In this unit, you will learn about the important concepts revolving around the key terminology for identifying problems with animals.
Learning Objectives
I will:
1. Identify key terminology for identifying problems with animals.

Parasites

Parasitism is the relationship between two organisms where one of those organisms benefits at the expense of the other. There are some key terms that need to be discussed:

• Veterinary parasitology: The study of parasites and their animals hosts.
• Host: The animals that the parasite benefits from.
• Parasite: An organism that benefits from another organism.
• Ectoparasites: They live on the surface of the host.
• Endoparasites: They live inside the host.
• Epiparasites: They are parasites' that feed on other parasites.

Watch the following video to learn more about parasites.

https://youtu.be/g09BQes-B7E

Toxicology

Toxicology is the study of the harmful effects of chemical compounds on organisms. When discussing toxicology, you will want to know the following terminology:

• Veterinary toxicology: It is the study of the properties, effects, and treatment of biotoxins (or poisons from biological sources).
• Toxicity: The amount of a substance that is needed before a harmful effect is seen.
• Toxicosis: The disease or harmful conditions produced by a toxin.
• Tolerance: When an organism shows less of a response to a toxin than it did in a previous exposure.
• Synergism: The increased effects that can result when an organism is exposed to two or more toxins that act in the same way on the body.
• Acute toxicosis: The effects that occur within the first 24 hours.
• Chronic toxicosis: The effects that happen due to continued exposure to toxin.
• Half-life: The time it takes for half of the chemical or toxin to be expelled from the body.

Additionally, it is important to understand that there is a difference between poisons and venom. Watch the following video to learn about poisons and venom.

https://youtu.be/KnJ4_xRfxpA

Diseases and Disorders

A disease is a harmful deviation from the normal structural or functional state of an animal. Typically, they are associated with certain signs and symptoms.  A symptom is a mental or physical feature that indicates a certain type of condition, such as a type of disease.
There are a variety of types of diseases and disorders that may be discussed:

• Infectious diseases: Caused by organisms, such as bacteria, viruses, fungi or parasites.
  • When discussing infectious diseases, there are different incubation periods. An incubation period is the first time from when the animal is first infected to the time when symptoms first appear.
• Deficiency diseases: Cause by the lack of some essential element in the diet.
• Hereditary diseases: It is inherited genetically.
• Physiological disorders: An organ in the body malfunctions and causes an illness.
• Musculoskeletal disorders: Conditions that affect that muscles, bones and/or joints.
• Nervous system diseases/disorders: These affect the brain and nervous system.
• Endocrine diseases/disorders: This is an imbalance in hormone levels.
• Gastrointestinal diseases/disorder: This affect the digestion or absorption of food. It 

Additionally, there are zoonotic diseases. Click on the following button to learn about zoonotic diseases.

Zoonotic Diseases

Also, there are diseases that can be transmitted from humans to wild or domestic animals. These types of diseases are called reverse zoonosis.