Phurpa Lhamo | Gasa

Every October, livestock officials scale the snow-covered peaks in Laya and Lunana, the northern-most parts of Bhutan, with a single mission to eliminate hypodermosis.

Hypodermosis or warbles are somatic myiases caused by larval stages of Hypoderma species of flies (Diptera, Oestridae). It is recognised as one of the major arthropod parasitic infection inducing huge economic losses to cattle industries as well as in yak rearing areas worldwide.

A two-week programme to treat yaks against the disease ended on October 16.

Gasa’s livestock officer Thinley Jamtsho said that the treatment was to break the cycle of the flies. “We have to inject the animals right now when the eggs are still forming. If we don’t inject, the eggs transform into larvae and attach to the skin.”

The larvae burrow into the skin, thus affecting the muscle tissues. While adult yaks survive such diseases, many of the calves die.

Hypodermosis affects a yak’s appetite and causes a decrease in milk yield.

Five livestock officials visited various herds located in Laya and Lunana. Apart from injecting the livestock against the disease, yaks were sterilised and those wounded were also treated.

Today, lack of fodder during winter and outbreak of gid (Gu-Yum) disease amongst the yaks are major challenges for the highlanders.

Lunana Gup Kaka said that in winter, shortage of fodder would lead to multiple deaths. In Lunana and Laya gewogs, highlanders lose dozens of calves to Gu-Yum disease.

Gu-Yum disease is a pathological condition in young yaks, mostly below three. It is caused by ingestion of eggs of dog tapeworms.

A farmer from Lunana, Samdrup Tshering, said that Gu-Yum would cause the animal to rotate in circles. “We have a large number of stray dogs here. Treatment is provided but I don’t know if it helps.”

The dzongkhag livestock sector also plans to visit the higher lands after two months to treat gid disease.

Yaks are also lost to wild animals every year. Gasa has 6,389 yaks of which, 3,584 are in Laya.