Health Problems for Pigs

Learn to recognize common health problems in pigs.

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by Unsplash/David Cashbaugh

Choosing and Keeping Pigs (Firefly Books Inc., 2009), by Linda McDonald-Brown is an expert guide for anyone interested in keeping pigs. The book details everything readers need to know about caring for and keeping a pig, covering topics ranging from housing to health and habitat management. The following excerpt is from Chapter 3, “Pests and Diseases.”

There are a number of health problems that can affect your pigs. Knowing a little about how to spot them and what remedial measures to take may help prevent them from becoming serious.

Common problems

Common problems range from heatstroke to mange to lameness. Some can be treated by the owner if caught early enough, while others require a vet’s intervention.


Heatstroke is quite common in pigs and occurs when the pig is unable to lose body heat and its temperature rises dangerously. In hot weather provide as much shade as possible, either in the form of trees or by erecting a pig shade. Ideally, arks should be insulated and ventilated to allow air to flow through. If it is very hot, replace the straw with something less insulating or take it away altogether. Ensure that buildings used for farrowing sows are kept cool and that the air flow is not restricted. If you are travelling with pigs, make sure all the trailer vents are down; dampen bedding in the trailer if the weather is extremely hot.

All outdoor pigs must be provided with a wallow in hot weather. The best ones are man-made wallows containing mud, which retains the moisture on a pig’s body far better than water in a galvanized steel wallow.

Once a pig has heatstroke, its temperature must be brought down as quickly as possible, but not in such a way that it causes shock to the animal. Never throw cold water over a hot pig, as this could result in death. Sponging cold water over the head and body, as well as spraying the air surrounding the pig and turning on a fan, will assist in bringing the pig’s temperature down. Vinegar dabbed behind the ears can also help to reduce the temperature; always take some with you when you go to a show or when travelling with a pig.

Signs of heatstroke

• Excessive salivation, sometimes with blood mixed in with the froth

• Rapid breathing and gasping

• Trembling limbs

• Staggering and uncoordinated movement


It is mostly pale-skinned pigs and young pigs that are susceptible to sunburn. On the whole, because of their darker colours, traditional breeds do not suffer from it.

Avoid sunburn through preventative care, similar to the measures used against heatstroke. Wallows should be provided as well as shade (or keep your pigs in during the day and let them out at night); rub a high SP-factor sun cream, of the type worn by humans, onto pigs that may be at risk (not forgetting snouts and ears). If your pigs do get a touch of sunburn, dabbing on calamine lotion will ease the discomfort.


Pigs should be wormed routinely — usually at eight weeks, and then about every six months afterwards if you are keeping them for breeding. In-pig sows and gilts should be dosed a couple of weeks prior to farrowing, and again when the litter is weaned. All new pigs that arrive on your property should be wormed before being allowed to join the other pigs.

Worming must go hand-in-hand with good paddock management. Pigs become infected when eating or drinking, while piglets usually pick up worms by suckling. Enclosures that have had pigs on them for a long time will carry a heavy burden of worms, so if possible it is good practice to regularly rest and crop-rotate the paddock.

Slaughter houses will reject pig livers that have been damaged by worms, which is known as ‘liver spot’.

Worming can be controlled by injecting the pig with an anti-parasite product or by means of an anthelmintic (parasite-expelling) preparation given in the food. Injections tend to be more reliable because you can be certain the pig has received the correct dose.

Symptoms of worms

• Failure to put on weight in growers

• Scours and coughing in young piglets

• Loss of condition

• Staring coat (dull and lifeless)

• Pot bellies

E. coli

The E. coli bacterium is usually the reason for high mortality rates in piglets, but infection can be prevented. Veterinary assistance should be sought quickly once E. coli is suspected. Sows can be vaccinated on a regular basis and boosters given prior to farrowing; this immunity is then passed on to the piglets via the mother. Although E. coli is a major problem in large pig units, even the small-scale pig­keeper can be affected by it, so vaccination is well worth considering. Good hygiene — especially in the farrowing area — also goes a long way towards keeping E. coli at bay.


Scouring (diarrhoea) can occur in adults and young pigs. Sometimes it is temporary, brought about by a change of food, worms, overeating or too much fruit or vegetables. However, if it goes on for too long, it can cause dehydration and even death in piglets. Scouring in piglets often occurs at weaning so they should be carefully watched to ensure that it is only temporary and not a bacterial infection, which can kill a piglet very quickly. Piglets that have been hand-reared often get the scours, as do piglets that have not received enough colostrum.

For scouring pigs, a proprietary powder that is soluble in water is an effective way of drying them up. Any shelters that have been used by the affected pigs should be cleaned and disinfected and the bedding burned.


Erysipelas is not as common as it once was and, thanks to vaccination, good hygiene and better awareness, it can easily be prevented. The bacterium that causes erysipelas can be carried by birds and rodents and is found in the soil. It is possible (but rare) for humans to catch it through cuts, so gloves should always be worn if erysipelas is suspected. The organism can survive for many months if the conditions are ideal, and is far more common in straw-bedded systems than in fully slatted units.

Erysipelas can cause reproductive failure in sows and lameness in younger pigs. Abrasions appear on the skin, often in the shape of diamonds, and pigs experience a high temperature and look extremely miserable. Other symptoms include lameness or stiff gait and an arched back.

If caught early on and treated with antibiotics, the rate of recovery is usually l00 percent. However, death is likely to occur if the early signs are not picked up. It is therefore vital to vaccinate against this disease. Sows are most susceptible to it in the later stages of pregnancy. They should be vaccinated and then given a booster three weeks before farrowing, which will pass some immunity to the piglets. Boosters should be given to all pigs (including boars) every six months.


Meningitis can be brought on by a bacterial infection or by stress, and pigs that suffer from it rarely recover. The first signs are depression and a reluctance to stand. As the disease progresses, convulsions take place and once this happens death will occur within a few hours.

For the animal to have any chance of recovering, antibiotics must be given rapidly. The pig must be removed from its pen and put in an area with deep bedding to prevent injury. Fluids containing electrolytes to counteract dehydration should be given, although they may have to be tubed if the pig is reluctant to drink. If meningitis is caught in time, recovery is swift. However, if no change has occurred within 48 hours, the pig will probably have to be put down.


Lice on pigs can easily be seen with the naked eye. They look like tiny crabs and can cause great discomfort to the pig, often grouping around the ears before spreading over the rest of the body. The louse has a lifecycle of around three to five weeks on the pig’s body; off the body, it can only survive for a few days. It lays its yellow eggs close to the skin, normally around the ears, jowl, belly, flanks and shoulders. Symptoms that your pig has lice are continual scratching and dry, flaky skin. Sucking lice can result in anaemia if treatment is not given in time.

Lice can be controlled by injecting pigs with an anti­-parasitic solution and using an anti-parasitic wash. If your herd is free from lice, pigs that are brought onto the property should be checked thoroughly before they are allowed near the others.


Mange is a skin disease caused by the Sarcoptes scabiei or Demodex phylloides mites and is usually brought in by a carrier pig. By far the most common is the sarcoptic mite, which burrows under the skin to lay its eggs, making the pig extremely uncomfortable. Mites favour the head and ears, and signs of mange are head shaking, redness and a crusty, sometimes bloody skin, plus continual scratching and rubbing. If the mange is allowed to continue, it will lead to loss of condition and possibly death.

The mite is capable of living off the pig for two to four weeks if the conditions are ideal, so this should be borne in mind when trying to eradicate mange in a herd. Injections of anti-parasitic solution have proved extremely successful, while some breeders use a water solution of tea-tree oil with good results.

Colds and pneumonia

Just like humans, pigs can catch a cold; the first sign is usually a runny nose and loss of appetite. The pig should be kept warm and in a ventilated shelter. If it will eat, feed it as normal. If it has lost its appetite, tempt it with warm mashes and succulent greens.

Pneumonia can pull a pig down rapidly and, once suspected, veterinary assistance should be sought if death is to be avoided. Signs of pneumonia (as opposed to a cold) are coughing and rapid breathing, plus a high temperature, diarrhoea and loss of appetite. Growers that have had pneumonia in the past and recovered often fail to put on weight as quickly.

The spread of the disease is either airborne or by pig-to-pig contact, so the affected pig must be isolated from other pigs until it recovers. Pigs can often be carriers of viral pneumonia and not show any signs. Antibiotics will be required to treat the affected pig.

Joint ill

Joint ill is caused by bacterial infection entering the body of the piglet, usually through the navel when it is born. However, it can also enter the body through abrasions on the skin, such as knee wounds caused by suckling, or occasionally through clipped teeth. Once in the body, it spreads to the joints, causing lameness and stiffness. The first sign that something is wrong may be that a piglet is reluctant to stand or appears lame; or swelling might appear in the affected joint and the piglet might squeal in pain when it is picked up.

For the piglet to recover, it is important that antibiotics are given as soon as possible. Painkillers may also be needed as joint ill can be very painful.

To prevent joint ill occurring, piglets’ navels should be dipped or sprayed with iodine, and all farrowing areas should be kept clean and disinfected. Bedding should be deep enough to prevent abrasions on the knee, and high standards of hygiene should be in place.

Gastric ulcers

It is thought that stress plays a part in pigs being affected by ulcers, which often occur in lactating sows. Ulcers are difficult to diagnose. The signs vary, depending on whether or not the ulcer is bleeding. Occasionally there is vomiting and the pig will appear tucked up (with a tight stomach). Death often occurs and sometimes this can happen suddenly and without much warning; pigs can recover, but this is rare.

Iron deficiency

If piglets don’t receive sufficient iron from the sow, they can suffer from iron deficiency and become anaemic, although piglets with access to soil do not normally suffer from this complaint. Injecting piglets with iron within a few hours of being born is normally the course of action recommended by vets, but this can bring on the scours. Most breeders put sods of earth in the creep area, which is just as effective.

Atrophic rhinitis

Rhinitis is a respiratory disease that results in the tissues of the nose becoming inflamed. It is transmitted either through the air or pig to pig. This disease can be found in two forms: the more common mild, non-progressive form, and the far more serious disease, progressive atrophic rhinitis (PAR). With the lesser disease, infection and inflammation usually occur over a period of around three weeks, but do no lasting damage.

Symptoms are usually apparent at three to eight weeks of age. Initial symptoms are sneezing, sniffling and a nasal discharge. If the disease progresses to PAR, the snout becomes distorted and wrinkled and starts to twist sideways or upwards. Pigs that have only been affected mildly by the disease will not show this distorting of the nose, but may be more prone to bronchitis and pneumonia.

It is possible to vaccinate sows and gilts against rhinitis, if the disease in present in the herd, but this is not recognized as a wholly effective preventative measure.

Swine Pox

This is caused by the swine-pox virus and is often linked to external parasites such as lice. It is highly infectious, and any pig that has swine pox should be isolated straight away, its bedding burned and its shelter thoroughly disinfected. Gloves should be worn when handling the pig and another set of clothing worn if having close contact with other pigs in your herd.

Initial signs of swine pox are areas of redness that quickly develop into a scab, which soon blackens. Swine pox may affect the whole body and there is no treatment, although the pig recovers quite well as long as there is no secondary infection of the scabs.


Mastitis is a painful inflammation of the udders that occurs just before or after farrowing. It has a number of causes, such as an E. coli infection, lying on cold floors or injury to the udders by the suckling piglets.

Mastitis causes the udder to feel hot and hard, and it will be painful to the touch. Often the sow will go off her food and have a high temperature. If mastitis is severe, the sow will not let piglets suckle. Treatment is usually antibiotics. A good standard of hygiene and management is necessary to prevent mastitis.


Sometimes sows do not let down milk and there is no obvious reason for this, but an injection of the hormone oxytocin should get the milk flowing. Agalactia, or lack of milk, can sometimes be due to an incorrect diet.


Surprisingly common in pigs, lameness can be brought on by a variety of causes, including injury, arthritis, inappropriate flooring or bacterial infection. Some it can be prevented, especially when it is caused by lack of bedding. Occasionally it is caused by poor skeletal structure, so when purchasing a pig you should inspect its conformation and how it stands and walks.

Flooring (especially concrete) can increase the risk of lameness, so ensure that all floors (including the trailer floor) are not slippery when wet. Lameness sometimes occurs through other types of injury, such as fighting or being trodden on, so prevent this as far as possible.

If there is no apparent cause for the lameness, a bacterial infection should be suspected and the vet should be summoned.

Notifiable diseases

If you suspect your pigs have a notifiable disease, it must be reported to the veterinary manager of the relevant government department (such as Defra in the UK) or your nearest animal-health office immediately. All precautions should be taken to isolate the animals and prevent visitors from entering.


Foot-and-mouth is a highly contagious and notifiable disease and, if suspected, it should be reported straight away. It is caused by a virus, and symptoms include lameness, salivating at the mouth, a very high temperature and blisters, possibly on the snout, tongue and heels. Pigs can recover from it, but if foot-and­ mouth is confirmed the animal will be slaughtered.

Classical swine fever

Good bio-security measures are required to prevent this highly contagious disease. The virus survives for a long time off the pig and can be transmitted by vehicles, equipment and footwear, as well as by infected pigs and pig meat. Symptoms are constipation followed by diarrhoea, coughing, blotchy discolouration of the skin and weakness of the pig’s hindquarters. In its acute form, there is a high mortality rate.

Exotic diseases

The serious diseases African swine fever and anthrax are less frequently encountered in Western herds.

African swine fever

This highly contagious disease is caused by flies and ticks, as well as by direct contact with infected pigs. The incubation period for the virus is between five and 15 days, and the first signs are a lack of appetite and a high temperature, followed by coughing, diarrhoea and a darkening of the skin, especially around the ears and snout. The pig will appear weak and reluctant to stand.


Caused by a bacterial infection, anthrax is often found in South America, Asia, Africa and the Middle East. Anthrax in pigs is characterized by nausea, appetite loss, swelling around the neck, severe diarrhoea and often vomiting of blood. The disease progresses rapidly and treatment by antibiotics must be swift to prevent death, although this is often how it ends. It is possible to vaccinate against this disease in some countries.

When to call the vet

Over time you will get to know your pig and recognize what gives cause for concern. It is time to call the vet when your pigs are not behaving in their usual manner. You may be used to them going off their food when they are in season, but if lack of appetite is coupled with your pig looking tucked up and miserable, there is something wrong and you should summon help.

Some skin problems, such as lice and mange, can be dealt with without the intervention of a vet. Wounds that are not deep or gaping can be eased by a spray of antiseptic. Every pig owner should know how to inject, even if just for worming purposes and if antibiotics are required; calling the vet out every time you need to inject your pigs will be a costly business.

Spend some time researching the various illnesses and symptoms that affect pigs. If you have a general understanding of what diseases and ailments a pig can suffer from, you will be in a better position to know when to summon expert help.

More from Choosing and Keeping Pigs:
The Healthy Pig
Natural Remedies for Your Pigs
Plants That Are Toxic to Your Pigs

Excerpted from Choosing and Keeping Pigs, by Linda McDonald-Brown. Used with permission from Firefly Press, Inc., © 2009.