Albumin serves as a carrier for endogenous and exogenous compounds, serves as a buffer molecule during acid-base derangements, is the primary protein responsible for maintenance of colloid oncotic pressure, and also acts as a scavenger of reactive oxygen species. Hypoalbuminemia can be the result of numerous conditions, such as protein losing nephropathy, protein losing enteropathy, intra-cavitary effusions, liver failure, or severe hemorrhage. Hypoalbuminemia in critical illness can lead to fluid retention, deranged drug metabolism, poor healing, and increased morbidity and mortality. The use of albumin replacement for the treatment of hypotension, hypoalbuminemia, and decreased oncotic pressure is well documented in human (Dubois 2006, Dellinger 2013) and veterinary medicine. Prior to the availability of canine serum albumin, albumin replacement required transfusion of plasma or the use of human serum albumin.
Although effective, both options carry potential risk. Use of frozen plasma to correct hypoalbuminemia requires a dose 22.5ml/kg for an expected increase by 0.5mg/dL in albumin. This volume may be of concern in small patients or in patients at risk for fluid overload. Human serum albumin requires a much smaller volume to replenish patient albumin level. Because the product is not from a canine source, however, it is highly antigenic and complications including glomerulonephritis, polyarthropathy, and acute or delayed allergic reactions may occur.
Canine albumin is considered a safer alternative to both plasma and human serum albumin. The product contains 98% albumin with no components of plasma or preservatives. It may be less likely than plasma to induce allergic reactions and acute lung injury. A prospective veterinary study evaluating the use of canine serum albumin in cases of septic peritonitis (Craft 2012). Of the seven patients randomized to receive canine albumin, only one patient displayed potential adverse effects.
Canine albumin is most commonly administered to hypoalbuminemic patients with the goal of raising the serum albumin to 2 g/dL. A 5% solution of canine albumin is administered based on the following calculation:
Canine albumin can also be administered to hypotensive canine patients for the purpose of volume expansion and maintenance of intravascular volume. Fluid overload is a concern when using the concentrated solution.