Page 1083 - Veterinary Toxicology, Basic and Clinical Principles, 3rd Edition

Fumonisins Chapter | 71 1015

VetBooks.ir in the serum and tissues of calves to the same degree that samples contain very high concentrations of toxin with low
levels of fungus, while others samples have heavy growths of
has been shown in pigs and horses.
When a group of 26 dairy cattle were fed a ration con-
Fusarium fungus with little to no detectable fumonisin. This
taining 100 ppm of fumonisin for the first 70 days of their is partly because the fungus that produced fumonisin also
lactation period, they had a significant decrease in dry produces other mycotoxins. Therefore, the definitive
matter intake and a lower milk yield as compared to the diagnosis of fumonisin toxicosis in animals must involve
control group (Diaz et al., 2000). Milk production aver- analyzing the feed for the presence of the actual toxin. Many
aged 7 kg lower in the group fed the ration containing diagnostic laboratories across the world offer assays to detect
fumonisin and there was a 13% decrease in feed intake both fumonisin B 1 and B 2 in corn and feed samples. The two
over the duration of the study period. Therefore it has most commonly used methods for toxin detection are
been recommended to avoid fumonisin concentrations chromatography (HPLC) and immunologic (ELISA) assays.
higher than 30 ppm in the total ration of dairy cattle. To date, there are no commercially available assays that
detect fumonisin in serum or tissues of animals.
Another assay that may be used more commonly in the
Fumonisin Toxicity in Poultry
future to diagnose fumonisin toxicosis in animals is the
Fumonisins can be toxic to both chickens and turkeys with sphinganine-to-sphingosine ratio (Sa:So ratio). Because of
concentrations in the feed as low as 100 mg/kg causing the fumonisin-induced disruption of sphingolipid biosyn-
decreased body weight gain, diarrhea, and hepatotoxicity thesis (Wang et al., 1992), the Sa:So ratio increases in the
(Bermudez et al., 1997; Ledoux et al., 1992). There has also serum and tissues of pigs and horses exposed to fumonisin.
been an association between F. verticillioides (the fungus that It has been suggested that this assay could be used to diag-
produces fumonisin) and an acute death syndrome recognized nose fumonisin toxicosis when feed analysis is not possi-
in young chicks called spiking mortality syndrome. It was ini- ble. Sphinganine and sphingosine data may be available
tially hypothesized that fumonisins were directly cardiotoxic to from enough pigs and horses in the near future to provide
poultry and were the cause of this syndrome; however, more values for normal and affected animals.
recent research has suggested moniliformin (another To date there have been no treatments described for
F. verticillioides produced mycotoxin) is primarily responsible. either ELEM or PPE. Generally the onset of clinical signs
is acute and the progression of disease is rapid for both
DIAGNOSIS AND TREATMENT syndromes. The most important treatment is to identify
and remove the source of contaminated feed to prevent
In addition to pathologic findings in animals, diagnosis of other animals from developing clinical signs.
fumonisin toxicosis typically relies on detecting the actual Guidelines for the maximum recommended levels of
toxin in feed samples. Fungal culture of feeds has little value fumonisins in animal feeds have been published by the
in diagnosing fumonisin toxicosis because some corn FDA Center for Veterinary Medicine (Table 71.3). It is

TABLE 71.3 Recommended Levels for Total Fumonisins (B 1 and B 2 ) in Animal Feeds
Animal Recommended Maximum Level of Recommended Maximum
Total Fumonisins in Corn to be Level of Total Fumonisin
Used for Feed (ppm) in the Ration (ppm)
Horse a 5 1
Swine 20 10
Ruminants b 60 30
Poultry c 100 50
Ruminant and poultry breeding stock d 30 15
Catfish 20 10
Other animals e 10 5
a
Includes donkeys, asses, and zebras.
b
Cattle, sheep, goats, and other ruminants that are .3 months of age and are being fed for slaughter.
c
Turkeys, chickens, ducklings, and other poultry being fed for slaughter.
d
Includes lactating dairy cows, bulls, laying hens, and roosters.
e
Includes dogs and cats.
Source: From the United States Food and Drug Administration, Center for Veterinary Medicine.