parvo-, parvi- +

(Latin: [parvus] small, little; minute, minuscule)

Little things contribute to perfection, and perfection is not a little thing.
—John Rayoa
parvoviral
Caused by or relating to a parvovirus.
parvovirus
1. Any of a group of very small animal viruses consisting of some single-stranded DNA in an icosahedral capsid without an envelope and occurring in a wide variety of vertebrates, often as a pathogen.
2. In veterinary medicine, an often fatal disease of dogs caused by a parvovirus, characterized by diarrhea and vomiting.
3. Parvoviruses; a genus of viruses of the subfamily Parvovirinae (family Parvoviridae) that infect mammals and birds. Viruses multiply in the nucleus and require S-phase cellular functions for replication.

Bovine parvovirus, a virus of the genus Parvovirus infecting cattle that causes diarrhea in calves; infection during the first or second trimesters of gestation may result in abortion. Infection is widespread and antibody to the virus can be found in a high proportion of adult cattle.

Canine parvovirus, a virus of the genus Parvovirus that causes myocarditis in dogs and a type of enteritis called canine parvovirus disease; it is sometimes considered to be a species-specific variant of feline parvovirus.

Feline parvovirus, a virus of the genus Parvovirus that primarily affects cats. Canine parvovirus, feline panleukopenia virus, and mink enteritis virus are sometimes considered to be host-specific variant strains.

Goose parvovirus, a virus of the genus Parvovirus that causes a highly fatal disease of young geese affecting the liver, thyroid, and pancreas.

Porcine parvovirus, A worldwide virus of pigs that has been associated with infertility and abortion.

Transmission is transplacental or by mechanical vector. Human parvoviruses cause transient aplastic crisis, acute arthritis, erythema infectiosum, hydrops fetalis, spontaneous abortion, and fetal death.

Animal pathogens include such animals as: bovine, canine, feline, and goose parvoviruses, feline panleukopenia virus, mink enteritis virus, Aleutian mink disease virus, and various murine parvoviruses.

parvule
In pharmacology, a very small pill, pellet, or granule.
parvum (small) opus (work)
Small work as opposed to magnum (big, great) opus (work).