1.1 Learning Objectives

Question 1

Aetiology:

Answer 1

Casual factors

Question 2

Pathogenesis

Answer 2

development of disease within body

Question 3

Lesions:

Answer 3

structural changes caused by disease

Question 4

Pathophysiology:

Answer 4

functional changes

Question 5

Sequelae:

Answer 5

consequences of disease

Question 6

Aetiology of disease – causal factors

Answer 6

Infectious:
- viruses, bacteria, fungi and parasites

Physical:
- trauma, pressure, heat, cold, radiation

Chemical:
- toxic organic and inorganic substances
- toxins produced by infectious organisms

Nutritional:
- deficiencies of vitamins and trace elements
- excess vitamins and trace elements

Genetic:
- range of lethal and sublethal defects

Question 7

Pathogenesis of disease =

Answer 7

The time course

Question 8

Pathogenic is of disease: acute

Answer 8

Acute: of sudden onset and short duration

Outcome:
- a. causes death of the animal, or
- b. resolves due to host defence or clinical therapy, or
- c. becomes chronic disease

Question 9

Pathogenesis of disease: Chronic

Answer 9

Chronic:
of insidious onset and protracted course

Outcome
- a. progressively destroys tissue compromising its function and endangering life, or
- b. its course is halted and the tissue repairs by scarring

Question 10

Pathogenesis of disease – interplay of factors involved

Answer 10

•Animal- related: e.g. age, nutrition,immune status
•Agent-related: e.g. dose, virulence, single or mixed infection
•Environment related: e.g. overcrowding, management, temperature extremes

Question 11

Lesions:

Answer 11

Abnormalities or changes due to disease in living tissues: observed in
•the live animal,
•tissues surgically removed from the live animal, and
•in animals soon after death (necropsy, post-mortem examination)

Lesions do not occur in dead animals – major changes that occur after an animal dies are due mainly to autolysis and putrefaction

Question 12

Necropsy:

Answer 12

gross changes in the dead body

Question 13

Histopathology:

Answer 13

microscopic examination of tissues selected from the dead body after necropsy, or biopsy/excision of lesions in the living animal

Question 14

Pathology is fundamental to disease diagnosis:

Answer 14

Diagnosis
- history
- clinical examination
- clinical pathology
- biopsy or post-mortem examination
Prognosis and Treatment
Control and Prevention - the ideal situation

Accurate pathology enables accurate diagnosis, therapy and control