Electrolytes and macrominerals are important for maintaining several physiological functions. In veterinary medicine, an imbalance of these components could disrupt bodily mechanisms like blood circulation, muscle contraction, metabolism, endocrine function and more.
The Texas A&M Veterinary Medical Diagnostic Laboratory, TVMDL, provides comprehensive diagnostic services to help veterinarians develop effective treatment plans combating issues like analyte imbalances.
Maintaining physiological stability
The proper balance of electrolytes (e.g., sodium, potassium and chloride) and macrominerals (e.g., calcium, phosphorus and magnesium) is essential for smooth functioning of biological systems within an animal.
“It’s really not uncommon for electrolytes and micromineral levels to fall outside their reference interval” said Megan Cramer, a laboratory coordinator in the clinical pathology section. “It could be a result of many things, including dietary imbalances, dehydration, kidney dysfunction and endocrine disorders such as Addison’s disease.”
Consequences of imbalances can vary, and they depend on which minerals are affected. Common indicators of improper electrolyte or micromineral levels include muscle weakness, lethargy, irregular heart rhythms, dehydration and in severe cases, organ failure.
Testing for imbalances
TVMDL assesses electrolytes and macrominerals through various testing panels. Serum is the preferred sample type; however, plasma may be submitted as long as ethylenediaminetetraacetic acid, EDTA, is not added for transport. Lithium heparin plasma may also be submitted, if necessary. Additionally, urine can be submitted for fractional excretion studies.
Sample collection and handling
Maintaining the integrity of the sample is critical for accurate test results. For example, it’s important to avoid serum sitting on the clot for longer than an hour before and after being centrifuged as this may impact sample quality.
“It’s important to keep in mind how these samples are handled in clinic,” Cramer said.
“We understand the in-clinic situations being balanced while caring for patients. Having an awareness of situations that affect sample quality can be helpful in handling these samples in a way that ensures accurate patient results.”
Hemolysis is another consideration when sampling blood for electrolyte and micromineral testing. While the severity may differ between species, hemolysis of any magnitude generally results in increased levels of potassium, phosphorus and magnesium, as the analytes are released from lysed red blood cells.
“Anticoagulant type is very important when submitting plasma,” Cramer said. “If using EDTA plasma, we will see falsely decreased calcium and magnesium levels and falsely increased potassium values.”
Storage and stability time of samples are also important. Generally, once the serum is removed from the clot, clients should ship the sample on a cold pack to keep it cool for next-day delivery.
TVMDL advises against shipping samples on Fridays, as they will sit over the weekend before being processed on Monday. In scenarios like these when next-day delivery cannot be achieved, it is best to separate serum from blood cells and freeze the sample until it can be shipped in a single day.
Interpreting results
Interpretation of the results for electrolyte and macrominerals depends heavily on the clinical signs of each patient.
For example, a horse experiencing muscle spasms and low magnesium levels could likely be suffering from a magnesium deficiency. However, it is important to consider other factors such as diet, stress, genetics and the presence of other illnesses.
Electrolyte and mineral imbalances can often be redeemed with dietary adjustments, IV fluids or oral supplements, but veterinarians should tailor the treatment based on the specific imbalance and the patient’s overall health status.
Most importantly, veterinarians should encourage the provision of balanced nutrition, clean water and routine checkups and lab tests to catch potential health issues early on and prevent damaging animal health outcomes.
For more information about testing at TVMDL, visit https://tvmdl.tamu.edu or call the College Station lab at 888-646-5623.
