Oestrus ovis

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The larva and fly of the sheep-nostril-fly (Oestrus ovis). C Wellcome V0022564

Oestrus-ovis-larva

Oestrus ovis is a species of fly belonging to the family Oestridae. Commonly known as the sheep bot fly, it is a parasitic insect that primarily affects sheep and goats. The larvae of Oestrus ovis are known to cause a condition called Oestrosis, which can lead to significant health issues in the affected animals.

Life Cycle

The life cycle of Oestrus ovis involves several stages: egg, larva, pupa, and adult. The adult female fly deposits larvae directly into the nostrils of sheep and goats. These larvae then migrate through the nasal passages to the sinuses, where they develop further. After completing their development, the larvae are expelled from the host and pupate in the soil. The adult flies emerge from the pupae to continue the cycle.

Pathogenesis

The larvae of Oestrus ovis cause irritation and inflammation in the nasal passages and sinuses of the host. This can lead to symptoms such as nasal discharge, sneezing, and difficulty breathing. In severe cases, secondary bacterial infections can occur, exacerbating the condition. The presence of the larvae can also cause behavioral changes in the host, such as head shaking and restlessness.

Diagnosis

Diagnosis of Oestrus ovis infestation is typically based on clinical signs and the presence of larvae in the nasal passages. In some cases, endoscopic examination may be used to confirm the presence of larvae. Serological tests can also be employed to detect antibodies against the larvae.

Treatment and Control

Treatment of Oestrus ovis infestation involves the use of antiparasitic medications, such as ivermectin or moxidectin. These medications are effective in killing the larvae and alleviating symptoms. Control measures include regular treatment of at-risk animals and management practices to reduce exposure to the flies. This may involve the use of insecticides and the implementation of good husbandry practices.

Economic Impact

Oestrus ovis infestation can have a significant economic impact on the livestock industry. The condition can lead to reduced productivity, increased veterinary costs, and, in severe cases, the death of affected animals. Effective management and control of Oestrus ovis are essential to minimize these economic losses.

Related Pages

• Oestridae
• Oestrosis
• Ivermectin
• Moxidectin
• Parasitic diseases of animals