Parasitic infections generally cause diarrhoea or constipation, anorexia, weight loss, stunted growth, loss of production, abortions, etc. resulting in economic losses to the livestock owners. Some parasite sucks blood of the animals resulting into blood loss, jaundice, hair loss. External parasites cause itching, hide losses etc.

The roundworms, particularly Toxocara spp., that predominantly effects cow and buffalo calves, are the major endoparasites resulting in mud coloured foul smelling diarrhoea 10-15 days after their birth or constipation and death in untreated cases. Apart from this, infections with liver flukes and amphistomes are also important resulting in bottle jaw, watery diarrhoea or brittle faeces, weight loss etc., jaundice may also be seen in liver fluke infections.

Drainage of pools and swamps to eliminate snail population, avoid feeding and grazing of animals from snail infested area, make hay/silage from the fodder sown near snail habitats and feed after two months. Rear ducks, fishes in the ponds to reduce the snail population, careful examination of the water bodies near tube wells and paddy fields for the presence of snails, spray of Copper Sulphate (0.5%) @22.5 Kg per hectare to kill the snails.

Always keep the animals in clean surroundings, provide hygienic food and water to the animals, dispose of the faeces in the pit to destroy the eggs of the parasites, deworming of the animals should be done after diagnosis of the parasitic infection.

Haemoprotozoan parasitic diseases like theileriosis, babesiosis and anaplasmosis are mainly transmitted by ticks. However surra/trypanosomosis is transmitted by bite of tabanid flies. Mechanical transmission of anaplasmosis may also occur by equipments used in surgery, castration, dehorning and through blood transfusion.

Majority of signs in these infections are anaemia, high fever, anorexia, emaciation and decreased milk production. In babesiosis, there is additionally coffee coloured urine, while in theileriosis there is swelling of lymph nodes, lacrymation and serous nasal discharge. In anaplasmosis there is severe anaemia, jaundice and dark brown colour urine while in surra there is intermittent fever, nervous excitement, encircling movement and staggering gait in bovines, urticarial plaques on neck and flank in horses and corneal opacity, oedema of larynx leading to change in voice in dogs.

The ticks are found on body surface like, muzzle, head, pinna, udder, tail and inside the legs, of animals along with cracks and crevices of dairy sheds. They can be controlled by spray/bath/dip of commercially available chemical acaricides as per recommendation of veterinarian at proper dosage and rotation on host and shed during peak period (March to September). Animal shed should be free from cracks and crevices to eliminate breeding sites. If possible cows and buffaloes should be reared separately and animals should be reared on pucca floor. The rearing of domestic poultry in sheds can also be useful as a bio-control.

The flies cause annoyance and irritation in dairy animals, resulting in decrease feed intake and lower production. Additionally they cause anaemia and transmit variety of parasitic , bacterial and viral infections to animals. Some flies also cause myiasis in animals.

Keep animal surroundings clean, always clean the manger immediately after feeding, cover doors and windows with screens/meshwire, dispose the dung in a pit and regular interval and afterwards use it as manure in fields. Traditional method of smoking will be more effective if 1 tablespoonful of fennel seeds (25-30 gm) is added as fennel act as fly repellent, but care must be taken to prevent the death of animals due to suffocation. Spray different insecticides rotation wise in and around the sheds in summer or rainy season as per the recommendation of veterinarian and may be repeated after 10-14 days, if required.