macro - large

macrophages - infection fighting cells

maggot - insect and fly larva found in rotting matter

mahogany bay - slang for a rich mahogany bay coat color
 
maiden mare - a mare that has never been bred

mail order ad - advertising intended to make a sale without additional forms of advertising or promo

maintenance - when a horse is at rest

malaise - an overall general feeling of being sick or ill

malabsorption - excessive nutrient loss through fecal matter

malignancy - cancer

malignant - the opposite of benign and often used to describe cancers

malignant edema - type of disease caused by clostridia

malignant hyperthermia - genetic disorder triggered by anesthesia that affects temperature regulation

mammal - a warm-blooded animal that nurses its young

mandate - decree

mandible - lower jaw bone

mane - the long hairs on the top of the neck

manger - a feed box or trough made for horses

manure - livestock feces

mare - an adult female horse

mark - trademark

mark - behavior in which a stallion urinates or defecates on the urine or feces of another horse

marketable - in demand by the public and available for sale

marketing - various methods used to gain customers or clients

marketing plan - the planned marketing details of a business for a specific time period

mascara - black or dark eye lashes when the area surrounding the eye is white

mash - a soft feed mix sometimes fed to mares after foaling or elderly equines

mastatrophy - mammary gland atrophy

masticate - to chew

mastitis - udder inflammation

matures - synonym for the silent generation

maxilla - upper jaw bone

maxim - a statement regarding a general law principle

meals on wheels - slang for when livestock are fed directly from a vehicle

mealy - a muzzle that is lighter in color than the base coat

mechanical - transmission carried on the surface

meconium - waste matter typically expelled by a foal within hours of birth

media - various types of broadcasting, publishing and web institutions

mediation -  a means of settling civil disputes

meiosis - cell division in which gametes half the number of chromosomes are produced

mercy killing - to painlessly and mercifully put a horse to death

melena - blood in feces

member - a person or horse that is a part of a body or division of the Pintabian Horse Registry, Inc.

membrane - thin covering

mentor - a trusted advisor willing to spend time to guide another

metabolic disease - that which breaks down a body's processes

metabolism - changes and utilization of nutrients after absorption from the intestine

metastasis - the transfer from one organ to another

metastasize - to spread to other organs or tissues

methylsulfonylmethane - substance commonly prescribed for pain management 

MF - Brotherhood of Working Farriers Association initialism for 'Master Farrier Certification'

MF - Worshipful Company of Farriers initialism for 'Master Farrier'

MH - initialism for malignant hyperthermia

MIAEP - IAEP initialism for 'Member of the Institute of Applied Equine Podiatry'

micro - small

micro-flora - organisms that break down cellulose

micron - one millionth of a meter

microorganisms - small organisms invisible to the naked eye

midge - a type of small fly known to cause allergic reactions in horses

.mil - the end of a military web address

milk replacer - formula fed to orphan foals

millenials - synonym for the generation y

mimic - to reproduce the actions of another

mineral lick - a mineral block for livestock

mineral oil - a laxative

minimal white - a tobiano that is mostly of the base color

minor - one that is not of legal age

misconduct - dishonest or improper behavior

misrepresentation - to use the Pintabian mark when a horse is not eligible for registration in the PHRI

mission - the stated tasks or responsibilities of a business

mitigate - duty to minimize losses incurred by the breach of an obligation

mitochondria - the part of the cell that produces adenosine triphosphate for energy

meiosis - division of a cell that reduces genetic material by half

mitosis - cell division in which the chromosome number remains the same

mix - the four marketing elements of product, promotion, place and price

MLD - acronym for minimum lethal dose

mock hunting - popular form of cross-country where hounds follow a scent

modifying - roan and gray genes that modify the base color

molasses - by-product of sugar beets and sugar cane

mold - fungus

monkey crouch - slang for riding in a racing-type position over the shoulders of an equine

monensin - an antibiotic that causes death in horses and dogs

monosomy - chromosomal abnormality

morbid - causing disease

moribund - dying

mortality - death

mortality insurance  - when a company agrees to pay a sum in the event of the untimely death of a horse
 
mortality rate - death rate

motility - the percentage measurement of sperm that move forward normally

mount - a horse that a person is sitting upon

mount - to get on a horse

mountain sickness - high altitude sickness caused by oxygen deprivation

mounting block - a step used by a rider to get on a tall horse more easily

mousy - a grayish-brown color

mouse - grayish-brown color that some genetically black horses are born with before they shed to black

moustache - when a horse with a white muzzle has a black marking on its upper lip

mouthpiece - bit

MRI - acronym for magnetic resonance imaging

MSM - acronym for methylsulfonylmethane

muck - to clean a stall

mucous membrane - lining of cavities in the body

mucus - slimy membrane substance

mule - an infertile hybrid cross between a donkey jack and a Pintabian mare

multiparous - refers to a mare who has raised more than one foal

musty - moldy odor

mutagen - agent in the environment that damages DNA

mutation - abrupt permanent genetic change that can affect phenotype

mutual grooming - grooming behavior exhibited by equine companions

muzzle - the soft area around the nose and mouth of a horse

mycosis - fungal disease

mycotoxins - naturally occurring substances produced by fungi that cause harm to biological systems

myopathy - muscle tissue degeneration or disease