Cardiorespiratory Flashcards
What are the two types of asthma?
Severe equine asthma - sEA (RAO and SPAOPD)
Mild to moderate asthma - mEA (IAD)
What does SPAOPD stand for?
Summer pasture associated obstructive pulmonary disease
What percentage of neutrophils is seen on bronchioalveolar lavage with mEA?
10-25%
What percentage of neutrophils is seen on bronchioalveolar lavage with sEA?
> 25%
What is the pathophysiology that occurs with equine asthma?
Airway hyperresponsiveness
Bronchospasm
Inflammation
Mucus accumulation
Tissue remodelling
What two medications are required to treat equine asthma?
Glucocorticoids and bronchodilators
What additional medications can be used for mEA?
Immune modulation (interpheron-alpha) and omega-3 supplementation
Which bronchodilators are effective at treating equine asthma?
Beta-adrenergic
Parasympatholytic
Which environmental management techniques should be used to help manage sEA?
Keep outside at all times
Access to well ventilated shelter
Free of urine/manure
Pelleted feed or hay cubes
Soak hay/steam, haylage
What management should be undertaken for the management of summer pasture associated obstructive pulmonary disease (SPAOPD)?
Clean, cool environment
Stabling
Low respirable dust
Do not feed in nets or round bales outside
How long can it take a horse to recover from equine asthma?
Clinical remission: 4-8 weeks
Reduction of smooth muscle mass: 12 months
What breeds are pre-disposed to ventricular septal defects?
Section As, standardbred, Arabians.
What are some prognostic criteria for ventricular septal defects?
- Size of VSD and chambers
Maximal shunt velocity
Present of arrythmias and murmurs
CHF
What conditions could cause myocardial disease?
Electrolyte abnormalities
Increased myocardial muscle mass
Increased chamber size
Myocarditis
Which bacteria are related to myocarditis?
Staphlococcus aureus, steptococcus equi and clostridium equi
What physiological dysrhythmia is most common in the horse?
2nd degree AV block
What breeds are particularly susceptible to atrial fibrillation?
Thoroughbreds, standardbreds, draught horses
What are the clinical signs of atrial fibrillation?
None
Exercise intolerance/poor performance
Epistaxis
Weakness/syncope
Myopathy
Colic
CHF
What are the treatment options for atrial fibrillation?
Quinidine sulphate
DC cardioversion
What side effects can occur with using quinidine sulphate to treat atrial fibrillation?
Fatal dysrhythmias
Colitis
Laminitis
Nasal oedema
Ataxia
What pharmacological treatment options are available for ventricular dysrhthymias?
Lidocaine
Magnesium
Procainamide
Amiodarone
Definition of endocardiosis
Valvular degeneration (progressive)
List the common clinical signs of bacterial endocarditis
Congestive heart failure
Fever
Cardiac murmur
Tachycardia
Tachypnoea
What are the clinical signs of pericardial disease?
Venous distention
Ventral oedema
Muffled heart sounds
Pericardial friction rubs
Pleural effusion
What pathogens are commonly associated with pericardial disease?
Equine viral arteritis
Equine influenza
Streptococcus pneumoniae
E.coli
Actinobacilus
How is Influenza A virus transmitted?
Aerosol (and fomites) - downwind 1 mile
What are the clinical signs of influenza A?
Fever
Cough
Nasal discharge
How is equine herpes virus 1 and 4 transmitted?
Inhalation of aerosol
Contact with infected fomites
Reactivation from latency
What are the clinical signs equine herpesvirus 1 and 4?
Fever, occasional mild cough, slight nasal discharge, poor performance
How do you treat equine herpesvirus 1 and 4?
Rest in athletic animals, EHM, nursing care and anti-inflammatories, vaccinations
How is equine viral arteritis transmitted?
Respiratory, venereal and congenital
Indirect means
What is the pathogenicity of equine viral arteritis?
Invades upper and lower respiratory tract. Infected monocytes and T lymphocytes transport EAV to the regional lymph nosed where it undergoes a further cycle of replication before being released into the bloodstream
What are the clinical signs of equine viral arteritis?
Asymptomatic
Fever
Nasal discharge/ conjunctivitis
Loss of appetite/ depression
Respiratory distress
Skin rash/muscle soreness
Abortion
What is the main source of lungworm via pasture contamination?
Donkeys
Describe the normal heart sounds of the horse:
S4 - onset of atrial systole
S1 - Onset of ventricular systole, closure of AV valves, opening of semilunar valves
S2 - Onset of diastole, closure of semilunar valves, open AV
S3 - Rapid ventricular filling
What features help to aid classification of a heart murmur?
Grade/intensity
Timing
Radiation
Point of maximal intensity
How is a mitral valve murmur classified?
Timing - holosystolic, pansystolic, mid-late systolic
Grade - any
PMI - Left over mitral valve
Radiation - caudo-dorsally
Character and shape - band, crescendo
What general structures are typically involved with unilateral nasal discharge?
Anything rostral to the nasal septum
When investigating nasal discharge, what other examinations may be helpful to aid diagnosis?
Oral/dental exam
Neurological exam
What are common differentials for unilateral discharge in the young horse?
Primary infections and congenital problems
What are common differentials for unilateral discharge in the older horse?
Neoplasia, ethmoid haematoma and dental disease
What is haemoptysis?
Coughing up blood
How long until acute blood loss can be detected on PCV?
12-24 hours
What are the indications for blood transfusion in acute blood loss?
Tachycardia and tachypnoea
Decreased pulse quality
Cool extremities
Pale MMs
Mentation changes
Increased blood lactate
Decreased PCV
What structures are involved in bronchopneumonia?
Bronchi and parenchyma
What are the 3 stages of pleuropneumonia?
Exudate stage
Fibrinopurulent stage
Organisation stage
What are the risk factors for pleuropneumonia?
After viral infections, strenuous exercise, transportation and elevation of the head, GA, overcrowding, dysphagia
What are the clinical signs of pneumonia?
Tachycardia/tachypnoea
Respiratory distress
Fever
Anorexia, depression
Nasal discharge
Exercise intolerance
Crackles and dull areas on auscultation
What additional signs are seen with pleural pneumonia?
Pain intercostal spaces
Reluctance to walk, colic
Grunting during respiration
Abduction of elbows
Ventral oedema
What is the typical 1st line treatment of pneumonia?
Penicillin and gentamicin IV
Additional metronidazole if aspiration pneumonia.
In which intercostal space in thoracocentesis performed?
7/8 above costochondral junction
What are the risk factors for respiratory disease in foals?
Systemic sepsis (FPT), congenital abnormalities, meconium aspiration, milk aspiration, birth trauma
What is acute respiratory distress syndrome in the foal?
Non-cardiogenic pulmonary oedema, decreased pulmonary compliance and ventilation/perfusion mismatching
What can meconium aspiration result in?
Mechanical airway obstruction
Regional air trapping
Surfactant inactivation and displacement
Chemical pneumonitis and alveolitis
Persistent pulmonary hypertension
What are the pre-disposing factors for milk aspiration?
Generalised weakness, poor suckle reflex, dysphagia, congenital abnormalities
Where is the most common site of rib fracture in the foal?
At the costochondral junction
What parasite can cause pneumonia in the foal?
Parascaris spp
What is the most common bacterial pathogen to cause pneumonia in the foal?
E.coli
What are the clinical signs of Rhodococcus equi in the foal?
Insidious, LRT infection
Fever, lethargy
Coughing, tachypnoea, dyspnoea
Extrapulmonary disorders
What pathogen causes strangles?
Streptococcus equi
What are the clinical signs of strangles?
Sudden pyrexia
Mucopurulent nasal discharge
Retropharyngeal and submandibular LN abscessation
Pharyngitis
How soon after strangles infection does abscessation of lymph nodes occur?
3-14 days
What is the treatment for strangles?
NSAIDs
Soft, palatable, calorific diet
Abscess management
Isolation
Nursing care
What are common conditions of the external nares?
Epidermal inclusion cysts
Redundant alar folds
Lacerations
What is dynamic pharyngeal collapse?
Collapse of the pharyngeal wall when negative pressure is at its highest. May be associated with guttural pouch tympany and DDSP.
What are the complications associated with recurrent laryngeal neuropathy?
Dysphagia, aspiration pneumonia, avoid excessive abduction and implant failure with laryngoplasty
What are the pre-disposing factors for jugular thrombosis?
Systemic inflammatory response syndrome
Multi-organ dysfunction syndrome
Irritant drugs
Poor catheter placement
Poor catheter use
What is the treatment for jugular thrombosis?
Broad spectrum antibiotics
Anti-inflammatories
Heparin
Vasodilators
Raise head
What is an aortoiliac thrombosis?
Partial or complete occlusion of the terminal aorta and external/internal iliac arteries by an organising thrombus.
What are the clinical signs of aortoiliac thrombosis?
Poor performance
Exercise-associated hindlimb lameness
Breeding failure in stallions
Cold limbs and weak pulses after exercise
How do you treat aortoiliac thrombosis?
NSAIDS, aspirin, fenbendazole
What is the most common form of sudden death exercise in horses?
Vascular rupture
What horses are pre-disposed to aorto-cardiac fistula?
Intact males
