While the degree of dysplasia has been shown to be an important predictor of malignant change, many have challenged its use due to the low predictive value from the lack of objectivity of grading dysplasia. While 10% of leukoplakia lesions show dysplasia when biopsied, as many as 18% of oral lesions undergo malignant change in the absence of dysplasia. Leukoplakia located on the floor of the mouth, the posterior and lateral tongue, and the retromolar areas (the region behind the wisdom teeth) have higher risk, whereas white patches in areas such as the top surface of the tongue and the hard palate do not have significant risk. Although these "high risk" sites are recognized, statistically, leukoplakia is more common on the buccal mucosa, alveolar mucosa, and the lower labial mucosa. Leukoplakia of the floor of the mouth and tongue accounts for over 90% of leukoplakias showing dysplasia or carcinoma on biopsy. This is thought to be due to pooling of saliva in the lower part of the mouth, exposing these areas to more carcinogens held in suspension. Red lesions (erythroplasia) and mixed red and white lesions (erythroleukoplakia/"speckled leukoplakia") have a higher risk of malignant change than homogeneous leukoplakia. Verrucous or nodular areas have a higher risk. Although smoking increases risk of malignant transformation, smoking also causes many white patches with no dysplasia. This means that statistically, white patches in non-smokers have a higher risk. Older people with white patches are at higher risk. Larger white patches are more likely to undergo malignant transformation than smaller lesions.
If not reduced quickly, prolapses in pigs become necrotic and infected, and risk being cannibalized by other pen mates. If the latter happens it normally results in death of the animal by sepsis, shock or faecal peritonitis. Horses and mules
Rectal prolapse occurring in horse and mule would be better termed anal prolapse, as it only involves mucous membrane moving posteriorly to form a circular protrusion outside the anus  The condition is not painful. In mares after parturition, it is described as a 10 to 60 mm mucous protrusion.In young mules and foals, anal prolapse occurs with a frequency similar to that of Gasterophilus haemorrhoidalis. In extensive breeding conditions, the disease is only recognized after some days, leading to intense edema of prolapsed tissues and necrosis of the mucous membrane. Early cases in should be treated with the application of hygroscopic substances like powdered sugar followed by purse-string suturing. When prolapsed tissues are edematous and necrotic, amputation is performed. The prognosis is fair as the removed tissues do not contain any important organs or large blood vessels. References
External links
 Media related to Pelvic prolapses at Wikimedia Commons