Respiratory Flashcards
What are the 3 most common clinical signs associated with nasal disease?
Nasal discharge, sneezing, stertor (stridor is less common and is due to narrowing of nares; reverse sneezing is not pathologic)
What are some less common clinical signs related to nasal disease?
Pawing, rubbing muzzle, facial deformities (neoplasia, fungal infection), CNS signs, mouth breathing (secondary to obstruction)
Where does the nasal discharge most commonly originate from?
Nasal cavity, frontal sinuses, nasopharynx (nasal polyps in cats)
What factors of nasal discharge should you be assessing clinically?
The physical characters of it (blood, serous, mucus, mucopurulent, etc.), acute or chronic, unilateral or bilateral, response to prior therapy, seasonality/environmental change?
T/F: tumors and fungal infections of the nares most commonly has bilateral discharge that progressed from unilateral discharge with chronicity.
TRUE
What on PE should you focus for nasal disease?
Oral exam (thorough one needs anesthesia), ocular disease, check ocular retropulsion (neoplasia, abscess, fungal granulomas), fundic exam (esp cats with polyps), aural exam (cats with polyps), lesions in nares, submandibular lymphadenopathy, patency of nares, palpate muzzle (pain, boney abnormalities)
What diagnostic tests can help with diagnosing nasal diseases?
CBC, BCHEM, urinalysis, culture, coagulation tests, complete oral exam under anesthesia, nasal flush (cytology and culture), radiographs, CT, otoscope cone, rhinoscopy, biopsy
If you suspect FIV, what diagnostic tests can be done?
Retroviral testing, feline respiratory pathogen PCR panels (can identify carriers with no clinical signs)
When do you use a coagulation test for nasal disease?
When there is epistaxis or pursuing biopsy
What should you be measuring in epistaxis cases?
Platelet numbers, platelet function tests, Pt/PTT, blood pressure
What tools might you use to diagnose dental disease?
Dental mirror, spay hook, x-rays
Combination of what 3 diagnostic tests are required for diagnosing chronic disease?
CT, rhinoscopy, biopsy
What should you absolutely not pass when getting a biopsy?
Do not pass the medial canthus or you’ll biopsy the brain
Primary bacterial rhinitis (cats and dogs) is _______ (common/uncommon)
Uncommon
What kind of nasal discharge might you see with primary bacterial rhinitis?
Mucopurulent (but tehre are for more likely primary etiologies)
What might be some common primary pathogens (cats > dogs) associated with bacterial rhinitis
Chlamydia felis, bordatella bronchoseptica, Streptococcus canis, Streptococcus equi spp zooepidemicus, Mycoplasma, Pasteurella multocida
What type of tissue/fluid should you get a culture on for bacterial rhinitis?
Deep tissue biopsies and/or nasal flushes are more representative of the pathogen causing rhinitis as there is less contamination than superficial or mucous swabs
What kind of tissue or fluid should you conduct cytologies on?
Nasal lavage/brushings > mucus/secretions
What fungal species causes Canine sinonasal aspergillosis?
Aspergillus fumigatus (opportunistic fungus) and is ubiquitous (everywhere in environment)
What do you normally see clinically with a A. fumigatus infection?
Fungal plaques in caudal nasal cavity and/or frontal sinus
What’s the typical signalement for canine sinonasal aspergillosis?
Young male dog, GSD or rotty (longer nosed dogs, dolycephalic), less common in cats
What does the fungus do to the turbinates?
The fungus secretes necrolitic toxins that eat away at turbinates and starts off as mucopurulent discharge which then becomes epistaxis
How do you diagnose canine sinonasal aspergillosis?
CT (will see lesions in turbinates, turbinate destruction), radiographs (soft tissue/fluid densities within frontal sinus, periosteal reactions), serology (good specificity, moderate sensitivity < not good screening: if it’s +ve it’s likely aspergillosis)
If you see a fungal plaque with a rhinoscope, what should you do now?
Biopsy the fungal plaque, do cytology and histopathology +/- culture
How should you treat canine sinonasal aspergillosis?
Debridement, topical antifungals in nasal cavities and sinuses (flush + cream), may need systemic antifungals
What are the 2 classifications of canine inflammatory rhinitis?
Lymphoplasmacytic and eosinophillic
How should you diagnose inflammatory canine rhinitis?
Disease of exlusions since inflammation hides many diseases (neoplasia, fungus, FB, dental disease) so do CT, rhinoscopy, biopsy
If a dog did have inflammatory rhinitis, what might you see on CT, rhinoscopy and biopsy?
CT: will not see mass, turbinate destruction, just inflammation and mucus. Rhinoscopy will be negative for FB, mass, etc < just edema, discharge and hyperemia. Biopsy: would see inflammatory populations, no cancer cells or abnormal cells
What’s the treatment for lymphoplasmacytic or allergic inflammatory rhinitis?
Lymphoplasmacytic: air humidifaction, corticosteroids/immunosuppression, address dental disease if present, identify possible allergens; allergic: air humidifer, corticosteroids, antihistamines, trial anti-parasitics, identify possible allergens
What type of mite (mite name) is responsible for sneezing, reverse sneezing, mild serous nasal discharge?
Pneumonyssoides caninum
How do you treat canine nasal mites?
Milbemycin oxime (once weekly for 3 weeks); ivermectin (twice 3 weeks apart); selamectin (every 2 weeks for 3 treatments)
What type of breed (large or small) are foreign bodies most common in nares?
Large breed
What are some tell tale history clues that it’s a foreign body stuc up the nares?
Acute onset sneezing, unilateral discomfort, and with chronicity there is muco-purulent discharge
What is upper respiratory disease in cats often referred to as?
FURD = feline upper respiratory disease
What are the primary agents that causes upper respiratory infection?
Viral: calici virus and herpes virus (FHV1); bacterial: Mycoplasma, bordatella, chlamydophila, streptococcus < usually multiple
How is upper respiratory infection transmitted?
respiratory, ocular, oral transmission, contact with contaminated environment (especially calicivirus), aerosal not a major route.
Can calicivirus have carrier cats?
yes
What are some of the most common clinical signs of feline calicivirus?
Oral ulcers (anorexia, hypersalivation), sneezing, conjunctivitis, ocular and nasal discharge (not as bad as feline herpesvirus)
T/F: variability in clinical signs occurs due to different viral strains
TRUE
What are the most common acute clinical signs of feline herpesvirus?
Sneezing, serous ocular and nasal discharge (often progresses to mucopurulent), inappetence, pyrexia, fever, conjunctivitis, ulcerative keratitis
What are some diagnostic approaches for acute FHV or FCV?
History and PE (oftentimes we don’t pursue from here since it wouldn’t change the treatments); culture and PCR (only when unusual or severe signs, legal issues, detecting carriers)
How do we treat FCV or FHV?
Most often self limiting, supportive care, saline nebulization to combat airway dehydration to increase secretions to help clear things. Make sure to clean the nasal secretions cause cats really depend on smell to eat
What are some additional treatments to help with FCV and FHV?
Lysine (works similar to fortiflora and interferes with herpes viral replication, good for chronic cases), antivirals like famiclovir, probiotics, stress relief management
How important is antibiotics for FCV or FHV?
Shouldn’t give based on mucopurulent discharge alone, only if signs > 10d with coinfections. Doxycycline is a good choice but if it doesn’t improve then do more workup
What is the two tiered approach to controlling FCV/FHV outbreaks?
1) increase immunity via vaccinations or general health checks; 2) decrease exposure
What’s the most common cause of feline chronic rhinosinusitis?
Viral cause, secondary to FHV1 epithelial/turbinate damage; bacterial; immune mediated; retroviral status (not really considered now)
What are clinical signs of feline rhinosinusitis (chronic)?
Non-specific (sneezing, stertor, nasal discharge, preservation of airflow, often healthy but may be inappetent with lots of nasal discharge
How do you diagnose feline chronic rhinosinusitis?
Diagnosis of exclusions: Could do PCR panels, otic exams, ask about travel; may due oral exam under sedation and imaging, rhinoscopy, nasal biopsies (neutrophilic or lymphoplasmacytic inflammation)
How do you treat chronic rhinosinusitis?
Antibiotics, air humidifier, lysine, antivirlas, probiotics, nasal flushing, intranasal vaccine, steroids. You end up controlling it, not curing it so prognosis is meh
Why is doxycycline not used in cats?
It causes esophageal strictures so always follow it with water if you do use it or get it compounded into liquid
What is feline nasal cryptococcus?
It’s a fungal infection via cryptococcus neoformans and gattii and the cats get it by inhaling the spores
What does cryptococcus infection cause?
Upper respiratory tract problems like granulomatous lesions on nasal bones, neurological signs, skin and systemic and ocular disease might show up
How do you diagnose cryptococcus infections?
Latex capsular agglutination test (LCAT) on serum and CSF, cytology (thick non-staining capsule = cryptococcus)
How do you treat cryptococcus infections?
Oral or injectable antifungals (oral for confined to nasal cavity infections like Fluconazole or itraconazole) for at least 6 months; then make sure to do titres as therapeutic monitoring. Prognosis is good without neurologic environment but it can relapse
Nasal planum SCC is locally invasive and metastasizes often
False: it is locally invasive and slow to metastasize
What type of cats are predisposed to nasal planum SCC?
white haired cats, not common in dogs
What might a biopsy show for a nasal planum SCC?
Just a bunch of inflammation
How do we treat SCC?
surgery, radiation or chemotherapy
What kinda of cough (name the sound of the cough) that is kinda pathognomonic for tracheal disease
Good honking cough
T/F: Tracheal collapse remains in the tracheal rings and doesn’t extend past this (maybe also includes the trachealis muscles.
False: it could extend to the mainstem bronchi and cause tracheobronchial collapse
What are some reasons for tracheal collapse?
Defective chondrogenesis or degeneration of hyaline cartilage (both are softening of cartilaginous rings)
What factors exacerbate the disease?
Obesity, Chronic coughing (cardiac disease, lower airway disease), increased respiratory efforts/pressures (BOAS)
Explain the change in pressures as you inhale and exhale and how this affects the trachea
As you inhale, there is expanding of the lungs which causes negative pressure cause you draw air in, the more negative pressure in the trachea, the higher the pressures outside of the trachea compared to inside which causes it to collapse. As you exhale, pressures in the thoracic cavity will get higher and the intrathoracic trachea to collapse
what’s the typical signalement of a tracheal collapse case?
Small breed dog, narrow muzzle, domed head (Chichi, pomeranian, toy poodles, yorkies) often in middle-older dogs and might have comorbidities like cardiac disease, chronic bronchitis
How do you diagnose tracheal disease?
Signalement, radiographs (it’s a dynamic disease though), tracheobronchoscopy, fluoroscopy (make sure to include cervical trachea)
With a tracheal collapse: with inspiratory it is the _____ (intra or extrathoracic) trachea that collapses and with expiration it is the _____ that collapses
Extrathoracic; intrathoracic
How do we grade tracheal collapse?
Grade 1 (25% collapse, cartilage rings circular); grade 2 (50% collapse, dorsal membrane stretched); grade 3 (75% collapse, dorsal membrane pendulous), grade 4 (95% collapse).
What are two look alikes of tracheal collapse on x-ray?
There is a redundant tracheal membrane that shows up on x-ray (check slides) and it changes with phase of respiration with inhalation having it protrude more into lumen, but the trachea remains open and see the dorsal wal and there is no history of coughing. A superimposed esophagus
What’s the medical and surgical treatment of tracheal collapse?
Medical: weight loss, cough suppressants, bronchodilators, anti-inflammatories, harness, avoid excessive excitement and stress, fix concurrent diseases (if distress give oxygen, anxiolytics, sedation); surgical: intraluminal stents or extrathoracic rings
What are 3 types of cough suppressants used for collapsing trachea?
Hydrocodan, butorphanol, loperamide (balances sedation/cough suppression/QOL)
If we keep an animal on steroids long term, what could happen to the tracheal collapse disease?
We don’t keep them on steroids long term cause it could make the tracheal collapse worse
What’s the prognosis of tracheal collapse?
Depends on severity and extent, but it is a progressive disease which can be slows. Guarded prognosis if there is poor response to medical management
What is a hypoplastic trachea?
It is when the trachea lumen is smaller, it often occurs with concurrent diseases like BOAS
T/F: tracheal hypoplasia is congenital
TRUE
What are the most common affected breeds of hypoplastic trachea?
English bulldogs, boston terriers, french bulldogs
What’s a common clinical sign seen with hypoplastic trachea?
Aerophagia, gulping of air causing a distended stomach
Often Canine infectious respiratory disease complex (Kennel cough) is due to >1 organism, what are some of these pathogens?
Distemper, Canine influenza, pasteurella, streptococcus zooepidemicus
What are some other names for CIRDC?
Kennel cough, canine infectious tracheobronchitis, parainfluenza, adenovirus-2, bordatella
What type of cough is most common with Kennel cough?
Dry hacking cough
Is there a fever associated with CIRDC? And if so why?
Yes fever when progressing to pneumonia which indicates systemic illness
What kind of fluids are you sampling when diagnosing CIRDC?
Airways, swabs of conjunctiva, tonsils, pharynx for culture and cytology and PCR
T/F: antimicrobials will address the viral infections of CIRDC
False: the antimicrobials will not address viral infections. They are generally not recommended for uncomplicated infection, complicated inefctions (fever, lethargy, inappetence, mucopurulent discharge) could be addressed with antimicrobials
What are some signs of pneumonia that we should be watching for in CIRDC?
Crackles on auscultation, productive cough, hypoxemic, no improvement within 7 days
When do we most often see tracheal rupture?
After ET intubation in cats
What does tracheal rupture result in?
Pneumomediastinum and subcutaneous emphysema
How do we diagnose tracheal rupture?
x-rays
How do we treat tracheal ruptures?
Most heal without intervention, monitor patient and changes in respiratory status
What’s a common neoplasia of the trachea, what about tracheal parasite?
Osteochondroma = neoplasia; Parasites: oslerus osleri
What is the cause of canine chronic bronchitis?
It’s an inflammatory related disease of the lower airways
What signalement is most common for chronic bronchitis dogs?
Middle-older aged, small breed dogs that have comorbidities like cardiac disease, tracheal collapse, lower airway disease
How do we diagnose chronic bronchitis?
Exclude other causes of cough: heartworm testing, fecal sample, minimum database, radiographs (might be normal), airway cytology and culture, bronchoscopy
What’s considered normal cells on a bronchoalveolar wash or trans tracheal wash? What’s considered normal from the deeper bronchi?
Normal cells on wash: respiratory epithelial cells, deeper in bronchi = macrophages (not super high numbers)
What do glucocorticoids treat in terms of chronic inflammation of the lungs? Give an example of a steroid and dose
Glucocorticoids help treat the inflammation since the lungs are releasing inflammatory meditors and in general you use a 1mg/kg/day (immunosuppressant dose) and then taper down. You can also use inhalent (fluticasone) but try it after oral steroids cause you need to teach the dog to use an inhaler
If we’re controlling chronic bronchitis, not treating it… why treat it at all?
The ongling inflammation will cause: damage to elastic and muscular components, ciliary mechanisms which predisposes the animal to pneumonia. You could get bronchiectasis which is permanent airway dilation, or bronchomalacia which causes airway collapse
What are two feline bronchial disease that are similar in presentation and treatment?
Feline asthma and feline chronic bronchitis
What’s the main differences between feline asthma and feline chronic bronchitis?
Feline asthma more commonly affects younger cats (more eosinophilic component and has active bronchoconstriction), chronic bronchitis has more neutrophils, you see changes in bronchioles that causes the constriction (it’s not active)
Describe the pathogenesis of feline asthma
Airway inflammation –> excessive mucous secretion –> bronchial wall edema/remodeling –> bronchoconstriction **INFLAMMATION*
What c/s are we seeing with feline asthma?
the signs we see are due to narrowing of airways (a 50% reduction in airway diameter is a 16 fold decrease in airflow), wheezing, coughing, airway edema, mucus. Often misdiagnosed with vomiting, coughing hairball, cardiac disease
What will asthma lead to chronically and due to what?
Asthma will lead to chronic bronchial changes over time due to spasmodic bronchoconstriction
What are the three things causing airway narrowing in feline asthma due to inflammation?
Bronchoconstriction, airway remodelling (due to chronic inflammation), excessive mucus secretions (causing airway edema)
What are 3 of the most common causes for respiratory distress in cats?
Cardiac disease, pleural effusion, asthma
How do we diagnose feline asthma?
No specific tests, rule out other things. 20% of cats may show peripheral eosinophilia (do a heartworm and parasite eval just to rule these out), x-rays (may be normal), airway samples (cytology and culture sample)
What might you see on radiographs of a cat with asthma?
Could be normal (23%); bronchial patter (maybe interstitial), collapse of R middle lung lobe, hyperinflation (lungs look hyperlucent, right up against diaphragm)
What are the differences in cytology results between asthma and bronchitis?
Feline asthma will see increased eosinophils (need to rule out parasites), bronchitis will see increased neutrophils; a few times there will be mixes of the two
How do we treat feline asthma?
Glucocorticoids (decreases airway inflammation), bronchodilators (reduce bronchoconstriction) < chronic inhaled albuterol can actually promote bronchospasm and inflammation
If a cat comes in super unstable with asthma, or bronchitis, what do we do?
Oxygen, sedation (butorphanol), bronchodilator (injectable aminophylline or terbutaline or inhaled albuterol), inject steroid (dexamethasone IV), antibiotics –> usually stable cat in 24 hours
What are two types of glucocorticoids (inhaled or oral) that we could give for chronic treatment of feline asthma?
Cats can’t have prednisone, so we give prednisolone (1-2 mg/kg/day) taper, inhaled fluticasone (inhaled better chronically to minimize side effects)
What bronchodilator can we give for acute flareups?
Salbutamol (= albuterol = ventolin)
How do we change the environment to better accommodate our asthmatic cats?
Put them in the bathroom with you when showering, get air humidifiers, remove scented candles or eliminate smoking
What the heck is eosinophilic lung disease in dogs?
It’s an inflammatory disease where eosinophils infilrate the bronchi and lungs and is likely due to a hypersensitivity reaction
What must be sure to rule out when we suspect eosinophilic lung disease in a dog?
Parasites like Heartworm or neoplasia
What’s the typical signalement and c/s of eosinophilic lung disease?
Young-middle aged dogs (siberian huskeis or malamutes), coughing, gagging, retching, nasal discharge, tachypnea, dyspnea, exercise intolerant. Could have systemic signs like anorexia, weight loss, but it’s usually mild or absent
How do we diagnose eosinphilic lung disease?
CBC (50-60% have peripheral eosinophilia), x-rays (bronchial or bronchointerstitial = railways and tram lines with lots of donuts pattern), CT scan (bronchial wall thickening, mucus/debris plugging bronchial lumen, bronchiectasis, pulmonary nodules, lymphadenopathy), bronchoscopy (granulomas, irregular mucosa), airway sampling (increased eosinophils)
How do we treat eosinophilic lung inflammation?
Glucocorticoids (1-2 mg/kg/day to start), fluticasone for chronic management, deworm them, remove potential allergen sources
What’s the prognosis of eosinophilic lung disease?
Fair to good, high relapse rate, espeically when you start to taper pred but if you see granulomas it may have a worse prognosis but this form is less common
What are some bacterial and viral causes of pneumonia?
Bacterial: bordatella bronchiseptica, Mycoplasma, Pasteurella, E. coli , Streptococcus; Viral: CAV-2, Distemper, canine influenza, parainfluenza
What are two other reasons, other than bacterial and viral that could cause pneumonia?
Aspiration (GI contents, etc.), fungal causes but beware of imposter neoplasia (blastomycosis «_space;super common, cryptococcus, coccidiomycoses, histoplasmosis
T/F: it is unusual for young healthy pets to get bacterial pneumonia
True: especially in cats
What are some underlying causes of bacterial pneumonia?
Megaesophagus, laryngeal dysfunction, immunosuppression, recent anesthesia, foreign body, viral injury, hematogenous disease, penetrating wounds (bringing bacteria into lungs)
Why might a patient have aspiration pneumonia?
Esophageal disease, vomiting, neuro disease, laryngeal disease, anesthesia, breed
What might you see on radiographs of a dog with pneumonia?
Interstitial-alveolar pattern, ventral distribution commonly aspiration, recurrent lesions, mild pleural effusion in some cases
Compare bacterial and inflammatory bronchitis cytology reports:
Bacterial pneumonia: may see leukocytosis, left shift, toxic change, would see bacteria, degenerate neutrophils; inflammatory bronchitis: eosinophils, neutrophils but non-degenerate in chronic bronchitis
How long should you continue antibiotic therapy for in a case of pneumonia?
1-2 weeks then re-evaluate before discontinuing
Why must we maintain hydration in dogs with pneumonia?
Airway mucus traps bacteria and inhaled debris, and the mucus is made up of watery layer (cilia moves this), overlying gel trap and so dehydration inhibits cilia movement
What are the most common clinical signs with pleural space disease?
Tachypnea (restrictive/paradoxical pattern), muffled heart and lungs sounds (fluid, air, tissue)
What are the most common causes of chylothorax?
Trauma, IDIOPATHIC!, cardiac disease, mediastinal mass, thoracic duct anomalies
Which breeds are most predisposed for idiopathic chylthorax?
shiba, afghan, himalayan, persian cats
What kind of fluid are you going to see with a chylothorax?
Modified tranusdate or exudate with small lymphocytes. Triglyceride levels are higher in the fluid than in the serum (the triglycerides differentiates it from lymphoma or thymoma)
How do you treat a chylothorax?
Usually it’s idiopathic and may need a thoracocentesis then it could self resolve. Sometimes if you use rutin, it increases number of macrophages which are thought to remove proteins and increase absorption of fluid, make sure to change the diet to a low fat diet
What kind of surgery might fix chylothorax?
Thoracic duct ligation +/- pericardectomy (consider it early)
describe the pathogenesis of fibrosing pleuritis from a chylothorax
Continuous thoracocentesis, infection, parenchyma fails to re-expand post thoracocentesis, just chronic inflammation causes inflammation of the pleura. They’re more likely to get a pneumothorax cause the hole from the thoraco doesn’t seal up
What’s the most common neoplasia that occurs in the mediastinal space?
Lymphoma, then thymoma
What can you often see with thymomas (see the FUN x-ray in lecture)
Myasthenia gravis is often seen with thymomas and presents with megaesophagus
What are some clinical signs seen with mediastinal masses?
Respiratory compromise, decreased lung sounds (mass with effusion), dysphagia, coughing (something compressing airways), horner’s syndrome (sympathetic trunk runs through mediastinum), edema of head and neck
What might we start with in terms of diagnostic tests for a mediastinal mass?
X-rays
What other forms of imaging can we use to help with diagnosing mediastinal masses?
CT, ultrasound to guide cytological or biopsy samples
