Mycotoxins are toxic metabolites of fungi such as Aspergillus spp. that causes a range of diseases in many species.:53 Mycotoxicoses is the disease that is caused by a mycotoxin.
Aflatoxin is produced by Aspergillus flavus and Aspergillus parasiticus and may be found in moldy feeds, especially peanuts.:53:190 Aflatoxin B1 (AFB1) is of primary concern because it is the most abundant and the most toxic.:190 The acute, oral median lethal dose of aflatoxin is about 0.3 mg/kg body weight.:190
Zearalenone is an oestrogenic substance that is frequently recovered from maize and other grains contaminated by Fusarium graminearum.:191
Trichothecenes, specifically T-2 toxin and vomitoxin, is another group of toxin produced by some strains of the fungus Fusarium tricinctum.:191 It is relatively common in fibrous raw materials that have been harvested or stored in poor conditions.:191 Administration per oz of 4 mg/kg body weight of T-2 toxin causes death within 24 hours.:192 Vomitoxin (4-deoxynivalenol) may be found in cereal grains.:192
Ochratoxin, a nephrotoxin, is produced by toxigenic strains of Aspergillus ochraceus.:192
Citrinin, another nephrotoxin, is found in moldy cereals contaminated by various fungal species of Aspergillus and Penicillium. Some rabbits die less than 24 hours after oral administration of a single 100–130 mg/kg body weight dose.:192
Mycotoxicoses appears in chronic and acute forms.:190 The acute form is caused by a rapid ingestion of large amounts of toxins over a short period of time.
Some symptoms of aflatoxic poisoning in rabbits include the following::190-191
- decreased feed intake (anorexia)
- weight loss and emaciation
- lesions in the liver
- changes in blood constituents
- jaundice (icterus) in the terminal stages
Some symptoms of zearalenone toxicity in rabbits include the following::191
- hypertrophic development of the genital tract of the female rabbit
- changes in blood serum enzyme activities
Some symptoms of T-2 toxin poisoning in rabbits include the following::192
- feed refusal
- lesions of the digestive tract
- impairment of blood-clotting mechanisms
- alteration of ovarian activity of sexually mature female rabbits
Some symptoms of vomitoxin toxicity in rabbits include the following::192
- feed refusal
- fetal resorption in female rabbits
Some symptoms of citrinin toxicity in rabbits include the following::192
- acute erosive gastritis
- fluid diarrhea
- renal damage with tubular dysfunction and necrosis
Mold growth can occur on stored grains or other raw materials because of non-hygenic storage conditions or in the field on standing crops or during the harvesting of feedstuffs due to certain fungi.:190
- Cristina Forbes, Mold and Mycotoxins in Rabbit Feed
The following are some journal articles about mycotoxins and rabbits:
- Abdelhamid, A.M. (1990). Effect of Feeding Rabbits on Naturally Moulded and Mycotoxin-Contaminated Diet. Archiv Für Tierernaehrung, 40(1-2), 55-63.
- Hanika, C., Carlton, W., & Tuite, J. (1983). Citrinin mycotoxicosis in the rabbit. Food and Chemical Toxicology, 21(4), 487-493.
- Mézes M., Balogh K. (2010). Mycotoxins in rabbit feed: A review. World Rabbit Science, 17(2).
- Mézes M. (2008). Mycotoxins and other contaminants in rabbit feeds. Nutrition and Digestive Physiology, 491-506.