This document discusses heart disease in captive gorillas and other great apes. It notes that cardiovascular disease is a leading cause of death in adult gorillas. The most common type is fibrosing cardiomyopathy. Treatment may include medications like ACE inhibitors, beta blockers, and diuretics. For one male gorilla with congestive heart failure, a cardiac resynchronization therapy device with defibrillator was surgically implanted. This improved his ejection fraction and heart function. He survived over a year with monitoring and medication adjustments before passing away from pneumonia.

1. Emily Hall
DVM Candidate 2016
RUSVM Student

2. • Heart disease was initially detected only in
individual apes during necropsy.
• 1994 survey of AZA North American SSP
necropsies cardiovascular disease is the
primary cause of death in 41% of adult gorillas
• Male gorillas over 30 years old= 71%
• Bonobos= 45%
• Chimpanzees= 45%
• Orangutans= 20%

3. • Most gorillas show clinical signs after 11yrs old
• Males are most affected
• Is present in wild
• In wild is lower incidence and not primary
cause of death

4. • Fibrosing cardiomyopathy
– Gorillas
– Orangutans
– Chimpanzees
– Bonobos
• Aka idiopathic myocardial fibrosis
– chimpanzees

5. • Lesions maybe dramatic
• Fibrotic patches frequently near or
around small-caliber intrinsic coronary
arterioles
• Left ventricular hypertrophy or dilated
and flabby?...either
• Myocardial fibrosis=end-stage stage
lesion, which doesn’t imply a particular
etiology or pathogenetic mechanism
Heart of an adult male chimpanzee that
died unexpectedly, with myocardial
fibrosis
Histologic section of the
myocardium of the adult male
chimpanzee with fibrosing
myocardiomyopathy

8. Treatment
• Angiotensin converting
Enzyme (ACE) inhibitors
– Left ventricular hypertrophy
• Beta Blocker
– Depressed ejection fraction
• Diuretics as needed
• Dietary management
– Na limitation
– Fluid intake
– Higher fiber (biscuits and
browse)
– Remove citrus prevent acid
reflux
– Bananas increase potassium
– famotidine
Monitoring= helps fine tune drug
dosages & avoid hypotensive crises
• Regular body weight
• Strict fluid & salt intake and
output control
• Awake blood pressure
• Electrocardiography
• Serial cardiac ultrasound

9. • This ICD is meant to
correct dyssynchronony
• Defibrillator
incorporated
• Has been used in
humans for decades:
– New York Heart
Association (NYHA) Class
III/IV heart failure
– Ejection fraction of <0.35
– Continual symptoms
despite drug therapy
The original cardiac resynchronization
therapy device with defibrillator
implanted surgically under the left
pectoral muscle.

10. • Resynchronization of
ventricular contraction
– Electrical stimulus to LV
– Contraction of RV
– Coronary sinus lead
• Intravascular leads
placed at myocardium
– Read electrical stimulus
– Emit electrical stimulus
Lead Placement via fluoroscopy:

11. • Coordination of the lateral & septal cardiac walls in
contraction
• Improvement of the ventricular activation sequence
• Increase ejection fraction
• Decreased NYHA classification
• Reduced mitral regurgitation
• Increased pulse pressure
• Increased LV diastolic filling time
• Improving pumping efficiency without increasing O2
demand

12. • Signalment: 24 yr old, Male western lowland gorilla
(Gorilla gorilla gorilla)
• Clinical signs: Applying pressure to pectoral area
with balled fist (March 2003), decreased appetite
and activity, decreased responsiveness to training.
• Diagnosis: Congestive heart failure NYHA Class III
that progressed to class IV over 16 months despite
medical therapy.
• Final treatment: Cardiac resynchronization therapy
(CRT-D) devise with defibrillator along with
medications and monitoring

13. First:
• Immobilized with
tiletamine/zolazapam
• Transthoracic ultrasound
– decreased cardiac function
– Evidence of fibrotic myocardial
change
– Heart not enlarged, walls normal
thickness, LV function significantly
reduced, 160-180bpm, BP
231/167mm Hg
• Large abscess ventral to left ear
drained & flushed
• Cefdinir
• Furosimide trial
Second:
• Intubated this time
• Gastroesophageal eval via
endoscope
• Transesophageal echocardiology
(TEE)
– LV EF 0.25-0.30 (N= 0.66+/- 0.06)
– Global systolic hypokinesia
– Ventricular dilation
– Myocardial hyperechogenicity 
fibrotic change
– Delayed systolic contraction of LV
free wall
• Thoracic radiographs
– Mild pulmonary venous distention
– Interstitial edema
• Oral furosemide decreased to
200mg PO for 21 days & enalapril
maleate

14. • Telazol + ISO
• TEE Decreased cardiac function
– EF 0.20-0.25
– 5-10% decrease in function
• Meds continued
– Enalapril divided into 20mg PO am & 30mg PO pm
– Furosimide
• Dietary & behavior
– No significant changes

15. • Congestion exhibited
• Furosimide
– Increased to 300mg PO BID

16. • Ketamine hydrochloride 200mg/ml, 600mg IM, hand syringe with
supplemental ketamine (100-400mg to effect) and ISO face mask +
Diazepam for ISO sparing
• EF= 0.10-0.15
• Lost ~37kg in 30 days
• Enalapril
– 25mg am
– 35mg pm
• Furosimide
– 200mg PO BID to 800mg PO TID
• Acetylsalicylic acid 81.5mg PO SID
• Carvedilol 1.56 mg PO SIT
• Metolazone 5mg PO BID
• Bumetanide- 10mg PO SID

17. • Final months prior to implantation:
– Anorexic wouldn’t take meds orally
– Lethargic
• Week prior to implantation:
– Severe clinical pulmonary congestionMultiple doses
furosimide
• Exercise intolerance
• Tachypnea
• Restlessness
• Wouldn’t rest in dorsal recumbancy
• Training reluctance
• Deep, productive cough
• Rapidly declined 72 hrs prior to sx

18. • Ejection Fraction improved
– Pre-op: 0.10-0.15
– Post-op: over 0.35
• TEE saw significant improvement
– synchrony of rhythm
– movement of the LV free wall
• Only visual sign of surgery…
– 3.8cm long incision site on left pectoral region
with no external sutures

19. • Replacement once due to a squabble with another animal
• Battery replacement about every 24 months
• 24hr monitoring 2weeks post op
• Medications
– Carvedilol increased to 25mg PO BID
– Furosemide decreased to 200mg PO am, 100mg PO noon,
200mg pm
– Metolazone discontinued
– Occasional daily manipulation depending on
• BID daily weights
• Resp rate and effort
• Training response
• Appetite
• Activity level
• HR or ECG changes
• Dietary
• Behavioral

20. • Euthanasia for pneumonia
• No major cardiac events noted
• No clinical presentation of cardiac disease
• No failure or device dysfunction or disruption
• Necropsy, histopathology
– Fibrosing cardiomyopathy
– Dilative cardiomyopathy
– Fibrinopurulent pneumonia

21. • Electrical conduction
systems mapped
• Biomarkers
• Endomyocardial biopsies for
the diagnosis for
myocarditis or
cardiomyopathy is done in
humans
• Coronary angiography
• More cases needed:
placement of implantable
monitors and/or
defibrillator monitors
• Behavioral training for
noninvasive procedures:
– Chest auscultation
– Blood pressure measurement
– Ultrasound exams
– Blood collection

22. Works Cited
• Miller, R. Eric., Murray E. Fowler, and Murray E. Fowler. Fowler's Zoo and Wild
Animal Medicine: Current Therapy. St. Louis, MO: Elsevier/Saunders, 2012. Print
• Murphey, Hayley Weston, DVM, Patricia Dennis, DVM, William Devlin, MD, Tom
Meehan, DVM, and Ilana Kutinsky, DO. "Echocardiographic Parameters of Captive
Western Lowland Gorillas (Gorilla Gorilla Gorilla)." Journal of Zoo and Wildlife
Medicine 579th ser. 42 (2011): 572-79. Web. 20 May 2015.
• Rush, Elizabeth Marie, DVM, Anna L. Ogburn, DVM, and Jeffery Hall, DVM.
“Surgical implantation of a Cardiac Resynchronization Therapy Device in a Western
Lowland Gorilla (Gorilla Gorilla Gorilla) with Fibrosing Cardiomyopathy." Journal of
Zoo and Wildlife Medicine ser. 41 (2010): 395-403. Web. 25 May 2015.
• Rush, Elizabeth Marie, DVM, Anna L. Ogburn, DVM, and Denise Monroe, BSRN.
"Clinical Management of a Western Lowland Gorilla (Gorilla Gorilla Gorilla) with a
Cardiac Resynchronization Therapy Device." Journal of Zoo and Wildlife
Medicine 276th ser. 42 (2011): 263-76. Web. 21 May 2015.
• https://www.youtube.com/watch?v=4utL6a4SmU4