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Ensuring cattle are at optimum health is important for welfare and productivity benefits. As with all species, parasite management control varies throughout the year with turnout and housing being the key periods for cattle.


Gastro-intestinal nematodes

Gastro-intestinal nematodes can cause clinical disease in animals and loss of production

  • Ostertagia ostertagi has potentially the most impact economically and can cause diarrhoea, thirst, bottle jaw and weight loss
  • Cooperia oncophora affects calves in their first grazing season. It is associated with loss of appetite and poor weight gain1
  • Rainfall, temperature, previous exposure and concurrent disease are all additional risk factors of GI disease

Liver fluke

Liver fluke has spread over the last decade and is now found across the country. This is due to:

  • Greater movement of infected animals
  • Inadequate (or sub-optimal) quarantine treatments
  • Changing weather patterns – increased rainfall and milder winters

The objective of liver fluke control is to reduce the risk of infection to a level that does not impact on animal welfare or affect the efficiency or economics of production

Liver fluke has 3 stages in the animal early immature, immature and adult all of which cause liver damage

Liver condemnations at slaughter or acute liver fluke disease are obvious losses. Subclinical disease cause:

  • Reduced milk yield and quality:
    • Milk yield losses of up to 1 kg per day over a 305 day lactation2
    • Reduced milk butterfat concentration
  • Reduced reproduction:
    • Reduced conception rates in heifers by 50%3
    • First oestrus in dairy heifers delayed by 39 days4
  • Reduced growth rates:
    • Reduced live weight gain by up to 1.2 kg per week2


In the warmer, summer months, flies cause irritation, stress and seriously affect cattle productivity due to reduced weight gain and milk yields.5,6

Flies are also responsible for the spread of significant cattle diseases such as summer mastitis, salmonella and New Forest Eye (Moraxella bovis7,8

The most common species that affect cattle productivity are:

  • Non biting flies – house flies and face flies – these flies do not bite, but they breed easily in manure, quickly forming large numbers which can cause great irritation and transmit diseases. Animals that are distracted by flies will graze less and hence not perform as well.
  • Biting flies – horse flies and stable flies – these flies deliver extremely painful bites, with both males and females feeding on blood. Horn Flies are blood sucking flies and are extremely irritating and can cause production losses.


Lice are mainly a problem with housed cattle in the winter. It can reduce cattle productivity and also downgrades the leather.

  • Symptoms include itching, hair loss, hide damage and anaemia (sucking lice).
  • There are sucking and biting lice:
    • Sucking lice pierce the skin and suck the blood and can cause anaemia. They tend to be found around the head and neck of cattle;
    • Biting lice feed on skin debris, blood and scabs. They tend to be found on the neck, shoulders, back and rump.


Mange mites cause irritation, thickened scaly skin, hair loss, hide damage and reduced productivity. It is mainly a problem in autumn, winter and early spring. Different mites are commonly found in different body areas as follows:

  • Surface mites – neck, legs and tail head, causing areas of hair loss which increases in size and causes irritation;
  • Burrowing mites – neck and loin area next to the tail, producing intense irritation and severe skin damage. Large areas become thick, crusted and eventually infected;
  • Psoroptic mange – back, shoulders and tail head causing severe dermatitis, scabs and intense itching.