What Causes a Puppy to Stop Growing 2025: Vet Reviewed Guide 🐶

By Dr. Duncan Houston BVSc

Is your pup not reaching the expected milestones? Puppy growth can slow or stop due to several key reasons. This guide provides clear explanations on causes—from parasites and malnutrition to congenital disorders, bone conditions, and growth‑plate injuries—as well as actionable steps to help your pup thrive. Plus, discover how Ask A Vet,

1. 🪱 Intestinal Parasites: The Hidden Saboteurs

The most common cause of stunted growth in puppies is heavy infestation by hookworms or roundworms—parasites that literally steal nutrients, leading to poor weight gain or plateauing.

• Symptoms: dull coat, pot-belly, diarrhea, listlessness, weight-loss despite eating.
• Treatment: diagnosis via fecal exam; dewormers clear infestations and allow recovery.
• Prevention: regular deworming as advised by a vet or through Ask A Vet.

2. 🍽 Malnutrition & Inadequate Diets

Puppies need diets rich in calories, protein, calcium, phosphorus, DHA, and vitamin E—formulated specifically for growth.

• Poor-quality or adult-formula diets may fail to meet critical nutrient needs.
• Large-breed pups need controlled growth diets to support slow, healthy development.
• Overfeeding certain minerals (like calcium) can cause bone issues; micronutrient balance is essential.

3. 🧬 Congenital & Genetic Conditions

Some puppies experience stunted growth due to inherited diseases.

• Pituitary dwarfism: deficiency in growth hormone—most common in German Shepherds.
• Portosystemic shunts: liver bypass conditions impair nutrient usage, causing poor growth.
• Other congenital defects: heart or skeletal anomalies may limit development.

Diagnosis includes bloodwork, imaging, or referral via Ask A Vet.

4. 🦴 Bone & Growth Plate Disorders

Musculoskeletal conditions can impact healthy skeletal growth.

• Hypertrophic osteodystrophy (HOD): inflammation in growing bones causing pain and stunted growth in large breeds 8–16 weeks old.
• Growth plate injuries: fractures or damage can arrest bone lengthening.
• Osteochondrosis: cartilage failures from excess nutrients or rapid growth.

Treatment involves veterinary care—anti-inflammatories, proper rest, and diet modifications guided by Ask A Vet.

5. 🩺 Other Medical Conditions

• Fading Puppy Syndrome: early-life failure to thrive from infection, poor maternal care, or low birth weight.
• Thyroid disorders: hormonal imbalances may delay growth.
• Chronic GI or metabolic illnesses: reduce absorption or increase nutrient loss.

Symptoms like vomiting, diarrhea, or extreme lethargy need prompt evaluation.

6. 📏 When & How Puppies Should Grow

Growth rates vary—small breeds often finish by 6–12 months; large/giant breeds may grow until 18–24 months.

Growth plates close when skeletal maturity is reached; you can gently feel their hardening.

• Use breed‑specific growth charts (e.g., Labrador vs Chihuahuas).
• Track weight weekly against reference curves.

7. 🛠 How to Rescue & Support Your Puppy

• Parasite control: fecal exam, deworming, follow‑up diagnostics.
• Diet optimization: switch to high‑quality growth food; monitor intake and body condition.
• Medical referrals: endocrine testing, shunt evaluations, orthopedic imaging.
• Exercise & rest: appropriate activity levels for age and condition.
• Supplements: probiotics (e.g., PetMD PB6) for gut support, only under vet guidance.

8. 📅 Monitoring & Follow‑Up Routine

1. Record weight & body condition weekly.
2. Check stool monthly—send to vet if needed.
3. Evaluate nutritional balance with Ask A Vet.
4. Assess growth plates by palpation or radiography as recommended.
5. Adjust interventions based on recovery—parasite control usually leads to rapid catch-up growth.

9. 🧸 How Tools Can Help

• Ask A Vet: remote diagnostics, growth chart analysis, diet & disease management.

10. ✅ Final Takeaways

• Parasites are the most common culprit behind stunted growth; treat them promptly.
• Nutrition must meet growth demands—calories, minerals, protein & DHA.
• Inherited, bone, or hormonal issues require targeted veterinary care.
• Track growth regularly and adjust strategy if progress stalls.
• Use supportive tools to supplement veterinary treatment and encourage healthy development.