GLOSSARY

Words followed by this symbol are defined here

allele---

one of the alternative forms of any gene on a chromosome. Each allele represents a different variation of a physical trait and each has one corresponding allele on the chromosome’s paired counterpart. For example, one blue-eye allele will have one corresponding allele that carries either a blue, green or brown-eye trait.

anemia---

shortage of red blood cells, commonly caused by excessive bleeding, infection, dietary deficiency or presence of toxins in the body.

body condition score

(BCS)---a designation, based on a nine-point numeric scale, indicating the amount of fat on a horse’s body. A BCS is assigned after a visual and hands-on appraisal.

chromosome---

the self-replicating genetic structure of cells containing the cellular DNA that bears in its nucleotide sequence the linear array of genes. Each species has a constant number of chromosomes set in pairs in the nucleus of each body cell; the horse has 64, or 32 pairs.

dominant---

pertaining to a gene that guarantees the appearance of its trait in the offspring, regardless of the nature of the gene with which it is paired.

equine metabolic syndrome---

endocrine disorder characterized by increased fat deposits in specific locations of the body or overall obesity; insulin resistance, which leads to abnor- mally high levels of the hormone circulating in the bloodstream; and a predisposition toward laminitis in the absence of other recognized causes.

equine protozoal myeloencephalitis

(EPM) ---inflammation of the brain and spinal cord caused by protozoal infection.

insulin resistance---

metabolic disorder, similar to type-2 diabetes, that occurs when certain cells in the body become less sensitive to the action of insulin, and normal amounts of the hormone can no longer keep adequate amounts of glucose moving into the cells for use as fuel.

laminitis---

inflammation of the sensitive plates of soft tissue (laminae) within the horse’s foot caused by physical or physiologic injury. Severe cases of laminitis may result in founder, an internal deformity of the foot.

Acute laminitis sets in rapidly and usually responds to appropriate, intensive treatment, while chronic laminitis is a persistent, longterm condition that may be unresponsive to treatment.

Lyme disease---

potentially debilitating and even fatal bacterial infection spread by deer ticks (Ixodes dammini), affecting people and domestic animals, including horses. Signs of infection in horses include lethargy, fever, swollen joints, shifting leg lameness, laminitis, ocular inflammation and hypersensitivity of the skin and underlying muscle.

pituitary pars intermedia dysfunction

(PPID, Cushing’s disease)---disease caused when the cortex of the adrenal gland produces excessive amounts of hormones, including cortisol; signs include persistent long hair, thin skin, fragile bones, stupor, weakness and sweating.

proud flesh---

excess granulation tissue rising out of and above the edges of a wound, forming a raw, exposed mound that makes further healing delayed or impossible without medication or surgery.

recessive trait---

genetic trait that appears only when both of its corresponding alleles are identical and in the absence of its dominant counterpart allele. For example, the recessive trait of blue eyes will appear in persons only if both parents pass on blue-eye genes. Otherwise, a dominant brown-eye gene will subordinate the blue-eye and the offspring will be brown-eyed.

seborrhea---

skin condition resulting from malfunction of the oil-forming (sebaceous) glands; can be characterized by dry, waxy or excessively oily accumulations on the skin.

white cells

(leukocytes, white blood cells)--colorless blood cells active in the body’s defense against infection or other assault. There are five types: neutrophils, lymphocytes, eosinophils, monocytes and basophils.

white line---

zone on the bottom of the horse’s hoof where the insensitive laminae and the interlaminar horn attach the wall to the margin of the sole.

white line disease---

bacterial and/or fungal infection of the stratum medium, the middle layer of the hoof wall; characterized by a widened, depressed area with a powdery texture along the white line, where the hoof wall meets the sole.