Lectures 3-5 Flashcards
How important are respiratory diseases in horses?
Cattle?
Second to MS system regarding limiting horses athletic abilities
Significant cause of morbidity in cattle
What are some clinical signs exclusive to respiratory system?
What signs can be commonly associated with (but not exclusive to) resp disease?
Cough, nasal discharge, epistaxis, hemoptysis, resp distress, abnormal resp noises
Tachypnea, fever, cyanosis, exercise intolerance
What are important components of history taking?
Signalment, intended use, nature/duration/progression of clinical signs, number of animals affected, previous treatments, vaccine hisotry
What things should you do in your general exam for resp disease
Observe from distance Look for nasal discharge Evaluate airflow through nose Check mm color and CRT Palpate larynx and trachea Percuss paranasal sinuses Check ventral abdomen, muzzle, and limbs for edema
What should normal paranasal sinuses sound like?
Symmetric drums
What are the normal resp rates for horses, cattle, and sheep/goats?
Horses: 8-24; 25-40 for neonates
Cattle: 12-36; 30-60 for neonates
Sheep/goats: 12-40; 30-70 for neonates
What do crackles sound like and what are they caused by?
Short, sharp, explosive sounds
Come from when a collapsed lung suddenly pops open from pressure
What other abnormal lung sounds might you hear?
Wheezes
Friction rubs
Absence of lung sounds (fluid everywhere)
Increased lung sounds (pneumonia or other disease process where only large airways are open
What can you do increase lung sounds for you to hear
Rebreathing exam
What is the purpose of thoracic percussion?
Differentiates airated lung from fluid filled lung
Identify consolidation, abscesses, and pleural effusion
What structures can you identify with endoscopy?
Nasal cavities Ethmoid turbinates Pharynx Larynx and epiglottis Trachea/bronchi Guttural pouches
What structures can you evaluate through upperairway radiography
Head- nasal cavities, sinuses, ethmoids, teeth
Pharynx- epiglottis, soft palate, guttural pouches
What structures can you evaluate using lower airway radiography
Lungs- different patters
Heart- not used a lot in horses
When would you use ultrasound?
To evaluate pleural space and peripheral lung
Cannot penetrate lung parenchyma or deep lesions within the lung
When would you use a nasal wash?
To detect microorganisms that do not usually colonize upper airways (like S. Zooepidemicus)
Can detect viruses or S. Equi equi
When would you do a tracheobronchial aspirate/transtracheal wash
To obtain culture of lower airways when pneumonia is suspected
When would you do a bronchoalveolar lavage?
When diffuse disease is present NOT when a focal disease (like pnemuonia) is suspected because it is just taking a tiny piece of lung
When would you perform a thoracocentesis
When pleural effusion is suspected
What are the infectious diseases of the upper respiratory tract
Strangles
Guttural pouch diseases
Sinusitis
Viral respiratory diseases
What are diseases of the lower respiratory tract?
Foal pneumonia Rhodococcus equi Pneumonia/pleuropneumonia Exercise induced pulmonary hemorrhage Heaves
What microbe causes strangles?
S. Equi qui
How is strangles transmitted?
Direct contact
Indirect contact through contaminated fomites (buckets, feed, pasture)
Clinical signs of strangles
Fever, depression, lymphadenopathy of retropharyngeal and submandibular lymph nodes, respiratory distress, random abscesses
When do most horses stop shedding strangles?
3-6 weeks after resolution of clinical signs but some horses may become chronic asymptomatic carriers
If a horse is an asymptomatic carrier, where is the site of carriage?
Guttural pouch
How would you diagnose strangles?
Clinical signs of abscessed lymph nodes, nasal/pharyngeal swab, nasal flush (3x), guttural pouch flush (1x)
If a horse has early clinical signs without lymph node abscessation, what can you treat it with?
What about after a horse has lymph node signs?
Penicillin
Supportive care and promote maturation/drainage of abscessed lymph nodes
What are complications that can arise from strangles?
Pneumonia Guttural pouch empyema and/or chondroids Bastard strangles Purpura hemorrhagica Myocarditis/endocarditis Glomerulonephritis
What is bastard strangles?
Abscessed lymph nodes elsewhere on the body
What is purpura hemorrhagica
Acute necrotizing immune mediated vasculitis
What clinical signs will you see with purpura hemorrhagica
Warm, painful edema of the limb, ventral abdomen, and face
Petechial hemorrhaging
Fever
Stiffness
How to treat purpura hemorrhagica
Peniciilin, corticosteroids, supportive therapy
Describe the strangles vaccines
Intramuscular and intranasal are available
Limited efficacy and side effects
What is in the medial compartment of the eustachian tubes
Internal carotid, cranial nerves 9,10,11,12, cranial cervical ganglion
What is in the lateral compartment of the guttural pouch
External carotid artery
Maxillary artery
Cranial nerve 7
What is guttural pouch empyema
Accumulation of exudate in guttural pouches- may solidify to become chondroids
Which vessel is most commonly affected by guttural pouch mycoses?
Internal carotid
What are the clinical signs of guttural pouch mycosis?
Epistaxis
Dysphagia
Other random things
How to treat guttural pouch mycoses
Surgically occlude the proximal and distal affected artery
Can use medicine if a mild case
What is guttural pouch tympany
Distention of one or both guttural pouches with air; usually affects horses less than 1 year old
What are clinical signs of guttural pouch tympany
External swelling in parotid area
Dyspnea
Dysphagia
How to treat guttural pouch tympany
Surgery
What is primary sinusitis
General inflammation in a sinus
Usually it’s the maxillary sinus and s. Zooepidemicus that is most commonly involved
What is secondary sinusitis
Inflammation caused by tooth root abscess (usually M1)
What are clinical signs of sinusitis
Nasal discharge, ozena, ocular discharge, facial sensitivity/deformity
How to treat primary and secondary sinusitis
Primary- antibiotics and sinus flush
Secondary- antibiotics and extraction or repulsion of tooth
What is the most common cause of breakouts of upper respiratory disease in horses?
Influenza A
What are the two antigenic determinants of influenza virus
Hemagglutin and neuraminidase
Which two types of flu affect horses
H7N7- basically extinct
H3N8- major subtype
Antigenic drift
Mutation in HA or NA allowing the virus to escape antibodies
Antigenic shift
Not observed in equine flu
What makes the flu so contagious in horses
Short incubation and very infectious
What are complications of equine flu?
Bacterial pneumonia/pleuropneumonia
Myositis, myocarditis
How to treat equine flu
Rest at least three weeks!
Supportive care
Which equine herpes viruses cause resp disease
EHV-1 and EHV-4
What does EHV-1 cause
Abortion, perinatal disease and death, neurologic, resp disease
What does EHV-4 cause?
Just resp disease
How to diagnose EHV
Need nasal swabs AND whole blood since it can be viremic
Describe the vaccines for EHV
Not that effective but reduced shedding and severity of disease
What is the leading cause of mortality in foals
Foal pnemonia
What are clinical signs of foal pneumonia?
Cough Nasal discharge Fever Increased resp rate Resp distress
What is the most common pathogen that causes foal pneumonia
S. Zooepidemicus
