Treating mites, lice, worms and disease in poultry

Updated November 30th, 2020

Welcome to a quick guide to treating the most common infections in chickens. Please also see our pages on egg peritonitis or internal lay and cold and flu-like infections in chickens.

Intestinal Worms

Chickens should be wormed every 3 months. However, worm control also requires you to understand that worms come from worm eggs passed in droppings and then eaten by poultry during foraging. Unless you change litter and clean the yard regularly, worm eggs will build up into large numbers and make it extremely difficult to keep your birds healthy.

You should also take steps to prevent pigeons, doves and other wild birds from entering the yard or roosting over the foraging areas. The food supply should have a close fitting lid to prevent contamination by birds, rats and mice and food fed to chickens should be placed in flat containers, not directly on the ground.

So why do we try to avoid medications designed to be mixed in drinking water? If we want to enter a lottery, we’ll buy a lotto ticket.

  • Birds drink different amounts on hot and cold days
  • The dose received could either be high and toxic or low and useless
  • Sub-therapeutic dosing encourages resistance in bacteria and worms
  • Drugs are quickly deactivated by sunlight or organic matter like faeces
  • Cleaning and decontaminating the drinkers is often poorly done

There is no good alternative to catching each bird and dosing each one correctly for their body weight. Yes, this is hard work. We know- we’ve done it in aviaries of over 50 birds. The problem is that you simply may only be able to buy a wormer that goes in the water. If so, our advice is use products containing piperazine or oxfendazole and be careful.

If you lose any birds to illness we offer a post mortem examination service which can also check for worms. We have access to a wider range of effective bird dewormers which can be used if worm trouble is detected. However, the egg witholding periods can be very long afterwards.

Mite and Lice Treatments

We would prefer you monitor your birds closely before treating with insecticides that they may not need. Body lice produce a characteristic irritation to the skin which we can easily recognise, whereas feather lice are often visible in the plumage but only cause minor irritation. Mites can be nasty: they are sometimes visible in the feathers or on the skin, and often crawl onto the owner’s hands.  The red mite lives in the coop during the day and can be harder to identify on the bird.

If your chickens are having trouble with internal or external parasites, we advise making an appointment and allow us to diagnose and treat the problem. Read here for example, about the use of ivermectin to treat scaly leg mite.

*Fluoroquinolones (such as enrofloxacin), Nitroimidazoles (such as metronidazole and dimetridazole), Chloramphenicol & Cephalosporins. Very few antibiotics are registered for use in chickens laying eggs for human consumption and withholding periods when eggs must be discarded often apply. Remember if you feed eggs from treated chickens to other birds, they will then be exposed to the drug as well.

Giving Chickens Medicine

Medicating chickens is nothing like treating any other pet species. As a food producing animal, the law is very clear on what we can and cannot do. Why?

  • People may accidentally consume eggs or meat contaminated with hazardous drugs
  • Many drugs have not been tested in chickens
  • The use of certain antibiotics* is prohibited to prevent bacterial resistance spreading to humans via the food chain
  • Nearly all of the common medications we use in other species carry a small warning: “Not for use in food producing species”
chickens scratching litter

So what do we do? Whenever possible (and this is by no means always) we use drugs which have been registered for their intended use, and carry advice on what we call ‘Withholding Periods’. These are the amount of time which must pass after stopping a certain drug before meat or eggs may be safely consumed.

When this information is not available we have general guidelines on withholding periods but by no means are we as certain as we would like. This makes us tend to advise very long periods of abstinence. We have our own client advisory form which we supply clients with every treatment for their chickens.