Background Multiple diagnostic procedures, their results and interpretation in a case with severe lameness in fattening pigs are described. It is shown that selected diagnostic steps lead to identification of various risk factors for disease development in the affected herd. One focus of this case report is the prioritization of diagnostic steps to verify the impact of the different conditions, which finally led to the clinical disorder. Assessing a sufficient dietary phosphorus (P) supply and its impact on disease development proved most difficult. The diagnostic approach based on estimated calculation of phosphorus intake is presented in detail. Case presentation On a farrow-to-finishing farm, lameness occurred in pigs with 30–70 kg body weight. Necropsy of three diseased pigs revealed claw lesions and alterations at the knee and elbow joints. Histologic findings were characteristic of osteochondrosis. All pigs were positively tested for Mycoplasma hyosynoviae in affected joints. P values in blood did not indicate a P deficiency, while bone ashing in one of three animals resulted in a level indicating an insufficient mineral supply. Analysis of diet composition revealed a low phosphorus content in two diets, which might have led to a marginal P supply in individuals with high average daily gains with respect to development of bone mass and connective tissue prior to presentation of affected animals. Finally, the impact of dietary factors for disease development could not be evidenced in all submitted animals in this case. Conclusions Mycoplasma (M.) hyosynoviae was identified to be an important etiologic factor for disease. Other, non-infectious factors, such as osteochondrosis and claw lesions might have favored development of lameness. In addition, a relevant marginal P supply for pigs was found in a limited time period in a phase of intense growing, but the potential interaction with infection by M. hyosynoviae is unknown. The presented case of severe lameness in fattening pigs revealed that three different influences presumably act in pathogenesis. Focusing only on one factor and ignoring others might be misleading regarding subsequent decision-making for prevention and therapy. Finally, clinical symptoms disappeared after some changes in diet composition and anti-inflammatory treatment of individual animals.

BackgroundMultiple diagnostic procedures, their results and interpretation in a case with severe lameness in fattening pigs are described. It is shown that selected diagnostic steps lead to identification of various risk factors for disease development in the affected herd. One focus of this case report is the prioritization of diagnostic steps to verify the impact of the different conditions, which finally led to the clinical disorder. Assessing a sufficient dietary phosphorus (P) supply and its impact on disease development proved most difficult. The diagnostic approach based on estimated calculation of phosphorus intake is presented in detail.Case presentationOn a farrow-to-finishing farm, lameness occurred in pigs with 30-70 kg body weight. Necropsy of three diseased pigs revealed claw lesions and alterations at the knee and elbow joints. Histologic findings were characteristic of osteochondrosis. All pigs were positively tested for Mycoplasma hyosynoviae in affected joints. P values in blood did not indicate a P deficiency, while bone ashing in one of three animals resulted in a level indicating an insufficient mineral supply. Analysis of diet composition revealed a low phosphorus content in two diets, which might have led to a marginal P supply in individuals with high average daily gains with respect to development of bone mass and connective tissue prior to presentation of affected animals. Finally, the impact of dietary factors for disease development could not be evidenced in all submitted animals in this case.ConclusionsMycoplasma (M.) hyosynoviae was identified to be an important etiologic factor for disease. Other, non-infectious factors, such as osteochondrosis and claw lesions might have favored development of lameness. In addition, a relevant marginal P supply for pigs was found in a limited time period in a phase of intense growing, but the potential interaction with infection by M. hyosynoviae is unknown. The presented case of severe lameness in fattening pigs revealed that three different influences presumably act in pathogenesis. Focusing only on one factor and ignoring others might be misleading regarding subsequent decision-making for prevention and therapy. Finally, clinical symptoms disappeared after some changes in diet composition and anti-inflammatory treatment of individual animals.

ZusammenfassungIm Dezember 2017 kam es in einem Bullenmastbetrieb mit Fresseraufzucht in Westdeutschland innerhalb eines Tages plötzlich zu einem Rückgang der Futteraufnahme bei ansonsten zunächst ungestörtem Allgemeinbefinden der Tiere. Die reduzierte Futteraufnahme war am darauffolgenden Tag noch ausgeprägter; zudem zeigten einige Tiere eine Pansentympanie mit dorsaler Gasblase, die eine Behandlung erforderte. Als mögliche Ursache kam die Maissilage infrage, die seit dem Tag der reduzierten Futteraufnahme aus einem anderen Silobereich entnommen wurde als zuvor. Diese Maissilage-Partie stammte von einer Ackerfläche, auf der in einem gewässernahen Teilbereich übliche Pflanzenschutzmaßnahmen nicht erfolgt waren und die zudem stark von Windschäden betroffen war (viele abgeknickte Maispflanzen). Nur auf diesem Areal wuchs Gewöhnlicher Stechapfel, dessen Früchte und Samen in den inkriminierten Maissilageproben nachgewiesen wurden. Nach einem Austausch der Maissilage gegen nicht kontaminiertes Material und einer Behandlung der von einer Tympanie betroffenen Tiere mit einem Antitympanikum sowie einem Lebendhefe-Präparat erholten sich die Bullen innerhalb von 6 Tagen. Ursächlich für diese auffällige Symptomatik waren vermutlich die antinutritiven Inhaltsstoffe von Datura stramonium, die nachgewiesenermaßen die Magen-Darm-Motorik beeinträchtigen können.

Background: Multiple diagnostic procedures, their results and interpretation in a case with severe lameness in fattening pigs are described. It is shown that selected diagnostic steps lead to identification of various risk factors for disease development in the affected herd. One focus of this case report is the prioritization of diagnostic steps to verify the impact of the different conditions, which finally led to the clinical disorder. Disease is the consequence of previously acting factors, and the involved diagnostic institute is the last stage in the timeline. Some diagnostic findings might therefore no longer be significant. Assessing a sufficient dietary phosphorus (P) supply and its impact on disease development proved most difficult. The diagnostic approach based on estimated calculation of phosphorus intake is presented in detail.Case presentation: On a farrow-to-finishing farm, lameness occurred in pigs with 30-70 kg body weight. Necropsy of three diseased pigs revealed claw lesions and alterations at the knee and elbow joints. Histologic findings were characteristic of osteochondrosis. All pigs were positively tested for Mycoplasma hyosynoviae in affected joints. P values in blood did not indicate a P deficiency, while bone ashing in one of three animals resulted in a level indicating an insufficient mineral supply. Analysis of diet composition revealed a low phosphorus content in two diets, which might have led to a marginal P supply in individuals with high average daily gains with respect to development of bone mass and connective tissue prior to presentation of affected animals. Finally, the impact of dietary factors for disease development could not be evidenced in all submitted animals in this case.Conclusions: Mycoplasma (M.) hyosynoviae was identified to be an important etiologic factor for disease. Other, non-infectious factors, such as osteochondrosis and claw lesions might have favored development of lameness. In addition, a relevant marginal P supply for pigs was found in a limited time period in a phase of intense growing, but the potential interaction with infection by M. hyosynoviae is unknown. The presented case of severe lameness in fattening pigs revealed that three different influences presumably act in pathogenesis. Focusing only on one factor and ignoring others might be misleading regarding subsequent decision-making for prevention and therapy. Finally, clinical symptoms disappeared after some changes in diet composition and anti-inflammatory treatment of individual animals.

BackgroundVarious diagnostic procedures, their results and interpretation in a case with severe lameness in fattening pigs are described. It is shown, that selected diagnostic steps lead to identification of the key factors for disease development in the respective herd. One focus is the assessment of the impact of reduced dietary phosphorus level on disease development.Case presentationIn a farrow-to-finishing farm lameness occurred in pigs with 40-70 kg body weight. Necropsy of three diseased pigs revealed claw lesions and alterations at the knee and elbow joints. Histological findings were characteristic for osteochondropathia. All pigs were positively tested for Mycoplasma hyosynoviae in affected joints. In addition, analysis of diet composition revealed a low phosphorus content in two diets, which might had led to insufficient supply in individuals with high average daily gains with respect to development of bone mass and connective tissue. The impact of dietary factors for disease development could not be verified in the selected animals by blood analysis and bone ashings in this case. Finally, change in feed and antibiotic treatment of individual animals led to improvement of clinical symptoms.ConclusionsMycoplasma hyosynoviae was identified to be an important aetiological factor for disease. Other, non-infectious factors, as osteochondrosis and claw lesions might have triggered development of disease. A calculated marginal phosphor supply for pigs with high growth rates in a limited time period might further had weakened cartilage and connective tissue, and facilitated adherence of infectious agents in joints. Diagnostic of insufficient phosphorus supply by blood analysis and bone ashing might be not successful, when it occurs temporarily in time periods prior to sampling.