INTERACTIVE RADIOGRAPHIC CASE STUDIES

 
 

TazCase Background - Visit #1

 
Name Taz
Age 11 years
Sex Male, neutered
Breed Small mixed breed (9kg)
 

Please review Taz's clinical history.

New cough that started 1 week ago. The cough was initially noted in the evening but now occurs frequently throughout the day and night and the home resting respiration rate is 34 (Normal is < 30). The heart rate is 160 and regular and there is a grade 4/6 left apical systolic murmur. The lung sounds are harsh bilaterally with a respiration rate of 46.
Click here to view the circulation article on Resting Respiratory Rate.

View Taz's right lateral radiograph  
View Taz's ventral-dorsal radiograph  

TECHNICAL DETAILS

Location of images: Thoracic radiographs obtained.

Views of images: Right lateral and ventral-dorsal (VD)

RADIOGRAPHIC FINDINGS

Technical issues: Good quality films.

Cardiac size including VHS: VHS=11.6 There is loss of the caudal waist on the right lateral consistent with moderate left atrial enlargement.

Other Findings: There is a mixed interstitial pattern in the caudal dorsal lung fields that is moderately severe. There is evidence of venous distension.

 Radiographic Interpretation: Moderate generalized cardiomegaly with left atrial enlargement and pulmonary infiltrate (cardiogenic pulmonary edema) consistent with a diagnosis of Stage C MMVD.

 Discussion: Dogs with stage C MMVD have current or previous signs of congestive heart failure Click here for the ABCD Chart.
Treatment/Management: Initial treatment for CHF due to MMVD consists of furosemide and pimobendan. In this case they should be started immediately; furosemide at 2-3mg/kg IV or IM and pimobendan 0.25-0.3 mg/kg PO. An ACE inhibitor and spironolactone can be added at a later time. The parenteral dose of furosemide may need to be repeated q 1-2 hours until the dog appears stable. Additional supportive care may include oxygen supplementation and light sedation with butorphanol (0.2 mg/kg IV or IM) if the dog appears unduly stressed. Blood chemistries, a CBC, UA and blood pressure should be performed and once the dog is able to be switched to oral furosemide an ACEi should be added. Spironolactone can be added at a later time (1st or 2nd recheck). Dog should be rechecked in 10-14 days (rads and blood work) sooner if the cough and breathing rate do not improve. [Click here for the CEG Formulary: Cardiac Medications for Dogs]. The dog should be exercise restricted short term (until the stable i.e. until after the first recheck in 10-14 days). No dietary changes should be recommended at this time.
 

Please review Taz's follow-up.

Cough resolved by 90% and resting breathing rate is now 14. Heart rate is 130 and regular. The murmur is still present and unchanged in grade at 4/6. The lung sounds are normal and the respiration rate is 24.
Click here to view the circulation article on Resting Respiratory Rate.

View Taz's right lateral radiograph  
View Taz's ventral-dorsal radiograph  

TECHNICAL DETAILS

Location of images: Thoracic radiographs obtained.

Views of images: Right lateral and ventral-dorsal (VD)

RADIOGRAPHIC FINDINGS

Technical issues: Good quality films.

Cardiac size including VHS: VHS=11.0 (reduced from previous exam by 0.9) There is loss of the caudal waist on the right lateral consistent with moderate left atrial enlargement.

Other Findings: Within normal limits.

 Radiographic Interpretation: Persistent (although reduced from previous evaluation) moderate generalized cardiomegaly with left atrial enlargement. The lung parenchyma is within normal limits at this time and there is no evidence of venous distension consistent with resolution of the previously diagnosed congestive heart failure (cardiogenic pulmonary edema).

 Discussion: The pulmonary edema has resolved and the cardiomegaly is persistent although somewhat reduced. Click here for the ABCD Chart.
Treatment/Management: This dog has responded optimally to initial heart failure therapy that included furosemide (2.5 mg/kg BID PO), pimobendan (0.25 mg/kg BID PO) and benazepil (0.35mg/kg BID PO).  Blood chemistries were relatively unchanged and within normal limits and the dog is clinically stable thus there is no need to adjust the current medication doses and they should be continued chronically. Additionally, spironolactone at 1 mg/kg PO BID should be added as this may have a survival benefit long term. The owner could be encouraged to limit high sodium treats and start omega 3 supplementation. The dog should be allowed to exercise normally at this time i.e. set their own pace. Next recheck should be 2-3 months or sooner if resting respiration rate is reproducibly greater then 30 or the cough returns /worsens or other signs of heart failure develop.