Respiratory - Tracheal Disease Flashcards
What is the cough reflex?
- Elicited by irritation of mucous membranes int he pharynx, larynx, trachea, or bronchi
- mechanical, chemical, mucus
- CNS cough center in medulla
What is Kennel Cough
- Infectious Tracheobronchitis
- Caused by:
- Canine Parainfluenxa virus
- Canine Adenovirus-2
- Bordetella bronchiseptica
- Mycoplasma spp
- Others
- Any combination of the above
- Very contagious!
Which kennel cough virus has a vaccine that is considered “core”
- Adenovirus-2 = “core”
- Parainfluenza = “non-core”
What is Bordetella bronchiseptica?
- Aerobic Gram-negative bacteria
- one of the causative agents of Kennel Cough
- Common in dogs, less common in cats
What is the pathogenesis of Bordetella bronchiseptica infection?
- Colonize respiratory mucosa
- Adhere to and destroy cilia, causes ciliostasis
- Mucociliary clearance fails
- Release toxins and inflammatory mediators
- Other bacteria can then adhere and cause disease
What are the clinical signs of Kennel Cough?
- 3-10 day incubation period after exposure
- Dogs get classic loud honking cough
- “healthy” other than the cough
- Anorexia, fever, lethargy, nasal-ocular discharge possible
- Not typically seen
- Consider if it has progressed to pneumonia
How does a typical Kennel Cough dog present?
- BAR
- Energetic and happy
- Loud honking cough
How is Kennel Cough Diagnosed?
- Uncomplicated case:
- “healthy” kennel cough
- Exposure, cough, exam
- no further tests needd
- Complicated cases:
- “sick” kennel cough
- Anorexia, fever, lethargy
- Thoracic radiographs
- If show pneumonia, then consider tracheal was
- “sick” kennel cough
What is the treatment for Kennel Cough
- Viral component is self-limiting
- Healthy Kennel Cough:
- Hydrocodone or butorphanol for cough suppression
- Mechanism: opioids inhibit cough center in medulla
- side effects: sedation, decreased clearance of bacteria
- Hydrocodone or butorphanol for cough suppression
- Sick Kennel Cough:
- Antibiotic based on culture and susceptibility when available
- Doxycycline, amoxicillin, or Clavamox (empirically)
- Cough suppressants are contraindicated in pneumonia cases
- Antibiotic based on culture and susceptibility when available
What is the Vaccine for Bordetella bronchiseptica?
- Not core
- Minimizes risk of infection
- develop fewer clinical signs if infected
- 2 Types:
- IN: (MLV) quick onset, can develop cough
- SQ: (killed) initial dose requires booster in 2-4 weeks
- Booster annually or 1+ week prior to exposure
When should kennel cough dogs be isolated?
- During clinical signs and therapy
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Who are the hosts of Distemper Virus?
- Dogs (especially puppies 3-6mo)
- Large cats (tigers), seals, minks, ferrets, raccoons
How is Distemper virus spread?
- Mostly respiratory secretions
- Can be spread in all bodily fluids
- feces, urine, transplacental
- Can spread for up to 90 days after infection
What is the pathophysiology of Distemper Virus?
- Aerosol drops of fluids reach tonsils
- Infect macrophages, travel by lymphatics and bloodstream to many organs
- lymph nodes, lungs, spleen, liver, GI tract, eyes, marrow, skin and CNS
- If vaccinated/maternal antibodies - puppies can clear the infection with no/mild signs
What are the signs of Distemper Virus?
- Subclinical
- Acute Disease:
- Respiratory
- Nasalocular discharge
- Kennel cough/pneumonia
- Gastrointestinal Disease
- Decreased appetite
- Vomiting/diarrhea
- CNS
- Myoclonus, blindness
- seizures, ataxia, hypermetria, paralysis
- Respiratory
- Enamel hypoplasia
- Hard-Pads or pustular skin lesions
- KSC/uveitis/optic neuritis/blindness
How is Distemper Virus diagnosed
- CBC:
- may have lymphopenia, thrombocytopenia, regenerative anemia
- May see inclusions in blood cells from CBC or bone marrow
- Thoracic Radiographs: unstructured interstitial pattern that is diffuse or dorsocaudal in distribution
- Can have alveolar pattern if 2o bacterial penumonia
- PCR, IFA, Necropsy
- On respiratory secretions, conjunctiva, blood, CSF, feces, tissues
What is the treatment for Distemper Virus?
- For coughing/pneumonia
- +/- antibiotics, nebulization
- For GI:
- Antiemetics, nutrition, fluids
- For seizures:
- Anti-epileptics
- Poor Prognosis if neurologic
- Isolate suspect/confirmed dogs
How can Distemper be prevented?
- Vaccination
What are the Influnza viruses in Dogs?
- Canine Influenza (H3N8 and H3N2)
How is Canine Influenza (H3N8/H3N2) transmitted?
- Through respiratory secretions
- Via fomites
What are the signs of Canine Influenza (H3N8/H3N2)?
- Decreased appetite
- Fever
- cough
- lethargy
- nasal discharge
- can be subclinical
How is Canine Influenza (H3N8/H3N2) diagnosed?
- signs
- PCR
What is the treatment for Canine Influenza (H3N8/H3N2)
- supportive care
Is there a vaccination for Canine Influenza (H3N8/H3N2)
- Killed vaccine, requires booster in 3-4 weeks, then yearly
- only for at risk patients
What is the pathophysiology of tracheal collapse?
- 1o cartilage abnormality
- ⇣ glycoproteins and GAGs in tracheal rings, can’t retain water, lose rigidity
- 2o Initiating Factors
- Obesity
- inhaled irritants (smoke)
- Concurrent Resp Disease
- Infection, trauma, even just intubation
- Cardiomegaly
- Cushing’s Disease
What breeds commonly suffer from tracheal collapse?
- Toy/Miniature breeds
- Yorkies, Pomeranians, Chihuahuas, Mini Poodles
What are the signs of Tracheal Collapse? PE findings?
- Paroxysmal Cough
- Easily elicited, dry, nonproductive, goose honk
- Triggered by stress, excitement, exercise
- May have hypoxic collapse episodes
- Exam:
- Can induce cough on palpation
- Can hear turbulence when auscult trachea
- Otherwise can have unremarkable exam
- Can induce cough on palpation
How is Tracheal Collapse diagnosed?
- Radiographs
- during different phases of respiration
- Often radiographs don’t show collapse but make other differentials less likely
- Fluoroscopy
- Dynamic, real time
- Endoscopy
- Gold standard for visualization, not done routinely due to safety
- CBC and Tracheal wash
- if evidence of pneumonia
- high anesthetic risk!
- Chemistry Panel
- Hepatic dysfunction has bee reported
- true etiology unknown
- not typically clinically relevant
- Hepatomegaly is common - consider concurrent disease
- Hepatic dysfunction has bee reported
What is the medical management for an acute crisis with Tracheal Collapse?
- Oxygen
- Sedation
- Acepromazine - 0.01 - 0.02 mg/kg, IV, IM, SQ
- Butorphanol - 0.2 - 0.4 mg/kg IV
- +/- Anti-inflammatory dose of steroids
- Dexamethasone 0.05-0.1mg/kg IV, IM, Sq
What is the chronic management for Tracheal Collapse?
- No stress, Avoid triggers
- Weight loss
- harness, no collar
- Antitussives: hydrocodone, butorphanol, maropitant
- Treat underlying disease
- Brochodialators w/ concurrent lower airway disease
- Glucocorticoids (not standard)
Can a stent be placed for Tracheal Collapse?
- Try medical management first
- Possible complications
- stent breaks or moves
- granulation tissue forms
- Not a perfect cure
- many show great improvement
- Major complications requiring additional stent ~47%
- still cough (hopefully less0
- Still need daily meds
What is Tracheal Hypoplasia?
- Congenital defect
- may be hereditary
- do not breed
- may be hereditary
- Part of Brachycephalic Airway Syndrome
- stenotic nares
- everted saccules
- elongated soft palate
What are the signs of tracheal hypoplasia?
- Cough
- Dyspnea
- Stridor
What is the treatment for tracheal hypoplasia?
- no specific medical/surgical therapy
- Weight management
- protect from infections
What is the prognosis of tracheal hypoplasia cases
- incidental in some
- Poor in severe cases
- some improve with maturity
What is Ciliary Dyskinesia?
- Congenital defect of cilia
- Autosomal recessive (most likely)
- English springers, pointers, setters
- erratic beating, poor mucociliary clearance
- Typically present age 6-12 months
What are the clinical signs of Ciliary Diskinesia?
- Chronic rhinitis
- mucopurulent nasal discharge, sneezing
- Moist productive cough, can be dyspneic
- Hydrocephalus
- Otitis media
- Infertile
- May have chronic recurrent pneumonia
How is Ciliary Dyskinesia diagnosed?
- Radiographs:
- 50% can have situs inversus
- Bronchitis, pneumonia
- Bronchiectasis
- Can have rhinoliths
- Tracheal Wash:
- culture and susceptibility
- Mucociliary Clearance
- 99mTc albumin
- 1 drop at the tracheal bifurcation
- Watch for clearance (40min)
- Normal: 7-20mm/minute
- Dyskinesia: severely impaired or absence
- Not a perfect test, other resp. disease can slow clearance
- best used to rule out diskinesia
- Biopsy nasal or tracheal epithelium
- In vitro functional analysis
- Electron microscopy for structural defects
Why can checking sperm help diagnose Ciliary Dyskinesia?
- Sperm are poorly motile or nonmotile, dogs may be infertile
- An easy in-house test
What is the Treatment for Ciliary Dyskinesia?
- Manage recurrent infections
- Encourage coughing (pulmonary therapy)
- use coupage, nebulization to loosen mucus
- Provide oxygen when needed
What is the prognosis for Ciliary Dyskinesia?
variable, but not great for most dogs
