Vet Terminology starting with V on – from Vaccination to Vomeronasal Organ


The act of giving a vaccine. See also ‘immunization,’ since the two words have different meanings and are often confused.

Vaccine failure
A term often used to describe a condition in which an animal who was vaccinated against a disease still gets the disease. In truth, there is usually nothing wrong with the vaccine, but for some reason, the animal’s immune system did not adequately react to it.

Inflammation of blood vessels.

A decrease in the diameter of blood vessels.

Agent which dilates, or increases the diameter of blood vessels.

Vena cava
Either of two large veins carrying blood to the right atrium of the heart. The cranial vena cava brings blood from the head region, front legs, and upper chest to the heart; the caudal (or posterior) vena cava carries blood from the areas of the abdomen and hind legs to the heart.

The outside opening of the cloaca, which is a common passageway for feces, urine, and reproduction.

The chambers of the heart that pump the blood to the body or lungs.

Ventricular arrhythmia
A heart condition in which the heart beats irregularly and/or at an abnormal rate because of signals coming from the ventricles (chambers of the heart that pump the blood).

Animal with a vertebral column (spine); includes such animals as fish, birds, turtles, reptiles, amphibians, and mammals.

Small elevated area on the skin filled with a clear fluid.

Vestibular system
Portions of the inner ear, nerves, and brain which help the body maintain balance.

Microscopic projections which cover the intestine, greatly increasing the surface area and therefore, increasing the ability to absorb nutrients. Singular: Villus.

The smallest form of life, invisible with an ordinary microscope. An infectious unit that enters and uses cells of plants or animals for replication. Some viruses cause disease in animals or plants.

Pertaining to the internal organs and skin.

Thickness of a fluid, e.g., molasses is more viscous than water.

Vital signs
The signs of life which are pulse, respiration, and temperature.

Twisting of the stomach or intestine, which often has the effect of cutting off the blood supply to it.

Vomeronasal organ
Sensory organ also called ‘Jacobson’s organ,’ which detects pheromones.