What is Pathology and Lesion Descriptions
Secondary Intrinsic Etiologies
Influences that may modify expression of disease: - age - gender - coat color - genus - familial - breed - idiosyncratic reactions
Etiologic Diagnosis
Less descriptive and does not always identify a specific lesion focused on the cause of the lesion in affected organs or tissues
Animate Extrinsic Etiologies
Living forces - Bacteria - Viruses - Parasites - protozoa - prions
Do lesion tell and show you everything?
No, they are only the tip of the iceberg. - Examples of other factors: Neoplasia, Bacteria, Arrhythmias, Toxins
Inanimate Extrinsic Etiologies
Non-living forces - weather - radiation - trauma - toxins - chemicals - drugs - diet
Clinical Signs
Observable symptoms indicating disease presence. objective : measurable - temperature - Blood pressure - respiratory rate - heart rate - Rash, pustules, erythema - Diarrhea - vomiting
Can some lesions be due to euthanasia? If so what are they?
Yes, - Barbiturate Salts - Splenomegaly - Cranial Hemorrhage
Disease or Condition
a summation of everything you are seeing/observing with no descriptive component
Diagnosis
an INTERPRETATION of the nature of disease taking into context the lesions and clinical signs
Prognosis
an estimate of future outcome
Pathogenesis
development of disease
Primary Intrinsic Etiologies
genetic mutations
Statistical Significance
how likely it is that an obtained result occurred by chance - highly dependent on sample size
Are all lesions significant?
NO
Pathognomonic lesions
Specific lesions indicating a particular disease. - Very rare
How can you differentiate between antemortem and postmortem lesions?
- Is there a tissue reaction? (inflammation, edema, hemorrhage) - Does it make sense in context of the case? - What is the post-mortem interval?
How is prognosis expressed?
- in terms of "optimism" - excellent, good, fair, guarded, poor/grave
What does clinical significance take into consideration?
- the extent of chance - wether the change makes a difference in the subjects life - how long the effects last - consumer acceptability - cost-effectiveness - ease of implementation
What are three levels of looking at pathology?
1. Macroscopic -> Gross pathology 2. Microscopic -> Histopathology 3. Ultrastructure -> Electron Microscopy
What are the types of Diagnosis?
1. Morphologic 2. Etiologic 3. Disease or Condition
Incidental Findings
Findings that probably are not causing the clinical problem, disease, or death - very common especially in older animals
What are lesions?
Structural (morphologic) alterations in cells or tissues.
Etiology
Study of the cause of the disease process
Symptoms
Subjective characteristics of disease felt only by the patient, can be misleading, vague, non-specific, and should never be used alone for diagnosis Subjective: not measurable - Pain - fatigue - headache - anxiety - nausea
Should you treat the patient or the numbers ?
The patient
Clinical significance
The practical importance of research results in terms of whether they have genuine, palpable effects on the daily lives of patients or on the health care decisions made on their behalf
What do lesions represent?
Visual representations of tissue injury and response.
Do some lesions only appear post-mortem?
Yes - Algor Mortis -> postmortem cooling - Rigor mortis -> Rigidity - Liver mortis -> Blood pooling - Staining -> Bile imbibition, Hemoglobin imbibition, Pseudomelanosis, melanosis - Gas-distension -> Emphysema, Prolapse, Gastric Rupture - and more
What is pathology?
study of disease - structural and functional changes in cells, tissues, and organs - relating these changes to specific causes - How do these changes manifest and contribute to diseases
Morphologic diagnosis
the interpretation of the abnormalities in terms of severity, duration, lesion and distribution. Discusses one lesion
