Hyperimmune Plasma for Dogs with Parvoviral Enteritis

In the literature

Acciacca RA, Sullivan LA, Webb TL, Johnson V, Dow SW. Clinical evaluation of hyperimmune plasma for treatment of dogs with naturally occurring parvoviral enteritis. J Vet Emerg Crit Care. 2020;30(5):525-533.

The Research …

Passive immunization (PI) involves taking antibodies from a surviving patient that has developed humoral immunity against that pathogen and then administering those antibodies to another patient to prevent or treat disease.¹ PI was first used to treat diphtheria in the late 1800s² and continues to be used in modern medicine, most recently for coronavirus (COVID 19)-associated disease.³ The goal is to give the recipient sufficient antibodies to fight the disease before the recipient’s body can make its own antibodies; subsequently, the PI product must be given early in the disease process to be effective. If administered later, the recipient will already have a higher titer than might be achieved with a PI-product transfusion. PI has been evaluated in canine parvovirus (CPV) with mixed results.^4-7 

This study* evaluated the effects of a commercially available CPV hyperimmune plasma (HIP) product in dogs hospitalized for management of CPV infection.⁴ Thirty-one dogs were included—16 in the HIP group and 15 in the control group. Both groups received the same supportive care and feeding regimen. Within 6 hours of hospitalization, the treatment group received HIP (10 mL/kg IV), and the control group received saline (10 mL/kg IV).

The HIP group had a lower shock index and plasma lactate concentration than did the placebo group 24 hours after admission. There was no difference in clinical severity of illness between the groups at any time point, nor any difference in time to resolution of vomiting or return of voluntary appetite. No difference in survival or length of hospitalization was found, but the study was underpowered to detect a difference in these outcomes.

Recommendation for or against HIP use based on this study is difficult. Differences in shock index and plasma lactate concentration between groups were small; there was considerable overlap in range values between groups, and confidence intervals were not reported. Other markers of clinical improvement did not differ between groups, making it difficult to discern the clinical implications of a slightly higher lactate or shock index. Also, because the control group was administered saline instead of low-titer plasma, the effects may not have been secondary to administration of a plasma product and not due to HIP specifically. Further study is needed to make a definitive statement.

… The Takeaways

Key pearls to put into practice:

• High-quality supportive care for clinical signs remains the mainstay of CPV management.

• Early enteral nutrition is the most commonly cited therapy shown to reduce recovery time and decrease disease morbidity.⁴

• If used, PI as part of therapy should be initiated early in the course of disease and should not replace high-quality supportive care and early enteral nutrition.

* This study was funded by Plasvacc USA.