Abstract;
A hyperemic moist eczematous syndrome was reported in Cattle and Buffales in Jhapa district of Nepal during month of September after prolong spell of drought followed by heavy rainfall causing water loging.A total 56 cattle and buffalo were affected and out of which 12 animal died.Rest of ill animal swere treated with 5%of Antidegnala liquor and Pentasulfate.Straw and Skin samples revealed Penicillium sp.Fungus.
Literature Review:
Facial eczema is a disease of sheep and cattle which occurs in warmer districts of the North Island during late summer and autumn and is responsible for serious production losses in some years. It is caused by a fungus, Pithomyces chartarum, which proliferates on dead plant material in pasture under warm, humid conditions. The minute spores of this fungus contain a substance, sporidesmin, which produces severe toxic effects in the liver. The appearance of livers of affected animals varies, according to the severity of the damage, from slight mottling with light patches to gross discoloration, distortion, and atrophy of large areas. Frequently the severely damaged portions are surrounded with new liver tissue. As a result of this damage the functions of the liver are impaired. Blockage of bile ducts may prevent the excretion of waste substances in the bile; for example, accumulation in the fat and skin of bile pigments, derived from the normal breakdown of old red corpuscles, produces the jaundice or yellow staining commonly seen in the carcasses of affected sheep. Of particular importance is the loss of ability to excrete the substance phylloerythrin. This is formed in the digestive tract of ruminants through the degradation of chlorophyll and is absorbed from the intestine and carried to the liver, where it is normally excreted in the bile. If this excretory mechanism is upset, phylloerythrin passes into the bloodstream which supplies the whole of the body. Phylloerythrin belongs to a class of flourescent pigments which are capable of making the skin sensitive to sunlight, causing reddening, intense itching, swelling, and scab formation. It is these effects, generally showing on the face of affected animals but also on other unpigmented skin exposed to light, such as the teats and udders of cows, which give rise to the popular name "facial eczema". These skin effects are, however, secondary to the much more serious impairment of liver function.
The fungus that produces the spores containing the sporidesmin toxin requires a number of environmental conditions to occur in order for it to survive and replicate. The fungus only grown on dead leaf litter, not green growing grass, and so the times of year when grass is dead or has a lot of dead litter at the base is in the Summer and Autumn. Topping of pasture will increase the amount of dead leaf litter at the base of the pasture. The other environmental conditions required by the fungus are a base grass temperature above 10 degrees celsius continuously for a period of 2-6 days, and a degree of moisture equivalent to 5mm rain. Heavy dews and high relative humidity can exert the same moisture requirement as rain itself.
Epidemiology
Animal factors
• sheep, cattle, deer susceptible
• horses resistant
Plant/environmental factors
• fungus grows on the dead leaf litter of pasture
• most frequent pasture is perennial rye grass, but can occur on other species
• requires warmth and humidity to promote rapid fungal growth and sporulation
• typical weather conditions involve autumn break rains after dry summer, several days of consistent warmth (T ºC>15.5 ºC) and high humidity (>80%)
• fungus concentrates toxin in spores which may be distributed throughout whole pasture sward
• most toxic part of pasture is base of sward
Clinical Signs
• initial dullness, lethargy and anorexia
• variable onset of jaundice and photosensitisation .
• some animals may die without either being observed
• photosensitisation:
o sheep - non wool skin including muzzle, ears, face, escutcheon
o cattle - non black pigmented areas including teats
o deer - generalised
• some animals develop chronic ill-thrift
• some progress to a hepatic encephalopathy
• dullness, depression
• tremor, recumbency
Necropsy
• skin lesions - photosensitization
• acute - swollen mottled liver
• chronic - severe hepatic fibrosis, nodular surface
• left lobe often atrophied
• marked fibrosis of bile duct
Diagnosis
• history
• clinical signs
• clinical pathology
• necropsy
Treatment
• 5% Anti Degnala liquor 5-10ml S/c or I/m for 4time in week alternate day
• Penta-sulphate 30-60g orally for 10 days
• supportive therapy
Control
• meteorological data allows prediction of potentially dangerous periods
• regional spore counting supplements above data
• on farm spore counting to identify dangerous pastures
• graze
o pastures with low spore counts
o long pastures for short periods
• alternative feeds - hay, silage, crops
• zinc oxide as a prophylactic
• benzimidazole fungicides to inhibit fungal growth
• breed for resistance
• vaccine development in progress