INTERACTIVE CASE STUDIES

 
 

HersheyCase Background

 
Name Hershey
Age 14 years
Sex Female
Breed Cockapoo
Weight 9.4 kg (20.68 lbs)
Reason for Visit Cough: dog was treated for kennel cough about 6 months ago. Helped for a "little while" then the cough came back. Multiple antibiotic trials produced minor improvement. Prednisone trial resolved cough but cough returned after prednisone was discontinued.
Medications Amoxicillin 500mg: 1 capsule q 12hrs
 
 CURRENT MEDICATIONS:  DETAILS:
 Heartworm Prevention  Receiving monthly preventative 12/12 months.
 Doxycycline 1st  Cough improved but not gone, dog vomited on doxycycline.
 Amoxicillin-clavulanic acid  No change in cough, discussed further workup, decided on prednisone trial and referral if no response.
 Prednisone, tapering dose (next  after amoxicillin-clavulanic acid)  Cough resolved on prednisone therapy then returned after prednisone was discontinued.  Patient was referred for further evaluation.
   

Please review Hershey's clinical history.

 
Attitude/Demeanor Bright/Alert
Coughing Leash elicits cough, coughs in middle of night and with excitement. Non-productive honking cough
Abnormal Respirations None
Exercise Intolerance Normal
Sleep Patterns Sometimes coughs in the middle of the night
Weight Change (loss or gain) Gained weight when receiving prednisone
Appetite Increased appetite when receiving prednisone
Usual Diet Purina One® with some table scraps and cold cut treats
Vomiting None since stopping doxycycline
Diarrhea None
Syncope No
Change in Urinary Habits None
Change in Drinking Habits Increased urination when receiving prednisone
Other Symptoms or Signs Increased water intake when receiving prednisone
 

Please review the results of Hershey's physical exam.

General Body Condition Normal
Attitude Normal
Mobility | Gait Normal
Posture Normal
Hydration Normal
Body Temperature 101.6 F
Arterial Pulse - rate, regularity, intensity 120 bpm, regular, normal strength
Respiratory Rate & Effort 30, Normal
Mucous Membranes - Color & CRT Pink < 2 sec
Jugular Venous Pulse & Pressure Non-distended
Abdominal Palpatation No abnormalities, soft, non painful
Lymph Nodes Normal
Oral Cavity Mild dental tartar is present without evidence of periodontal disease
Other Abnormalities None
 

Let's auscult Hershey's heart & lungs.

Listen to Hershey's heart and lungs

What do you hear?

Hershey has a normal auscultation with no murmurs, gallops, clicks or arrhythmias.
Hershey has a normal auscultation with no murmurs, gallops, clicks or arrhythmias.
Hershey has a normal auscultation with no murmurs, gallops, clicks or arrhythmias.
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Direct HR: 120 bpm
Heart Rhythm: Rhythm is regular
Intensity of Heart Sounds: Normal
Extra sounds - clicks or gallops: None
Precordial Palpation: No abnormalities

The following are potential diagnosis for you to consider at this time. Based on the history and the physical examination, please indicate the likelihood of each as:
  • High (could explain most or all of the signs)
  • Possible (less likely to explain most of the signs)
  • Unlikely

Respiratory Disease

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Cardiovascular Disease

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The CEG considers the following differential diagnosis as most likely (and why):

The presence of the clinical sign of cough without abnormal cardiac auscultatory findings make a respiratory cause of the cough more likely in this patient. However some cardiac diseases, like dilated cardiomyopathy, may not have a heart murmur on auscultation, so cannot be completely ruled out in this case. The history of a positive clinical response to steroids also supports a respiratory etiology for the cough; most patients that have a cough due to cardiomegaly will not improve with steroid therapy. Possible common respiratory conditions that could be associated with a cough in older small breed dogs include tracheal collapse, pneumonia, airway inflammation (bronchitis, either infectious or inflammatory) and pulmonary neoplasia. Other less common causes of cough may include problems like airway foreign body, laryngeal dysfunction or hilar lymphadenopathy.

BLOOD PRESSURE

Non-invasive blood pressure

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CLINICAL LABORATORY

CBC with platelet count

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Coagulation profile

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Serum biochemical profile (includes electrolytes)

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Urinalysis

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Serum thyroxine (T4)

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Heartworm antigen test

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Heartworm antibody test

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Heartworm microfilaria test

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NT-proBNP

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Cardiac troponin-I

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Blood culture

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Thoracocentesis or abdominocentesis for diagnosis or therapy

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DIAGNOSTIC IMAGING (some may require a referral)

Thoracic radiographs

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Abdominal radiographs

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Echocardiogram Doppler studies

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Abdominal ultrasound

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ELECTRODIAGNOSTICS (some may require a referral)

ECG rhythm strip or 6 lead ECG

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Ambulatory ECG - Holter ECG or event monitor

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  • You considered the following to be higher priority
    • You considered the following to be lower priority
      • You considered the following to be not indicated

        The CEG considers the following diagnostic tests as the highest priority: 

        Since the history and physical exam findings make respiratory disease more likely as a cause of cough than cardiac disease, the CEG considers thoracic radiographs to be the highest priority test in this patient. Thoracic radiographs will provide the best opportunity to examine the airways and pulmonary parenchyma for evidence of disease. In addition, the appearance of the pulmonary vasculature can be scrutinized for findings compatible with pulmonary hypertension (e.g. main pulmonary artery enlargement, enlarged and/or tortuous peripheral pulmonary arteries). Lastly, the cardiac silhouette can be examined for evidence of chamber enlargement that might indicate development of pulmonary hypertension (i.e. right-sided chamber enlargement) or evidence of "silent" heart disease (e.g. dilated cardiomyopathy, with evidence of left-sided or four chamber enlargement patterns).

        Echocardiography may be viewed as a lower priority test, to be recommended if the thoracic radiographic results do not suggest a diagnosis or present confusing or conflicting results. Doppler-echocardiography can be used to screen for pulmonary hypertension and to provide evidence of anatomic or functional abnormalities that may be contributing to clinical signs.

        A laboratory evaluation consisting of a CBC, chemistry and urinalysis may be recommended as a screening tool for pneumonia (CBC) or metabolic abnormalities (chemistry/urinalysis) that may be complicating the clinical picture or may occur as a result of previous therapies in an older patient. This patient has had a relatively reliable heartworm preventative administration history, but a repeat heartworm antigen test may be indicated if the last test was > 1 year ago, or if the thoracic radiographs reveal findings compatible with heartworm disease (i.e. enlarged pulmonary vasculature, right-sided heart enlargement alveolar infiltrates).

        The CEG did not consider additional testing necessary at this time, but specific tests may be chosen if the first tests do not suggest diagnosis, or uncover additional abnormalities that require investigation.

        Systolic Blood Pressure: Not available for this case
        Diastolic Blood Pressure: Not available for this case
        Mean Blood Pressure: Not available for this case
        Consensus Statements of the American College of Veterinary Internal Medicine (ACVIM) provides the veterinary community with up-to-date information on the pathophysiology, diagnosis, and treatment of clinically important animal diseases. In 2007, ACVIM published guidelines for the Identification, Evaluation, and Management of Systemic Hypertension in Dogs and Cats in the the Journal of Veterinary Internal Medicine.
        Click here to view and download a PDF of the ACVIM Consensus Statement, Guidelines for the Identification, Evaluation, and Management of Systemic Hypertension in Dogs and Cats.  

        Please review Hershey's thoracic radiographs

        View right lateral radiograph  
        View ventral dorsal radiograph  
        Click here to see the CEG's recommendation on Evaluating Heart Size on Radiographs

        What is the vertebral heart score?

        Please select another answer
        You are correct
        Please select another answer
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        Is Hershey's heart enlarged?

        Hershey's heart is normal. There is equivocal left atrial enlargement on lateral view but moderate intrathoracic fat makes Hershey's heart appear mildly enlarged. Intrathoracic fat in obese dogs may augment the size of the heart on radiographs. Careful scutiny may allow the clinician to differentiate fat density around the heart from the soft tissue density of cardiac silhouette when measuring the VHS, but the actual edges of the cardiac silhouette may be unclear in many animals. Subjective assessment of heart size, taking into account chest cavity conformation, phase or respiration and amount of intrathoracic fat is as important as VHS measurement. In this dog with no auscultatory evidence or physical findings consistent with heart disease, a cardiac cause for cough is unlikely and the mild increase in VHS is likely a radiographic artifact.
        Please choose another answer
        Submit

        Is there evidence of congestive heart failure present (pleural effusion or pulmonary edema)?

        Please select another answer
        There is no pleural effusion present. Intrathoracic soft tissue ventral soft tissue density on the lateral view represents intrathoracic fat. No pleural fissure lines are present on the VD view to support a diagnosis of pleural effusion.
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        Are abnormalities of the pulmonary parenchyma or airways present?

        No pulmonary infiltrates are present in the views presented but mineralized airways and dilation of the cranial lung lobe bronchus is visible in the lateral view. This airway dilation, known as "bronchiectasis" is a finding supportive of chronic airway disease.
        Please select another answer
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        Technical Quality: Good positioning and exposure, lateral view is at end inspiration Pulmonary Venous Congestion: None  

        Please review Hershey's lab results

        SERUM CHEMISTRIES
        BUN 27 mg/dL Normal: <30 mg/dL
        Creatinine 0.7 mg/dL Normal: 0.6 - 2.1  mg/dL
        Sodium 151 mm0l/L Normal:138 - 154 mm0l/L
        Potassium 5.0 mm0l/L Normal: 3.6 - 5.2 mm0l/L
        Chloride 110 mm0l/L Normal: 105- 119 mm0l/L
        ALT 72 IU/L Normal: <75 IU/L
        ALP 96 IU/L Normal: <100 IU/L
        HEARTWORM
        Heartworm Test Results Negative Antigen Test
        URINALYSIS
        Urinalysis - USG 1.025
        Urinalysis - Protein Negative
        Urinalysis - Biochemical Not Done
        Urinalysis - Sediment Evaluation Quiet Sediment
        CBC
        White Blood Cells Total Count 9.92 x10^3/ul, normal differential
        Red Blood Cells 45%, TP: 7.4 g/dl
        Platelets 421 x 10^3/ul

        You're ready to form a diagnosis and treatment plan for Hershey! Please select your answer to each question below.

        What is your diagnosis for Hershey?

        Hershey is unlikely to have pneumonia as a cause of the cough due to the relative lack of response to reasonable antibiotics and lack of radiographic evidence of alveolar or interstitial infiltrates in one or more lung lobes. Hershey most likely has chronic non-septic bronchitis. This diagnosis is supported by radiographic evidence of bronchiectasis in the cranial lung lobes and the lack of left atrial enlargement and pulmonary infiltrates. The poor response to antibiotics but improvement with low doses of corticosteroids is consistent with the chronic airway inflammation associated with this condition.
        Hershey is unlikely to have degenerative valvular disease with CHF as a cause of the cough due to the chronicity and lack of progression of clinical signs, lack of physical examination evidence of heart disease (e.g. heart murmur, arrhythmia, clicks) and lack of left atrial enlargement on thoracic radiographs. If pulmonary edema were present, radiographic evidence of interstitial or alveolar infiltrates would be visible. Hershey most likely has chronic non-septic bronchitis. This diagnosis is supported by radiographic evidence of bronchiectasis in the cranial lung lobes and the lack of left atrial enlargement and pulmonary infiltrates. The poor response to antibiotics but improvement with low doses of corticosteroids is consistent with the chronic airway inflammation associated with this condition.
        Hershey most likely has chronic non-septic bronchitis. This diagnosis is supported by radiographic evidence of bronchiectasis in the cranial lung lobes and the lack of left atrial enlargement and pulmonary infiltrates. The poor response to antibiotics but improvement with low doses of corticosteroids is consistent with the chronic airway inflammation associated with this condition. Hershey is unlikely to have degenerative valvular disease with CHF as a cause of the cough due to the chronicity and lack of progression of clinical signs, lack of physical examination evidence of heart disease (e.g. heart murmur, arrhythmia, clicks) and lack of left atrial enlargement on thoracic radiographs. If pulmonary edema were present, radiographic evidence of interstitial or alveolar infiltrates would be visible. Hershey is unlikely to have pneumonia as a cause of the cough due to the relative lack of response to reasonable antibiotics and lack of radiographic evidence of alveolar or interstitial infiltrates in one or more lung lobes.
        Submit

        More Information: Fluoroscopy was recommended to rule out dynamic airway collapse as a cause of cough. The fluoroscopic study showed significant intrathoracic airway collapse during coughing. Dynamic tracheal collapse was diagnosed. Bronchoscopy can also be performed to diagnose airway collapse. Bronchoscopic examination can be combined with an airway wash for cytologic examination and culture.


        Click here to learn more about the stages of heart disease (ABCD Brochure)  

        What treatment(s) would you recommend for Hershey?

        Submit
        THE CEG RECOMMENDS: The CEG recommends treatment with a combination of corticosteroids (prednisolone 0.25-0.5 mg/kg PO q 24 hours) and oral cough suppressants (hydrocodone or butorphanol).  Anti-inflammatory doses of corticosteroids, if tolerated, will likely decrease the inflammation in the large airways and reduce the cough.  In most cases, corticosteroid doses should be tapered to the minimal effective dose over several months.
         ACTUAL TREATMENT
         Initial Therapy Prednisolone
        0.25-0.5 mg/kg PO once daily, if possible taper to lowest effective dose every other day for chronic therapy.
        Corticosteroids are effective to decrease the chronic inflammation that may cause "dry" cough in dogs with chronic bronchitis. Tapering the dose to the lowest effective dose helps to limit unwanted side effects of chronic corticosteroid administration.

        Hydrocodone


        1.25-2.5 mg PO up to 3 times per day as needed to lessen cough
        Hydrocodone was used as cough suppressant in this patient. Oral butorphanol can be used instead of hydrocodone if desired. Cough suppressants can be helpful for "night-time" coughers because of their mildly sedative side effects (vary with dose). The dose of cough suppressant should be decreased if the patient is excessively sedated.
         Lifestyle Adjustments Limit activity on hot/humid days if coughing is provoked. Use a harness rather than a collar for leash walks.

        Recommended Follow-up Treatment: Hershey's cough was well-controlled with corticosteroid and cough suppressant therapy, and most days were cough-free. His corticosteroid dose was eventually decreased to 0.5 mg/kg every other day, with hydrocodone given only as needed (usually before bedtime).
        Long term follow-up of heart disease: Hershey will return for yearly auscultation, with the owner asked to return sooner if any problems with recurrent cough, exercise intolerance or difficulty breathing develop.