Endocarditis in Dogs & Cats

WHat is the pathogenesis for endocarditis?

1. Endothelial injury

2. Sub endothelium attracts platelets

3. Bacteria bind to platelets and go to tissue below → hard to clear

How does fibrin enhance endocarditis?

it shields the bacteria from antibiotics and the immune system

Why is endocarditis hard to clear other than the fibrin shield?

No direct vessels to valves which makes ABX diffucult

C/S of endocarditis

• heart murmur

• fever

  • ABX might mask

• Tachycardia

• lethargy

• lameness → shifting

• ADR - MAINLY

WHat is the underlying etiology for endocarditis?

• turbulent blood flow

• hgih velocity blood flow

• abnormal endothelium

• congenital heart defect

  • Subaortic stenosis

  • ventricular septal defect

  • patent ductus arterosus

  • mitral regurg

Subaortic stenosis causes aortic valve damage from __________ and ___________.

high velocity; turbulent blood flow

True or False: Bacterial endocarditis is rare.

TRUE

Is there a relationship between dental disease and endocarditis?

NO

True or False: MMVD predisposes dogs to infective endocarditis.

FALSE

_______ defects commonly result in endocarditis.

Congenital

What is the most common valve affected in dogs, cats, and horses?

Aortic and Mitral

Mural Location

not a valve; lesion somewhere on the wall → uncommon

What is the most common underlying etiology in dogs?

Subaortic stenosis

What is the most common etiology in cows?

chronic extra cardiac infections (bacteria in VR)

What is the most common underlying etiology in horses and cats?

microscopic endothelial damage in left heart (high pressure)

True or False: Finding no etiology is common.

TRUE

WHat bacteria wouldn’t come up on culture?

Bartonelaa (intracellular)

What limb is most commonly affected by septic thromboembolism? WHy?

Right forelimb because of the aortic arch anatomy (1st branch supplies it)

What are the echocardigraphic signs?

• hyperechoic

• irregular (shaggy)

• moves independently

• on flow side of valve (atrial side)

• jet lesions from high velocity blood

True or False: A culure is always recomended

TRUE

How many samples should you take for culture?

3 samples from different sites 30 mins apart

• commonly no growth even with bacteremia

What is the most common diagnostic with bartonella?

Joint fluid culture or PCR/serology due to Immune-complx synovitis common

Why is a urine culture recommended?

immune complex gloerular nephritis common if no bacterial growth is seen

WHat is the prognosis with endocarditis?

POOR

A high proportion of cats with endocarditis present in _____ ± _______

CHF; FATE

How do you treat endocarditis?

• ABX based on culture / empiric therapy for 1-2 weeks IV in hospital

  • Some prolonged tx at home for 6-8 weeks (oral)

  • reevaluate after 2 weeks of ABX D/C

WHy should you only D/C one antibiotic at a time?

You don’t actually know whats working