Respiratory Flashcards
Left lobe
All domestic species have two lobes - cranial and caudal
Cranial clearly divided into two parts both supplied by some bronchus
- Cranial and caudal parts of left cranial lobe
- Not in horse
Accessory lobe
Ventral midline between caudal lobes of left and right lung
Own pleura - mediastinal recess
Right lobe
Four lobes - cranial, middle, caudal, accessory
Not horse
Ruminants:
- Look as though 5 lobes but two most cranial are supplied by the same lobar bronchus
- Cranial and caudal parts of cranial lobe
Ruminant and pig: cranial lobe supplied by tracheal bronchus
Visceral (pulmonary) pleura
Attached to surface of lung including fissures - contains abundant elastic fibres
Parietal pleura
Derived from the somatic mesoderm and it lines the wall of the pleural cavity
3 compartments:
- Costal pleura: lines inside of lateral wall of ribcage
- Mediastinal pleura: lines the mediastinal
- Diaphragmatic pleura: lines the cranial surface of the diaphragm
Mediastinum
Parturition between left and right pleural sacs
Contains: heart in pericardiac sac, thoracic trachea, thoracic oesophagus, thymus, mediastinal LN, great vessels, nerves
Does not contain: lungs, caudal, vena cava, right prenic nerve
Pharynx
Connect orals cavity with oesophagus and nasal cavity with larynx
Soft palate seperates rostral part of pharynx into dorsal and ventral portion: nasopharynx and oropharynx
Larynx
Bilaterally symmetrical tube-shaped musculocartiligenous organ connects pharynx and trachea Protects trachea from aspiration Increases intra-abdominal pressure Important for vocalisation Richly innervated by vagus nerves
Caudal laryngeal nerve
Paralysis of left recurrent laryngeal nerve - stertorous sounds produced at inspiration (roaring) - air flow passively vibrating a lax adducted vocal fold
Pores of Kohn
Gaps in the alveolar septa to enable more efficient movement of inspired air between alveoli
Infant respiratory distress syndrome
Stiff lungs with low compliance
Alveolar collapse
Alveoli filled with transudate
Treat with synthetic surfactant
Exercise induced pulmonary haemorrhage (EIPH)
Small blood vessels in lung burst under high pressure and bleed into airway
Epistaxis in small proportion of EIPH cases
Racehorses
Pulmonary embolism
Obstruction to a branch of pulmonary artery
May be fatal if both pulmonary trunk or both pulmonary arteries are blocked
Enlargement of bronchial arteries by dilation
Angiogenesis: new bronchopulmonary arterial anastomoses - can bypass obstructed PA
Fick’s law
Rate of transfer through a sheet of tissue is proportional to the tissue area and the difference in partial pressure between the two sides and inversely proportional to the the tissue thickness
Area of the respiratory surface
Thickness of the respiratory surface
PO2 difference between alveolus and capillary
Pulmonary oedema
Guttural pouch
Air filled pouch
When infected, carotid artery bleed into nasal cavity and out of nose
Brachycephalic respiratory issues - anatomy
Larynx and nasal cavities - greatest resistance to airflow
Brachycephalics have:
- Narrow nasal passages
- Shorter jaw and misaligned teeth
- Wider optical cavity
- Longer nasal cavity
More resistance to airflow - increase respiratory effect
Longer soft palate - more effort, inflammation, less space - positive feedback
Narrow trachea, laryngeal collapse can occur
Tracheal collapse
Common in some breeds of dog e.g. Yorkshire terrier
Reduced exercise capacity
Not ventilating properly
Apply tracheal stent - good for younger dog
Pulmonary surfactant
Oppose surface tension
Polar phospholipid secreted from type II alveolar cells (pneumocytes)
Increases compliance, promotes alveoli stability, keeps alveoli dry
Alveoli emphysema
Sometimes die to ischaemia of alveolar wall due to obstruction of bronchial arterial supply or alveolar capillaries
Hormonal control of airway diameter
Presence of many beta2 adrenergic receptors:
- Highly sensitive to adrenaline
Cytokine production by inflammatory cells:
- Mostly bronchoconstrictors (histamine, prostaglandin D2, F2alpha etc.)
- Prostaglandin E2 and prostacyclin are bronchodilators
Haemoglobin
O2 binds loosely and reversibly with the heme portion of Hb
High PO2 - O2 binds to Hb
Low PO2 - O2 released from Hb
Bohr effect
Shift of oxygen-haemoglobin dissociation curve to the right due to increased CO2 concentration
Shift to the right enhances O2 unloading in the tissues and increasing oxygenation of blood in the lungs
The Haldane effect
Binding of O2 with Hb tends to displace from the blood
When O2 binds Hb in the lungs, the Hb becomes a stronger acid
Causes displacement of CO2 from blood to alveoli
Avian air sacs
1 interclavicular sac 2 cervical sacs 2 anterior thoracic sacs 2 posterior thoracic sacs 2 abdominal sacs
Act as bellows to ventilate the lungs
Recurrent Airway Obstruction (RAO)
(chronic obstructive pulmonary disease)
Horses
Hyperactive airway disease - due to straw bed and dry hay
Usually bronchiolitis
Mucus plugging of bronchioles
Mucus flooding of adjacent alveoli
Accumulation of neutrophils in airway lumen
Decreased compliance, slightly impaired gas exchange, reduced arterial PO2, V/Q (ventilation/perfusion) mismatch, airway closure during expiration (air trapped)
Short-term: atropine
Longer term: bronchodilators, clenbuterol (s/e sweating, trembling, tachycardia, excitement), salbutamol (inhaled), iatropium (inhaled), steroids (dexamethasone, risk of laminitis), mucolytics
Management
Nature of cough
Upper airway: harsh, loud, non-productive
Lower airway: soft, muted productive
Painful conditions: more muted cough
Normal respiratory rates
Horse: 8-15 Cow, sheep, pigs: 10-30 Goats: 25-35 Neonates - foal/calf: 20-40 Dog: 10-30 Cat: 24-42 Rabbit: 30-60
Expriatory distres
Intrathoracic airway obstruction
Bronchoconstriction - RAO
Farmer’s disease in cattle
Tracheal collapse in dogs and horses
Orthopnoea
Difficulty breathing while recumbent
E.g. Pleural fluid accumulation, neonates, diaphragmatic hernia, congestive heart failure
Nasal discharge
Serous, mucoid, purulent, sanginous (haemorrhagic)
Discharge of ingested food material or fluids e.g. dysphagia
Profuse or scant, continuous or intermittent
Unilateral: originate in structures rostral to the caudal end of the nasal septum although low volumes of discharge from lower in the respiratory tract can be unilateral
Bilateral: caudal structures or bilaterally affected rostral structures
Foul odour: may indicate anaerobic infection, necrotising conditions or connection to oral cavity
Epistaxis or haemophysis (blood in the sputum)
Alveolar macrophage
Phagocyte resident within the alveolus - normally one per alveolus
Ingest particles that reach the alveolus
Atelectasis
Primary atelectasis: failure of lung tissue to expand at birth
Secondary atelectasis: acquired/collapse
- Compression: pulmonary or mediastinal masses, prolonged recumbency in LA, prolonged abdominal distension in LA, hydrothorax, pneumothorax
- Obstruction: common in cattle (lack of collateral ventilation between lobules, thick fibrous septums between lobules), due to bronchiolar obstruction by exudate, distended alveoli collapse as trapped air is absorbed, collapsed alveoli contain a little fluid and macrophages
Emphysema
Excessive air in the lung
- Alveolar: permanent abnormal enlargement of air spaces distal to the terminal bronchioles often due to destruction of alveolar walls by neutrophil elastase (e.g. RAO)
- Interstitial: septal lymphatics are dilated with air secondary to forced expiration e.g. pneumonia in cattle
- Compensatory: emphysema is adjacent to an area of consolidation
Pigmentation
Melanosis: deposition in alveolar walls - health animal but meat may be condemned
Anthracosis: accumulation of carbon in alveolar macrophages -has to be very severe to be clinical, keeps macrophages busy, causes infection
Hyperaemia
Increased blood flow into tissue - acute inflammation
Affected areas of lungs are dark red in colour
Cranioventral lungs often affected in association with aspiration pneumonia
Congestion
Decreased blood flow from tissue
Diffuse in cardiac failure
Grey/blue parts of lungs
Terminal pulmonary congestion is also seen in animals euthanised with barbiturates
Pulmonary oedema
Flooding of alveoli by fluid - mixes with surfactant - foam - compromises ventilation
Pathogenesis:
- Cardiogenic
- Neurogenic (sympathetic stimulation in acute brain damage - increases pulmonary capillary hydrostatic pressure)
- Excessive fluid therapy
- Damage to endothelium or epithelium - toxic substances, acute inflammation process
- Haemorrhage, thrombosis, embolism, infarction
Rhinitis and sinusitis
Acute, subacute, chronic
Localised or part of a systemic disease e.g. malignant catarrhal fever (herpesvirus)
Infectious or non-infectious (allergic or idiopathic)
Serous, catarrhal (mucoid), purulent/suppurative, necrotising, ulcerative, haemorrhagic
Sequelae: resolution, healing by scar formation, extension to other parts of the respiratory tract
Inflammation may localise and persist in the guttural pouches
Bronchopneumonia
Bacterial infection
Cranioventral region of lung
Spread by extension form lobule to lobule along the airways or by necrosis of alveoli and septa (toxin-producing bacteria)
Sequelae: resolution, detrioration, (abscesses, pleuritis, death -hypoxaemia, toxaemia), persistance (fibrosis or bronchiectasis - permanent dilation of some bronchi)
Lobar pneumonia
Sequelae: commonly death, fibrosis of affected areas in surviving animals
Pathogenesis:
- Inhaled mycoplasmas and some viruses
- Initially inflammatory reaction in the bronchioles
- Interstitial lymphocytic proliferation often to the extent of forming complete lymphoid follicles around the airways (‘cuffing’)
- Lymphoid follicles - cell mediated response to chronic persistent antigenic challenge
- Mostly of economic importance - reduced growth rate
Interstitial pneumonia
Secondary to haematogenous rather than inhaled damage
Inflammation is centred on interstitial septa rather than airways
Diffuse distribution rather than cranioventral
Acute:
- Infections e.g. distemper
- Inhaled chemicals e.g. smoke
- Ingested toxins e.g. paraquet or tryptophan ‘fog fever’
- Systemic conditions e.g. uraemia
- Hypersenstivity reactions e.g. lungworm
Chronic:
- Infections e.g. Jaagsieke in sheep
- Inhaled dusts e.g. coal dust or silica
Paraquet
Herbicides, cats and dogs
Pneumotoxin: selectively damages alveolar epithelium, allows exudation of fluid into the alveolar lumen - loss of respiratory function
Low doses: accidental ingestion, moderate pulmonary oedema, clinical signs of respiratory distress - widespread fibrosis of alveolar walls interferes with gas exchange
High doses: malicious, severe fatal pulmonary oedema, haemorrhages
Tryptophan
Acute Bovine Pulmonary Oedema and Emphysema ‘Fog Fever’
Adult cattle moved to lush pasture (autumn)
High morbidity and mortality
Pathogenesis: excess tryptophan in autumn grass metabolised in the rumen - toxic to type I pneumocytes
Pathology: lungs enlarged and wet with markedly widened interlobar septa (oedema and emphysema) - flooding of alveolar with protein-rich fluid)
Granulomatous pneumonia
Caused by agents such as mycobacteria e.g. TB and fungi e.g. aspergillosis
Inflammation is chronic and peristent
Macrophages - predominant cell type
Granulomas may be mistaken for tumours
Acid-fast bacilli in mycobacterial infections - Ziehl-Neelsen (inset)
Fungi stain with PAS or silver stains
Tumours and tumour-like lesions of the URT
Nasal and nasopharyngeal polyps:
- Single or multiple (often pedunculated) masses secondary to chronic irritation/inflammation
- Composed of hyperplastic or ulcerated epithelium, granulating to be fibrous stroma and varying numbers of inflammation cells
Nasal and paranasal sinus tumours: usually malignant carcinomas or sarcomas
Lung neoplasia
Primary: usually invasive carcinomas, hilar region before spreading within lung and to regional LN
Secondary: mostly metastases - mammary tumours, haemangiosarcoma and osteosarcoma
Paraneoplastic disease
Marie’s disease: space occupying lesion in lungs maybe associated with periosteal thickening of long bones (hypertrophic pulmonary osteopathy)
Viral infections of the LRT
Influenza (horses, pigs, dogs)
Bovine respiratory syncytial virus (BRSV) (cattle)
Bordetella bronchiseptica
Strict aerobe, Gram negative rod, slow growing (48h)
Normal inhabitant of URT
Associated with kennel cough and bronchopneumonia following distemper
Pathogenesis and pathology:
- Initial trauma, viral infection
- Adhesion to respiratory epithelium (cilia) of trachea
- Proliferation of B. bronchiseptica in the airway
- Release of toxins -> irritation and coughing
- Epithelial necrosis
- Peribronchial inflammation and interstitial pneumonia
- Severe pneumonia sue to secondary invaders e.g. beta haemolytic streptococcus
Pathogenecity: adherence to respiratory ciliated epithelium: FHA, fibriae, pertactin
Toxins: adenylate cyclase (leucocyte toxin), tracheal cytotoxin (inhibits DNA synthesis in ciliated cells), dermonecrotic toxin CADP-ribosylation
Pasteurella multocida
Gram-negative rod Oxidase-positive Large grey mucoid colonies Strong catarrhal smell Secondary URT infections Common bacteria in dog bite wounds Capsular serotypes A and D (and Pasteurella pneumotropica)
Dogs and cats: severe suppurative pneumonia and pleuritis
Rabbit snuffles: chronic nasal discharge and sneezing, (sometimes fatal) respiratory disease, colonisation of respiratory tract, middle ear, genitalia, (maybe) lungs
Streptococcus
Found in normal URT
Beta Haemolytic Streptococci highly virulent in the lung
Streptococcus zooepidemicus:
- Many animal sp. esp horse and dog
- Inhabits skin, respiratory mucosa
- Secondary invader post viral disease in horses, wound infections
Streptococcus canis
M. proteins, toxins, capsules, superantigen
Actinomyces
Gram-positive, filamentous, branching
Aerobic growth
Commensal in canine oral cavity
Cause of granulomatous thoracic infections in dogs
Localised granulomatous abscesses of skin: chronic and progressive
Nocardia spp.
E.g. Nocardia asteroides (soil bacteria)
Gram positive rods, thin, short filaments
Partially acid fast
Growth within and destruction of macrophages
Chronic progressive, suppurating thoracic granulomas
Resistance to penicillin and some other antimicrobials
Prolonged use of TMP, tetracyclines, ampicillin
Pathology: copious red-brown exudate in pleural cavity, may be chronic with adhesion formation
Chlamydophilia felis
Intracellular gram negative rods
Conjunctivitis in cats, nasal discharge progresses to interstitial bronchopneumonia
Vaccination
Canine nasal aspergillosis
Aspergillosis furnigatus
Surgical delivery of antifungal
Pathology:
- Nasal turbinates progressively destroyed by chronic granulomatous (and eosinophilic) inflammation
May be yellow green mycotic exudate in the caudal nasal cavity
Numerous fungal hyphae on histopath exam
Special stains: Grocott and PAS
Bovine respiratory disease complex
Enzootic pneumonia or ‘shipping fever’
Bovine herpesvirus: IBR, fibrinous laryngitis and tracheitis, intranuclear viral inclusions, vaccines
Bovine respiratory syncytial virus (BRSV): Paramyxoviridae, URT infections, bronchitis, bronchiolitis, vaccines
Bovine parainfluenza virus: Paramyxoviridae, aka parainfluenza3 (PI3), URT infections, vaccines
Bovine respiratory disease comples
Secondary infections
Mannheimia haemolytica: nasopharynx commensal
- Epizootic (epidemic) pneumonia in cattle - shipping fever
- Bovine pneumonia pasteurellosis: (And P. multicida), bronchopneumonia is fibrinous to necrotising, pleuritis frequent
- Also indicated in meningitis and polyarthritis (2-4m housed calves)
- Sporadic cases of peracute fatal mastitis in cow (from suckling calves may transfer the organism)
Vaccination
Pasteurellosis in lambs
Septicaemia, severe pleuritis and pericarditis
Alse severe mastitis in sheep and goats
Pasteurella trehalosii:
- Acute or peracute septicaemia in older lambs: 5-12m
Histophilus somni
Normally commensal in genital tract Transient URT Cause of peracute death in young calves: - Acute thromboembolic meningoencephalitis - Pneumonia - Mycocarditis
Mycobacterium
Gram positive, acid fast
Strict aerobes, very slow growing
Resistant to drying and chemical agents]
Virulent species fully resist intracellular killing
Bovine tuberculosis
Chronic, eventually fatal, pneumonia and wasting
Open case: continuous shedding from lesions excreting to the exterior e.g. kidney, udder
Pathology:
- Granulomatous pneumonia and lymphadenitis
- Nodules have caseating (‘cheesy’) cut surface
Camelids are very susceptible - extra zoonotic risk
Mycoplasma infections
Smallest living bacteria, inhibit mucosal surfaces (genital tract esp horses)
Acquire host antigens to evade immune response
Involved in Bovine Respiratory Disease Complex
No cell wall, not susceptible to beta-lactam antibiotics
Cattle: M. bovis - arthritis, mastitis (and pneumonia)
Calves:
- Progressive cranioventral consolidation in the main airways of affected lobules with thickening of the surrounding connective tissue
- Lymphoid nodules and follicles around airways - may compress bronchial lumen
- Mixed cellular exudate in airways, partial alveolar collapse
- Slight thickening of alveolar walls with lymphocytes
Mycoplasma mycoides subsp SC - contagious pleuropneumonia (cattle):
- Notifiable, not in UK, USA, Australia
- Serious disease in Asia, Africa, Southern Europe
- Aerosol or close contact transmission
- Fibrino-necrotic bronchopneumonia with fibrinous pleuritis, dorsocaudal areas may be affected, interstitial septa markedly widened by fibrinous exudate and oedema
- Necrotic area may be encapsulated
- Usually unilateral lung involved
Respiratory viruses of sheep
Parainfluenza virus (PI3) - occasionally lambs, pneumonia
Respiratory syncytial virus (RSV)
Adenovirus (ovine and bovine)
May predispose to infection with Mannheimia haemolytica as part of enzootic pneumonia complex in sheep
Fungi in respiratory disease
Cattle and sheep
Aspergillosis Mycopolysporium Fungal allergy: A. fumigatus and others 'Farmer's lung': coughing, weight loss, increased respiratory rate, decreased milk yield Type I: rhinitis and fungal asthma Type III: allergic alveolitis
Rhodococcus equi
Gram positive rod, variably acid fast
Bacteria scavenged by alveolar macrophages but not killed - destruction of these macrophages leads to a pyogranulomatous response
Chronic suppurative bronchopneumonia - foals 1-6m
- Anorexia, depression, fever, dyspnoea, cough
Foci of caseous necrosis in lungs
High mortality rate (40-80%)
Dissemination to other viscera can occur especially abdominal organs - liver and intestine
- Depression, fever, diarrhoea, colic, weight loss/failure to grow, poor prognosis
Treat: erythromycin and rifampin, clarithromycin or azthromycin with rifampin
Adult horses are immune
Equine influenza virus (EIV)
Infection of URT that may spread to LRT and cause bronchitis and broncholiotis
Cough, pyrexia, depression
Secondary infections: Strep, Staph, Klebsiella
Vaccinate requirement for competing horse in UK
Equine herpesvirus (EHV)
EHV1: respiratory disease, abortion, paresis
EHV4: mainly respiratory disease, rarely abortion
EHV5: equine multinodular pulmonary fibrosis, infection of URT, nasal discharge, coughing, pyrexia
Vaccine EHV1 and EHV4 available
Equine arteritis virus
Arterviridae
Infection of URT, systemic spread and infection of endothelial cells and macrophages
May spread to lung in macrophages and cause interstitial pneumonia
Nasal discharge, conjunctivitis, oedema, abortions
Frequently subclinical if less virulent
Notifiable in UK in stallions or in mares covered or inseminated in the last 14d
Equine guttural pouch mycoses
Aspergillosis nidulans, severe bleeding form the nose/dysphagia
Treatment: local delivery of anti-fungals, ligation of carotid, systemic antifungals?
Atrophic rhinitis
Pigs
- Stimulate osteoclasts to resorb bone
- Combination of early colonisation with Bordetella bronchisepta (dermonecrotic toxin - damages osteoblasts) and P. multocida (osteolytic toxin - stimulates osteoclasts)
- Malformed twisted snout
Contagious pleuropneumonia
Pigs
Actinobacillus pleuropneumoniae Acute or chronic fibrinohaemorrhagic pneumonia with pleurisy in intensive pig production Can kill in 24h Spreads throughout all lung lobes Pleural adhesions found in chronic cases
Actinobacillus suis: pleuopneumonia-like disease (mild)
Haemophilus parasuis:
- Glassers disease
- Polyserositis (pleuritis, pericarditis, peritonitis)
- Suppurative pneumonia
- Meningitis and polyarthritis
Mycoplasma hyopneumonia:
- Enzootic pneumonia
- Widespread, common, predisposes to other respiratory diseases
- Transmitted by aerosol
- Cranioventral consolidation and red/grey discoloration
Other mycoplasma: M. hyosynoviae and M. hyorhinis
Porcine Reproductive and Respiratory Syndrome (PRRS)
Arteriviridae
Infection of URT, systemic spread in macrophages and endothelial cells (vasculitis)
May cause respiratory signs and lead to interstitial pneumonia
Part of porcine respiratory complex
Weaned pigs, tachypnoea, thumping, eyelid oedema, conjunctivitis
Swine influenza
H1N1, H3N2, H1N2
Sudden outbreaks of respiratory disease with barking cough and respiratory distress in naive herds
Bronchiolities and pneumonia
Aujeszky’s disease
Pseudorabies
Pig
Porcine herpesvirus
Sneezing, coughing, laboured breathing, fever and weight loss
CNS disease in piglets, abortion, still birth, mummification
Notifiable, Northern Ireland, Vaccinate
Porcine circovirus
Type 2
Immune suppressive - predispose pigs to other infections
Porcine respiratory disease complex
Post-weaning multisystemic wasting syndrome (PMWS) and porcine dematitis and nephropathy syndrome
2 vaccines available
Avian chlamydia
Psittacosis, zoonotic, notifiable
Spleen and liver of psittacine birds - parrots, parakeets, macaws
Faecal shedding - inhalation by other birds and humans
Mycoplasmas of poultry
M. gallisepticum: chronic respiratory disease - reduced growth, reduced egg production, adherence to ciliated epithelium, removes cilia, rare in UK
M. synoviae: synovitis in poultry, may include URT disease
M. meleagridis: air sacculitis in turkeys
Transovarian (vertical) transmission and respiratory route
Skeletal changes due to biotin deficiency
Equine influenza vaccination
1st vaccination -> 21-92d
2nd vaccination -> 150-215
3rd vaccination
Horses may not race until 8d after vaccination
Jockey club rules
Summer pasture associated pulmonary disease
(SPAPD)
Horses
Keep stabled
Allergens in pasture
Inflammatory airway disease
(IAD)
Horses
Young performance horse, 20-65%
Excessive mucus in airways
Cough and/or reduced performance
Implied cause:
- Bacterial (Strepococcus zooepidemicus, Strep pneumonia, Actinobacillus, Mycoplasma)
- Viral
- Blood from EIPH: causes inflammation and/or secondary infection
Kennel cough complex
Bordetella bronchiseptica:
- Attaches to cilia in URT
- Release of bacterial toxins damage the respiratory epithelium
Canine parainfluenza virus (CPIV):
- Mild respiratory disease
- More severe if combined with Bordetella
Canine adenovirus (CAV):
- Type I: hepatitis (ICH)
- Type II: respiratory disease
Canine herpesvirus1 (CHV1): systemic and often fatal in neonate puppies Canine respiratory corona virus: mild respiratory disease, highly contagious Mycoplasma: various types
Cough, retching, nasal +/- ocular discharge, sneezing
Systemic: depression, pyrexia, inappetence, bronchopneumonia
Treat: rest, antibiotics, cough suppressants, bronchodilators, mucolytics, supportive care
Intranasal vaccines
Stimulates mostly IgA and mostly on mucosal surface
Serum IgG also produced but at lower levels compared to parenteral application
Advantages: stimulates local response in respiratory tract, act more rapidly compared to systemic vaccines
Disadvantages: shorter duration of immunity, difficulty to administer to unco-operative dogs
At least 5d before kennelling
Canine distemper
Morbillovirus
Shed in all body fluids, spread by aerosol or close contact
Dogs with insufficient immune response:
- Spreads to epithelial cells of respiratory, GI and urinary tract and CNS
- Immunosuppression - secondary bacterial infections
- Typically interstitial pneumonia but frequently secondary infection thus more likely bronchointerstitial
Nasal/ocular discharge, cough, D, V, depression, anorexia
CNS signs:
- Seizures, inco-ordination, paresis/paralysis, muscle tremors, ocular lesions (degeneration of retina, optic neuritis)
- Neuronal destruction
- Demyelination
- Intra-nuclear and intra-cytoplasmic viral inclusion bodies
- Hard pad and hard nose - hyperkeratosis
- Distemper teeth: dogs that develop distemper before they have their permanent teeth - hypoplasia of the enamel
Treat: antibiotics, fluids, sedatives, anti-convulsives
Bronchial pattern
Mineralisation of the bronchial wall - age related change
Thickening of bronchial wall and/or increased diameter
End-on appearance of the bronchus
Increase bronchial diameter with no evidence of tapering of the bronchus in the periphery - bronchiestasis
Interstitial patterns
Elements of lung that don’t contain air
Classifed as local or diffuse and nodular or unstructured (hazy)
Metastatic neoplasia
Other Dx: haematoma, granulomas, fluid filled bronchi, abscesses
Pulmonary masses i.e. primary neoplasia: larger than nodules and may cause displacement of the mediastinal structures
Unstructured (hazy) interstitial pattern:
- Diffuse: Underexposed, taken during expiration, ‘old dog lung,’ lymphoma, pneumonia, disease in transition
- Localised: partial lung collapse, haemmorrhage/contusion, pulmonary embolism, bronchial FB, diseases in transmission
Alveolar pattern
Lack of air in alveoli
Uniform increased lung opacity with no visibility of pulmonary vessels in the affected area
Localised: bronchopneumonia, oedema, haemorrhage, neoplasia, lung collapse/atelectasis
Diffuse: severe bronchopneumonia, severe oedema, near-drowning, smoke-inhalation
Vascular pattern
Enlarged arteries: pulmonary hypertension
Enlarged veins: congestion due to mitral insufficiency
Enlarged As and Vs: overcirculation
Smal As and Vs: hypovolaemia, tetralogy of Fallot
Pleural cavity
Visibility increased by thickening of the pleural membrane or increased volume of pleural fluid result in widening of the pleural fissures
Pneumothorax: Radiolucent space between the cardiac silhouette and sternum, lack of pulmonary vessels in the periphery of the thorax
Pleural fluids: generalised increased opacity in the thoracic cavity, loss of clarity of the cardiac silhouette and diaphragmatic outline
Mediastinum
Contains trachea, oesophagus, heart, aorta and major branches, thoracic duct, lymph nodes, and nerves
V/D cranial mediastinum should not exceed 2x width of vertebral bodies
Displacement?
Pneumo-mediastinum:
- Radiolucency in the mediastinum with increased visibility of blood vessels, oesophagus and tracheal wall
- Secondary to pneumo-mediastinum: gas lucency into the fascial planes of the neck and thoracic wall, pneumo-retroperitoneum
Mediastinal mass:
- Soft tissue opacity
- Displacement of adjacent structures e.g. the trachea
- Thymus is normally visible in young animals
- Neoplasia, abscess, granulomas, cysts, sternal lymphadenopathy and oesophageal dilation (secondary to vascular ring anomaly)
Diaphragm
Thoracic surface usually visible because of adjacent gas filled lungs
Abdominal surface not usually seen due to ‘silhouettin’ with adjacent liver
Normal intersection point of diaphragm and spine is usually between T11 and T13 (T9-L1)
Caudal vena cava passes through the caval hiatus
Obstructive disease
Dyspnoeic dog or cat
Significant amount of URT or significant number of small airways of LRT
Nasal obstruction: rhinitis, FB, neoplasia, polyp
Trauma, laryngeal paralysis, FB, tracheal collapse
Brachycephalic obstructive airway disease: soft palate, stenotic nares, laryngeal collapse
Fillaroides, asthma, extralumenal mass lesions
Loss of thoracic capacity
Dyspnoeic dog or cat
Fluid/air in pleural space
Organs displaced from abdomen
Less common: neoplasia, marked cardiomegaly
Differential diagnoses: Pleural effusion, pneumothorax, neoplasia, ruptured diaphragm, gross cardiomegaly, cranial abdominal organ enlargment, PPDH (periocardio-peritoneo-diaphragmatic hernia)
Pulmonary parenchymal disease
Dyspnoeic dog or cat
Compromising gas exchange
Diffusion abnormalities due to disease of the alveolar wall and interstitium
Alveolar flooding with oedema, blood or exudate
Abnormal pulmonary vascular supply
Thromboembolism
V/Q mismatch
Differentials: bronchopneumonia, pulmonary oedema, neoplasia, pulmonary haemorrhage, pulmonary fibrosis, LRT parasites
Cat Flu
Feline infectious upper respiratory disease complex
Common problem in cat
Groups of cats
Feline herpesvirus, feline calicivirus, Chlamydophila felis, Bordetella, Mycoplasma, Reovirus, Cowpox
Feline viral rhinotracheitis
Conjunctivitis, rhinitis, tracheitis, laryngitis
Sneezing, hypersalivation, serous or mucopurulent oculonasal discharge
Dendritic corneal ulcers
Repro problems: abortion, congenitally infected kittens (encephalitis and hepatitis)
Feline calicivirus
Oral ulceration
Rhinitis, conjunctivitis, interstitial pneumonia
Arthritis/lameness syndrome
Concurrent infections: FIV/FeLV
Treatment: nursing care, patient support
- Assist respiration: clear secretion from external nares, decongestants, nebulise saline
- Fluids
- Nutrition
- Antibiotics
- Interferon? Aciclovir? Trifluorothymidine?
Chronic bronchitis
Chronic irritation to bronchial mucosa, mucosal hypoplasia, increased mucus production, decreased efficacy of respiratory defence mechanisms
Bronchospasm, reduced airflow, chronic cough
Old small breed overweight dogs
Insidious onset, dry, hacking cough
Drugs:
- Bronchodilators (theophylline, terbutaline, adrenaline, atropine)
- Antibiotics
- Expectorants/mucolytics
- Cough suppressants
- Anti-inflammatory medicine
Feline asthma
aka Feline Allergic Airway Disease (FAAD)
Most common cause of persistent coughing
Antigenic stimulus: inflammation, mucous, oedema and bronchoconstriction
Tracheal wash: inflammatory population with predominate eosinophils
Maintenance:
- Corticosteroid - tapered, nebulise
- Bronchodilators: terbutaline, theophylline
Aelurostrongylus
Feline lungworm
Occasionally results in clinical signs
Alveolar/intersitial disease
Prolonged course of Fenbendazole
Canine Lungworm
Angiostrongylus vasorum, Filaroides (Osterus) Osteri, Dirofilaria, other filaroides sp, crenosoma
Eosinophilia, evidence of parasite larvae
7d of fenbendazole
Milbemycin and moxidectin specifically licensed
Tracheal collapse
Loss of normal tracheal ring structure
Cervical trachea collapses on inspiration
Thoracic trachea collapses on expiration
‘Goose honk’ cough
Yorkshire terriers and poodles, 4-7y
Fluoroscopy - grade I-IV
Treat:
- Medical management like chronic bronchitis
- Surgery - high risk, intralumenal stent (palliative), placement of prosthetic rings around the trachea
Foreign bodies
Persistent focus of irritation, infection and airway obstruction
Cough +/- focal pneumonia
Treat: endoscopy +/- surgery
Pulmonary infiltrate with eosinophils (PIE)
Dogs
May be immune-mediated, seasonal, associated with atopy
Eosinophila, bronchial/alveolar pattern, bronchoscopy
Treat:
- Control secondary infection
- Corticosteroids at immunosuppresive doses
Pleural effusion
Septic effusion - fever and pain
Trauma - diaphragmatic hernia
Neoplastic effusion
Hypoproteinaemia
Fluid: cytology, Gram stain, total protein, triglyceride and cholesterol levels, bacterial culture and sensitivity
Hyperglobulinaemia in a cat with FIP
Specific tests: clotting times, virus titres (FeLV, FIV, FIP)
Radiography - before and after thoracocentesis
Ultrasound: Detection of masses with mediastinum and pleura, enhanced by presence of fluid, diaphragmatic hermia
Specific pleural diseases
Lung lobe torsion - surgery
Right side heart failure - management of heart failure
Neoplastic effusion - surgery or chemotherapy
Transudate due to hypoproteinaemia
FIP
Diaphragmatic hernia - surgery
Pyothorax
Highly inspissated and viscous nature of the pleural fluid
Drainage unlikely to be sufficient
Systemic antibiotic administration unlikely to penetrate
Implant drains and flush cavity - 5-7d and then antibiotics for 4-6 weeks
Consider exploratory thoracotomy
Chylothorax
Failure of lymph to drain via thoracic duct into the venous circulation - neoplasia, heart failure, idiopathic
Medical: low fat diet and rutin (50mg/kg q8-12h)
- May lead to a reduction in fluid formation
- Fluid can be drained intermittently - reasonable quality of life
- Consider diuresis
Surgery:
- Identification and ligation of all the branches of the thoracic duct and/or provide alternative route for drainage of the pleural fluid
- Pleurodesis also suggested - adhesions between visceral and perietal pleura - destroyed pleural space
Pneumothorax
Small volumes resorbed over a few days
If respiratory distress, drainage of pleural air necessary (dorsal thoracocentesis)
Large/recurrent volume of air/obvious lesion: surgical exploration, identification of the leak and surgical correction
Equine pleuropneumonia
Pasteurella spp., Bordatella spp., Bacteroides spp. (aerobes) - Cranioventral distribution
Pyrexia, lethargy, slight nasal discharge, shallow breathing, guarded cough, painful stilted gait, pleurodynia
Nostril flare, tachycardia, increased jugular pulse height, toxic mm, guarded soft moist cough, foetid nasal discharge
Ventral dullness, ultrasound, xray, transtracheal aspirate, thoracocentesis
Remove excess pleural fluid, antibiotics, anti-inflammatory and analgesia, supportive care
Complications: pulmonary abscesses, pleural adhesions, bronchopleural fistula, constrictive pericarditis, thromboplebitis
Bovine respiratory disease (BRD)
Painful, Expensive and Time consuming
Death, Poor or reduced growth
Welfare
Chronic: Environment
Colostrum (blood samples TP >5.5), mixing, transport, home bred or purchased, nutrition, standard of husbandry
Enzootic pneumonia: flare up, group of calves, reduced feed intake, dull, dry or moist coughing, pyrexia (>40), respiration (>40), tracheal pinch, conjunctivitis, oculonasal discharge, cranioventral
Mycoplasma dispar, bovis, canis, Ureaplasma spp., BVDV, PI3, BRSV, IBR, Bovine coronavirus
Less common: Reovirus 1, 2, 3, adenovirus 1, 2, 3, 4, rhinovirus 1, enterovirus, PI2
More serious infections: Mannhaemia haemolytica A1 and 6, Pasteurella multocida, Arcanobacterium pyogenes, Histophilus somni - DEATH
Treatment (>39.7), correct environment, PME, identify pathogens, revisit, consider vaccination
Bovine herpesvirus 1
Infectious Bovine Rhinotracheitis
Pyrexia, conjunctivitis, cough, tracheitis
Can progress to pneumonia
Genital form:
- Female: infectious pustular vulvovaginitis
- Male: Balanoposthitis
Ocular form, encephalitis, abortion, reproductive failure
Latent infection:
- Resides in trigeminal ganglion - can last indefinitely
- Can recrudesce, reactivate and start shedding again after very long period
- Recrudescence due to stress
- Cannot reliably detect
Status of herd:
- Dairy: bulk milk antibody titres regularly
- Beef: sample cohort
- Monitor abortions
- Investigate pneumonia
Vaccinate - works well, reduce level of virus and shedding
Calf Diptheria
Necrotic laryngitis
Fusobacterium necrophorum
Lesions in mouth, tongue, larynx - foul smelling necrotic lesions
Can be cause by food trapped between teeth and buccal mucosa, sharp teeth, poor hygiene of feeding equipment
Excessive salivation, foul breath, swollen cheeks and abscesses in cheek region, increased respiratory noise, auscultate over larynx and trachea
Antibiotics, tracheostomy or surgery
Chronic hyperplastic rhinitis
Whippets, Dachshunds and cats
Prolonged inflammatory processes with nasal cavity stimulate hyperplasia of mm and increased mucous secretion
Rhinotimy and turbinectomy
Intranasal neoplasia
Most malignant: solid carcinoma or adenocarcinoma, chrondro, fibro, osteo -sarcoma
Exploratory rhinotomy
Benign polypoid rhinitis
Defects in the secondary palate
Congenital: failure of fusionn unable to suckle, nasal return of milk, aspiration pneumonia, chronic nasal discharge (mild)
Acquired: forceful separation - direct trauma or tooth extraction, aspiration pneumonia, chronic nasal discharge, sneezing
BOAS surgery
Rhinoplasty
Staphylectomy
Resection of everted mucosa of lateral laryngeal ventricles
Temporary tracheostomy (optional)
Tracheostomy
Ventral midline skin incision - 2-4 caudal to the larynx
Separate sternohyoid/sternothyroid muscles midline to reveal the ventral trachea
Long stay sutures of 2-0 monofilament nylon are placed around tracheal rings with two tracheal ring separating them
Tranverse incision is made before 4th and 5th tracheal rings between the stay suture
Tube placed into the tracheal lumen
Skin is closed around the tracheostomy tube and the tube is secured by passing umbilical tape or similar around neck
Pre-placed stay sutures are tied in a loose bow
Care:
- Constant monitoring
- Insert sleeve removed and cleaned every 2h
- Nebulise every 4h
- Limit physical activity
- Suction tube only if necessary
Laryngeal paralysis
Congenitial: Bouvier des Flandres, Husky
Acquired (known): trauma, neoplasia, secondary polyneuropathy/polymyopathy
Acquired (idiopathic): Lab, Retriever, Setter, Afghan, St. Bernard
Chronic progressive exercise intolerance, dysphonia, increased respiratory noise, chronic cough, cyanosis and collapse
Left arytenoid lateralisation: suturing of the arytenoid to the thyroid or cricoid
Laryngeal neoplasia
Rare but malignant Congenital rhabdomyosarcoma (oncocytoma), squamous cell carcinoma, adenocarcinoma, chondrosarcoma, fibrosarcoma, lymphoma (cat)
Dysphonia, sonorous respiration, exercise intolerance, respiratory distress
Tracheal trauma
Neck bite wounds, traumatic intubation, blunt trauma to chest (cats)
Subcutaneous emphysema, pneumomediastinum, pneumothorax
Positive contrast study using water soluble, organic iodide solutions, bronchoscopy, exploratory surgery
Treat: conservative therapy if stable, surgical therapy warranted if progressive and respiratory distress is severe
Spontaneous pneumothorax
Lung suspected as the leak and no history of trauma
Ruptured pulmonary bullae or blebs, migrating inhaled plant material, bacterial pneumonia, chronic obstructive lung diseases, asthma, TB, pulmonary neoplasia airway parasite (filaroides)
Stabilise, surgically explore and remove disease lung, prolonged pleural evacuation
Lung lobe torsion
Uncommon
Narrow, deep chests - more frequent
Right middle and cranial lung lobes
Pleural effusions (chylothorax), trauma, thoracic surgery, neoplasia and chronic respiratory disease
Depressed, inappetent, febrile, dyspnoea and a cough, muffled lung sounds, thoracocentesis, u/s, xray, CT
Lobectomy
Diaphragmatic rupture
Muscular (weakest) part of the diaphragm
Effusion can lead to hydrothorax and compromise lung volume
Muffled heart sounds, loss of lung sounds, dull thoracic percussion and an ‘empty’ abdomen
Gastric decompression or emergency surgery
Peritoneopericardial diaphragmatic hernia (PPDH)
Failure of septum transversum to advance leaving space between the two advancing lateral pleuroperitoneal folds of failure of the lateral pleuroperitoneal
OR
Failure of the lateral pleuroperitoneal folds to unite or as a result of intrauterine trauma
May be associated with other developmental defects (sternal and ventral abdominal wall fusion defects, VSD, PS, ASD and PSS)
Repair asap in young animals to reduce risk of adhesions
May be elective in asymptomatic older patients
Oesophageal hitial hernia (EHH)
Defect in the formation of the oesophageal hiatus
Chinese Shar Pei
Chronic gastrointestinal reflux, regurgitation, vomiting
Leading to chronic oesophagitis, oesophageal hypomotility and aspiration pneumonia
Close hiatus and make sure stomach stays in the abdomen
Thoracic wall trauma
Non-penetrating can be managed conservatively
Penetrating:
- Undergo exploratory thoracotomy around traumatic thoracic opening
- Removal or injured or devitalised tissue, provision of pleural damage and closure of thoracic wall (native tissues or synthetic mesh)
Stabilise fractured ribs, consider ventilation
Thoracic wall tumours
Osteosarcoma and chrondosarcoma from costeochondral junction
Haemangiosarcoma, fibrosarcoma, mast cell tumours, infiltrative lipomas can also occur
Full thickness resection and reconstruction of thoracic wall
Bovine Lungworm
Dictyocaulus viviparous
- Trichostrongyle - found in trachea and larger bronchi
- Husk, hoose
Penetration phase (week 1): Larvae migrate to lungs
Prepatent period (weeks 1-3): Development and migration of larvae -> bronchiolitis -> eosinophilic exudate -> blocks passage of air -> alveolar collapse distal to blockage
Patent phase (weeks 4-8):
- Worms mature and egg-producing - Bronchitis (due to adult worms)
- Parasitic pneumonia (areas of consolidation due to re-aspiration of eggs and larvae -> cellular infiltrate by polymorphs, macrophages, FB, giant cells)
Post-patent phase (weeks 8-12):
- Most of worms expelled
- Clinical signs flare up in 25% cases - alveolar epithelialisation, interstitial emphysema, pulmonary oedema, secondary bacterial infection
Baerman technique, second half of grazing season, diaphragmatic lobes - plum-coloured,
Vaccinate 1st season calves, anthelmintic - doremectin
Ovine lungworm
Dictyocaulus filaria (less important: Muellerius, Protostrongylus)
Outbreaks unpredictable - treat affected stock, house/move to clean grazing
Equine lungworm
Dictycaulus arnfeildi
Raised area of over-inflated pulmonary tissue, hyperplastic bronchial epithelium, peribronchial ‘cuffing’
Grazed with donkeys
Ivermectin
Canine lungworm
Angiostrongylus vasorum:
- Metastrongyloid nematode
- Indirect
- Cardiorespiratory signs, coagulopathies, neurological signs
- Baerman technique
- Prepatent period 6-10w
- Bloods: hypochromic anaemia, eosinophilia, co-agulopathy tests, ELISA
- Moxidectin, Milbemycin, Fenbendazole
- Control
Filaroides (Oslerus) osleri:
- Atypical metastrongyloid nematode
- Direct
- Adult worms in tracheal nodules
- Diagnosis difficult - Baerman technique, endoscope
- Fenbendazole
Feline lungworm
Aelurostrongylus abstrusus
- Uncommon
- Typical metastrongyloid
- Indirect
- Faecal exam - Baerman technique
- Fenbendazole
Pre-weaned pigs
Progressive atrophis rhinitis Bordetella bronchisepticum Inclusion body rhinitis (pig CMV) Enzootic pneumonia (Mycoplasma sp) PRRSV Glasser's disease (Haemophilus parasuis)
Weaners, growers and finishers
Bordetella bronchiseptica Glasser's disease Actinobacillus pleuropneumonia Pasteurella multocida Mycoplasma hyopneumonia (EP)/hyorrhinis PRRSV Porcine respiratory coronavirus (PRCV) Influenza PMWS/PCVAD (Aujeszky's disease - pig herpesvirus 1)
Specific respiratory disease in non-immune adult pigs
Glasser's disease Actinobacillus pleuropneumoniae Pasteurellosis Enzootic pneumonia PRRSV Influenza
Mycoplasma hyopneumoniae
Great economic importance
Weaned pigs, increased cough, variance in growth, secondary infection
30-80% pigs have lung lesions at slaughter
Actinobacillus plueropneumonia
Explosive outbreaks of pneumonia with high morbidity and mortality to seroconversion with few clinical signs
Acute fatal respiratory disease with fibrinous pleuritis and firm lung infarcts (lesions largely produced by the toxins) - caudal lung lobe
Aujeszky’s disease
Swine herpesvirus type 1
Notifiable, not present in UK
Swine influenza virus
Rapid involvement of up to 100% pigs Pyrexia, lethargic, prostrate Skin erythema, anorexia Severe, coughing, sneezing, dyspnoea Conjunctivitis Recovery equally rapid (5d) Pregnant sows may abort
Sudden death
Sheep
Peracute pneumonia: Mannheimia haemolytica, ‘Enzootic pneumonia’
Septicaemia
Acute/sub-acute ill health, cough +/- discharges, fever
Acute bacterial/viral pneumonias (fever) Aspiration pneumonia (fever) Parasitic pneumonia (no fever)
Chronic ill-thrift, occasional cough
Lambs
Chronic pneumonia (Mycoplasma, resolved enzootic pneumonia) Lung damage - poor weight gain
Chronic weight loss and breathing difficulties
Adult sheep
‘Slow virus’ diseases - Maedi-Visna, Sheep Pulmonary Adenomatosis
Lung tissue replaced with solid tissues
Only 1-2 animals affected at a time
Ovine pneumonia agents
Mannheimia haemolytica, Pasteurella trehalosi
(Pasteurella multocida, Bordetella papertussis)
Mycoplasmas
PI3, adenovirus, respiratory syncytial virus, reovirus
Enzootic pneumonia
Sheep
Mannheimia haemolytica
Sudden death, fever, depressed, inappetent, dyspnoea, cough, nasal discharge, death, poor thrift
Maedi-visna
Lentivirus (slow virus)
Visna (wasting) and mastitis
Mainly vertical transmission
3y+, slow progression of signs, emaciation, severe respiratory distress +/- cough, nasal discharge
Sheep pulmonary adenomatosis
Jaagsiekte
Herpesvirus and adenovirus - slow progressive lung adenocarcinomas
Long incubation
Respirato transmission and vertical
Strangles
Classical acute disease
Streptococcus equi equi
Highly infectious 1-5y
Incubation period 2-6y, nasal shedding for 3-6w (may shed asymptomatically for years)
Classical:
- Fever, depression, inappetence, cough, nasal discharge
- Abscessation of mandibular or retropharyngeal LNs - rupture after 7-10d - no antibiotics, nursing, anti-pyretics, soft food
- Dyspnoea and dysphagia if abscesses compress larynx or interferes with cranial nerve to pharynx
- Mucoid to purulent nasal discharge
Early clinical signs: penicillin
Atypical strangles
Looks likes any respiratory tract infection
Internal abscessation - long term antibiotics penicillin or trimethoprim)
Purpura haemorrhagica:
- Generalised vasculitis - type III hypersensitivity reaction
- Death - pneumonia, cardiac arrhythmia, renal failure, GI disorders
- Penicillin, dexamethasone (0.05-0.2mg/kg) or prednisolone (0.5-1 mg/kg), NSAIDs, fluids
Other complications:
- Anaemia
- GP empyema and chondroids - draina and antibiotics
- Retropharyngeal abscessation
- Laryngeal hemiplegia
- Horner’s syndrome
- Abscesses of mammary glands
- CNS abscesses
- Endocarditis or myocarditis
- Agalactia
- Tracheal compression dye to cranial mediastinal LN abscess
- Suppurative bronchopneumonia
- Myopathies
Sinusitis in horses
Dental diseases: 09-11 (M1, M2, M3)
Bacterial, fungal
Neoplasia
Possible concurrent signs: decreased air flow, facial swelling, dullness on percussion
Medical: lavage and antibiotics
Surgical:
- Sinoscopy (including fenestration on ventral conchal bulls (VCB)
- Removal nod inciting cause
- Flap sinusotomy
Guttural pouch empyema
Bacterial infection - often Streptococcus equi
Endoscopy, xray - chondroids (inspissated pus)
Medical: Pouch lavage, antibiotics (penicillin and TMPS), remove choroids if necessary
Surgery: Viborg’s triangle approach for drainage, ventral paramedian approach for chondroid removal, dyspnoeic horses may require tracheostomy
Sites of URT obstruction in horses
Nostrils: alar fold/collapse/flutter, incomplete dilation of the nares
Nasal passages: septal disease, small nasal passages, eruption bumps (tubercula transitoria), mass lesions
Sinuses (expansile lesions): cysts, mass lesions
Pharynx:
- Dorsal displacement of the soft palate (DDSP): neuromuscular dysfunction - palatal and/or peripharyngeal musculature, dynamic endoscopy, Llewelyn technique/thermal palatoplasty/laryngeal ‘tie-forward’
- Postural compression (nasopharyngeal collapse)
- Pharyngeal cysts: subepiglottic, dorsal pharyngeal
Larynx:
- Recurrent laryngeal neuropathy (‘roaring’): Degenerate axonopathy of recurrent laryngeal nerve - left side, impaired function of cricoarytenoideus dorsalis muscle
- Epiglottic entrapment: envelopment of the epiglottis by the subepiglottic mucosa and aryepiglottic folds, midline division of the entrapping tissue
- Arytenoid chondritis:chronic infection of the body of the arytenoid cartilage resulting in thickening and intraluminal granulations
Progressive ethmoidal haematoma (PEH)
Horses
Progressively enlarging, non-neoplastic mass lesion originating in the ethmoid turbinate
May expand to occupy the nasal passages, maxillary and frontal sinuses or nasopharynx
- Radically excise
- Laser treatment
- Intralesional formulin
Guttural pouch mycoses
Fungal infection (Aspergillosis spp.) - roof of the medial compartment near the articulation of the stylohyoid bone with the temporal bone
Epistaxis: ligation, balloon occlusion or coil occlusion of affected vessels
Mycotic lesion: systemic/topical antifungals, antiseptics
Atheroma
Horses
Sebaceous cyst in the nasal diverticulum
Noticed shortly after birth and grow through the 1st/2nd year
Unilateral/bilateral
Cosmetic
Sinus cysts
Horses
Congenital cystic dysplasia of sinus mucosa
1.5y with facial swelling
Decreased air flow on affected side, nasal discharge, epiphora
Breakdown of cysts via flap sinuscopy
Sinus neoplasia
Horses
Squamous cell carcinoma
Many varieties of sarcoma also reported
Facial swelling, decreased airflow on affected side, nasal discharge, epiphora
Excision via flap sinusotomy, laser obilteration
Guttural pouch tympany
Excessive air accumulation of air in the guttural pouch
Congenital: neonates, due to abnormal formation of pharyngeal opening of the pouch
Acquired: older foals, yearlings, due to swelling involving pharyngeal opening of pouch
Tympanic swelling in parotid region, unilateral or bilateral
Assessing radiographs roentgen method
Size Shape Opacity Margination (contour) Position Number
