Mitral Valve Disease in Norwich Terriers
Mitral valve disease can develop in Norwich Terriers, particularly as they age. The heart's mitral valve degenerates over time, creating a murmur that your vet can detect. Modern treatment with pimobendan has significantly improved outcomes, delaying the onset of heart failure by over a year.
Prevalence
Common age-related finding
Typical Onset
8-12 years
Severity
Severe
Symptoms to Watch For
If your Norwich Terrier shows any of these signs, monitor closely and consult your veterinarian.
Risk Factors
- •advancing age
- •small breed body type
- •male sex (slightly higher risk)
- •dental disease and chronic bacterial exposure
- •untreated progression — delay in starting pimobendan
Diagnosis
Heart murmur on auscultation (left apex, systolic). Echocardiogram confirms valve thickening, regurgitation, and chamber enlargement. Chest radiographs show heart enlargement and pulmonary changes. Resting respiratory rate monitoring at home (count breaths while sleeping — normal is under 30/minute).
Treatment
Stage B1 (murmur, no enlargement): monitor every 6-12 months. Stage B2 (murmur + enlargement): pimobendan starts — proven to delay onset of heart failure by 15 months. Stage C (heart failure): pimobendan + furosemide + ACE inhibitor. Stage D (refractory): add spironolactone, increase diuretics. Mitral valve repair surgery is now available at specialized centers with excellent outcomes.
Prevention
Choose breeders who cardiac-screen with echocardiography (especially Cavaliers). Maintain dental health — dental bacteria enter the bloodstream and can worsen valve disease. Keep body weight lean. Monitor resting respiratory rate at home weekly in senior small breeds.
When to See a Vet
See your vet if sleeping respiratory rate exceeds 30 breaths/minute, or if you notice new coughing, exercise intolerance, or fainting. If already diagnosed, any sudden breathing change is an emergency.
Other Health Conditions in Norwich Terriers
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