breed

O

obesity

A medical condition in which an animal possesses an abnormally large amount of fat in the body

obligate aerobe

A type of organism that only has the ability to live in a free oxygen environment

obligate anaerobe

An organism that only has the ability to live in an environment free of free oxygen

obligate parasite

A type of parasite that must be confined to a certain type of host and can only survive as a parasite

obligate saprophytes

A type of micro organism that gets its nutrients from dead tissue and inorganic materials

obligate symbiotic

A type of organism that depends on another organism to exist

oblique projection

A beam that passes through the body at a certain angle

obstetrical chain

A type of chain used by a vet to help animals to deliver their young; used with cows and horses and helps to provide enough traction for the young.

obstetrics

The form of medicine that handles the birthing of young and the care of the mother during pregnancy

obstruction

The blockage of a passage or canal

obtunded

Depressed

occlusal surface

The surface of a tooth designed for chewing

occlusion

The type of contact that occurs between the teeth where chewing is concerned

occult

Something that is difficult to view; partially or fully hidden

occults spavin

A form of bone spavin that occurs at the hock in a horse

ocular

Anything having to do with the eye

odontomata

A type of tumor that forms in tissue before teeth are formed

off-side

The right side as pertaining to a horse

offal

The part of the carcass that is inedible; includes certain organs and tissue in an animal that has been slaughtered

offspring

The term for an animal’s young

oil gland

A type of gland found at the base of a chicken’s tail that secretes a type of oil used in preening

ointment

Salve; usually made of fat or petroleum and is often used for medicinal purposes

old-crop lambs

The term for a sheep over one year old that has lamb teeth

olfactory

Anything having to do with an animal’s sense of smell

oligodendrocyte

A type of cell with very few dendritic hairs or branches

oligospermia

A medical condition in which few sperm are found in semen

oligotrophia

A medical condition in which nutrients are lacking

oliguria

A medical condition in which there is not enough urination

omasum

The term for the third compartment in the stomach of ruminant animals

omnivore

A type of animal that lives off of both animal products and plant products

on feed

The term for an animal that is being fed grain or milk, usually for the production of meat

on pasture

The term for livestock that is being allowed to graze on pasture

oncology

The study of cancer and tumors

ontogeny

The process of development when it comes to living things; from egg to adult

onychectomy

The process of surgically removing the claw of an animal

onychomycosis

An infection of the claw by fungus

oocyst

The stage in the life of certain parasites in which they are encapsulated and usually passed through droppings

oogenesis

The processes in which germ cells are produced by female animals

oogonium

The first germ cell produced

oon egg

An egg that is expelled with no shell

oophorectomy

The removal of one or both ovaries by surgery

open heifer

The term for a female cow that is not yet pregnant

open herd

A mass of animals that allows for the entry of other animals

open herding

The process of allowing a band of animals to spread out and graze

open range

A large area in which animals are allowed to graze unrestricted

open-faced

The term for sheep with little to no wool over their eyes

ophthalmia

A medical condition in which the eye ball or lining becomes inflamed

ophthalmic

Anything having to do with the eye or care of the eye

ophthalmologist

A professional skilled in the study of the eye

ophthalmology

The study of the parts and health of the eye

ophthalmoscope

A type of tool used to look inside the eye

opportunistic

The ability to create a disease where a disease might not normally be found, usually due to an ill timed or unlikely weakness

optic chiasm

A condition in which the nerves in the brain having to do with vision become crossed

optic disk

A blind spot in the eye

optimum condition

The perfect environment for an organism to thrive in

orchidectomy

The removal of the testes through surgical means

orchitis

A condition in which the testes become inflamed

organic

Anything produced by animals or originating in animals; also has to do with chemical compounds that have carbon in them

organism

Any living thing made of cells

organogen

A type of chemical element in which organisms are not able to exist

organoleptic

Anything having to do with the senses, like taste, temperature, smell, etc.

orifice

Any body entrance or exit

orogastric intubation

The process of passing a stomach tube from the mouth to the stomach

oropharynx

The part of the throat that is found between the soft palate and the epiglottis

orthopedist

A person whose profession is charged with preserving or restoring parts of the skeletal system

os penis

The bone inside the penis of canine animals

osmophyllic

A type of organism that is known to grow in a solution high in osmotic pressure

osmosis

The transfer of water through a type of membrane

osmotic pressure

The amount of pressure required to cause osmosis to stop

ossification

The production of bone

ostealgia

Pain in the bones

ostectomy

Removal of the bone through surgical means

osteitis

A medical condition in which the bone becomes inflamed

osteoarthritis

A disease of the joints in which the cartilage and bone become degenerative

osteoblast

A cell that is used in the formation of bones

osteochondrosis

The degeneration of bone after regeneration

osteocyte

A bone cell

osteofibrosis

The loss of calcium salts in bones; this causes fragility. This condition is found in horses, pigs, goats, dogs, and certain types of animals

osteology

The study of the bones

osteomalacia

The softening of the bones; not normal in animals

osteomyelitis

A medical condition in which bone and bone marrow becomes inflamed

osteonecrosis

A medical condition in which bone tissue dies

osteophyte

A projection that can be found at the area where cartilage has begun to degenerate; sometimes they are free floating

osteoporosis

A medical condition in which bone porosity increases and bone density decreases

osteosarcoma

A neoplasm made up of bone, malignant in nature

osteotomy

An incision made into bone

otalgia

Pain of the ear

otic

Anything having to do with the ear

otitis

A medical condition in which the ear becomes inflamed

otitis externa

Inflammation of the external parts of the ear

otitis interna

Inflammation of the inner part of the ear

otitis media

Inflammation of the middle parts of the ear

otolith

A stone found in the utricle

otomycosis

An infection of the ear due to fungus

otopathy

A disease of the ear

otoplasty

A surgical repair made to the ear

otopyorrhea

A discharge of pus from the ear

otorrhea

Discharge from the ear

otoscope

A type of instrument used to look inside the ear

ototoxic

Something that is poisonous to the ear

outbred

Young from parents that are not related

outbreeding

Mating between animals who are not at all related

ova

The word for female eggs

oval window

The thin membrane between the middle ear and inner ear

ovarian cyst

The result of the accumulation of fluid in the female gonads

ovicide

Anything that is known to kill parasites while they are still eggs

oviducts

The term for the tubes that run from the uterus to the ovary; fallopian tubes

ovigenesis

The production of the female gamete

ovigonium

The germ cell that is used in creating the female gamete

ovine

The name for the species to which sheep belong

oviparous

Eggs that produce young

oviposition

The laying of an egg

ovotestis

The gonad, made up of the tissue of the ovaries and the testicles

ovulation

The process of the maturation and release of eggs

ovule

The mass that becomes the seed after fertilization

ovum

The female gamete

oxidase

Enzymes that are oxidizing

oxidation

A chemical change that has to do with adding oxygen or something like it

oxyhemoglobin

Any substance that is created when oxygen and hemoglobin are formed together

oxytocin

A type of hormone that is released during parturition that aids in the contraction of the uterus and causes milk to be released

ozena

A discharge of the nose that is caused by the inflammation of the mucous membranes; has to do with a disease of the nose bones