What began last year as isolated incidents at a handful of pig farms has now become a recurring phenomenon in pigsties across the Netherlands. A variant of a parvovirus never before seen in pigs is causing an increasing number of piglets to develop protruding eyes and red, wrinkled skin—and its closest “relative” was actually found in the feces of Dutch foxes more than a decade ago.
This is not a highly lethal epidemic, but it is precisely because it “appears non-fatal” that the industry should be on high alert.
The Condition: Easily Recognizable, Yet Hard to Define
Affected piglets have a very distinctive appearance: bulging eyes, misaligned eye positions, and in some cases, redness, hair loss, and wrinkled skin. First observed in weaned piglets, the condition later affected even 2– to 3-week-old suckling piglets. Symptoms appear in a small number of individuals across 20%–70% of litters, but have not yet resulted in mortality and tend to resolve spontaneously over time. It is precisely this characteristic of “coming on suddenly and fading just as quickly” that led it to be initially dismissed as an isolated management or nutritional issue.
The Spread: From 1 Farm to 50, and Then “Widespread Across Multiple Locations”
Only by looking at the timeline in its entirety does the full picture emerge. In late 2024, veterinarians at several pig farms in the Netherlands first reported these unusual symptoms to the animal health agency Royal GD; by mid-2025, confirmed cases had spread to approximately 50 pig farms, concentrated in eastern and southern Netherlands; and by 2026, the latest reports in industry media had shifted from “a few farms” to “widely observed across the Netherlands.” In just a year and a half, it had evolved from an isolated incident to a widespread phenomenon.
The Mystery: A “Suspect” Has Been Identified, but No Conclusion Can Be Reached
Royal GD launched a comprehensive investigation covering epidemiology, pathology, and microbiology, but initially could not pinpoint the culprit. It wasn’t until researchers employed advanced virus detection technology that they identified this parvovirus variant in the tissues and blood of affected animals—pathological examinations also revealed its presence in multiple organs, including the eyes, brain, liver, and kidneys. However, authorities remain cautious: the causal link between the virus and all clinical symptoms has not yet been fully established, the pathogenic mechanism remains unclear, and the possibility that other infections or environmental exposures may have played a contributing role cannot be ruled out. In other words, the suspect is on the scene, but the evidence of guilt is missing the final piece.
A Hidden Concern: Existing Vaccines May Be Completely Ineffective
What truly sends a chill down pig farmers’ spines is the virus’s lineage. Genetic comparisons show that it is most closely related to the parvovirus strain found in fox feces samples from the Netherlands in 2012, though it has accumulated several additional mutations. It is genetically very distant from Porcine Parvovirus Type 1 (PPV1)—a virus all too familiar to pig farms—which primarily causes reproductive disorders in sows and has been effectively controlled by established vaccines for years. However, precisely because of this genetic distance, the industry widely believes that herds vaccinated against PPV1 are highly unlikely to be protected against this new variant. A defense line that has been in place for years may prove to be virtually useless against it.
Currently, Royal GD is collaborating with the Dutch Ministry of Agriculture, Nature and Food Quality (LVVN) and the Dutch Pig Producers’ Association (POV) to continue the investigation. The focus is on establishing a definitive causal relationship, mapping the transmission routes, and determining whether co-infections or environmental factors are contributing to the outbreak.
A reminder to the industry: While this incident cannot yet be classified as a “confirmed outbreak of a highly contagious disease,” it serves as a more subtle warning—atypical abnormalities characterized by low mortality rates and merely cosmetic changes may, in fact, be the first sign that a new pathogen has quietly infiltrated the production system. When you observe piglets with protruding eyes, reddened skin, hair loss, or wrinkled skin, do not be quick to attribute these symptoms to management or nutritional issues. Instead, keep detailed records and promptly submit samples for testing if cluster cases emerge. This is the correct approach to ensure sufficient samples and time are available for further assessment.
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This is not a highly lethal epidemic, but it is precisely because it “appears non-fatal” that the industry should be on high alert.
The Condition: Easily Recognizable, Yet Hard to Define
Affected piglets have a very distinctive appearance: bulging eyes, misaligned eye positions, and in some cases, redness, hair loss, and wrinkled skin. First observed in weaned piglets, the condition later affected even 2– to 3-week-old suckling piglets. Symptoms appear in a small number of individuals across 20%–70% of litters, but have not yet resulted in mortality and tend to resolve spontaneously over time. It is precisely this characteristic of “coming on suddenly and fading just as quickly” that led it to be initially dismissed as an isolated management or nutritional issue.
The Spread: From 1 Farm to 50, and Then “Widespread Across Multiple Locations”
Only by looking at the timeline in its entirety does the full picture emerge. In late 2024, veterinarians at several pig farms in the Netherlands first reported these unusual symptoms to the animal health agency Royal GD; by mid-2025, confirmed cases had spread to approximately 50 pig farms, concentrated in eastern and southern Netherlands; and by 2026, the latest reports in industry media had shifted from “a few farms” to “widely observed across the Netherlands.” In just a year and a half, it had evolved from an isolated incident to a widespread phenomenon.
The Mystery: A “Suspect” Has Been Identified, but No Conclusion Can Be Reached
Royal GD launched a comprehensive investigation covering epidemiology, pathology, and microbiology, but initially could not pinpoint the culprit. It wasn’t until researchers employed advanced virus detection technology that they identified this parvovirus variant in the tissues and blood of affected animals—pathological examinations also revealed its presence in multiple organs, including the eyes, brain, liver, and kidneys. However, authorities remain cautious: the causal link between the virus and all clinical symptoms has not yet been fully established, the pathogenic mechanism remains unclear, and the possibility that other infections or environmental exposures may have played a contributing role cannot be ruled out. In other words, the suspect is on the scene, but the evidence of guilt is missing the final piece.
A Hidden Concern: Existing Vaccines May Be Completely Ineffective
What truly sends a chill down pig farmers’ spines is the virus’s lineage. Genetic comparisons show that it is most closely related to the parvovirus strain found in fox feces samples from the Netherlands in 2012, though it has accumulated several additional mutations. It is genetically very distant from Porcine Parvovirus Type 1 (PPV1)—a virus all too familiar to pig farms—which primarily causes reproductive disorders in sows and has been effectively controlled by established vaccines for years. However, precisely because of this genetic distance, the industry widely believes that herds vaccinated against PPV1 are highly unlikely to be protected against this new variant. A defense line that has been in place for years may prove to be virtually useless against it.
Currently, Royal GD is collaborating with the Dutch Ministry of Agriculture, Nature and Food Quality (LVVN) and the Dutch Pig Producers’ Association (POV) to continue the investigation. The focus is on establishing a definitive causal relationship, mapping the transmission routes, and determining whether co-infections or environmental factors are contributing to the outbreak.
A reminder to the industry: While this incident cannot yet be classified as a “confirmed outbreak of a highly contagious disease,” it serves as a more subtle warning—atypical abnormalities characterized by low mortality rates and merely cosmetic changes may, in fact, be the first sign that a new pathogen has quietly infiltrated the production system. When you observe piglets with protruding eyes, reddened skin, hair loss, or wrinkled skin, do not be quick to attribute these symptoms to management or nutritional issues. Instead, keep detailed records and promptly submit samples for testing if cluster cases emerge. This is the correct approach to ensure sufficient samples and time are available for further assessment.
Disclaimer: Some of the content in this article is sourced from the internet. The sources have been clearly indicated, and all copyrights belong to the original authors. The content is provided for readers’ reference only. If you believe your rights have been infringed, please contact us promptly via the comments section so we may remove the content.