Common Pig Diseases

Raising pigs comes with the reality that your animals may get sick at some point, and knowing what diseases you might encounter helps you respond quickly when problems arise. Pigs are generally hardy animals, but they remain susceptible to a range of bacterial, viral, and parasitic diseases that can spread rapidly through a herd if not identified and addressed promptly. The key to managing pig health lies in recognizing the early signs that something is wrong before a minor problem becomes a serious crisis affecting multiple animals.

Many pig diseases share similar early symptoms, which can make identification tricky without experience or veterinary guidance. A pig that goes off feed, seems lethargic, or separates itself from penmates could be dealing with any number of conditions ranging from a simple digestive upset to something far more serious. Learning the specific signs associated with common diseases in your area, combined with careful daily observation of your pigs' normal behavior and appearance, builds the foundation for catching problems early when treatment has the best chance of success.

Some pig diseases have significant implications beyond the individual animal, either because they spread easily to other pigs or because they can occasionally affect humans who work closely with infected animals. Understanding which diseases carry these risks helps you make informed decisions about biosecurity, treatment approaches, and when certain conditions require reporting to agricultural authorities. Your veterinarian serves as an essential resource for navigating these situations and ensuring you meet any legal requirements associated with certain reportable diseases.

Prevention remains far more effective and economical than treating established disease outbreaks, which is why experienced pig keepers focus heavily on biosecurity, vaccination programs, and management practices that reduce disease pressure. Many common pig diseases can be largely prevented or minimized through appropriate vaccination, quarantine protocols for new animals, and attention to the environmental conditions that promote disease transmission. Building these preventive practices into your routine from the beginning costs far less than dealing with disease emergencies later.

This guide covers the diseases you are most likely to encounter when raising pigs on a small scale, focusing on recognition, basic management, and knowing when professional veterinary care becomes essential. While this information helps you understand what you might be facing, it does not replace professional diagnosis and treatment recommendations. Your relationship with a veterinarian familiar with swine medicine provides irreplaceable support for keeping your pigs healthy and responding effectively when disease does strike.

Respiratory diseases rank among the most common health problems in pigs and can range from mild infections that resolve on their own to serious pneumonias that cause significant losses. Pigs with respiratory infections typically show coughing, labored breathing, nasal discharge, and reduced appetite. They may stand with heads down and sides heaving, reluctant to move around or eat. Some respiratory diseases spread extremely easily through the air, so isolating affected pigs quickly helps protect the rest of your herd while you determine what you are dealing with and begin appropriate treatment.

Diarrhea affects pigs of all ages but presents particular dangers in young piglets who can dehydrate rapidly and die within hours of onset. Scours in piglets may result from bacterial infections, viral diseases, or parasites, and determining the cause guides treatment decisions. Adult pigs with diarrhea usually tolerate the condition better than young stock but still require attention to identify the underlying cause and prevent spread to other animals. Bloody diarrhea, persistent diarrhea lasting more than a day or two, or diarrhea accompanied by other symptoms like fever or complete appetite loss warrants prompt veterinary consultation.

Skin conditions including mange, ringworm, and various bacterial infections show up commonly in pig operations and affect both pig comfort and growth performance. Mange causes intense itching, hair loss, and thickened crusty skin that starts around the ears and eyes before spreading across the body. Ringworm appears as circular patches of hair loss with scaly skin that spread outward. Greasy pig disease, caused by bacteria, produces brownish crusty lesions and flaky skin particularly in young pigs. All these conditions require treatment to prevent spread and allow affected pigs to resume normal growth.

Lameness can result from injuries, infections in joints or hooves, nutritional deficiencies, or problems with the flooring and housing environment. Pigs that limp, refuse to stand, or show swollen joints need evaluation to determine whether the cause is infectious, physical, or nutritional. Joint infections in young pigs often result from bacteria entering through navel infections or wounds and can become serious quickly without treatment. Foot rot and other hoof problems develop more commonly when pigs stand in wet, muddy conditions without access to dry areas where hooves can dry out periodically.

Reproductive problems including abortions, stillbirths, weak piglets, and breeding failures may indicate infectious diseases affecting the breeding herd. Several viral diseases cause reproductive losses, and some bacterial infections can spread through breeding activity. When reproductive problems occur in otherwise healthy-appearing animals, disease investigation becomes important both for treating the immediate issue and protecting future breeding success. Your veterinarian can help determine whether testing is warranted and what diseases should be considered based on the specific symptoms and circumstances.

Sudden deaths without obvious prior illness always warrant investigation because they may indicate conditions that could affect other animals in your herd. Pigs can die suddenly from heart problems, internal ruptures, toxins, or acute infections that overwhelm them before symptoms become apparent. While necropsy examinations cost money, they provide valuable information when unexplained deaths occur, potentially revealing problems you need to address to protect remaining animals. Save carcasses in cool conditions and contact your veterinarian promptly when sudden deaths occur.

Daily observation forms the cornerstone of disease detection because pigs that feel unwell almost always show subtle changes in behavior before developing obvious symptoms. Healthy pigs approach feeding time eagerly, interact with penmates normally, and move around their space readily. A pig that hangs back at feeding, stands apart from the group, or seems reluctant to move deserves closer examination even if nothing appears obviously wrong. The earlier you catch developing problems, the better your chances of successful intervention.

Temperature checking provides objective information about whether a pig is fighting infection, as normal pig body temperature runs between 101 and 103 degrees Fahrenheit. A rectal thermometer gives accurate readings and should be part of your basic health assessment when pigs seem unwell. Temperatures above 104 degrees suggest infection or inflammation that likely requires attention, while temperatures below normal can indicate shock or severe illness. Keep a thermometer in your pig supplies and know how to use it before you need it in an emergency.

Isolation facilities allow you to separate sick pigs from healthy ones, reducing disease spread while providing focused care to affected animals. Ideally, your isolation area sits some distance from your main pig housing and uses separate equipment to prevent carrying pathogens back to healthy stock. When isolation space is limited, even moving a sick pig to a different pen or area helps reduce direct contact with healthy animals. Always care for healthy pigs first, then tend to sick animals, and change clothes and wash thoroughly before returning to healthy stock.

Maintaining treatment records helps you track what medications you have used, when you used them, and how animals responded. This information proves invaluable when discussing cases with your veterinarian and ensures you observe proper withdrawal times before butchering treated animals for meat. Record the pig's identification, symptoms observed, treatments given, dosages, dates, and outcomes. Good records also help you identify patterns over time, such as recurring problems in certain pens or during particular seasons.

Vaccination programs provide crucial protection against several serious pig diseases and should be developed in consultation with your veterinarian based on diseases present in your region. Erysipelas, a bacterial disease causing diamond-shaped skin lesions and potentially fatal systemic infection, responds well to vaccination and represents standard protection for most pig operations. Depending on your location and operation type, vaccines for respiratory diseases, reproductive diseases, and clostridial infections may also be recommended. Breeding stock often requires different vaccination timing than market animals to provide optimal protection during pregnancy and nursing.

Parasite control affects both pig health and growth efficiency, as internal parasites rob nutrients and can cause significant damage to intestinal tissues, lungs, and other organs. Strategic deworming based on fecal egg counts or routine treatment schedules keeps parasite loads manageable without contributing to resistance development through excessive or inappropriate treatment. External parasites like lice and mange mites cause discomfort, skin damage, and growth setbacks that respond well to appropriate treatments. Your veterinarian can recommend effective products and help you develop a sensible parasite management program.

Antibiotics require careful consideration because inappropriate use contributes to resistance problems while also potentially leaving residues in meat from treated animals. Only use antibiotics under veterinary guidance for diagnosed conditions, and always observe the withdrawal periods specified for any product before butchering treated pigs. Some antibiotics previously used routinely in pig feed are now restricted, requiring veterinary prescriptions and specific disease indications. Work with your veterinarian to have appropriate treatments available for likely conditions while avoiding unnecessary antibiotic use that provides little benefit and carries real costs.

Zoonotic awareness matters because some pig diseases can spread to humans who work closely with infected animals. Erysipelas, certain parasites, and some strains of influenza can potentially affect people, though proper hygiene practices substantially reduce these risks. Wash hands thoroughly after handling pigs, especially before eating. Wear gloves when dealing with sick pigs, birthing fluids, or dead animals. If you develop unusual symptoms after exposure to sick pigs, inform your doctor about your pig contact so they can consider relevant possibilities.

Heritage and traditional pig breeds often demonstrate somewhat greater disease resistance than highly selected commercial breeds, though they remain susceptible to the same range of conditions. The robust constitutions that helped these breeds survive before modern veterinary medicine existed may provide some advantages under challenging conditions. However, heritage breed advantages should not encourage neglect of basic health management, as even hardy breeds succumb to serious diseases when conditions favor pathogen spread or when disease pressure becomes heavy.

Commercial pig breeds have been selected primarily for rapid growth and efficient feed conversion rather than disease resistance, which means they may require more intensive health management than traditional breeds. These pigs often perform best under controlled conditions with well-designed health programs, which partly explains why commercial operations invest heavily in biosecurity and veterinary services. Small-scale producers raising commercial genetics can usually maintain adequate health without commercial-level intensity, but should pay attention to the increased susceptibility these breeds may show under stress.

Smaller pig breeds and pet pigs face some unique health considerations because their owners may not recognize signs of illness as quickly as experienced livestock producers would. Pot-bellied pigs and miniature breeds suffer from many of the same diseases as farm pigs but may also develop obesity-related problems and hoof issues from their smaller stature. Finding veterinary care for these animals can prove challenging in some areas because many large animal vets lack experience with miniature pigs, while small animal vets may feel uncomfortable treating pigs of any size.

Feral pig contact poses disease risks for any domestic pigs regardless of breed because wild swine can carry numerous diseases they spread through direct contact or environmental contamination. African swine fever, pseudorabies, brucellosis, and various parasites circulate in feral pig populations in many regions. If feral pigs exist in your area, preventing any contact between wild and domestic pigs becomes essential for protecting your herd from potentially devastating diseases. Strong fencing and biosecurity measures help reduce these risks.

Waiting too long to seek veterinary help ranks as perhaps the most damaging mistake pig keepers make when facing disease situations. The instinct to wait and see whether a pig improves on its own often allows conditions to worsen past the point where treatment can succeed, while also giving contagious diseases more time to spread through the herd. Veterinary care costs money, but early intervention usually costs less than treating advanced disease and certainly costs less than losing animals entirely. Develop a relationship with a veterinarian before you need emergency help so you have someone to call when problems arise.

Treating symptoms without identifying the underlying cause leads to wasted medications, prolonged illness, and potentially dangerous misuse of antibiotics or other drugs. A pig with diarrhea might have a bacterial infection requiring antibiotics, a viral disease that antibiotics cannot touch, or a parasite load needing dewormers. Throwing medications at symptoms without understanding what you are treating rarely produces good outcomes and may mask serious conditions while they continue to progress. When in doubt, get a diagnosis before beginning treatment.

Neglecting biosecurity allows diseases to enter your operation and spread within it when relatively simple precautions could have prevented problems entirely. Buying pigs from unknown sources, allowing visitors unrestricted access to your pigs, sharing equipment with other pig keepers, and failing to quarantine new animals all create pathways for disease introduction. Once diseases establish in your herd, eliminating them may prove difficult or impossible. Preventing entry costs far less than managing established disease.

Ignoring vaccination recommendations because your pigs seem healthy leaves them vulnerable to diseases you could have prevented entirely. Vaccines provide their protection before animals are exposed, not after disease symptoms appear. The cost of routine vaccinations is modest compared to the losses from outbreaks of preventable diseases, and some diseases like erysipelas can kill previously healthy pigs quite rapidly once infection takes hold. Work with your veterinarian to determine which vaccines make sense for your operation and maintain those programs consistently.

Failing to complete treatment courses when pigs seem to improve encourages development of resistant bacteria and often leads to disease relapse that becomes harder to treat the second time. Antibiotics need to be given for their full prescribed duration even when pigs appear recovered, as stopping early leaves surviving bacteria that are more resistant to future treatment. Similarly, some parasite treatments require repeat dosing at specific intervals to break reproduction cycles, and skipping follow-up treatments allows parasite populations to rebound quickly.