chickens in a run

Information and advice from the RVC Farm Animal Clinical Centre on keeping chickens.

It is advisable to purchase chickens from private breeders or small-scale livestock sales where you can obtain information about their history. Birds should be checked for poor health before purchasing. If you intend to rescue end-of-lay battery hens, be aware that they are likely to be low producers and may show significant morbidity and/or mortality in the first few months of obtaining them and may need further care.

Feed and management

It is a legal requirement to register your chickens with the Department for Environment, Food & Rural Affairs (Defra) if you keep 50 or more birds on your premises and a CPH number will be needed.

Your chickens should have access to a chicken house and outdoor run/roaming space. Housing should protect your chickens from the elements and determined predators while also being well-ventilated and easy to clean. Perches should not be too high as this can lead to bumblefoot infection from the impact of jumping. Rounded perches encourage chickens to perch and reduce foot problems. Laying hens need a secluded area where they can lay eggs.

Chickens need to drink around 120 mls of water a day. Fresh water is vital as botulism may result from stagnant water. Feeders or drinkers should be washed and disinfected on a weekly basis with a non-toxic disinfectant.

As a disease control measure, it is illegal to feed kitchen scraps. Most commercial poultry feed contains all the nutrients your chicken needs. If you have layer hens it is important to ensure they are getting enough calcium as their requirements are higher than other birds.

Obesity can be a serious issue in pet chickens and lead to diseases, including fatty liver haemorrhagic syndrome (see below). One sign of obesity is multiple yolked eggs. Regularly weighing your chickens and restricting the amount of treats you give them can help avoid obesity. Oyster shell should not be part of a chicken’s diet as it is too fine and gets impacted in the crop.


chicken in a run

As commercial vaccines can only be purchased in lots of around 1000 vaccinating pet birds is rarely an option. Good biosecurity is therefore critical. This includes preventing contact with wild and migratory birds, good hygiene measures and buying in disease-free birds only.

Chickens can get a variety of worms, including roundworm (Ascaridia galli), gapeworm (Syngamus trachea), hairworm (Capillaria contorta), caecal worm (Heterakis gallinarum), coccidiosis and tapeworm (Cestodes). Most of these can be treated with fenbendazole licensed powder (Flubenvet™), others will need more specific treatment from your vet.

Common diseases – symptoms and treatments

examining a chicken

It is important to know some common diseases so you know to call a vet when your birds are exhibiting symptoms. It is also important to be aware of the normal range of vital signs for chickens. The normal temperature range is from 40.6 – 43C, heart rate 250-300 beats per minute and respiratory rate between 12 and 37 breaths per minute.

Egg binding

Egg binding can occur in any laying birds. Obese, calcium deficient or dehydrated birds are all at increased risk. The most notable sign is absence of egg laying in a normally regular layer or the bird may pass wet droppings, have shaky wings, reduced or absent appetite, and they may frequently sit down. If you suspect egg binding you should call a vet as soon as possible as this can progress to fatal egg peritonitis (see below). Treatment involves administration of a calcium injection and placing the bird in a warm bath to hydrate the vent and encourage the egg to pass. If this does work the egg may need manually expressing.

Egg peritonitis

This results from damage to the oviduct resulting in the yolk entering the abdominal cavity. This is a rich environment for growth of E.coli bacteria. Symptoms include dullness and depression with a distended and guarded abdomen. Unfortunately there is little that can be done for these birds and they are usually euthanised on welfare grounds. 

Fatty liver haemorrhagic syndrome

Excess energy in the diet results in an enlarged liver engorged with fat. This makes the liver friable (brittle) and slight trauma or pressure from straining to lay eggs can result in a fatal haemorrhage into the abdominal cavity. A signs of the condition is pale combs. The best prevention is monitoring body weight. 

Avian influenza (HPAI) and exotic Newcastle disease (END)

Although not commonly diagnosed in small flocks, these highly contagious notifiable viruses can spread rapidly and cause up to 100 percent fatality in a chicken flock. Signs and symptoms include severe depression, purplish discoloration of the comb and the face, respiratory stress, reddish shanks and diarrhoea. If your flock experiences sudden deaths, report it immediately to your vet or a government animal-health (APHA) official. HPAI and END can strike so fast that chickens die before developing symptoms. There is no treatment available and therefore prevention is essential.Prevent contact with wild or migratory birds (ducks and geese), eliminate the introduction of new chickens to an existing flock, and adhere to strict biosecurity practices. These diseases are notifiable and treated very seriously because they pose a serious risk to the commercial poultry industry and human health.  


Mycoplasmosis is a common chicken respiratory disease caused by a bacterial infection. The symptoms, which are slow to develop, resemble a standard respiratory infection. These include watery eyes, dirty nostrils, coughing and sneezing. It also causes decreased egg production, lowered fertility and decreased hatchability.

There are various species of Mycoplasma that can infect chickens, but the most common in small flocks is Mycoplasma gallisepticum (MG). The disease can have a long course of infection and can lead to the accumulation of a ‘cheesy’ material in the eyelids and sinuses, and can cause noticeable outward swellings in their head.

Chickens that recover from MG remain asymptomatic carriers for life. Therefore, introduction of seemingly healthy chickens to an uninfected flock can become a source of infection. Infected breeders can transmit the disease through the egg to the chicks. It is therefore important to purchase MG-free chickens.


Coccidiosis is caused by the parasite Eimeria. Chickens are susceptible to five different species of Eimeria—which target various portions of the chicken’s intestines. Mild infections result in weight loss and pigmentation loss. Severe infections cause bloody diarrhoea and can be fatal if untreated.

Coccidia are passed through chicken faeces in the form of oocysts, or tiny eggs. Chickens will ingest these eggs, which resist most environmental extremes and disinfectants, when pecking the ground. The oocysts remain dormant until temperature and humidity conditions are right. Warm and humid areas rich in faeces are the main source of infection.

Coccidiosis is often a problem in floor pens, which have dirt floors where oocysts build up in the soil over time. Exposure to high levels of oocysts over time results in severe disease, while exposure to low to moderate numbers of oocysts over time can result in immunity. Young chickens and poorly fed chickens are most susceptible.

Preventative measures include improving drainage, rotating water and changing the topsoil in a floor pen yearly. Coccidiosis can also be prevented with medicated starter and growth chicken feeds and can be treated likewise with medications.

chicken in a run

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