Vet Terminology starting with I on – from Iatrogenic to Isoflavone


A condition resulting from the action of the doctor; e.g., an allergic reaction resulting from administration of an injection by a veterinarian.

Commonly referred to as jaundice. A yellowing of the tissues, usually as a result of abnormal liver function.

Insulin dependent diabetes mellitus (IDDM): A form of diabetes in which so little insulin is produced that supplemental insulin must be given for the animal to live. Also called Type I diabetes mellitus.

Of unknown cause.

A condition in which there is an absence of muscular contractions of the intestine which normally move the food through the system; can result in an intestinal obstruction.

Immune system
The body’s defense system which recognizes infectious agents and other ‘foreign’ compounds (such as pollen), and works to destroy them.

Immune-mediated reaction or disease: A condition or disease caused by abnormal activity of the immune system in which the body’s immune system either over-reacts (e.g., immune-mediated contact dermatitis) or starts attacking the body itself (e.g., autoimmune hemolytic anemia). See also autoimmune.

A condition in which the animal’s immune system has been primed and is able to protect the body from a disease-causing agent such as a certain virus or bacteria. An animal could have immunity to one agent, such as parvovirus, but not have immunity to another agent, such as rabies.

The process of rendering an animal protected (immune) against a certain disease. Vaccination is a way to produce immunization. However, just because an animal has been vaccinated (received a vaccine) does not necessarily mean the animal is immune. If the body did not correctly react to the vaccine or if the vaccine was defective, immunity would not occur. No vaccine produces immunity in 100% of the population to which it was given. ‘Vaccination’ is not the same as ‘immunization.’

Reduced function of the immune system of an animal, making it more susceptible to infectious disease. Can be an inherited defect or caused by drugs, radiation, or viruses.

A compound which stimulates the immune system to work more effectively to kill bacteria, viruses, or cancer cells.

Something, for instance a drug, hormone, or virus, that reduces the function of the immune system of an animal. An animal with reduced function of its immune system is called ‘immunosuppressed.’

The inability to control the excretion of wastes; generally used to describe the inability to control urination.

Incubation period
The time between the exposure to a disease, causing agent, and the onset of signs of the disease.

The invasion and replication of microorganisms in tissues of the body; generally causes disease or local inflammation.

Infectious agents
The organisms that cause infection; can be viruses, bacteria, fungi, or parasites.

A term used to describe an invasion of parasites.

A condition in which tissue reacts to injury and undergoes changes during the healing
process. As an example, a toe with a sliver of wood in it would be inflamed and show the signs of inflammation which include redness, increased temperature, pain, swelling, and a loss of or disordered function. The toe is swollen, red, hot, painful, and the animal is reluctant to walk on that toe.

Microscopic organisms which are cultured as a food for the fry of freshwater fish.

A trait passed from one generation to the next in the genes from each parent.

A permanent characteristic that is present because of the genetic make-up of the animal.

Insoluble carbohydrate
Also, insoluble fiber. Fiber that resists enzymatic digestion in the small intestine.

A hormone produced by the pancreas which is necessary for glucose to be able to enter the cells of the body and be used for energy.

Insulin resistance
A condition in which the blood glucose level remains higher than it should at an insulin dosage of 2 units/pound of body weight per day in cats.

Insulin-producing tumor of the pancreas; the increased production and blood level of insulin resulting from these tumors can cause low blood sugar (hypoglycemia).

Intermediate Host
In the life cycle of some parasites, the immature form of the parasite must pass through a different type of host (animal, insect, snail, etc.), called the intermediate host, before it can re-enter and infect the type of animal it came from. An example would be heartworms. The adult worm lives in the dog or cat. The immature form, laid by the adult heartworm, is taken up by the mosquito. The immature form develops within the mosquito, and is then reintroduced into another dog or cat where it develops into the mature adult and the cycle repeats itself. The intermediate host for heartworms, then, is the mosquito.

Between parts or within the spaces of tissue.

The part of the digestive system extending from the stomach to the rectum; includes both the small and large intestines and functions in the absorption of water and nutrients; also called bowel or gut.

An action taking place within a cell.

Originating within the cranial (brain) cavity.

Into the muscle (IM).

Into the nose.

Into the bloodstream via a vein.

A condition in which one part of the intestine ‘telescopes’ into another.

The colored portion of the eye is called the iris. As with humans, dogs’ iris colors vary. In the center of the iris is the black opening called the pupil. This opening can be made larger or smaller by muscles called ciliary bodies, that attach to the colored iris, causing it to expand or contract.

An estrogen-like substance produced by pasture plants; a type of phytoestrogen.