Treating significant hypoalbuminemia (albumin < 2.0 mg/dL) in dogs requires careful consideration of each available albumin product.
Albumin performs many important functions in the body, including maintaining colloid oncotic pressure and scavenging free radicals. The bulk of total body albumin is distributed within the interstitial space. “Inarguably, [albumin] is one of the most important proteins in the body,” said Elisa M. Mazzaferro, MS, DVM, PhD, DACVECC, who spoke at the 2017 International Veterinary Emergency and Critical Care Symposium in Nashville, Tennessee.
Hypoalbuminemia can have serious consequences. When albumin concentration drops below 2.0 g/dL, intravascular hydrostatic pressure exceeds colloidal oncotic pressure, eventually causing edema. Edema’s consequences are numerous, including decreased tissue perfusion, tissue ischemia, and delayed wound healing. Hypoalbuminemia can also cause or exacerbate chronic illnesses.
Fresh-frozen plasma was the only veterinary treatment for hypoalbuminemia until about the mid-2000’s. However, plasma treatment is often inefficient and cost-prohibitive, given the amount of plasma needed to raise serum albumin levels: 20—30 mL/kg for a 0.5-g/dL increase in albumin concentration. Fresh-frozen plasma, Dr. Mazzaferro noted, can also be immunogenic.
Other albumin products—canine albumin, bovine serum albumin, and human albumin—are available. Canine albumin has been tested in healthy dogs and dogs with hypoalbuminemia and septic peritonitis. In healthy dogs, intravenous canine albumin administration caused no adverse effects (AEs). In the sick dogs, postsurgical canine albumin treatment markedly raised albumin levels without owner-reported AEs. Unfortunately, canine albumin is not readily available.
BSA is readily available yet reportedly has caused anti-albumin antibody development and hypersensitivity reactions in healthy dogs.
Given these safety and availability concerns with canine and bovine albumin, human albumin presents another treatment option for canine hypoalbuminemia. Importantly, canine and human albumin have about a 20% difference in their amino acid sequences, Dr. Mazzaferro noted, which could lead to anti-albumin antibody development and other AEs in dogs.
Studies of healthy and critically ill dogs have reported mixed safety and efficacy results with human albumin treatment. For example, in one study of healthy dogs, all dogs receiving human albumin developed anti-albumin antibodies and several developed hives or angioneurotic edema; AEs responded well to treatment. In contrast, critically ill dogs treated with human antibody had few AEs and experienced marked increases in serum albumin concentration.
Performing Albumin Infusions
Albumin infusions have many indications, including:
Albumin infusions are less beneficial and could potentially worsen quality of life in chronic end-stage diseases like liver failure. Recommendations for albumin infusions include:
Albumin concentration should be maintained at 2.0 g/dL. If polyarthritis develops following albumin infusion, Dr. Mazzaferro recommended treatment with doxycycline and prednisone.
Treating veterinary patients with albumin can increase serum albumin concentrations and improve wound healing, among other benefits. However, given the low but real threat of immunogenic reactions, Dr. Mazzaferro stated that “the benefits must outweigh the potential risks of [albumin’s] use as we strive to improve outcome…in our most critically ill patients.”
Dr. Pendergrass received her Doctor of Veterinary Medicine degree from the Virginia-Maryland College of Veterinary Medicine. Following veterinary school, she completed a postdoctoral fellowship at Emory University’s Yerkes National Primate Research Center. Dr. Pendergrass is the founder and owner of JPen Communications, a medical communications company.