Horse Health Glossary

Not sure what that veterinary word means? Look it up below!

Reprinted with permission from the University of California, Davis, The Book of Horses edited by Mordecai Siegal.

RABIES:
Inevitably fatal viral disease, primarily of bats and carnivores, characterized by neurologic dysfunction; caused by a rhabdovirus.
RADIOGRAPH:
An X ray film.
RADIOGRAPHY:
The use of X rays or gamma rays to view the internal structures of the body.
RADIOISOTOPES:
Radioactive elements.
RADIOTHERAPY:
Radiation therapy.
RAIN-SCALD:
Common term for dermatophilosis.
RECESSIVE GENE:
A gene that can be expressed only when both members of a chromosome pair contain the same allele for a given characteristic (i.e., the same allele must be inherited from both the dam and the sire).
RECOMBINATION:
Genetic exchange among chromosomes, producing new combinations of genes.
RECTAL-VAGINAL FISTULA:
A tear from the top of the vestibule (entrance to the vagina) to the floor of the rectum.
RECTUM:
Lowermost portion of the large intestine, immediately adjacent to the anus.
RECUMBENCY:
Inability to stand.
RECUMBENT:
Lying down.
RECURRENT UVEITIS:
Periodic ophthalmia.
REDIA:
Larval stage of flukes arising from the sporocyst stage.
REDUCTION:
The setting of a bone fracture.
REFLEX:
In general, muscle movement orchestrated by the nervous system in response to a stimulus and without conscious (voluntary) control; an example is the knee-jerk reflex.
REFLUX:
Backward flow.
REFRACTIVE:
Light-bending.
REFRACTOMETER:
Small hand-held device that can be used for determining how concentrated or dilute a urine sample is (a measurement referred to as urine specific gravity).
REGURGITATION:
Involuntary return of undigested food to the mouth after swallowing; differs from vomiting in that it is a passive process (i.e., unaccompanied by the reflex, propulsive movements characteristic of vomiting).
RENAL:
Pertaining to the kidneys.
RENAL PELVIS:
"Collecting funnel" deep within each kidney into which the kidney tubules drain filtrate.
RESERVOIR HOST:
An animal from which infection may be passed to domesticated stock or to human beings.
RESORPTION:
Biochemical dissolution or loss of tissue.
RESPIRATION:
Breathing.
RETCHING:
Abdominal contractions in preparation for vomiting.
RETICULATED LEUKOTRICHIA:
A form of leukotrichia seen primarily in Quarter Horses.
RETINA:
The light-sensitive layer of cells at the back of the eye.
RETINITIS:
Inflammation of the retina.
RETROGRADE:
Backward.
RHABDOMYOMA:
A benign tumor of striated muscle cells.
RHABDOMYOSARCOMA:
A malignant tumor of striated muscle cells.
RHINITIS:
Inflammation of the nasal passages.
RHINOPNEUMONITIS:
Respiratory condition of horses caused by equine herpesvirus.
RHINOSCOPY:
Visual examination of the nasal passages, using an endoscope, otoscope, or other instrument.
RHINOSPORIDIOSIS:
An uncommon disease caused by an as yet poorly characterized fungus, Rhinosporidium seeberi; it is a chronic localized infection characterized by the formation of polyps (fleshy masses protruding from the surface of a mucous membrane) in the nasal passages.
RHYTHMIC SEGMENTATION:
Rhythmic muscular movements of the intestinal tract that serve to delay the passage of intestinal contents until digestion and absorption have been completed.
RIBONUCLEIC ACID (RNA):
A nucleic acid occurring in all cells and involved in cell division, gene expression, and protein synthesis; also serves as the genetic material for some viruses.
RICKETTSIAE (SINGULAR: RICKETTSIA):
Specialized bacteria that multiply only within host cells and that are usually transmitted to animals or human beings by lice, ticks, fleas, or mites; examples include Ehrlichia risticii, the cause of Potomac horse fever (equine monocytic ehrlichiosis), and Ehrlichia equi, the cause of equine granulocytic ehrlichiosis.
RINGBONE:
Disorder characterized by new bone growth adjacent to either the pastern or coffin joints; caused by tearing of the collateral ligaments stabilizing the joint. High ringbone describes bone growth around the pastern joint, while low ringbone describes bone growth around the coffin joint.
RINGWORM:
A common skin infection caused by ringworm fungi (dermatophytes), which invade the outer, superficial layers of the skin, hair, and nails; also called dermatophytosis.
RNA:
See ribonucleic acid.
ROARING:
Common name for laryngeal hemiplegia.
RODS:
Photoreceptor cells in the retina of the eye that are responsible for night vision and detection of motion.
ROOT:
The portion of a tooth that lies below the gumline.
ROOT CANAL:
The chamber within each tooth that contains nerves, blood vessels, and lymphatic channels; also known as the pulp chamber.

Free Newsletters

Sign up for the latest in:

From our partners