THE health of livestock affects production while a number of diseases inflict losses to this sector. Ectoparasitic infestation is a major veterinary problem prevalent in many parts of the world.

The ectoparasitics decrease the economic value of livestock products. The warble fly infestation (hypodermosis) is common among cattle, buffalo, sheep and goats in semi-hilly, mountainous and riverine areas of Southern Punjab. The disease is widespread from July to November. The rainfall and humidity nutures the developmental cycle of this fly.

The loss due to disease cannot be calculated due to a number of factors while hide damage is the most important consequence of the infestation resulting in low price on account of holes formed by the warble fly. Pakistan produces 7.5 million hides and 36.3 million skins, annually.

The Department of Veterinary Parasitology, University of Agriculture, and Faisalabad conducted a research survey to estimate the losses in endemic areas of Punjab. The pattern of its lifecycle was studied which revealed that the fly lays eggs on animal hair in groups of 5-15.

Each female deposits about 100 eggs on the animal. The larvae hatched are penetrated in the skin and migrate to subcutaneous tissue damaging the meat. The larvae visit the oesophagus and get mature. It is called third stage or mature larvae which are ready to pupate. It makes nodules (called warbles) on the skin. Afterwards a hole in the centre of the warble comes out which is permanent.

The hide merchants of southern Punjab were surveyed to estimate the price of infested hide. The average price per hide was calculated from the data used to calculate the losses in terms of rupees. Estimations were calculated by the prevalence (per cent infestation) of disease.

Loss per hide was calculated by the price difference of warble-free and warbled hides using the price index. The economic losses were based on the total population of cattle and buffaloes infested with hypodermosis. The net loss caused by this disease was calculated in term of money per year.

The estimated losses in Dera Ghazi Khan and Rajanpur districts were calculated at Rs12.9 million and Rs9.9 million, respectively. The total loss was estimated at Rs22.8 million,Rs20.6 million from cattle and Rs2.2 million from buffaloes.

Hypoderma is also found in goats where it is named as Przhevalskiana silenus. Its larvae do not penetrate the body tissues and are superficial. The best preventive measure of this infection is a single subcutaneous injection of ivermectin before the onset of risky months.

The economic importance of the disease varies from region to region. Control measures are needed to enhance the livestock productivity.

For the eradication of hypodermosis from this area, the following means/subjects should be given priority:

* Awareness campaign should be launched using electronic media, particularly in the risky months.

* A national programme for the control of the disease should be started.

* Need to investigation the available control methods/strategies.

* Regular use of insecticides on cattle and buffaloes is required during mid- September every year.