Glomerulonephritis in Pigs

Glomerulonephritis is inflammation of the glomeruli, the tiny filters inside the kidneys that help remove waste while keeping important proteins in the bloodstream. When these filters are damaged, protein can leak into the urine, the kidneys may stop working as well, and fluid balance can change throughout the body.

In pigs, glomerulonephritis is usually considered an immune-mediated kidney problem rather than a disease that starts on its own. That means the kidney damage often develops after the immune system reacts to another issue, such as a chronic bacterial infection, ongoing inflammation, or certain systemic diseases. Merck notes that immune-complex glomerulonephritis is seen in farm animals and is especially recognized in pigs in association with erysipelas and streptococcal infections.

Some pigs have only subtle early changes, while others develop more obvious illness. Depending on how much kidney tissue is affected, signs can range from mild protein loss and reduced thriftiness to swelling, high waste levels in the blood, and kidney failure. In herd settings, the condition may be suspected after poor performance or sudden losses. In pet pigs, it may show up as a pig that seems tired, puffy, or "not quite right."

Because kidney disease can look similar to several other problems, your vet will need to sort out whether the main issue is glomerulonephritis, another type of kidney disease such as pyelonephritis or interstitial nephritis, or a broader infection affecting multiple organs.

In pigs, glomerulonephritis is most often tied to immune-complex deposition. This happens when antigen-antibody complexes circulate in the blood and become trapped in the kidney filters, where they trigger inflammation. Merck describes membranoproliferative glomerulonephritis as an immune-complex disease and notes that, among farm animals, it is most common in pigs and is usually associated with erysipelas and streptococcal infections.

Other infectious and inflammatory conditions may also contribute to kidney injury in pigs, even if the exact lesion is not always classic glomerulonephritis. For example, porcine circovirus-associated porcine dermatitis and nephropathy syndrome (PDNS) can cause severe renal lesions including necrotizing and fibrinous glomerulonephritis. Leptospiral infection is another important pig kidney disease, although it more commonly causes interstitial nephritis rather than primary glomerulonephritis.

In some cases, the underlying trigger is never fully identified. That is true in other veterinary species as well, where chronic infection, inflammation, or neoplasia may stimulate the immune system long enough to damage the glomeruli. Your vet may therefore look beyond the kidneys and search for skin disease, joint disease, chronic wounds, dental or reproductive infection, systemic bacterial disease, or herd-level infectious problems.

Vaccination history, recent illness, housing conditions, herd exposure, and whether the pig is a pet pig or production pig all matter. These details help your vet decide whether the kidney disease is likely part of a larger infectious problem, a chronic inflammatory process, or a more isolated renal disorder.

Diagnosis starts with a careful history and physical exam. Your vet will ask about appetite, weight change, water intake, urination, swelling, recent infections, herd health concerns, and vaccination history. Because glomerular disease can be subtle at first, routine bloodwork and urinalysis are often the first clues.

Typical testing includes a CBC, serum chemistry panel, and urinalysis. Your vet is looking for protein in the urine, changes in kidney values such as urea and creatinine, low albumin, electrolyte shifts, and evidence of inflammation or infection. Merck notes that severe glomerular disease can lead to proteinuria, hypoalbuminemia, edema, and sometimes nephrotic syndrome. If urine protein is present, a urine protein-to-creatinine ratio or similar quantitative assessment may help show how significant the loss is.

Additional testing may include urine culture, infectious disease testing based on the pig's risk factors, blood pressure measurement when practical, and ultrasound to assess kidney size and structure. Imaging can also help rule out other urinary problems. In severe or progressive cases, a definitive classification of glomerular disease requires renal biopsy, although Merck notes that biopsy is not appropriate in every patient because of cost, handling needs, and bleeding risk.

In some pigs, especially production animals, the diagnosis is made presumptively from clinical signs and lab findings, while confirmation may come from necropsy and histopathology. That approach can still be very useful, because it helps your vet guide treatment for the individual pig and make prevention plans for the rest of the group.

Prevention focuses on reducing the chronic infections and inflammatory triggers that can damage the kidneys over time. Good herd hygiene, prompt treatment of bacterial disease, careful quarantine of new arrivals, and routine health monitoring all matter. Because immune-complex glomerulonephritis in pigs is associated with erysipelas and streptococcal infections, controlling those diseases is one of the most practical prevention steps.

Work with your vet on a vaccination and biosecurity plan that fits your pig's lifestyle. For pet pigs, that may mean routine preventive care, clean housing, parasite control, and fast attention to skin wounds, lameness, or fever. For small farms and production settings, it also includes sanitation, stocking density review, minimizing stress, and separating sick animals quickly.

Preventing other kidney insults is helpful too. Make sure pigs always have access to clean water, avoid unnecessary medication use without veterinary guidance, and address urinary or reproductive infections early. If a pig has had previous kidney disease, periodic rechecks may help catch protein loss before more obvious illness develops.

Not every case can be prevented, especially when the trigger is subtle or never identified. Still, early veterinary involvement gives your pig the best chance for timely care and helps protect the rest of the group if an infectious cause is involved.