Theileriosis Disease: economic threat to Livestock Industry and Its Control Strategies
October 20th, 2017 | Dr. Rashid Fayyaz | No Comments
Theileriases is tick born Protozoan parasitic disease in livestock population caused by Theileria parva (East cost fever) and Theileria annulata (Tropical or Mediterranean). Tick born diseases causes huge economical losses in dairy industry in tropical and subtropical areas where 80 % of total cattle population. Tick transmitted Theileriasis commonly known as East cost fever that probably the most important livestock disease in Africa causing annual loss of 1.1 million cattle and $ 168 million as of 1992. It is found in Sudan, South Africa, Swaziland, Zimbabwe, Zambia, Tanzania, Kenya, Uganda. In Pakistan environmental conditions favour the ticks that is why tick can transmit the diseases to humans, livestock as well companion animals. In Indo-Pak the T.annulata is more common in all species including Cattle, Buffalo, and up to some extent in small ruminants. There are 6 species of Theileria but the most pathogenic and economically important are Theileria parva and Theileria annulata. Most often disease occur in subclinical form leading significant economic losses without treatment in which case fatality reach up to 80% in exotic breeds (Boss Taurus) as compared to ingenious breed (Bos indicus) with 20%. T.annulata cause severe losses in dairy industry in endemic countries including Africa and Asia. The primary vectors for Theleria are Ticks (Ixodidae family). The T.parva was first reported in Zimbabwe in 1902 , however misdiagnosed as Redwater ( Disease caused by protozoa Babesia bigemina). High Temperature as well Humidity is required for tick growth. A form of east cost fever called corridor disease when organism is transmitted from the African buffalo to cattle.
Theileria species are the only eukaryotic organism known to transform the Lymphocytes. Life cycle of these organism is completed in the Lymphocytes (Schizonts) and in RBCs (Piroplasm). Theileria utilize WBCs and RBCs for life cycle completion in mammals. The highly pathogenic species of Theileria (T.parva and T.annulata) parasitic multiplication occur within the WBCs of host, less pathogenic species occur in the RBCs. Clinical signs includes swelling of prescapular lymph nodes, Temperature 106 F after 7-10 of infecting ticks, Bulged eyes, anorexia, emaciation, nasal discharge, dyspnea, Lacrimation, corneal opacity, sometime shizonts and piroplasm block the capillaries that led to hypoxic injury in brain (nervous signs), poor growth, anemic, jaundice due to destruction in RBCs . Just before death a sharp decline in body temperature and pulmonary exudates oozes out from nostrils. Post mortem signs involving myocardial degeneration, pulmonary edema, lymph nodes enlargement, Hemorrhages in liver, spleen and milk clots in Abomasums is typical for Theileriasis in Calves. Theileriasis Differentially Diagnosed from Trypanosomiasis (largest blood parasite extracellular) Babesiosis (Haemoglobinurea).
From 1990s Buparvaquone (Bupralax® by Star, Parvan® by Selmore Zubalex® by Zekphas 1ml/20kg body weight) at dose rate of 2.5 to 3mg/kg body weight is used in bovines theileriosis with remarkable results 90 to 98 % recovery. The classical treatment protocol used Long Acting oxy- tetracycline (OXY-LA® 20-30ml IM) with dose rate 20mg/kg body weight cannot provide efficiency more than 50%.
Control of tick population by an idea of development of disease resistant ticks. Domestic animals free from ticks are the major concern in tropical countries with large livestock populations especially in indopak. Control of High temperature and Humidity that is favorable for tick survival. Chemicals pesticides (acaricides) should being applied in dipping baths, spray races as well use of cattle breed with good ability to acquire immune resistant to the vector ticks like Sahiwal breeds in indo-pak should be used for control measures. Hence we can avoid from hemoprotozoan diseases by proper control strategies discussed in article. In this regard by applying such control measures we can minimize our economic losses in terms of health as well production of animals of domestic importance.
This article is collectively authored by Dr. Rashid Fayyaz , Dr. Asghar Abbas, Dr. Rao Zahid Abbas, Dr. Safdar Imran and Dr. Tahir Aleem.
Short Link: http://www.technologytimes.pk/?p=18910