is enlarged,
• Oedema of the gallbladder.
• Prolonged feeding of low concentrations may result in diffuse liver fibrosis (cirrhosis) and, rarely, carcinoma of the bile ducts or liver.

REFERENCES

• Plant Poisonings of livestock in South Africa, Kellerman, Coetzee, Naude, Botha
• MSD Veterinary manual