Parasite Control – What to consider at housing?
November 7, 2024
Parasite Control – What to consider at housing?
Housing time is a great opportunity to manage any parasite burdens on cattle. It is important to treat with the right product at the right time.
Questions to consider before deciding to treat:
- Do I have this parasite on my farm?
- Are my animals currently infected?
- Will the drug I want to use work for these parasites?
The four main parasites we need to consider at housing and how to test for them:
1 – Gutworm (Ostertagia):
All cattle at grass will pick up gut worms, however they can develop a strong natural immunity to ostertagia after just two grazing seasons, so younger animals are at higher risk. The most common signs of gut worms are scour, reduced weight gain and inappetence.
Testing: Faecal egg counts are useful at grass, especially in younger animals but can’t always tell the number of inhibited larvae over the house period. Blood testing younger animals at the time of housing for pepsinogen levels can be used to try to assess the overall worming status on the farm.
2 – Lungworm
Lungworm main signs are coughing and difficulty breathing. Cattle are most of risk of lungworm disease in the late summer and autumn and is more common in wetter areas. They will develop natural immunity if they are exposed to small amounts of lungworm each year, however vaccinating can enhance this immunity.
Testing: If clinical signs are seen, faecal samples can confirm the diagnosis, but treatment is often needed urgently. We can also test via blood testing or confirm diagnosis via postmortems.
3 – Liver Fluke
This can infect both cattle and sheep and there is no natural protective immunity, so all ages of cattle can be infected. Fluke usually appears on the pasture from late summer through the autumn and into winter, however with the recent unpredictable weather, the appearance of liver fluke has become less reliable to predict.
Testing: Blood samples from calves at the time of housing or faecal sampling for all age groups can be used. Only the adult stages can be detected on a worm egg count, so where negative, re-testing can be done 4-8 weeks later.
4 – Lice
There are four different species of lice commonly found on cattle, but they can simply be split into either sucking or biting lice. All housed cattle will probably be exposed to some lice over the winter period but cattle that are unwell or on poor nutrition are more likely to show signs, which can include hair loss and intense skin irritation.
Treatment: If lice are seen, then examining these under the microscope to see if they are biting or sucking lice is useful to determine which treatment is needed.
There is a wide variety of products on the market and are many types of applications such as spot-on, pour-ons, injections and drenches. It is important to choose the correct product for the parasite you are choosing to treat or prevent.
Please give us a call to speak to one of our vets or Harriet on 01373 451115 if you would like to discuss which products you need or if you are interested in a bespoke worming plan for your farm.