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Respiratory - veterinary

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Indication that the mucosal defense and mucociliary clearance mechanisms are no longer able to prevent bacterial colonization?
When the nasal discharge changes from serous to purulent.

Virtually all intranasal lesions that cause a purulent discharge are preceded by a serous discharge.
viral upper respiratory infections are considered as a predisposing factor in secondary bacterial infections of the nasal passages, sinuses, and middle ear. Why?
it is believed that they disrupt the normal protective function of the mucociliary apparatus in the upper respiratory tract which allows bacteria to adhere to surface epithelium. They also reduce the host's immune response and disrupt macrophage function.
The presence of blood in a purulent nasal discharge is from?

Most bacterial infections of the nasal cavity and frontal sinuses in dogs/cats are considered to be primary or secondary?
the result of tissue destruction (NOT trauma from sneezing)


Secondary
Mucoid nasal discharge:
a) appearance
b) consistency
c) duration
d) produced by
e) caused by
a) clear to cloudy
b) gel like
c) copious, intermittent, +/- blood tinged
d) produced by the goblet cells located in the epithelium lining the nasal cavity
e) often seen in older dogs and cats with intranasal carcinoma.
Sneezing may/may not be a presenting sign.
mucopurulent nasal discharge:
a) appearance
b) denotes ?
c) often associated with?
a) viscous and opaque (contains both mucus and inflammatory cells)
b) chronicity and secondary bacterial infection
c) nasal aspergillosis, cryptococcosis, or intranasal tumors

Bleeding is more likely from tissue destruction than sneezing.
Epistaxis:
a) What is it?
b) more prevalent in cats/dogs?
c) indicative of ?
d) hematocrit similar to?
e) distinguished from blood tinged discharge by?
a) nosebleed
b) dogs
c) a serious underlying coagulation or platelet abnormality (not normally a primary intransal lesion)
d) similar to peripheral blood
e) amount, usually copious and intermittent
Bacterial Rhinitis:
What can predispose cats to bacterial Rhinitis?
any chronic inflammatory process involving the nasal passage including parasitic rhinitis, fungal rhinitis, nasal aspiration of food or liquid, neoplasia, dental disease, oronasal fistula, bacterial bronchopneumonia.
Previous herpesvirus infections of the nasal passage is a likely cause for many cats.
Bacterial Rhinitis:
Reason for presentation
chronic mucopurulent nasal discharge
Bacterial Rhinitis:
Clinical signs
Sneezing, mucopurulent nasal discharge (uni- or bilateral). Lesser seen signs include:
epistaxis (usually with mycotic rhinitis or neoplasia); pawing at the face. Respiratory signs may be noted.

** Severe weight loss, facial deformity, or neurological sings should suggest other diseases.
Bacterial Rhinitis:
Differential Diagnoses
1. parasitic or fungal rhinitis
2. nasal foreign bodies
3. tooth root abscesses
4. oronasal fistula
5. bacterial bronchopneumonia and cleft palate
6. primary ciliary dyskinesia (more
likely in younger animals)
Bacterial Rhinitis:
Diagnostic testing and findings;
Complete oral examination to rule out oronasal fistula, cleft palate, or significant dental disease (tooth root abscesses).
Cytologic examination and culture of discharge
nasal radiographs
rhinoscopic examination of the nasal cavity and biopsy.
CT or MRI may also be used, esp with chronic patients.
Bacterial Rhinitis
radiographic findings
increased density within the nasal cavity secondary to accumulation of inflammatory debris.

NASAL TURBINATES ARE RARELY DESTROYED.
Bacterial Rhinitis
Cytologic findings
non-specific or negative findings do not rule out differential diagnoses. neutrophils usually predominate in bacterial, fungal, or viral infections.
Bacterial Rhinitis
1. Rhinoscopy

2. Nasal flush
1. May be of limited value as you may not be able to see much because of the presence of copious amounts of discharge.
2. can help reduce the amount of mucus and debris
Bacterial Rhinitis;
1. biopsy

2. culture of discharge
1. a)the nasal cavity and frontal sinuses
b) usually show signs of chronic inflammation without showing the specific etiologic agent.
2. a)Cats usually are Pastuerella spp.
b) dogs usually E. coli, Bacillus, Neisseria, Staph, and Strep.
c) which can make interpretation difficult since these are normal flora.
d) if one is of heavy growth though, that may be more significant.
e) isolates obtained from the caudal nasal cavity and sinuses at surgery are more diagnostic.
Bacterial Rhinitis:
Treatment
1. treat and remove underlying cause!
2. antimicrobial therapy is only temporary if #1 isn't accomplished!
3. if not a specific culture, long term antibiotics are used (4-6 weeks)
Bacterial Rhinitis;
Supportive Therapy
1. Clean discharge from external nares often.
2. keep hydrated
3. nebulization may aid in mobilization of secretion and help to relieve obstructed nasal passages.
4. topical nasal decongestants may improve airflow, increase drainage, and decrease production of secretion because of a secondary effect of alpha adrenergic-mediated nasal vasoconstriction (less edema and nasal congestion)
May need to 1 -2 drops per nostril for 3 days in a row/week to alleviate rebound congestion.
5. Corticosteroids may provide relief of clinical signs in a few cases (also helps to get cats eating)
Bacterial Rhinitis;
Alternative Therapy
usually for chronic cases that can't be treated medically successfully.
Rhinotomy followed by turbinectomy, though morbidity afterwards can be marked.
Surgical ablation of the frontal sinuses can work sometimes (glue)
Bacterial Rhinitis:
Prognosis
1. usually responsive to antibiotic therapy
2. need to clear up the primary problem in order to not become chronic.
Upper Airway Disorders
1. Tonsillitis
2. Tracheal Disorders
Tonsillitis
1) occurs when?
2) Clinical signs
3) diagnosis
1. in juvenile dogs
2. coughing, retching, fever and inappetance (caused by inflammation of the pharyngeal mucosa), may/may not have tonsillar enlargement
3) based on history and PE findings. tonsils may be inflamed wth small punctate hemorrhage and have white or yellowish plaques (inflammatory exudate) on them.
Tonsillitis
1) treatment
1. culture and sensitivity NOT indicated because of the similarity with normal flora.
Amoxi or another broad spectrum antibiotic. Tonsillar enlargement may remain for a couple of weeks after treatment is complete.
Tonsillitis
Chronic/recurrent
suggested to be normal part of cellular and humoral immunity growth. Others think it is may lead to autoimmune disorders.
Tonsillitis
Secondary -
caused by chronic vomiting/regurgitation, upper or lower respiratory tract infections, periodontal disease, open mouth breathing and licking mucocutaneous regions or infected skin.

Treat underlying cause and do culture and sensitivity!
Tonsillitis --

Tonsillectomy -
1) when?
2) complete healing occurs?
1a) in dogs with chronic or recurrent tonsillitis that is unresponsive to antibiotics
1b) in dogs with tonsillar enlargement that results in upper airway obstruction (this doesn't seem to affect their appetite or ability to swallow, but may make noise (or cause stridor) when the animal is running).
2a) 10- 14 days
2b) antibiotics should be given for a week after surgery and soft foods on second day for 2 weeks. No food for first 24 hours after surgery.
Tracheal disorders can be located where?
intrathoracic, extrathoracic, or both.
Extrathoracic signs include:
a) result in inspiratory distress or difficulty
b) sonorous inspiratory breathing, inspiratory wheezes, palpable abnormalities of tracheal anatomy, cough, gagging, and occasionally cyanosis
Intrathoracic signs include:
a) result in expiratory distress or difficulty
b) sonorous expiratory breathing, expiratory wheezes, palpable abnormalities of tracheal anatomy, cough, gagging, and occasionally cyanosis.
signs of both extrathoracic and intrathoracic include:
sonorous breathing, inspiratory/expiratory wheezes, palpable abnormalities of tracheal anatomy, gagging, cough and occasionally cyanosis.
how does the cough differ when it is due to both intra/extrathoracic problems?
it is often paroxysmal in nature and induced by things such as excitement, pulling on a collar or chain, drinking water, among other things.
Tracheobronchialmalacia is?

What part is involved?

What are the clinical signs?
tracheal and bronchial walls are especially soft and pliable.

Can involve the whole tracheobronchial tree or just a portion of it.

Clinical sings are occasional episodes of stridor, coughing, or complete airway obstruction.
1. Tracheobronchial collapse is classified as:

2. Acquired/congenital?
1. large and small airway disease

2. mainly acquired disease
Tracheobronchial collapse
1. commonly seen in ?

2. Presenting complaint?
1. middle aged and older small dogs weighing less than 10 kg (22 lbs).

2. chronic coughing without systemic disease
1. during normal inspiration, the intrathoracic tracheobronchial lumen ______ because of?

2. the trachea and large airways don't collapse (even with high intrathoracic pressures)in normal patients because ....
1 a. dilate
b. due to the difference between intrathoracic and intraluminal airway pressures.

2. of the rigidity of the trachea (tracheal rings) and large airways
in patients with tracheobronchial collapse, the condition can be exacerbated by?
normal adjacent structures such as the filling of the left atrium and the distension of the esophagus while swallowing a bolus of food.
Etiology of tracheobronchial collapse?
1. hereditary predispostion
a. most animals affected are small breeds such as toy/miniature poodles, chihuahuas, yorkies, and poms.
2. many patients are significantly obese.
3. the cartilaginous portion of the trachea shows distinct changes including loss of chondroiton sulfate, glycosaminoglycan, and calcium. Some areas seem to more like fibrocartilage or fibrous tissue than cartilage. These are not uniform findings throughout the trachea, but the rings that are affected tend to collapse in a dorsoventral direction.
4. recurrent upper airway infections may play a role in this diseases development.
5. Cardiac disease, especially chronic valvular disease (endocardiosis of the mitral valve) IS a predisposing cause because of the enlargement of the left atrium.
1. Signalment
2. Clinical signs of Tracheobronchial collapse
1. older aged, overweight small breed dog
2. Both crackles (from the opening of peripheral airways) and wheezes and often a loud snapping sound can be heard at the end of expiration (from closing of the large airways) during auscultation of the thorax.
Gentle tracheal palpation will often yield a paroxysmal cough and should be done to document the character of the cough.
If the patient has cardiac disease, a systolic murmur in the region of the mitral valve is often heard. Pulmonary hypertension may be found (esp if you hear a right sided murmur, an accentuated second heart sound, or notice signs of right sided heart failure).
In advanced disease, mucous membranes may be cyanotic, patient unwilling to exercise. These guys need to be handled with care and may need supplemental oxygen.
Differential diagnoses of tracheobronchial collapse
1. tracheitis
2. tracheobronchitis
3. dirofilariasis
4. chronic bronchitis
5. left sided heart failure
The most helpful diagnostic test or procedure is?
a good thoracic radiograph (in conjunction with signalment and PE findings) which is taken during both inspiration and expiration.
1. Which is seen better on inspiratory radiographs?

2. Which is seen better on expiratory radiographs?
1. cervical tracheal collapse

2. intrathoracic trachea and mainstem bronchi. This will be enhanced if you can elicit a cough during expiration.
1. Which occurs most often: intrathoracic or extrathoracic tracheal collapse?

2. Thoracic films may also show?
1. intrathoracic tracheal collapse

2. evidence of significant interstitial disease with poor inflation of the lungs.
Grade 1 Collapsed trachea
1. treatment
2. shape
3. lumen diameter
1. medical
2. tracheal cartilage circular
3. 25% reduction
Grade 2 Collapsed trachea
1. treatment
2. shape
3. lumen diameter
1. surgical
2. tracheal cartilage partially flattened
3. 50% reduction
Grade 3 Collapsed trachea
1. treatment
2. shape
3. lumen diameter
1. surgical
2. tracheal cartilage nearly flat
3. 75% reduction
Grade 4 Collapsed trachea
1. treatment
2. shape
3. lumen diameter
1. surgical
2. tracheal cartilage flat or inverted
3. nearly obliterated
Tracheobronchial collapse:
1. prognosis
1. depends on the severity of the disease and on concurrent disease.
2. many show marked improvement following extraluminal prostheses placement, though laryngeal paralysis can occur if there is entrapment or fibrosis of the recurrent laryngeal nerve by the prostheses.

All patients need to be reexamined within a few days to assess the therapy. Medication dosages and combinations may need to be adjusted and there may need to be reduction of the patient's activity, sedation, or even a change of environment.
Diet is key, but can take a while.
Tracheobronchial collapse:
1. Surgery
best done early in the disease. most rewarding when there isn't concurrent peripheral airway collapse.
Can be done if medical therapy is not acceptable to the owner
Treatment of tracheobronchial collapse:

1. palliative/curative?
2. treatment plan?
1. palliative... symptomatic treatment
2. a) WEIGHT REDUCTION! may make the coughing go away by itself.
b) corticosteroids for a short period
c) antitussives (hycodan or torbutrol)- decrease cough and gives some sedation which helps also.
d) bronchodilators (theophylline or terbutaline) suggested, but may not help if there is significant central airway collapse as they will work on the peripheral airways)
e) If endocardiosis present, it needs to be treated. (diuretic -- furosemide and enalapril; +/- digixon (depending if there are supraventricular tachyarrhythmias or if contractility is poor);
Treatment of tracheobronchial collapse:

Antibiotics
Probably not necessary, but if used, use a broad spectrum antibiotic such as a cephalosporin or clavamox.
Documentation of endocardiosis by:
thoracic radiographs (generalized cardiomegaly with left atrial enlargement)
Electrocardiogram (evidence of left ventricular hypertrophic pattern and left atrial enlargement (though not always seen))
Echocardiogram (left ventricular enlargement, incrased contractility of the left ventricle, thickened mitral valves, and enlargement of the left atrium)

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