Equine Respiratory Diseases Flashcards
what can equine respiratory diseases be divided into?
upper and lower respiratory tract diseases
what type of diseases tend to effect weanlings and yearlings?
viral and bacterial URT infections
what conditions tend to affect performance horses?
exercise-induced pulmonary haemorrhage
inflammatory airway disease
what condition tends to affect middle-aged horses?
asthma
what infection tends to affect foals?
rhodococcus infections
how does the environment of a horse affect disease development?
exposure - new horses, local endemic infections, dust
vaccination history
what will you check during the physical exam of a horse presenting with respiratory issues?
demeanour, stance (orthopnoea?)
nasal discharge
submandibular lymph nodes
RR and effort
presence/absence of heave line
what is the normal respiratory rate of a horse?
8-10 breaths/min
why might you assess the respiratory effort of a horse by
inducing rebreathing?
impossible to auscultate a horse effectively during exercise
what types of imaging and sampling are available for investigating respiratory issues in horses?
nasal/nasopharyngeal swab
endoscopy
x-ray
CT scan
ultrasound
where does endoscopy allow you to visualise?
URT down to the tracheal bifurcation
to what level can you place an endoscope in an exercising horse?
can only view URT/larynx
what is a sinoscopy?
exploration through endoscopy of the paranasal sinuses via a trephine or flap
what does CT scanning of the head allow you to visualise effectively?
nasal turbinates paranasal sinuses teeth nasopharynx guttural pouches skull
why might you take a swab of the respiratory secretions?
for bacterial/viral culture, PCR, cytology
what is a tracheal wash?
sample respiratory secretions and cells that accumulate in the trachea - they are a collection from the entire lower respiratory tract
what is bronchoalveolar lavage?
sampling a specific peripheral lung segment by washing the airways with sterile saline and recollecting
what are the advantages and disadvantages of BAL?
a = more accurate sample d = more invasive (requires sedation), only samples specific area so could miss disease
how much sterile saline is used in BAL?
300-500ml - draw back up 50-80%
how can you tell if you have a good sample from BAL?
presence of froth (surfactant) = good sample
why might you ultrasound a horses chest?
for peripheral lung disorders - may need to combine with x-ray
what is the most common presenting complaint for horses with disorders of the nasopharynx/larynx?
abnormal respiratory noise during exercise (without stethoscope)
what is DDSP?
dorsal displacement of the soft palate
which horses most commonly get DDSP?
racehorses during exercise
can be seen in sport/pleasure horses
what are the signs of DDSP?
poor performance and abnormal expiratory noise (gurgle)
how is DDSP diagnosed?
exercising endoscopy
how is DDSP treated?
soft palate cautery (surgery) to stiffen soft palate
laryngeal tie-forward surgery
what is arytenoid cartilage collapse also called?
recurrent laryngeal neuropathy
laryngeal hemiplegia
laryngeal paralysis
which side of the larynx is affected by arytenoid cartilage collapse?
left side
what are the signs of arytenoid cartilage collapse?
inspiratory noise (whistling, roaring) exercise intolerance
how is arytenoid cartilage collapse dianosed?
exercise endoscopy is best
how is arytenoid cartilage collapse treated?
ventricolochordectomy removes the noise
laryngeal tie-back helps with exercise intolerance but carries risk of aspiration pnemonia
what is sinusitis?
accumulation of exudate within sinus cavities
what are the 2 types of sinusitis?
primary - sequela of bacterial/viral URT
secondary - dental disease
what is the main clinical sign of sinusitis?
nasal discharge with unpleasant smell
how is sinusitis diagnosed?
endoscopy (to check for other causes)
x-ray
CT
sinoscopy
what is guttural pouch mycosis?
potentially life-threatening fungal infection of the guttural pouch
what are the clinical signs of guttural pouch mycosis?
epistaxis
some have cranial nerve dysfunction
how is guttural pouch mycosis diagnosed?
endoscopy of the pouches
how is guttural pouch mycosis treated?
surgical occlusion of the vessels
may need topical anti-fungal
might not recover from cranial nerve deficits
what is strangles?
URT bacterial infection (streptococcus equi equi)
what are the clinical signs of strangles?
dullness
fever
purulent nasal discharge
enlarged, abscessing submandibular and retropharyngeal lymph nodes
what are the complications of strangles?
difficulty breathing
abscesses can seed round the body
immune-mediated complications
how is strangles diagnosed?
culture/PCR from abscess
endoscope and GP lavage for culture
how is strangles trated?
penicillin in some
drains abscessed lymph nodes
which part of the respiratory tract does influenza affect?
upper and lower
what are the clinical signs of influenza?
coughing pyrexia serous nasal discharge submandibular lymphadenopathy inappetence depression
how is influenza diagnosed?
virus detection (ELISA/PCR)
virus isolation with swab
serology
how is influenza treated?
rest
NSAIDs
prevent with vaccination
what can equine herpes virus cause?
respiratory and neurological signs
abortion storms
which herpes viruses can we vaccinate horses against?
EHV1 and EHV4
what is pleuropneumonia?
‘shipping fever’ - opportunistic infections from pharynx to lungs in travelled horses
what are the signs of pleuropneumonia?
history of long-distance travel fever dull nasal discharge difficulty breathing weight loss
how is pleuropneumonia diagnosed?
clinical exam
chest x-ray and US
TW and pleural fluid sample for culture and cytology
how is pleuropneumonia treated?
affected often very sick - requires aggressive treatment
penicillin
chest drains
what is asthma?
allergic airway disease, usually to dust in stables/straw/hay
what are the signs of asthma in horses?
coughing and wheezing
increased respiratory effort
heave line
how is asthma diagnosed in horses?
endoscopy
TW, BAL
airway neutrophilia but not bacteria on culture
how is asthma managed?
environmental management
inhaled/nebulised steroid and bronchodilator
