DISEASES OF THE CARDIOVASCULAR SYSTEM:

CardiomyopathiesCogenital malformation

CHFAcquired Valvular disease

Infectious

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

L HR

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)

– Enalapril (avoids retention of fluid): ACE inhibitor, vasodilator

– Pimobendan: Helps pump blood efficiently

– 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 pleural effusion andASCITES

NOTE: THE LOSS OF ABDOMINALDETAIL

Ascites. Blood backs up in vena cava and this back up causes back overload, liver overloaded with fluids. Vascular permeability, leaky vessels.

TRICUSPID VALVE INSUFFICIENCY

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

• Lasix: Diuretics

• Enalapril: Reduces retention of fluids

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:

CardiomyopathiesCogenital malformation

CHFAcquired Valvular disease

Infectious

DISEASES OF THE CARDIOVASCULAR SYSTEM

HEARTWORM DISEASE

CATS HWD

DISTRIBUTION OF CANINE HEARTWORM DISEASE

CANINE HEARTWORM DISEASE• PARASITE CAUSING HEARTWORM

DISEASE: DIROFILARIA IMMITIS

MICROFILARIA OF D. IMMITIS ADULT HEARTWORMS

CANINE HEARTWORM DISEASE

ONLY FEMALE MOSQUITOES BITE

Mosquito transmits L3 stage.L1 – L3 develops in the mosquito.Dog mff goes to mosquito. Dog L3 – L5

CANINE HEARTWORM DISEASE

Intermediate host

Definitive host

CANINE HEARTWORM DISEASE

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

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

GRADING

• Class 1:  No symptoms or mild symptoms such as an occasional cough.

• Class 2:  Mild to moderate symptoms such as an occasional cough and tiredness after moderate activity.

• Class 3:  General loss of body condition, a persistent cough, and tiredness after mild activity.  Trouble breathing and signs of heart failure are common. For class 2 and 3 heartworm disease, heart and lung changes are usually seen on chest x-rays.

• Class 4:  Caval syndrome.  There is such a heavy worm burden that blood flowing back to the heart is physically blocked by a large mass of worms.  Caval syndrome is life-threatening and quick surgical removal of the heartworms is the only treatment option.  The surgery is risky, and even with surgery, most dogs with caval syndrome die. 

• The yellow arrows point to the tortuous and severely enlarged pulmonary arteries.

• There is a mild increase in the size of the right atrium. • The pulmonary parenchyma also has a slight interstitial pattern.

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

Heartworm embolectomy procedure. Basket forceps placed throught he right jugular vein and into the right heart were used to retrieve the heartworms from this Rottweiler with caval syndrome. Seventy-one worms were removed from this patient's right heart

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

• REVOLUTION– Selamectin

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

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 (WOLBACHIA)

Heartworm Treatment – Slow Kill Method – VTI

Team: Dr. B, Dr. Dev, Miss Kennar, Miss Foitnik

•Doxycycline: 5 – 10 mg/ kg (SID or BID)

•Prednisone: 1 mg/kg : BID X 7 days; SID X 7 days, EOD X 7 days 

•DAY 1

– Buprenex: 0.015 mg/ kg OR Tramadol: 1mg/lb BID X 3 days PO before melarsomine injection

– Famotidine 0.5 mg/kg SQ: before melarsomine injection

– Melarsormine: 0.1 mls/ kg IM 

•DAY 30

– Buprenex: 0.015 mg/ kg OR Tramadol: 1mg/lb BID X 3 days PO before melarsomine injection;

– Famotidine 0.5 mg/kg SQ: before melarsomine injection

– Melarsormine: 0.1 mls/ kg IM 

•DAY 31

– Buprenex: 0.015 mg/ kg OR Tramadol: 1mg/lb BID X 3 days PO before melarsomine injection;

– Famotidine 0.5 mg/kg SQ: before melarsomine injection

– Melarsormine: 0.1 mls/ kg IM

THANK YOU ROYALS 2011

References• Alleice Summers, Common Diseases of Companion

Animals

• http://veterinarynews.dvm360.com/dvm/article/articleDetail.jsp?id=156665

• VIN: Robert Prosek DVM, MS, DACVIM-Cardiology, DECVIM-CA

• Echocardiography in the Dog, Cat and Horse: Dr. Francesco Porciello, 2009

• http://www.vin.com/WebLink.plx?URL=http://www.vmth.ucdavis.edu/cardio/cases/

References

• http://cardiology.vetmed.lsu.edu/Education/AcquiredCardiacDiseases/HeartwormDisease/tabid/448/Default.aspx

• http://www.heartwormsociety.org/