DISEASES OF THE CARDIOVASCULAR SYSTEM

ACQUIRED VALVULAR DISEASES

CHRONIC MITRAL VALVE INSUFFECIENCY

SMALL BREED/TOY BREED DOGS, USUASLLY OLDER THAN 10 YEARS

THE PREVALENCE OF THIS DISEASE INCREASES WITH AGE, AND IS PROGRESSIVE. IT ACCOUNTS FOR ~95% OF ALL HEART FAILURE CASES

CHRONIC MITRAL VALVE INSUFFICIENCY

ONE OF THE MOST COMMONCAUSES IS CHRONIC PERIODONTALDISEASE!

BACTERIA THAT LIVE IN TARTAR,GET SHOWERED INTO THE BLOODSTREAM AND COLONIZE IN THEVALVE LEAFLETS.

CHRONIC MITRAL VALVE INSUFFICIENCY

1.Lungs: Pulmonary fibrosis, bronchitis, and chronic obstructive pulmonary disease.

2.Heart: Endocarditis, mitral valve regurgitation, and myocardial

degeneration.

3.Liver: Hepatic parenchymal inflammation and hepatopathy.

4.Kidneys: Interstitial nephritis and glomerulonephritis.

CHRONIC PERIODONTAL DISEASE CAN AFFECT SEVERAL ORGAN SYSTEMS

MITRAL VALVE INSUFFICIENCY

THIS IS THE OPEN LEFTVENTRICLE SHOWING THEMITRAL VALVE LEAFLETS. WHAT ARE THE STRING-LIKESTRUCTURES THAT ATTACHTHE VALVES TO THE PAPILLARY MUSCLES?

MITRAL VALVE INSUFFICIENCYCHORDAE TENDINEAE

MITRAL VALVE INSUFFICIENCY

BOTTOM LEAFLET ISTHICKENED AND NODULAR. THISIS DUE TO INCREASED FIBROBLASTIC TISSUE WITHINTHE VALVE LEAFLETS

TOP LEAFLET IS NORMAL

CHRONIC MITRAL VALVE INSUFFICIENCY

DURING LEFT VENTRICULARCONTRACTION, BLOOD FLOWSBACK INTO THE LEFT ATRIUM

THE STIFF MALFORMED VALVE FAILS TO CLOSE SUFFICIENTLYDURING SYSTOLE.

MITRAL VALVE INSUFFICIENCY

IF BLOOD CONTIUES THIS BACKWARDFLOW, THE ANIMAL MAY EXPERIENCELEFT-SIDED HEART FAILURE CHARACTERIZED BY PULMONARY EDEMA

CHRONIC MITRAL VALVE INSUFFICIENCY

• DIAGNOSIS:– Radiographs– Echo– Systolic murmur at left apex; “whooping” quality

• There is no treatment to delay the onset of clinical signs. Treatment is aimed at improving symptoms of heart failure– Diuretics (lasix)– ACE inhibitor, vasodilator (Enalapril)– Diet change: low sodium

TRICUSPID VALVE INSUFFICIENCY

TRICUSPID VALVE INSUFFICIENCY

TRICUSPID INSUFFICIENCY RESULTSIN RIGHT-SIDED HEART FAILURECHARACTERIZED BY PLEURAL EFFUSION

TRICUSPID VALVE INSUFFICIENCY

RIGHT-SIDED HEART FAILURE ALSOLEADS TO ASCITES

NOTE: THE LOSS OF ABDOMINALDETAIL

TRICUSPID VALVE INSUFFICIENCY

• Treatment and client info are the same as for mtiral insufficiency; repeated abdominocentesis may be needed in these cases.

LIVE LIFE TO THE FULLEST!

“You only live once, but if you work it right, once is enough.”

-Joe E. Lewis, comedian

DISEASES OF THE CARDIOVASCULAR SYSTEM

HEARTWORM DISEASE

CANINE HEARTWORM DISEASE• PARASITE CAUSING HEARTWORM DISEASE:

DIROFILARIA IMMITIS

MICROFILARIA OF D. IMMITIS ADULT HEARTWORMS

CANINE HEARTWORM DISEASE

ONLY FEMALE MOSQUITOES BITE

DISTRIBUTION OF CANINE HEARTWORM DISEASE

CANINE HEARTWORM DISEASE

ADULT HEARTWORMS LIVEIN THE PULMONARY ARTERIES. THE HEART MUSTWORK EXTRA HARD TO PUMP AGAINST THIS OBSTRUCTION.

CANINE HEARTWORM DISEASE

ADULT HEARTWORMS INRIGHT VENTRICLE AND PULMONARY ARTERY

CANINE HEARTWORM DISEASE

• PREDOMINANT PATHOLOGY: DAMAGE TO THE PULMONARY ARTERY FROM ADULT HEARTWORMS– Endothelial damage and sloughing– Inflammation (leukocytes, platelets)

• Risk of thromboemboli– Pulmonary hypertension– Disruption of vascular integrity

• Thickened, fibrosed

• RIGHT VENTRICULAR HYPERTROPHY AND RIGHT-SIDED HEART FAILURE– The right ventricle compensates by dilating and increasing

muscle thickness– Ultimately, there is decompensation and heart failure

CANINE HEARTWORM DISEASE

• Severe infection can lead to CAVAL SYNDROME– Worms back up into the right atrium and venae

cavae• Found in heavy worm burdens (>60)• Associated with a poor prognosis• Surgical treatment: pull worms from the right heart

and venae cavae via jugular venotomy

CANINE HEARTWORM DISEASE

CANINE HEARTWORM DISEASE

IDEXX SNAP TEST

ADULT FEMALE ANTIGEN

CANINE HEARTWORM DISEASE

CANINE HEARTWORM DISEASE

CANINE HEARTWORM DISEASE: PREVENTION

• HEARTGARD/IVERHEART– Ivermectin/pyrantel pamoate

• INTERCEPTOR/SENTINEL– Milbemycin oxime/ milbemycin oxime+lufeneron

• REVOLUTION– Selamectin

• ADVANTAGE MULTI/PROHEART 6– Moxidectin– Q 6 month injectable

• TRIFEXIS– Moxidectin + spinosad

CANINE HEARTWORM DISEASE: TREATMENT

STANDARD PROTOCOL: 1 epaxial injection, followedBy a second injection on the opposite side 24 hours later

ALTERNATIVE PROTOCOL: 1 Injection given followed in 4-6 weeks by 2 injections given 24 hours apart

ONLY KILLS ADULT (L5) STAGE WORMS; DOXYCYCLINE IS REC. AS COMPLIMENTARY TX