**5.12 Herbals**

An interest in natural products including herbs, plants and their extracts/metabolites as antiviral drug candidates has increased in the last few decades especially due to rising emergence of antimicrobial resistance globally and potential side-effects of many antimicrobials [123]. Very recently, anti-parvoviral activity of propolis, a traditional Chinese medicine, prepared from honeybee hives has been documented [124]. The *in vitro* study on PK-15 cells showed that ferulic acid (FA), an important component of propolis attenuates the replication of porcine parvovirus by blocking proapoptotic factors (Bid, Bcl-2 and Mcl-1), and inhibiting the mitochondria-mediated response by hindering the activation of the Bid-related signaling pathway. The FA may serve as potential antiviral against CPV [124].

### **5.13 Fecal microbiota transplantation**

Alteration in the gut microbiome is reported in enteric viral diseases including CPVE and other gastrointestinal diseases in dogs [125]. The disruption of gut microbiota leads to impediment in the enterocyte nutrition, immune regulation, protective barrier function, and gastrointestinal motility [126]. Therefore, restoration or re-establishment of the microbiota could have a good interest therapeutically. Recently, a randomized clinical trial showed that administration of fecal microbiota (10 g feces diluted in 10 mL of sterile 0.9% saline) obtained from healthy donor rectally at 6–12 hours post-admission caused faster resolution of diarrhea, shortened the duration of hospitalization and reduced the mortality in young dogs with CPVE when compared with standard therapy alone [126].
