Saprophyte that is fungus grow on decaying biomass they are fusarium,aspergillos,penicillium, when rice straw contaminated with these fungus when they metabolose in body thye produce mycotoxin in turn the toxin causes elastin fiber to elastinase,collagen fiber to cillgenese,keratin to keratinase. That's why there is drying and sloughing of extremity,chalk like powder coming from hoof.if not loosing body condition,drop in milk yield repeat breeding
Dear Dr. KK Sharma You are right, as you know its Dignala is fungal disease, so only one factor is not 100% sure to cause disease. This problem starts when we storing rice paddy in high moisture for long time then Fusarium equisitti become grow. When we offer that paddy to animals, problem become starts. Favourable conditions are very important for the growth of fungus. Second point, the symptoms of Degnala are more or less similar to Selenium toxicity, so sometimes we confuse it with selenosis (with prominent hoof lesions). All are my personal experiences and views, although I am not expert of this field.
There are many query Dr.Bista khari in darchula baitadi till date finding indicate that it is choronic selenosis with combine mycotoxicosis. Furthermore it is what I call Nepales vet disease syndrome. No it does not restrict to buffaloes only. Although the name of diseaes is Degnala. I have mentioned about its history. Now I will say it is moldy straw, feed, fodder poisoning in livestock pig, poulty, sheep, goat too, and equine is more venerable, so far there are documentation about it like in cattle it causes Endemic Moist Examatous syndrome, goat Dhakeri Bange Syndrome. In finisher broiler Sudden Death Syndrome. In Early chicks Spiking mortality Syndrom. In Sheep Facial eczema,in equine spp Equine Lucko Encephalomalacia. In pig HBS.
Nepal Agricultural Research Council (NARC) has carried out an extensive research on Khari diseases as referred to by Dr Bist in the western districts of Baitadi, and Drachula. In the early 2012, NARC has already handed over a complete package of practice to the Department of Livestock Services (DLS), Government of Nepal for preventing, control and treatment of the Khari Disease syndrome. Yes, it is a complex disease syndrome. So Khari is no more a mysterious disease as it used to be 20 years ago. It is a syndrome (rather than a disease) and the treatment has been effectively used at the field level in Baitadi and Drachula districts.
I live and do veterinary practice and dairy consultancy in the degnala disease District Shekhupura, Pakistan. DEGNAL is a drain for water supply to the surronding area this area is richly peddy growing area. Peddy is winter season crop when high moisture is present giving excellent environment for fusarium growth this provide fodder to the buffaloes. Buffaloes are more prone to this disease. Petasulphate mixture is the drug of choice for this problem.