AUTOSOMAL RECESSIVE CHOLESTEROL DEFICIENCY IN A HOLSTEIN CALF

Introduction Cholesterol deficiency (CD), a newly identified autosomal recessive inherited genetic defect in Holstein cattle, has been reported to have unresponsive diarrhea as a clinical sign, failure to thrive, hypocholesterolemia and the animals usually die within the first weeks or months of life (Kipp et al., 2016). CD is caused by a mutation of the APOB (Menzi et al., 2015). Methods The study was carried out on a 6-month Holstein calf with clinical history of intermittent diarrhea and erosions in the buccal cavity was admitted at the Clinic. This case report included a full clinical examination, a complete blood count and blood chemistry. Total blood cholesterol was also measured in the dam, sister 1 and sister 2. The calf was spontaneously died 33 days after the admission at the clinic and necropsied. A genetic test was performed using blood for sampling (calf, dam, sister 1, sister 2) and semen (sire) to determine the APOB genotype. Results The calf was confirmed homozygous for the APOB mutation. The sire and the dam resulted heterozygous carriers of the APOB mutation whereas the two sisters were free from the APOB mutation. The clinical phenotype included failure to thrive and intermittent diarrhea. The culture of buccal swab resulted positive to Candida albicans. Marked hypocholesterolemia was present in the affected the calf; in the dam it was slightly decreased. Gross pathology and histology did not show specific findings: the buccal lesions were accompanied by ulcerative erosions in the oesophagus. The intestine showed segmental enteritis and the meningeal vessels were hyperemic. Slight inflammation of the respiratory tract was also ev ident. Conclusions The findings that was possible to obtain during the investigation of the affected calf were quite similar to the recent reports on CD that can be found in the literature (Mock et al., 2016). The lesions at the level of the upper digestive tract, the lung and the central nervous system were considered of secondary origin. They might be a consequence of an increased susceptibility to secondary infecti ons resulting from vitamin deficiency. In the FHBL (Welty, 2014) the malabsorption of lipid-soluble vitamins (A, D, E, K), leading to retinal degeneration, neuropathy, and coagulopathy is a well-known pathogenetic element (Lee & Hegele, 2014). Moreover, in human patients with FHBL oesophagitis is described as one of the possible complications of the disease (Lee & Hegele, 2014). To our knowledge, the presence of esophagitis as not been reported in bovine CD.