Hooo-Hooo Volume 11 Nr 3 - Page 12

WildLife Group 4. of the SAVA Manganese Musculoskeletal degeneration and skeletal abnormalities are associated with manganese deficiency, particularly in neonatal animals. A deficiency of manganese causes decreased production and increased degradation of cartilage in neonates resulting in skeletal deformities including congenital joint laxity, dwarfism (in-utero growth retardation), congenital spinal defects and congenital chondrodystrophy. Adult animals usually do not show any external signs of manganese deficiency, but neonates born to dams fed manganese deficient rations during pregnancy, may show various degrees of skeletal deformity. 5. Iron Iron excesses are far more prevalent than iron deficiencies. Excess dietary iron can induce iron overload disorders as well as interfering with copper absorption. Pathology is characterized by accumulation of iron pigments predominantly in the liver associated with hepatic degeneration and necrosis. Bone analysis Bone tissue is the tissue of choice for analysis of calcium, phosphorus, magnesium and fluoride levels at post-mortem. Buffered formalin contains phosphate buffered saline and so interferes with the phosphorus levels recorded on bone tissue preserved in 10% buffered formalin. 10% formalin prepared with de-ionized water is suitable for bone fixation for mineral analysis, but is impractical in the field for wildlife veterinarians. Therefore, collection of fresh bone material (rib bone), which is transported on ice is the more practical option. Fixation in de- ionized water formalin can then be performed at the laboratory on reception of the samples. Bone ash analysis for calcium, phosphate and magnesium is most commonly employed to 12 investigate metabollic bone disease, while bone fluoride analysis is more commonly utilized to investigate potential fluorosis or fluoride deficiency. Metabolic bone diseases are characterised by failure of production, mineralization or maintenance of bone matrix. The classic osteodystrophies include osteopaenia/osteoporosis, osteomalacia, rickets and fibrous osteodystrophy. These conditions denote a continuum of processes that occur due to dietary Ca/P imbalances, hypovitaminosis D, other trace mineral deficiencies (copper, manganese, fluoride) glucocorticoid therapy or physical inactivity. When investigating metabolic bone disease in young animals it is always important to collect sections of long bones, which include the growth plate, into 10% buffered formalin for histological examination. These various metabolic imbalances produce characteristic changes in the ossification process at the growth plate which facilitates the diagnosis. Further Reading 1. Keneko et al - Clinical Biochemistry of Do- mestic Animals 6th edn 2008. 2. Kincaid – Assesment of trace mineral status of ru- minants: A review. Proceedings of the Ameri- can Society of Animal Science. 1999; 1-8. 3. Last et al – VDX Laboratory Manual 2nd edn 2010. Vetlink Publications, Pretoria. 4. Maxie – Pathology of Domestic Animals 6th edn 2016. Saunders-Elsevier, Edinburugh. 5. Njaa – Diagnosis of Abortion and Neonatal Loss 4th edn 2012; Wiley-Blackwell, Chichester, United Kingdom. 6. Orr et al – Investigation of the selenium status of aborted calves with cardiac failure and myocardial necrosis. Journal of Veterinary Diagnostic Investigation 1997; 9:172-179. 7. Plumblee – Clinical Veterinary Toxicol- ogy 2004; Mosby, St Louis, USA. 8. Smith – The effect of preserving liver tissue on the concen- tration of trace minerals in the liver. Masters Dissertation. University of Pretoria. 9. Van Saun et al - Maternal and fetal selenium concentrations and their interrelation- ships in dairy cattle. Journal of Nutrition 1989; 119:1128. 10. Waldner & Blakley - Evaluating micronutrient concentra- tions in liver samples from abortions, stillbirths, and neonatal and postnatal losses in beef calves. Journal of Veterinary Diagnostic Investigation 2014 26: 376-389.