Vitamin E and Selenium Levels are Within Normal Range in Pigs Diagnosed with Mulberry Heart Disease and Evidence for Viral Involvement in the Syndrome is Lacking

Abstract

Mulberry heart disease (MHD) in pigs is characterized by lesions of acute haemorrhagic myocarditis and myocardial necrosis. The objectives of this study were to determine the levels of vitamin E and selenium and 13 other trace minerals in heart and liver tissues and to determine the prevalence of certain viral infections in heart tissues from MHD-affected and MHD-unaffected pigs and the vitamin E and selenium concentration in feed samples from selected farms with MHD. Based on the pathological examination, 114 pigs were separated into MHD lesion-negative (L-NEG) (n = 57) and MHD lesion-positive (L-POS) (n = 57) groups. Seventy-three samples (40 L-NEG and 33 L-POS) were subjected to chemical analysis, and 66 (32 L-NEG and 34 L-POS) were subjected to PCR detection for viral pathogens. Lower (P < 0.05) levels of myocardial copper, lower (P < 0.05) levels of hepatic magnesium and higher (P < 0.05) levels of myocardial and hepatic sodium were detected in the L-POS cases. Although lower (P < 0.05) levels of hepatic selenium were detected in L-POS group, all were within the normal range. Analysis of feed samples (n = 22) revealed that selenium levels in all the samples were above the legal limit (0.3 ppm) for pigs. Vitamin E levels in all feed samples were above 20 IU/kg. Among the 66 pigs subjected to PCR detection, there were 19, 4, 13, 8, 2 and 1 animals positive for porcine circovirus type 2, porcine reproductive and respiratory syndrome virus, pan-herpes virus, porcine enterovirus, pan-pestivirus and porcine parvovirus, respectively. Clear evidence of viral association with L-POS was lacking.

Outbreaks of nutritional cardiomyopathy in pigs in Brazil

“…There are few reports of DCM in pigs compared to humans and dogs, in which DCM is the main type of cardiomyopathy diagnosed (Sisson et al 1999a, Lobo & Pereira 2002, O'Grady & O'Sullivan 2004, Elliott et al 2008, Shen et al 2011. Similary to the present study, the "round heart disease" in turkeys has an unknown etiology and pathogenesis (Stenzel et al 2008); additionally, mulberry heart disease, which is an important heart disease that affects nursery pigs and does not have a defined etiology.…”

“…Similary to the present study, the "round heart disease" in turkeys has an unknown etiology and pathogenesis (Stenzel et al 2008); additionally, mulberry heart disease, which is an important heart disease that affects nursery pigs and does not have a defined etiology. However macroscopic and microscopic lesions are different from these cases (Shen et al 2011).…”

Postweaning mortality in commercial swine production. I: review of non-infectious contributing factors

“…Mulberry heart disease and hepatosis dietetica have historically been associated with deficiencies of vitamin E and/or selenium ( Van Vleet et al, 1970 ; Sharp et al, 1972a , b ; Mahan et al, 1973; Moir and Masters, 1979 ; Rice and Kennedy, 1989 ). Recent investigations have shown the presence of the disorder in the absence of vitamin E/selenium deficiencies indicating a more complex pathogenesis ( Pallares et al, 2002 ; Shen et al, 2011 ). Interactions between heavy metals ( Van Vleet, 1976 , 1981 ) and other pro-oxidant substances including iron, oxygen, ozone, and various drugs ( Van Vleet and Ferrans, 1992 ) potentially contribute to loss of biological antioxidant capacity.…”

Prevalence and phylogenetic analysis of the current porcine circovirus 2 genotypes after implementation of widespread vaccination programmes in the USA

“…Real-time PCR for PCV1, chimeric PCV1-2a and PPV. PCV1 (Shen et al, 2011), PCV1-2a (Shen et al, 2010b) and PPV (Shen et al, 2010b) real-time PCR assays were performed as described previously. PCV1 real-time PCR was performed in a non-quantitative manner with a correlation coefficient of more than 0.90 in serial dilutions of PCV1 viral genomic DNA; there were no cross-reactions with PCV2a, PCV2b and PCV1-2a.…”