Lecture 22: Equine Lower Respiratory Tract disease: Bacterial Flashcards
What are some signs of pneumonia
Creamy nasal discharge, increase HR, enlarged LNs, stertorous breathing, milked crackles, wheezes
What are some signs of pleuropneumonia
Muffled lung sounds, crackles/ friction rubs, plaque ventral edema, pleurodyna
Horse presents with suspected pneumonia what is an appropriate diagnostic plan on farm
SAA, lactate iSTAT, CBC/chem, fibrinogen, ultrasound, trans tracheal wash, nasal swab
Horse presents with suspected pleuropneumonia what is appropriate diagnostic plan on farm
Stabilize and refer
Streptococcus equi is a highly contagious pathogen of ___
Upper respiratory tract
What are some clinical signs of Strangles
Fever >103, mucopurulent nasal discharge, acute swelling, abscess formation in submandibular and retropharyngeal LN’s
What is the pathogenesis of strangles
Bacteria enters mouth or nose and reaches tonsil tissue within hours
Nasal shedding of S. Equi occurs when and lasts for how long
2-3 days after fever and persists for 2-6 weeks
If chondroids develop due to strangles horses can shed the virus for ___
Years
75% of horses recovered from strangles develop immunity that lasts for __yrs
5yrs
What is the cold standard to dx strangles
Culture of purple t material
What is the best sample to culture for strangles to the worst
Guttural pouch washes> nasopharyngeal wash> rostal nasal wash
To dx strangles you can do a PCR for ___ which is useful for detecting ___
M protein, asymptomatic carriers
To dx strangles you can do an ELISA for __ which is useful for __,___,___, or ___
SeM protein, useful for vaccination, exposure, purpura and bastard strangles
How would you manage group of horses that have evidence of strangles on farm
Isolate, undergo tx
How would you manage horses on a farm that were exposed to strangles
Isolate, twice daily temp checks, if fever tx with antibiotics
How would you manage horses on a farm that were not exposed to strangles, but still on same farm
Isolate, twice daily temp checks, vaccinate in 2 weeks
Horses shed strangles for ___weeks following last clinical sign
6 weeks
What are some appropriate biosecurity measures for prevent strangles spread
- Dedicated clothing and equipment to each group
- If personal must work with all groups clean in order: 3, 2,1
- Disinfect
- Pastures rested for 4 weeks
What is tx for mild strangles
Isolate, soft palate feeds, and NSAIDS
What is a complication of strangles (why it is called strangles)
Upper respiratory obstruction
What is the appropriate treatment for strangles causing upper respiratory obstruction
- Tracheostomy or drain LN
- Treat with penicillin- procaine penicillin G, NSAIDS, Iv fluids
What is the most common complication of strangles following obstruction
Pneumonia/ bronchopneumonia
What is tx for bastard strangles
- Potentiated sulfonamides + rifampin
- Cephalosporin
What is purpura hemorrhagic
Aseptic necrotizing autoimmune vasculitis characterized by petechial and ecchymotic hemorrhages
What is tx for purpura hemorrhagic
Corticosteroids (dexamethasone), antibiotics, NSAIDS, supportive care
What is tx for Immune mediate myositis caused by strangles
Corticosteroids
What vaccine is used against strangles
Live IN pinnacle- two administrations, 2 weeks apart
Do not give the Live pinnacle IN vaccine in the ___, it will cause abscesses
Muscle
What are the inductive sites for the strangles IN vaccine
Pharyngeal and lingual tonsils
How long will horses test positive on PCR after strangles vaccine
6 weeks
What is the most common bacteria implicated in pneumonia
Streptococcus
Horses depend on ___head position for normal mucocillary apparatus so long ___with heads tied up can stop this defense mechanism
Lowered, trailer rides
What are some clinical signs of bronchitis
May be normal at test with a cough at exercise +/- fever
What are some signs of bronchopneumonia/ pneumonia
Fever, anorexia, nasal discharge, cough, weight loss, tachypnea, respiratory distress
What are some signs of pleuropneumonia/ pleuritis
Pleurodynia, unwillingness to move, grunting, abducted elbows, pleural friction rubs, plaque ventral edema
What is the pathogenesis of pneumonia
Infiltrate neutrophils, consolidation of lung parenchyma or focal abscess that interfere with gas exchange
What occurs inn severe pneumonia pathogenesis
Sterile fluid fills pleural space, bacteria invade pleural fluid, results in septic exudate and fibrin deposition
25% of horses with pleuropneumonia have a history of ___
Recent long distance transport
12% of horses with pleuropneumonia have a history of ___
Recently undergoing anesthesia
What are some clinical pathology signs associated with pneumonia
- Leukocytosis with neutrophila +/- left shirt
- Hyperfibrinogenemia
- Increase SAA
- Hyperglobinemia
- Anemia of chronic dz
What is an SSA value indicative of infection and what is normal
Infection >50
Normal <15
What is an valuable diagnostic imaging for pleural disease
Ultrasound
What is the most helpful diagnostic in pleural disease
Transtracheal wash
How can you collect tracheal fluid
Pop needle into trachea or via endoscopy
What cytology of transtracheal wash is indicative of pleural dxz
Neutrophilic with intra and extracellular bacteria
Why is a thoracocentesis helpful for pleural dz
Diagnostic and therapeutic
What is an appropriate anti microbial therapy for mild pleural dz/ pneumonia
Cephalosporins (Excede), potentiated sulfonamides
What is typically cause of mild pleural dz/ pneumonia
Streptococcus equi zooepidemicus
What is an appropriate tx for moderate pleural dz/ pneumonia
- Penicillin/Gentamicin
- Cephalosporins/ Gentamicin
What is an appropriate antimicrobial therapy for severe pleural dz/ pneumonia
- Pencillin/ Gentamicin/ metronidazole
- Pencillin/ Enrofloxacin/ metronidazole
Bacteriodes fragilis is typically present in severe pleural dz/ pneumonia and is resistant to ___, so must use ___ to tx
Pencillin, metronidazole
Which aerobe that can cause pleural dz/ pleural pneumonia carriers a guarded prognosis, 48% don’t survive
Klebsiella spp
Which has a worse prognosis for return to athleticism: aerobes or anaerobes
Anaerobes
What is the appropriate supportive therapy on the farm for pleural dz/ pneumonia
NSAIDS, Iv fluids
What is the appropriate tx for pleural dz/ pneumonia in hospital
Opioids, oxygen, cryotherapy, nebulization of antimicrobials, pleural drainage/lavage, heparin to prevent microthrombi
Why is early pleural drainage best
Fibrin deposition forms loculation that impair drainage
What are some complications associated with pleural dz/ pneumonia
Thrombophlebitis and coagulopathies, diarrhea, endotoxemia, laminitis, pleural abscesses, bronchopleural fistula, pericarditis
To perform a thoracotomy and rib resection you must have a ___
Closed mediastinum
T or F: thoracotomy incision is left open and closes by granulation over 2-3 months
True
What is prognosis for mild to moderate bronchopneumonia
Good prognosis for return to previous athletic performance
What is prognosis for pulmonary abscess
50-90% returned to previous athletic performance
What is prognosis for uncomplicated pleuropneumonia
56-61% returned to previous athletic performance
What is prognosis for complicated pleuropneumonia
88% survive to discharge, 46% returned to previous level of activity
