Review on bovine lungworm. Feyera Gemeda Dima * , Tamene Fikedu Department of Agriculture and Veterinary Medicine, Jimma University, Jimma, Ethiopia Abstract Production is a major agricultural activity with a huge economic impact in Ethiopia. An increase in large ruminant could contribute to the attainment of food self-sufficiency in the country especially in requirement for the growing human population and to increase export earnings. The bovine lungworm DictyocauIus viviparous is responsible for the disease known as verminous or parasitic bronchitis in cattle. The nematode viviparous is the only lung worm of cattle. Adult Dictyocaulus worms are slender, medium sized roundworms and up to 8 cm long. Bovine parasitic bronchitis is a sporadic and largely unpredictable disease. The life cycle of D. viviparous is direct. Migrating D. viviparous larvae provoke little damage until they reach the lungs. Outbreaks vary in severity from sporadic coughing with no apparent production loss to acute cases with a rapidly fatal outcome. Adult D. viviparous is up to 8 cm long and easily seen when the trachea and bronchi are cut open. Fecal samples can be submitted for analysis of L1 in Berman techniques. The anthelmintic available for the treatment of bovine parasitic bronchitis are the modern benzimidazoles, levamisole and avermectin. The best method of preventing parasitic bronchitis is to immunize all young calves with lungworm vaccine. Bovine dictyocaulosis caused by the species D. viviparous is the most common parasitic disease of cattle with a worldwide distribution. Applying rotational grazing system for different seasons of the year would apparently reduce pasture contamination. Therefore farmers should be informed to use this technique at least after harvesting their crop. Keywords: D. viviparous; Rotational grazing; Infective larvae. Accepted on 16 August, 2021 Introduction Production is a major agricultural activity with a huge economic impact in Ethiopia. An increase in large ruminant could contribute to the attainment of food self-sufficiency in the country especially in requirement for the growing human population and to increase export earnings. Infectious diseases of respiratory tract of farm animals are caused by combination of infectious agents and pre disposing factors such as inclement weather, stress of weaning, transportation and poorly ventilated housing, each of which can weaken defense mechanism of animals. Dictyocaulus is a genus of very harmful parasitic roundworms that infects cattle, sheep, goats, horses and many other domestic and wild mammals. It is found worldwide, particularly in regions with temperate or cold climate. The most relevant species for livestock are: Dictyocaulus filarial infects mainly sheep and goats as well as camelids and other wild ruminants. D. viviparous infects mainly cattle and other bovine, as well as camels, deer, elk, reindeer, etc. Dictyocaulus arnfieldi infects horses, donkeys, mules and other equine [1]. Bovine dictyocaulosis caused by the genus D. viviparous is the most common parasitic disease of cattle. Bovine parasitic bronchitis or lungworm disease is caused by the roundworm, D.viviparous. Infections with this parasite may occur in all ages of cattle, the disease is mainly seen in calves during their first season at grass. However, lungworm disease has recently emerged as a disease of second grazing season and older animals. On most organic farms, a gradual infection occurs in young animals resulting in development of a natural immunity. However, on some farms this gradual infection does not take place and large numbers of infective larvae may build up on pasture. The challenge may be sufficient to cause clinical disease in cattle which have not developed adequate immunity. The increase in bovine dictyocaulosis has been attributed to several factors, including climate change, a reduction in usage of the vaccine and/or common use of anthelmintic treatments to control lungworm and gastrointestinal parasites, which preclude adequate parasite antigen exposure, depriving the animal from subsequent immunological boosting. These challenges highlight the need for extensive research efforts to better understand the epidemiology and pathophysiology of bovine dictyocaulosis, with the aim of developing improved therapeutic interventions. Lungworm infection is one of the most important respiratory diseases of cattle, which is a roundworm (Nematode) parasite similar to gut worms. However, it completes its life cycle in the lungs rather than in the gastrointestinal tract. Affected herds usually indicate high disease prevalence and mortality depending on the degree of pasture contamination. Clinical signs in naturally affected animals are: loss of appetite, reduced growth, increase respiratory rate and coughing. D.viviparus has been implicated as a parasite that causes high mortality in cattle. Healthy animals get infection through intake of contaminated grass. Chronic inflammatory changes in infected lungs were in the form of ciliated epithelial cells loss, per bronchiolitis, eosinophilia bronchiolitis and atelectasis [2]. Review Article https://www.alliedacademies.org/journal-bacteriology-infectious-diseases/ J Bacteriol Infect Dis 2021 Volume 4 Issue 4 1