What does Stage B vs Stage C vs Stage D look like in a real Cavalier?

Day-to-day, the stages feel very different. Stage B1: dog is asymptomatic. The only sign is a heart murmur on vet exam. Normal exercise, normal eating, normal sleep. Annual cardiology echo. No medication. Stage B2: still asymptomatic, but echo shows heart enlargement. Pimobendan starts. Sleeping respiratory rate counted weekly. Cardiology echo every 6 months. Most Cavaliers spend years in this stage feeling normal. Stage C: clinical signs appear — coughing (especially after exercise or at night), tiring on walks faster than before, sleeping respiratory rate creeping up, sometimes one episode of fluid in the lungs (pulmonary edema) requiring an ER visit. Once stabilized: pimobendan + ACE inhibitor (benazepril or enalapril) + furosemide (Lasix) diuretic. Daily medications, sodium-restricted diet, sleeping respiratory rate counted daily. Calgary cost: $60–$200/month meds, $400–$700/year monitoring. Stage D: refractory CHF — fluid in the lungs not controlled by standard meds. Higher furosemide doses or torsemide substitution, sometimes spironolactone, sometimes pimobendan dose increases. Cavaliers in Stage D can live months to a year with intensive management. Mitral valve repair surgery is the only curative option, available at a small number of specialty centres ($15,000–$25,000+ — referral typically out of Alberta). End-of-life decisions usually come at Stage D when respiratory rate cannot be controlled or quality of life declines.

How do I count my Cavalier's sleeping respiratory rate?

This is the single most important home-monitoring skill for an MVD Cavalier owner. The rule: sleeping respiratory rate >30 breaths per minute = veterinary emergency. How to count: wait until your Cavalier is fully asleep (not panting, not dreaming/twitching), watch the chest rise and fall — each rise + fall counts as ONE breath. Count for 30 seconds and multiply by 2, or count for a full 60 seconds. Normal Cavalier sleeping respiratory rate is 10–25 breaths per minute. Track daily once your Cavalier is in Stage B2 or higher. Use a smartphone app (Cardalis, Your Dog's Heart, or just a notes file) to log the number daily. Trends matter more than single values: if your dog's normal sleeping rate is 18 and it's suddenly been 26 for three nights in a row, call your vet — even though 26 is still under 30. Why this matters: sleeping respiratory rate begins to climb 1–4 days BEFORE clinical signs of pulmonary edema appear. Catching the climb early means a same-day vet visit and oral furosemide adjustment instead of an ER visit at 2am. Real-world example: a Stage C Cavalier on pimobendan + benazepril + furosemide whose sleeping rate creeps from 22 → 28 → 33 over 4 days needs a furosemide dose increase, not an ER admission, if caught at day 2.

Do heart supplements actually help my Cavalier?

The evidence is mixed and depends on which supplement. Honest summary: omega-3 fatty acids (fish oil): the strongest evidence. Reduce systemic inflammation, support cardiac muscle function, and modest cardiac benefit shown in studies. Most cardiologists recommend EPA + DHA at ~40 mg combined per kg body weight daily for Cavaliers. Calgary cost: ~$25–$50/month from veterinary brands (Welactin, Nordic Naturals Pet). Taurine: useful in dogs with documented taurine deficiency. Most Cavaliers are NOT taurine-deficient unless on a grain-free or boutique diet (the FDA grain-free diet investigation linked taurine deficiency to dilated cardiomyopathy in some breeds). If your Cavalier has been on grain-free food, ask your cardiologist about a taurine blood test. Routine supplementation in non-deficient Cavaliers shows mixed results. L-carnitine: similar story to taurine — beneficial in deficient dogs, modest evidence in others. Some cardiologists include in their MVD protocols. CoQ10: theoretical mitochondrial support for cardiac muscle. Anecdotal evidence; controlled studies in Cavalier MVD specifically are limited. Generally safe; some cardiologists include in their protocol. Hawthorn, ribose, vitamin E: insufficient evidence. The evidence-based default protocol most cardiologists recommend for Stage B2+ Cavaliers: omega-3 fatty acids + cardiac prescription diet (which includes taurine, L-carnitine, antioxidants). Skip the boutique “heart support” multi-supplement blends from pet stores — most are not formulated at therapeutic doses.

What about MVD clinical trials — are there any in Canada?

Yes, occasionally. The University of Calgary Faculty of Veterinary Medicine and Western Veterinary Specialist Centre periodically participate in multi-centre cardiac trials, typically through CKCSC partnerships, the AKC Canine Health Foundation, or pharmaceutical-sponsored studies. Past trials Cavalier owners have participated in include the EPIC trial (pimobendan in Stage B2), DELAY trial (delaying CHF in Stage B), and several mitral valve repair surgical technique trials. To find current trials: ask your veterinary cardiologist directly at your next appointment — they typically know which research is recruiting. Search the AVMA Animal Health Studies Database (ahsd.avma.org) for “Cavalier King Charles” and “mitral valve.” Contact CKCSC of the USA (ckcsc.org) and the Cavalier Health Foundation (chf-cavalier.org) — both maintain trial recruitment lists. Trial participation often includes free or reduced-cost echocardiograms and medications during the study period — meaningful for Cavalier owners facing 12+ years of cardiac costs. Honest framing: most clinical trials require relatively early-stage Cavaliers (Stage B1 or B2) — owners hoping for “last-resort” trial enrollment at Stage D will usually find the door is closed. Enroll early or not at all.

Living With a Cavalier With MVD &mdash; Calgary Owner&apos;s Guide

Q: How fast does MVD progress once my Cavalier has a murmur?

Variable — but slower than most owners fear. Cavalier MVD progresses in stages over years, not months. From first murmur (Stage B1) to onset of clinical symptoms (Stage C) typically averages 3–5 years; some Cavaliers stay in Stage B for 5–8+ years. Approximately 10% of Cavaliers per year progress between stages once a murmur is detected. The single most important question is whether the heart is enlarged (Stage B2) — pimobendan started at Stage B2 has been shown in the EPIC trial to delay the onset of congestive heart failure by ~15 months on average. That means the day-to-day reality for most early-stage Cavaliers is monitoring, not crisis. Annual echocardiogram by a board-certified cardiologist (DACVIM-Cardiology) is the right cadence at Stage B1; every 6 months once Stage B2 is confirmed. Calgary specialty cardiology echo: $400–$700 at Western Veterinary Specialist Centre or VCA Canada West.

Q: When does my Cavalier need pimobendan (Vetmedin)?

At Stage B2 — when the echocardiogram shows heart enlargement, even if your dog has zero symptoms. The EPIC trial (2016) was the landmark Cavalier study: dogs started on pimobendan at Stage B2 lived ~15 months longer before reaching congestive heart failure compared to dogs not started until Stage C. Translated to ownership: starting pimobendan early adds about a year of pre-CHF life. Pimobendan does NOT reverse MVD, does NOT cure it, and is NOT useful at Stage B1 (murmur without enlargement). It is a positive inotrope + vasodilator that helps the heart pump more efficiently. Calgary cost: pimobendan (Vetmedin) typically $30–$80/month at Cavalier dosing (0.25–0.3 mg/kg twice daily). Generic pimobendan is now available and is dramatically cheaper than brand Vetmedin — ask your vet. The trigger for starting pimobendan is the echocardiogram showing left atrial enlargement (LA:Ao ≥1.6) AND left ventricular enlargement (LVIDDN ≥1.7) — not auscultation alone. If your vet wants to start pimobendan based only on a heart murmur grade without an echo, ask for a cardiology referral first.

Q: What is the difference between an MVD cough and a heart failure cough?

This is one of the most important things a Cavalier owner can learn. MVD cough (Stage B2/early C — left atrial enlargement pressing on the trachea/main bronchi): a dry, honking cough triggered by activity, excitement, pulling on a leash, or pressure on the throat. Often worse first thing in the morning or after rest. Cavalier is otherwise comfortable, normal energy, normal breathing rate. Heart failure cough (Stage C — fluid building in the lungs, pulmonary edema): a wet, gurgly, productive-sounding cough. Often accompanied by elevated sleeping respiratory rate (>30 breaths per minute), restlessness, reluctance to lie down flat, sometimes pinkish-tinged foam from the mouth or nose, exercise intolerance noticeably worse than baseline. Heart failure cough is an EMERGENCY — go to the Calgary 24-hour ER (Paramount, VCA Canada West, CARE Centre) immediately. Do not wait until morning. Pulmonary edema responds dramatically to IV furosemide if treated early; left untreated for hours, it kills. The single most reliable signal that distinguishes “just MVD cough” from “developing heart failure” is the sleeping respiratory rate. If your Cavalier's sleeping respiratory rate is consistently >30 breaths per minute, the cough is heart failure until proven otherwise.

Q: What diet changes do I make when my Cavalier has MVD?

Diet changes are stage-dependent. Stage B1: no specific diet changes — keep your Cavalier lean. Obesity dramatically worsens MVD outcomes; every extra pound of body fat is extra cardiac workload. Calgary tip: Cavaliers are notorious food thieves; weigh kibble portions, eliminate table scraps. Stage B2: still keep lean. Some cardiologists recommend modest sodium reduction (avoiding obviously salty treats, deli meat, cheese sticks) but full prescription cardiac diets are typically not needed yet. Stage C: this is where prescription cardiac diets start to matter. Target dietary sodium <0.30% on a dry-matter basis. Common options: Hill's Prescription Diet h/d, Royal Canin Cardiac, Purina Pro Plan Veterinary CC. These reduce fluid retention pressure on the failing heart. Available at Calgary vet clinics (Bow Bottom, McKnight, Northwest Animal Hospital) and Calgary Co-op Pet Health, typically $90–$140 per large bag. AVOID: high-sodium treats (rawhide, deli meat, cheese, processed treats), high-sodium human food (bacon, ham, pizza). Use low-sodium treats: plain cooked chicken, blueberries, apple slices (no seeds), green beans. Some cardiologists also recommend supplemental taurine, omega-3 fatty acids (fish oil), L-carnitine, and CoQ10 — see the supplements question below. Always make diet changes in consultation with your cardiologist; sodium that is too low can also cause problems.

Q: How much exercise should my Cavalier with MVD get?

Exercise is encouraged, just calibrated. Stage B1/B2: normal exercise, no restrictions. A Stage B2 Cavalier should still get 30–45 minutes of daily activity (walks, gentle play). Cardiac fitness HELPS; deconditioning hurts. The Calgary winter consideration: cold-weather walks are fine for MVD Cavaliers — wind chill below -20°C is the only routine concern. Indoor play days are better than skipping exercise. Stage C: moderate, calibrated exercise. Most Stage C Cavaliers tolerate two 15–20 minute relaxed walks per day. Avoid exhausting exercise, hot summer days, prolonged uphill climbs. Watch for the early-tiring signal — if your dog suddenly wants to turn around at 10 minutes when 20 was normal, that is information. Call your cardiologist if pattern persists. Stage D: gentle, dog-led exercise only. Five-minute potty walks, indoor sniffing games, slow leisurely wandering. If your dog stops, the walk is over. The right framework: think of exercise as “your Cavalier should be tired, not exhausted.” Do not force exercise on a Cavalier who is reluctant. Avoid: doggy daycare with high-energy play once Stage C, dog parks where they will run themselves into pulmonary edema, hot Calgary summer afternoons (always early morning or evening). Encourage: daily sniffing walks (mental fatigue without cardiac stress), low-impact backyard time, scent games indoors.

Q: What are the end-stage signs and when do I make the euthanasia decision?

A hard but essential question. Most Cavalier owners face this decision at Stage D when standard medications can no longer keep pulmonary edema controlled. Signs that quality of life is declining: persistent elevated sleeping respiratory rate (consistently >35–40 breaths per minute despite maximum medication), inability to sleep lying down comfortably (orthopnea), repeated emergency vet visits for pulmonary edema 2–4 weeks apart, severe appetite loss (Cavaliers are notoriously food-motivated; refusing favorite foods is significant), profound lethargy, reluctance to move, syncope (fainting episodes), abdominal distension from ascites, blue or grey gums (cyanosis). The HHHHHMM scale (Hurt, Hunger, Hydration, Hygiene, Happiness, Mobility, More-good-days-than-bad) is a useful framework — score weekly, share with your cardiologist. The decision is highly individual; many Calgary cardiologists will have a frank conversation about prognosis when you are ready. In-home euthanasia is available in Calgary through services like Compassionate Care Vet, Lap of Love (Alberta network), Pet Loss at Home — typically $400–$700, less stressful than a final clinic visit for cardiac dogs. After: the Calgary specialty cardiologist who managed your Cavalier may participate in CKCSC or AKC Canine Health Foundation MVD research — donation of cardiac tissue or echocardiogram history can advance MVD research and is a way some owners find meaning in the loss.

The short answer

Once your Cavalier has a heart murmur, the day-to-day is mostly monitoring, not crisis. Pimobendan starts at Stage B2 (echo shows heart enlargement) — the EPIC trial showed this delays heart failure by ~15 months. Count sleeping respiratory rate daily — consistently >30 breaths/minute is a veterinary emergency. MVD cough is dry and honking; heart failure cough is wet and productive — the second is an ER visit. Stage C: prescription cardiac diet (sodium <0.30% dry matter), pimobendan + ACE inhibitor + furosemide. Exercise is encouraged at every stage, just calibrated. End-of-life decisions usually come at Stage D when respiratory rate can't be controlled despite max meds — in-home euthanasia available in Calgary.

Sleeping respiratory rate is the single most important MVD home-monitoring skill

Wait until your Cavalier is fully asleep. Count chest rise + fall as one breath. Count for 60 seconds. Normal is 10–25 breaths per minute. Consistently over 30 = veterinary emergency. Sleeping respiratory rate begins to climb 1–4 days BEFORE clinical signs of pulmonary edema. Catching it early means a same-day vet visit and an oral medication adjustment — not a 2am ER visit. Use the Cardalis or Your Dog's Heart app, or just a notes file. Track daily once your Cavalier is in Stage B2 or higher.

How fast does MVD progress once my Cavalier has a murmur?

Variable — but slower than most owners fear. From first murmur (Stage B1) to onset of clinical symptoms (Stage C) typically averages 3–5 years. Some Cavaliers stay in Stage B for 5–8+ years. Roughly 10% of Cavaliers per year progress between stages once a murmur is detected.

The single most important question is whether the heart is enlarged (Stage B2). Pimobendan started at Stage B2 has been shown in the EPIC trial to delay congestive heart failure by ~15 months on average.

Day-to-day reality for most early-stage Cavaliers is monitoring, not crisis. Annual cardiology echo (board-certified cardiologist, DACVIM-Cardiology) is the right cadence at Stage B1; every 6 months once Stage B2 is confirmed.

Calgary specialty cardiology echo: $400–$700 at Western Veterinary Specialist Centre or VCA Canada West.

When does my Cavalier need pimobendan (Vetmedin)?

At Stage B2 — when the echocardiogram shows heart enlargement, even if your dog has zero symptoms. The EPIC trial (2016) was the landmark Cavalier study: dogs started on pimobendan at Stage B2 lived ~15 months longer before reaching congestive heart failure compared to dogs not started until Stage C.

Pimobendan does NOT reverse MVD, does NOT cure it, and is NOT useful at Stage B1 (murmur without enlargement). It is a positive inotrope + vasodilator that helps the heart pump more efficiently.

Calgary cost: pimobendan (Vetmedin) typically $30–$80/month at Cavalier dosing (0.25–0.3 mg/kg twice daily). Generic pimobendan is now available and is dramatically cheaper than brand Vetmedin — ask your vet.

The trigger for starting pimobendan is the echocardiogram showing left atrial enlargement (LA:Ao ≥1.6) AND left ventricular enlargement (LVIDDN ≥1.7) — not auscultation alone. If your vet wants to start pimobendan based only on murmur grade without an echo, ask for a cardiology referral first.

What does Stage B vs Stage C vs Stage D look like in real life?

Stage	Clinical reality	Medications	Calgary monthly cost
B1	Asymptomatic, murmur on exam, normal echo	None	$30–$60 (annual echo amortized)
B2	Asymptomatic, but echo shows enlargement	Pimobendan	$60–$120
C	Coughing, exercise intolerance, sleeping rate creeping up, fluid in lungs episode possible	Pimobendan + ACE inhibitor + furosemide	$120–$250
D	Refractory CHF — fluid not controlled by standard meds	Higher furosemide / torsemide, spironolactone, possibly increased pimobendan	$200–$500+

Most Cavaliers spend years in Stage B feeling normal. Stage C usually starts subtly — one episode of pulmonary edema requiring an ER visit, then daily medications and monitoring. Stage D Cavaliers can live months to a year with intensive management.

Mitral valve repair surgery is the only curative option, available at a small number of specialty centres ($15,000–$25,000+). Referral typically out of Alberta.

What is the difference between an MVD cough and a heart failure cough?

One of the most important things a Cavalier owner can learn.

MVD cough (Stage B2/early C)

Dry, honking, triggered by activity, excitement, leash pulling, or pressure on throat. Worse first thing in morning or after rest. Caused by left atrial enlargement pressing on trachea. Cavalier is otherwise comfortable, normal energy, normal breathing rate. Not an emergency.

Heart failure cough (Stage C)

Wet, gurgly, productive-sounding. Often with elevated sleeping respiratory rate (>30/min), restlessness, reluctance to lie flat, sometimes pinkish foam from mouth/nose, exercise intolerance worse than baseline. Pulmonary edema. EMERGENCY — ER immediately.

The single most reliable signal that distinguishes “just MVD cough” from “developing heart failure” is the sleeping respiratory rate. If your Cavalier's sleeping respiratory rate is consistently >30 breaths per minute, the cough is heart failure until proven otherwise. Calgary 24-hour ER: Paramount, VCA Canada West, CARE Centre. Pulmonary edema responds dramatically to IV furosemide if treated early; left untreated for hours, it kills.

How do I count sleeping respiratory rate?

The single most important home-monitoring skill for an MVD Cavalier owner.

The rule: sleeping respiratory rate >30 breaths per minute = veterinary emergency.

How to count:

Wait until your Cavalier is fully asleep (not panting, not dreaming/twitching)
Watch the chest rise and fall — each rise + fall counts as ONE breath
Count for 30 seconds and multiply by 2, or count for a full 60 seconds
Log the number daily once Stage B2 or higher

Normal Cavalier sleeping respiratory rate is 10–25 breaths per minute.

Trends matter more than single values. If your dog's normal sleeping rate is 18 and it's suddenly been 26 for three nights in a row, call your vet — even though 26 is still under 30. Sleeping respiratory rate begins to climb 1–4 days BEFORE clinical signs of pulmonary edema appear.

Recommended apps: Cardalis, Your Dog's Heart, or just a daily notes file. Real-world example: a Stage C Cavalier on pimobendan + benazepril + furosemide whose sleeping rate creeps from 22 → 28 → 33 over 4 days needs a furosemide dose increase, not an ER admission, if caught at day 2.

What diet changes do I make when my Cavalier has MVD?

Stage-dependent. Keep your Cavalier lean at every stage — obesity dramatically worsens MVD outcomes. Every extra pound is extra cardiac workload.

Stage B1: no specific diet changes. Calgary tip: Cavaliers are notorious food thieves — weigh kibble portions, eliminate table scraps, no “little tastes” from your plate.

Stage B2: still keep lean. Some cardiologists recommend modest sodium reduction (no obviously salty treats, deli meat, cheese sticks) but full prescription cardiac diets typically aren't needed yet.

Stage C: prescription cardiac diet starts to matter. Target dietary sodium <0.30% on a dry-matter basis. Common options: Hill's Prescription Diet h/d, Royal Canin Cardiac, Purina Pro Plan Veterinary CC. Reduces fluid retention pressure on the failing heart. Available at Calgary vet clinics and Calgary Co-op Pet Health, typically $90–$140 per large bag.

AVOID: high-sodium treats (rawhide, deli meat, cheese, processed treats), high-sodium human food (bacon, ham, pizza). Low-sodium treat alternatives: plain cooked chicken, blueberries, apple slices (no seeds), green beans.

Always make diet changes in consultation with your cardiologist — sodium that is too low can also cause problems.

Do heart supplements actually help?

Mixed evidence — depends on which supplement. Honest summary below.

Omega-3 fatty acids (fish oil) — strongest evidence. Reduce inflammation, support cardiac muscle. Most cardiologists recommend EPA + DHA at ~40 mg combined per kg body weight daily. Calgary cost ~$25–$50/month from veterinary brands (Welactin, Nordic Naturals Pet)
Taurine — useful in dogs with documented deficiency. Cavaliers are NOT typically deficient unless on grain-free or boutique diets (the FDA grain-free investigation linked taurine deficiency to DCM in some breeds). If your Cavalier has been on grain-free, ask for a taurine blood test. Routine supplementation in non-deficient Cavaliers shows mixed results
L-carnitine — similar story to taurine. Some cardiologists include in their MVD protocols
CoQ10 — theoretical mitochondrial support. Anecdotal evidence; controlled Cavalier-specific studies limited. Generally safe; some cardiologists include
Hawthorn, ribose, vitamin E — insufficient evidence

The evidence-based default protocol most cardiologists recommend for Stage B2+ Cavaliers: omega-3 fatty acids + cardiac prescription diet (which already includes taurine, L-carnitine, antioxidants).

Skip the boutique “heart support” multi-supplement blends from pet stores — most are not formulated at therapeutic doses.

How much exercise should my Cavalier with MVD get?

Encouraged at every stage, just calibrated. Cardiac fitness HELPS; deconditioning hurts. Think “your Cavalier should be tired, not exhausted.”

Stage B1/B2: normal exercise, no restrictions. 30–45 minutes daily activity (walks, gentle play). Calgary winter consideration: cold-weather walks are fine — wind chill below -20°C is the only routine concern. Indoor play days are better than skipping.

Stage C: moderate, calibrated exercise. Two 15–20 minute relaxed walks per day. Avoid exhausting exercise, hot summer days, prolonged uphill climbs. Watch for the early-tiring signal — if your dog suddenly wants to turn around at 10 minutes when 20 was normal, that is information. Call your cardiologist if pattern persists.

Stage D: gentle, dog-led exercise only. Five-minute potty walks, indoor sniffing games, slow leisurely wandering. If your dog stops, the walk is over.

AVOID: doggy daycare with high-energy play once Stage C, dog parks where they will run themselves into pulmonary edema, hot Calgary summer afternoons (always early morning or evening).

ENCOURAGE: daily sniffing walks (mental fatigue without cardiac stress), low-impact backyard time, scent games indoors.

What are the end-stage signs and when do I make the euthanasia decision?

A hard but essential question. Most Cavalier owners face this decision at Stage D when standard medications can no longer keep pulmonary edema controlled.

Signs that quality of life is declining:

Persistent elevated sleeping respiratory rate (consistently >35–40 breaths/minute despite max medication)
Inability to sleep lying down comfortably (orthopnea)
Repeated emergency vet visits for pulmonary edema 2–4 weeks apart
Severe appetite loss (Cavaliers are notoriously food-motivated — refusing favorite foods is significant)
Profound lethargy, reluctance to move
Syncope (fainting episodes)
Abdominal distension from ascites
Blue or grey gums (cyanosis)

The HHHHHMM scale (Hurt, Hunger, Hydration, Hygiene, Happiness, Mobility, More-good-days-than-bad) is a useful framework — score weekly, share with your cardiologist.

In-home euthanasia is available in Calgary through services like Compassionate Care Vet, Lap of Love (Alberta network), Pet Loss at Home — typically $400–$700. Less stressful than a final clinic visit for cardiac dogs.

The Calgary specialty cardiologist who managed your Cavalier may participate in CKCSC or AKC Canine Health Foundation MVD research — donation of cardiac tissue or echocardiogram history can advance MVD research and is a way some owners find meaning in the loss.

Are there MVD clinical trials in Canada?

Yes, occasionally. The University of Calgary Faculty of Veterinary Medicine and Western Veterinary Specialist Centre periodically participate in multi-centre cardiac trials.

Past Cavalier trials included: EPIC trial (pimobendan in Stage B2), DELAY trial (delaying CHF in Stage B), and several mitral valve repair surgical technique studies.

To find current trials:

Ask your veterinary cardiologist directly — they typically know which research is recruiting
Search the AVMA Animal Health Studies Database (ahsd.avma.org) for “Cavalier King Charles” and “mitral valve”
Contact CKCSC of the USA (ckcsc.org) and the Cavalier Health Foundation (chf-cavalier.org) — both maintain trial recruitment lists

Trial participation often includes free or reduced-cost echocardiograms and medications during the study period — meaningful for Cavalier owners facing 12+ years of cardiac costs.

Honest framing: most clinical trials require relatively early-stage Cavaliers (Stage B1 or B2). Owners hoping for “last-resort” trial enrollment at Stage D will usually find the door is closed. Enroll early or not at all.

Frequently Asked Questions

How fast does MVD progress?

Variable. Stage B1 to Stage C typically 3–5 years; some Cavaliers stay in B for 5–8+. ~10%/year progress between stages. Pimobendan at Stage B2 delays CHF by ~15 months (EPIC trial).

When does pimobendan start?

Stage B2 — echo shows heart enlargement (LA:Ao ≥1.6, LVIDDN ≥1.7). NOT at Stage B1 (murmur without enlargement). Calgary $30–$80/month; generic pimobendan now available.

Stage B vs C vs D?

B1: asymptomatic, no meds. B2: asymptomatic + enlarged heart, pimobendan. C: coughing/edema, triple therapy ($120–$250/mo). D: refractory CHF ($200–$500+/mo). Surgical repair $15K–$25K (typically out-of-Alberta referral).

MVD cough vs CHF cough?

MVD cough = dry, honking, triggered by activity, otherwise normal. CHF cough = wet, gurgly, with elevated sleeping respiratory rate, restlessness, pinkish foam. CHF = ER immediately.

Sleeping respiratory rate?

Count rise+fall as one breath, 60 seconds, fully asleep. Normal 10–25/min. >30 = ER. Climbs 1–4 days before clinical CHF. Cardalis or Your Dog's Heart app. Daily once Stage B2+.

MVD diet?

Lean weight at every stage. Stage C: prescription cardiac diet (Hill's h/d, Royal Canin Cardiac, Pro Plan CC). Sodium <0.30% dry matter. $90–$140/bag Calgary. Avoid deli meat, rawhide, cheese, bacon.

Heart supplements?

Omega-3 (strongest evidence, ~40mg EPA+DHA/kg/day). Taurine + L-carnitine for grain-free history dogs. CoQ10 plausible. Skip pet store “heart support” blends — underdosed.

Exercise with MVD?

Encouraged at every stage. B1/B2: 30–45 min normal. C: 15–20 min, twice daily, calibrated. D: dog-led only. Avoid Stage C+ doggy daycare and dog parks. Sniffing walks = mental tired without cardiac stress.

End-of-life signs?

Persistent SRR >35–40 despite max meds, orthopnea, repeated ER visits 2–4 weeks apart, severe appetite loss, syncope, ascites, cyanosis. HHHHHMM weekly score. In-home euthanasia $400–$700 Calgary (Lap of Love, Compassionate Care Vet).

Clinical trials?

Yes occasionally — UCalgary Vet Med + Western Veterinary Specialist Centre. AVMA AHSD database, CKCSC, Cavalier Health Foundation. Free echos + meds during study. Most need Stage B; Stage D rarely qualifies.

Related Guide

Living With a Cavalier With Heart Disease