Worm Control in Pigs

A frequent finding at the abattoir in finished pigs is Milk Spot liver. This classic sign of a pitted scarred liver is caused by the migration of large roundworms (Ascaris suum).  If you are getting condemnations from the abattoir it is important you take note, as a worm burden in your stock is one of the biggest causes of reduced productivity.  They can also increase susceptibility to other diseases such as pneumonia.
A loss of up to 10% in DLWG and 13% feed conversion in growing/finishing pigs can increase the cost of production by 11p/kg DW through increased food usage and reduced sale weight.

Other worms seen are the red stomach worm (Hyostringylus rubidus) often seen in outdoor kept sows.  Whip worms (Trichuris suis), can cause colitis in growing pigs that can be confused with Swine Dysentery.  Lungworm (Metastrongylus apri) uses an earthworm as an intermediate host and is therefore only seen in outdoor conditions.  Piglets can also get threadworm (Strongyloides ransomi). 

To find out if worms are an issue on your unit the BPHS health scores are invaluable. These are currently on hold, although hopefully restarting later this year. You can look out for clinical symptoms such as coughing, loss of body condition, hairy pigs, vomiting, sometimes blood in the faeces, anaemia and diarrhoea. But even if no symptoms are seen the regular taking of faecal samples is a useful tool to catch a problem early. 

25g samples should be collected from the following animals:

  • 5 lean dry sows
  • 5 lean suckling sows
  • 5 separate samples from weaner faeces at 12 weeks age
  • 5 separate samples from finishing pigs at 90kg 

These can then be dropped off at the surgery for in-house analysis.

Eggs are floated in salt solution and examined microscopically.  Ascaris are intermittent shedders so it is less likely these will be picked up on a single sample.  It is recommended to monitor dung samples every 6-12 months.  If high counts are seen, worming of all breeding animals should be done 2-4 times a year.

For some useful scenario examples of who and when to treat, go to the RUMA website:


There are 2 classes of anthelmintic available for use in the UK.  Benzimidazoles  - Flubendazole (Flubenol)  and Fenbendazole(Panacur) which can be given orally in feed or via the water; and Avermectins – Ivermectin and Doramectin (Dectomax) which can be injected or given in feed.

It is essential you use a suitable wormer appropriate for the level of infection and your production system, that you adhere strictly to your worming programme and record everything and review regularly.

Contact us if you need help with deciding on the best treatment for your herd.