Diseases of the Respiratory System (p461-637) Flashcards
What are the 5 primary means by which hypoxemia develops?
1) V/Q mismatch
2) Hypoventilation
3) Low partial pressure in inspired air
4) Diffusion limitation
5) Right to left shunting, intrapulmonary or intracardiac
Match the percentages of cell distribution in a normal horse BAL. 50-70%; 30-50%; < 5 %; < 3 %; <0.1%
A) Eosinophils B) Lymphocytes C) Macrophages D) Mast cells E) Neutrophils
50-70% C) Macrophages 30-50% B) Lymphocytes < 5% E) Neutrophils < 3% D) Mast cells < 0.1% A) Eosinophils
What is the most common pathogen isolated in bronchopneumonia?
A) Pseudomonas
B) Bordetella
C) Rhodococcus
D) S. equi subsp zooepidemicus
D) S. equi subsp zooepidemicus
What are some factors that significantly increase bacterial contamination of the lower respiratory tract in horses?
Head elevated, transportation and high-intensity exercises
List two viruses that can decrease the mucocilliary clearance in horses, up to 30 days after infection.
Influenza
EHV-4
At a cellular level, how does high-intensity exercise in horses lead to decreased bacterial clearance from the lungs?
High-intensity exercise leads to a decrease in blood neutrophil and bronchoalveolar macrophage phagocytic activity.
Is this the first, second or third stage of pleuropneumonia? Exudative stage - pouring of sterile fluid into pleural space due to inflammation of the pleura; there is an increased permeability of the visceral capillaries
A) Stage 1
B) Stage 2
C) Stage 3
A) Stage 1 - if antimicrobial therapy is initiated at this time, pleural effusion may not become septic
Is this the first, second or third stage of bacterial pleuropneumonia?
Fibropurulent stage - bacteria invade the pleural effusion from the pneumonia process and as the stage progresses fibrin is deposited in a continuous sheet
A) Stage 1
B) Stage 2
C) Stage 3
B) Stage 2 - degenerate neutrophils, bacteria and cellular debris accumulate in the pleural fluid; the fibrin sheet forms and there can be loculations and formation of limiting membranes, making drainage difficult
Is this the first, second or third stage of bacterial pleuropneumonia?Organizational stage - an inelastic pleural peel is formed,that can render lung functionless
A) Stage 1
B) Stage 2
C) Stage 3
C) Stage 3 - this stage of bacterial pleuropneumonia occurs when fibroblasts grow into the exudate from both the visceral and parietal pleura surfaces
What is the association between NCC count or protein concentration in pleural fluid and survival?
NONE
A pleural fluid pH of less than A) ____ and glucose concentration less than B)___ are suggestive of septic effusion in horses.
A) 7.1B) 40 mg/dL
Why should enrofloxacin never be used as a stand-alone therapy in horses with bronchopneumonia?
Enrofloxacin has a lack in activity against anaerobes and variable activity against streptococci.
List additional treatments for a horse with bronchopneumonia, other than systemic antimicrobial therapy.
Aerosolized antimicrobials NSAIDs Pleural drainage Pleural lavage Fibrinolytics Thoracoscopy Thoracotomy
Other than a poor response to conservative therapy, what are some other indications for pleural drainage?
1) sufficient volume to cause distress
2) emphysematous character
3) fetid odor
4) cytology or biochemical evidence of sepsis
Is there communication between the left and right pleural spaces, in horses?
Yes, the mediastinum is perforated and the left and right pleural spaces communicate.
List some fibrinolytic agents used in human medicine that could be used fibrinous pleuropneumonia.
Streptokinase, urokinase and recombinant tissue plasminogen activator (rtPAs: alteplase and tenecteplase)
There are 4 criteria for surgical intervention in horses with pleuropneumonia. What are these?
1) failure to response to antimicrobial therapy, pleural drainage and pleural lavage
2) stable systemic medical condition
3) presence of a large amount of fibrin, debris or pus in the pleural space
4) a walled-off lesion or presence of a complete mediastinum to prevent a bilateral pneumothorax
R. equi is the most common cause of pneumonia in foals between what age? A) 3 weeks - 5 months B) 3-4 months C) Less than 3 months D) 8-12 months
A) 3 weeks - 5 months
R. equi causes a suppurative bronchopneumonia foals. List some extra pulmonary diseases that it can also cause. (3)
Intestinal lesions - multifocal ulcerative enterocolitis, granulomatous or suppurative inflammation of the meds enteric and/or colonic lymph nodes
Polysynovitis - most common are tibiotarsal and stifle joints, likely resulting from a bacteremia
Ocular lesions - uveitis, keratouveitis, panophthalmitis
Which of the following is correct about the classification of the equine herpes viruses?
A) EHV-1 and 2 are Gammaherpesvirinae
B) EHV-3 and 4 are Gammaherpesvirinae
C) EHV-1 and 5 are Alphaherpvesvirinae
D) EHV-1, 3 and 4 are Alphaherpesvirinae
D) EHV-1, 3 and 4 are Alphaherpesvirinae. EHV-2 and 5 are Gammaherpesvirinae
Match the equine herpes with its disease process. EHV-1, EHV-2, EHV-3, EHV-4, EHV-5
A) Respiratory disease
B) Abortion
C) Equine herpes myeloencephalopathy
D) Equine multinodular pulmonary fibrosis
E) Unknown
F) Equine coital exanthema
A) Respiratory disease: EHV-1, 4
B) Abortion: EHV-1, sporadically EHV-4
C) Equine herpes myeloencephalopathy: EHV-1
D) Equine multinodular pulmonary fibrosis: EHV-5
E) Unknown: EHV-2 & 5
F) Equine coital exanthema: EHV-3
How does EHV-1 cause abortion?
Vasculitis of the small arteriolar branches of the glandular layer of the endometrium causes thrombosis, microcotyledonary infarction, perivascular cuffing and transplacental spread of the virus.
What kind of immunity is formed after a horse has been infected with equine herpes 1 or 4?
The protective immune response following infection is short lived. High titers of virus-neutralizing Ab before infection can reduce the amount and duration of virus shed from the nasopharyngeal but fail to prevent infection of the development of EHM or abortion.
Intracellular equine herpes virus is susceptible to which branch of the immune system?
Intracellular equine herpes virus is susceptible to cytotoxic T-lymphocytes (CTLs), and is MHC Class 1 restricted. This is mediated by CD8+ lymphocytes.
