FAILURE TO COME INTO HEAT (ANESTRUS)
WHAT THIS SYMPTOM USUALLY MEANS
Failure to enter heat for >12 months (dogs) or >6 months (cats) indicates reproductive suppression from disease, hormone imbalance, or systemic illness.
MOST COMMON CAUSES
MILD
• Natural seasonal variation (cats)
• Stress
MEDICAL
• Hypothyroidism
• Ovarian cysts
• Ovarian tumors
• Malnutrition
• Chronic illness
EMERGENCY
Not typically an emergency unless accompanied by abdominal pain or discharge.
RED FLAGS
• Intermittent bleeding without full heat
• Swollen abdomen
• Systemic illness
• If unsure, treat as urgent.
AT-HOME CARE
• Track behavior
• Maintain healthy weight
WHAT A VETERINARIAN WILL CHECK
• Hormone testing
• Thyroid panel
• CBC/chemistry
• Ultrasound
MOST LIKELY DIAGNOSES
• Ovarian failure
• Hormone suppression
• Thyroid disease
WHEN TO SCHEDULE
• Within 1–2 weeks: no heat for 12+ months
LONGEVITY IMPACT
Absence of estrus can reflect metabolic or endocrine disease needing early correction.
LONGEVITY CONSULT
Ideal for senior intact females or pets with metabolic suspicion.