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🩸 Neonatal Isoerythrolysis in Cats – 2025 Vet Guide by Dr. Duncan Houston BVSc 🐱👶
Neonatal isoerythrolysis (NI) is a life-threatening immune condition that affects newborn kittens. It occurs when kittens with blood type A (or AB) nurse from a type B queen 🧬. The colostrum (first milk) contains anti-A antibodies that destroy the kitten’s red blood cells—causing anemia, jaundice, and potentially death 💔.
🧪 What Causes NI?
Cat blood types include A, B, and AB. Type A is dominant. When a type B queen mates with a type A tom, the kittens may inherit type A or AB blood. If these kittens nurse from the queen in the first 24–72 hours, they ingest antibodies against their own blood type—leading to erythrolysis (red blood cell destruction).
🐾 Clinical Signs of NI
- 🍼 Normal nursing at first, followed by sudden weakness
- 📉 Failure to thrive (fading kitten syndrome)
- 🟡 Jaundice (yellowing of gums/skin)
- 🩸 Dark red or brown urine (pigmenturia)
- 🥱 Depression and lethargy
- ⚠️ Death within 1–2 days if not treated
🔬 Diagnosing Neonatal Isoerythrolysis
Diagnosis is based on:
- 💉 Blood typing of queen and kittens
- 🧪 Urinalysis showing pigmenturia
- 🩸 Blood tests showing anemia and hemolysis
🚫 Prevention Is Key
Since treatment is difficult and prognosis poor once signs appear, prevention is the best strategy 🧠💡:
- 🧬 Blood type breeding cats before mating
- 👩⚕️ Avoid mating a type B queen with a type A or AB tom
- 🍼 Do not allow at-risk kittens to nurse for the first 72 hours
- 🍼 Use milk replacer or a type A foster queen
💉 Treatment Options
For affected kittens, intensive care is required:
- 🛌 Supportive nursing care
- 🩸 Blood transfusion from a type A donor
- 🚫 Immediate cessation of nursing from the queen
⚠️ Even with treatment, prognosis is guarded. Many kittens do not survive once symptoms manifest.
📊 Breed Risk Table
| Breed | % Type B | Risk of NI (%) |
|---|---|---|
| Devon Rex | 41% | 24% |
| British Shorthair | 40% | 24% |
| Cornish Rex | 34% | 23% |
| Sphinx | 18% | 16% |
| Scottish Fold | 18% | 15% |
| Persian | 14% | 12% |
| Domestic Shorthair | 1% | 1% |
| Siamese | 0% | 0% |
📣 Final Word from Dr. Duncan Houston
Neonatal isoerythrolysis is rare—but devastating. The best defense is blood typing and planned breeding. Breeders should always confirm the blood types of both tom and queen. If you're concerned, consult a veterinarian early to develop a safe whelping and nursing plan 🐈❤️.
For further support, visit AskAVet.com or download the Ask A Vet app to speak with a licensed vet anytime 📱🩺
