SAM Exam 6 - Respiratory

Feline Upper Respiratory Infection

• Et: FHV, FVR, FCV, Chlamydophila, Bordetella, Mycoplasma

• Cs: Inappetence, lethargy, fever, Sneezing, coughing, Nasal/ocular discharge

  • FCV: Oral/nasal ulcers, viral pneumonia

    

  • FHV: Conjunctivitis, corneal ulcers 

    • Nasal Turbinate Damage

  • Chlamydophila felis: Chronic Conjunctivitis

• Dt: Not routinely needed, Ab/VI tests 

• Tx: Self limiting, Antibiotics (cillin/cycline/mycin), Antivirals (-uridine), omega/alpha-2b interferon

  • Lysine is ineffective

• Vax: FVRCP: improves CS only, 8 & 14 weeks, yearly, q 3y

Nasopharyngeal Polyps

• Young Cat issues

  • originate from eustachian tube

• Et: Benign growths in young cats

  • may extend to ear canal, middle ear, pharynx, nasal cavity

• Cs: Stertorous breathing, upper airway obstruction, Serous/mucopurulent nasal discharge, Otitis, Head tilt, nystagmus, Horner’s syndrome

• Dt: rads/scope, otoscopy, CT, PE/visual, histopath (definitive)

• Tx: Removal (Traction avulsion, Ventral bullae osteotomy)

  • +/- Transient Horner’s Syndrome

Nasal Tumors

• Et: Malignant, older, Dolichocephalic breeds

  • Dogs:adenocarcinoma, carcinoma, fibrosarcoma, CATS: chondrosarcoma, lymphoma, SCC

• Cs: Chronic nasal discharge (#1), Sneezing, Facial deformity, Neuro abnormalities, stertor

  • Often unilateral → progresses to bilateral

• Dt: rads, rhinoscope(retroflexed), CT, PE, histopath (definitive)

  • Mets: to reginal lymph nodes

    

• Tx: Sx(not an option), radiation, chemo(lymphoma), NSAIDS, pain meds

  • Poor prognosis

Cryptococcus neoformans

• Cats > dogs

  • Cats: nasal cavity, Dogs: CNS

    • Lungs can be affected in BOTH species

• Et: Nasal mycoses, Zoonotic, enviro > direct

  • Polysaccharide capsule: Inhibits plasma cell function, phagocytosis, leukocyte migration, complement

  • Dissemination: CNS, eyes, skin, lungs, kidneys, liver

• Dt: rads, CT, cytology(neutrophils/macrophages), biopsy, cytology(Cryptococcal yeast )

  • Capsule stains + used in Ag test

  • Capsular antigen test

• Tx: Itraconazole, Fluconazole 

  • 6m + 2m past CS

  • Good if no CNS issues,

    • concurrent infect → FeLV/FIV less likely to respond to tx

Aspergillus fumigatus (Sinonasal)

• Dogs > Cats

  • young, male

• Et: Normal inhabitant of nasal mucosa

• Cs: Chronic nasal disease, Nasal discharge, Sneezing, Depigmentation and ulceration of external nares 

  • form fungal “plaques”

• Dx: rads, rhinoscopy, CT, PE, histopath, Ab test

  • Antigen test for systemic NOT nasal!!

• Tx: Topical clotrimazole infusions

  • Make sure cribriform plate is intact

    

Nasal Parasites

• Fly larvae: Cuterebra

• Mites: Pneumonyssoides caninum 

• Nematodes: Eucoleus boehmi, Linguatula serrata

Rhinitis

• Bacterial

  • Et: secondary lesion**

  • Ddx: FB, Nasal tumor, Fungal disease, Dental disease

  • Tx: antibiotic responsive but must fix primary issue

• Inflam → dx by exclusion

  • Et: allergic or immune-mediated

  • Dt: exclusion, histopath

  • Tx: doxycycline, azithromycin, NSAIDs, corticosteroids

Nasopharyngeal Stenosis

• Post anesthetic reflux 

• Chronic upper respiratory infection

Upper Airway Signs

• Inspiratory dyspnea

• Inspiratory noise

  • Stertor (pharynx, palate)

  • Stridor (larynx)

• Vocal dysfunction (larynx)

• Cough

• Dysphagia, gagging

Laryngeal Paralysis (LARPAR)

• Et: Failure of arytenoid cartilage to abduct during inspiration, geriatric onset laryngeal paralysis polyneuropathy GOLPP

  • Older, Lg dogs

    • Most common: idiopathic

• Cs: Stridor, vocal change, coughing, acute decomp, cyanosis, syncope, death, CNS signs, toe scuffing

  • Progressive / chronic

• Dx: Laryngoscopy, thyroid panel, thoracic xrays (mega-esophagus)

  • ALWAYS use IV catheter and have ET tube ready, dopram

• TX: 

  • ECC: Oxygen, Ace, Opioids, ET tube, Tracheostomy, Arytenoid lateralization (tie-back),

    • Sx complications: no swimming / aspiration pneumonia

  • Mild: rest, loose weight, no collars, corticosteroids

• Prognosis: good

Brachycephalic Airway Syndrome

• Et: Stenotic nares, Elongated soft palate, Everted laryngeal saccules, Laryngeal collapse, Hypoplastic trachea (English bulldog)

  • Not collapsing trachea

  • Elongated soft palate - Primary malformations

• Cs: Signs of upper airway obstruction- Inspiratory issues, cough, vocal change, stertor/stridor, exercise intolerance, cyanosis, syncope

• Dt: PE, scope, rads

• Tx: medical management: rest, keep cool, corticosteroids, Sx, tracheostomy: last case/ not recommended

Obstructive Laryngitis

• Et: Non-neoplastic infiltration of larynx 

  • Inflammation 

• Cs: Inspiratory issues, cough, vocal change, stridor

• Dt: Histopath 

• Tx: Corticosteroids, excision, radiation

Laryngeal Neoplasia

• Neoplasia originating from larynx uncommon

• Et: compression/invasion: secondary > primary

  • Thyroid carcinoma, Lymphoma, SCC

• Cs: Inspiratory issues, cough, vocal change, stridor

• Dt: Histopath, rads, scope, CT, US, PE → neck palpation

• Tx: Sx, chemo, permanent tracheostomy(not common)

Canine infectious respiratory dz complex CIRDC

• Aka: Kennel cough, Infectious Tracheobronchitis

• Et: CAV-2, CPI, CIV, covid, distemper, CHV1, Bordetella, Strep, Mycoplasma
  Cs: Paroxysmal cough, Sneeze, Nasal/ocular discharge, Fever, Secondary infection → VERY contagious

• Dt: PE, history

  • Further diagnostics NOT routinely needed

• Tx: Self-limiting in 7-10d, Cough suppressants (Hydrocodone, Butorphanol), Humidifier

  • Antibiotics - Signs > 1 week, or suspected bacterial infection

    • No improvement = further diagnostics

• Vax: CAV-2, CPI: distemper (DHPP), Bordetella, CIV: H3N8 H3N2

Collapsing trachea

• Et: Sm breeds, Middle-aged

  • Inspiratory effort: extra thoracic collapse/ cervical trachea 

  • Expiratory effort: intrathoracic collapse / thoracic trachea, mainstem bronchi

• Cs: Cough, goose honk, exercise intolerance, resp distress, cyanosis, syncope

• Complicating dz: Left atrial enlargement, Airway inflammation, Upper airway obstruction, Obesity, hyperadrenocorticism

• Dt: Cough elicited by tracheal palpation, Rads, scope

• Tx: Medical management: Avoid collars, rest, cough suppressants (Hydrocodone, Butorphanol), Corticosteroids, Sx stenting 

  • Most controlled w/ medical management

Feline Lower Airway Disease

• Et: Inflam, airway hyper-reactivity, mucus hypersecretion, bronchoconstriction, bronchial smooth muscle hypertrophy, Fibrosis & emphysema

  • Asthma: reversible bronchoconstriction, Type I hypersensitivity, IgE, eosinophilic inflam

    • enviro, smoking households, allergy

  • Chronic bronchitis: neutrophilic inflam

    • permanent airway damage

• Cs: Cough, Dyspnea, Wheezing(expiration), Tachypnea, Expiratory distress, Barrel-chested

  • Episodic

• Dt: Eosinophilia, Baermann fecal (larva lung parasites), HW, Scope, Tx response, Airway wash (cytology/culture); Rads w/ Bronchial pattern, infiltrates, Hyper-inflation (air trapping), Collapsed right middle lung lobe, Spontaneous pneumothorax **

  

• Tx: eliminate triggers, corticosteroids (oral → inhalant) (dex, pred), Bronchodilators (terbutaline, albuterol, theophylline), Antibiotics (doxycycline, azithromycin), Oxygen, Cyclosporine (refractory cases)

Canine Chronic Bronchitis

• Et: Older Sm dogs, increased mucus

  • #1 chronic cough in older dogs

• Cs: Chronic cough, Increased bronchovesicular sounds, Wheezes, Crackles, Mucus hypersecretion

• Dt: CBC, Parasite exams (fecal, heartworm), Scope, Tracheobronchial collapse, Bronchiectasis, Airway cytology/culture; rads w/ infiltrates: "donuts", "tramlines", right ventricular enlargement (pulm. hypertension), Atelectasis of right middle lung lobe

  • Cough present Months → years

  • Diagnosis of exclusion!!

• Tx: Antibiotics (doxycycline, clavamox, azithromycin), Corticosteroids (oral → inhalant), cough suppressants (Hydrocodone, Butorphanol), dental care, controlled exercise 

  • Min rxn to bronchodilators, some rxn to anti-inflammatories

• Bronchoalveolar Lavage (BAL)

Paradoxical Abdominal Movement

• Upper airway obstruction

• Diaghragmatic rupture / paralysis

• Decreased lung compliance

• Severe pleural effusion

Bacterial Pneumonia

• Et: E. coli (G-), Pasteurella (G-), Strep (G+)

  • Young/old, immunocomp, dental dx, Laryngeal paralysis, downers, vomiting

  • Passive: Right cranial, right middle 

  • Forceful: Right caudal 

• Cs: Cough, tachypnea, dyspnea, fever (uncommon), lethargy, dehydration, crackles/wheezing, Increased bronchovesicular sounds, focal areas of decreased breath sounds

• Dt: CS, PE, CBC, Rads, Cytology, Culture 

  • Septic mucopurulent inflam

• Tx: Antibiotics, humidifier, lobectomy for unresponsive lobar consolidation, transtracheal washes (lg dogs), endotracheal washes

  • Avoid antitussives

Pulmonary Parasites

• NOT common - ingestion of infective forms

• Et: eosinophilic inflam 

  • Capillaria aerophila(whip): Cs rare, worm, routine fecal exams

  • Paragonimus kellicotti: fluke, snails/crayfish, Right caudal lung, Cats > dogs

  • Aelurostrongylus abstrusus

• Cs: Not all animals show clinical signs, spontaneous pneumothorax, allergic bronchitis

• Dt: eggs/larvae in feces or resp samples

• Tx: Fenbendazole

Eosinophilic Bronchopneumopathy

• Et: Eosinophilic infiltration of lung & bronchial mucosa

  • 2ndary to Immune-mediated hypersensitivity

  • Young dogs, Siberian Huskies 

• Cs: Cough, gag, retch, dyspnea

  • BAR unless pneumonia

• Dt: corticosteroid rxn, CS, Rads, Scope, Cytology

  • MUST Rule out HW, parasites, drugs, allergens

• Tx: Prednisone, steroids, deworming (fenbendazole)

  • Relapses common

Pulmonary Neoplasia

• Et: malignant, secondary > primary

• Carcinoma most common

  • adenocarcinoma, bronchoalveolar carcinoma, SCC

• Cs: asymptomatic, cough, exercise intolerance, dyspnea, weight loss, fever (if necrotic), pleural effusion, mediastinal compression, Hypertrophic osteopathy

  

• Dt: Rads, Cytology; TTW & BAL(not very useful), FNA, pleural fluid, Biopsy

• Tx: Lobectomy, antitussives, NSAIDs, PleuralPort

Pulmonary Edema

• Et: ↓ Oncotic pressure, ↑ Hydrostatic pressure (volume overload), Lymphatic obstruction, ↑ Vascular permeability (vasculitis)

  • PLE, PLN, hypoalbuminemia, CHF

• Cs: Acute cough, tachypnea, resp distress, crackles, Blood-tinged frothy fluid (pre-death), hypoxia 

• Dt: Rads w/ interstitial (early), alveolar (late); History of electrocution, seizures

• Tx: Oxygen, diuretics(cardio), colloids

Idiopathic Pulmonary Fibrosis

• Et: West Highland Terriers, Cairn, Yorkie, Staffordshire

  • Young to middle-aged

• Cs: progressive dyspnea, exercise intolerance, crackles, cough

  • Chronic, progressive

• Dt: labs/rads/bronchoscopy - WNL, Lung biopsy definitive

• Tx: Prednisolone, Pirfenidone (antifibrotic)

Pleural Effusion Clinical Signs

• Radiography - pre/post tap

  • Emergency xray after

• Exercise intolerance

• Labored breathing

  • Dyspnea

  • Tachypnea

  • Orthopnea (sternal)

  • Rapid & shallow - labored breathing

• Minimal or no cough

• Auscultation - muffled (Ventral)

• Percussion - dull

Thoracocentesis

• How: Tap 7–9th ICS

  • Dorsally for air

  • Ventrally for fluid

• Fluid: 

  • Transudate: <1.5p, <1c, clear

    • Hypoalbuminemia, PLN, Liver dx, PLE, CHF

    • Always (almost) associated with low Albumin

  • Modified Transudate: 2.5-5p, 1-7c

    • CHF, Neoplasia, Diaphragmatic hernia

  • Corylorus fluid: 2.5-6p, 1-20c, >TG

    • lymphangiectasia, HF, Vena cava thrombosis, trauma, neoplasia, HW, diaphragmatic hernia, lung lobe torsion

  • Hemmhorage: 3-6p, 5-20c

    • Coagulopathy, Trauma, Neoplasia

  • Neoplastic: 1-6p, Neoplastic cells

    • Pulmonary carcinoma, Mediastinal lymphoma

Pyothorax

• Et: Idiopathic, chest wounds, FB, Actinomyces, Nocardia, Corynebacterium, Staph, Strep, E. coli, Klebsiella, Pasteurella

• Cs: Exercise intolerance, labored breathing, no cough, muffled sounds, dull percussion, septic, fever, weight loss, rapid/shallow breathing 

• Dt: Rads (post tap), Thoracocentesis

• Tx: Antibiotics 4-6w, chest tube + lavage, thoracotomy

  • Unasyn (ampicillin + sulbactam), Timentin (ticarcillin + clavulanate), FQ, Clavamox (amoxicillin + clavulanate)

Chylothorax

• Et: Idiopathic, Secondary to thoracic disease → lymphangiectasia, HF, Vena cava thrombosis, trauma, neoplasia, HW, diaphragmatic hernia, lung lobe torsion

• Cs: Exercise intolerance, labored breathing, no cough, muffled sounds, dull percussion, rapid/shallow breathing

• Dt: Rads (post tap), Thoracocentesis, T4 in cats

  • Fluid triglycerides > serum, cholesterol/TG < 1

• Tx: Periodic thoracocentesis, low fat diet, oral rutin, MOST common → thoracotomy, thoracic duct ligation, pericardiectomy, omentalization

FIP Associated Pleural Effusion

• Et: covid in cats

• Cs: Exercise intolerance, labored breathing, no cough, muffled sounds, dull percussion, rapid/shallow breathing

• Dt: Rads (post tap), Thoracocentesis

  • Hyperglobulinemia, Hypoalbuminemia, High globulins in effusion

    • Serum A:G ratio often < 0.45

Cardiogenic Effusion

• Et: R CHF, Cats: most common (L or R)

  • modified transudate

• Cs: Exercise intolerance, labored breathing, no cough, muffled sounds, dull percussion, rapid/shallow breathing

• Dt: Rads (post tap), Thoracocentesis

Hemothorax

• Coagulopathy

• Trauma

• Cancer

  • Hemangiosarcoma

• Lung torsion

Lung Lobe Torsion Associated Pleural effusion

• UNCOMMON

  • young male pug

• Et: Left cranial lobe

  • Pleural effusion usually present

• Cs: Exercise intolerance, labored breathing, no cough, muffled sounds, dull percussion, rapid/shallow breathing

• Dt: Rads (post tap), Thoracocentesis

• Tx: Sx

Spontaneous Pneumothorax

• Et: Rupture of bullae or cavitary lesion, Pneumonia, Abscesses, Granulomas, Neoplasia

• Cs: Acute dyspnea in previously healthy patient

• Dt: Rads (post tap), Thoracocentesis

• Tx: Thoracocentesis, Chest tube, Sx