What is a blood ring in a hatching egg?

A **blood ring** is a well-defined red or dark circle you see against the inside of the shell when you candle an egg. It means the **embryo started to develop and then died** — usually in the first week. When the embryo dies, the network of blood vessels that was feeding it stops being held in place and **detaches from the embryo, drawing away toward the shell** where it collapses into a ring or arc. So a blood ring is not a stage of healthy growth; it only appears after death. On a live, developing egg you would instead see a dark central embryo surrounded by a branching spider-web of vessels, often moving. Mississippi State University Extension describes the blood ring as deteriorating blood vessels forming a dark ring after an embryo has developed for several days and then died. Common causes include temperature swings or overheating, improper egg storage, rough handling of shipped eggs, bacterial contamination, and genetics. Remove blood-ring eggs from the incubator promptly, because a dead egg can rot and burst, spreading bacteria to the eggs you are trying to hatch.

What is the difference between a blood ring and a quitter?

A **quitter** is any embryo that started developing and then stopped. A **blood ring** is one specific kind of quitter — typically an early, first-week death whose detached vessels form a clean ring. Later quitters may instead candle as a dark, motionless shadow, smeared or broken-up vessels, or an embryo that looks stalled next to its clutch-mates.

What causes blood rings and early embryo death?

According to Mississippi State University Extension, the usual causes are **incorrect incubation temperatures (often too high), temperature swings, improper egg storage, poor breeder-flock nutrition, inadequate ventilation, and bacterial contamination such as Salmonella**. For shipped eggs, rough handling and transit temperature extremes add to the toll. Some early death is also simply genetic.

Should I remove a blood ring egg from the incubator?

**Yes — promptly.** A dead embryo can rot, build up gas, and burst, spraying bacteria across your good eggs. Once you are confident an egg is dead (a clear blood ring, or no growth over two candlings), pull it. If you are unsure, wait one more candling rather than discarding a slow-but-living embryo.

Is it normal to have some blood rings and quitters in a hatch?

**Yes.** Even well-run hatches lose a few eggs to early death from genetics or minor setbacks, and this is expected rather than a sign of failure. **Shipped eggs** typically show higher losses because their air cells and temperatures are disturbed in transit. Set more eggs than you need.

Could a blood ring mean my breeding birds are sick?

A single blood ring is a normal candling finding, not a diagnosis. But **repeated, flock-wide fertility or embryo-death problems** can point to breeder-flock disease or nutrition issues. That is a veterinary question — do not medicate hatching eggs or breeders on your own. See PoultryDVM (https://www.poultrydvm.com) and consult an avian veterinarian.

Blood Rings and Quitters: Reading Dead Embryos on Candling

Verified September 2026

The short version

A blood ring is a red circle of detached blood vessels against the shell — the sign of an embryo that started developing and then died, so the vessels pulled away from the center and settled into a ring. A quitter is any embryo that began growing and quit partway through incubation. Common causes are temperature swings, rough shipping, bacterial contamination, and genetics. Pull blood rings and quitters as soon as you spot them: a dead egg can rot and burst, contaminating the whole hatch. Some early death is normal even in a good hatch.

What a blood ring and a quitter actually look like

When you candle a live, developing egg you see a dark central spot (the embryo) surrounded by a spider-web of branching blood vessels, often with visible movement. When you candle a blood ring, that spider-web is gone — instead a well-defined red or dark circle sits against the inside of the shell. Mississippi State University Extension describes this as deteriorating blood vessels appearing as a dark ring after an embryo developed for several days and then died. The blood ring is not a stage of growth; it only appears *after* death, as the vessels that once fed the embryo detach and collapse toward the shell.

A quitter is the broader term for any embryo that started and then stopped. A blood ring is one form of quitter — usually a first-week death. Later quitters candle differently: instead of a clean ring you may see a dark, shadowy mass that no longer moves, blood vessels that have broken up or smeared, or an embryo that looks stalled compared with its clutch-mates. If in doubt, candle again a day or two later — a live embryo grows and moves; a quitter does not.

Why embryos die early — the common causes

Mississippi State University Extension lists the usual culprits behind blood rings and early dead embryos: incorrect incubation temperatures (too-high heat is a leading cause), improper egg storage before setting, inadequate breeder-flock nutrition, and problems such as poor ventilation or bacterial contamination (including Salmonella). Temperature swings are especially hard on young embryos — a spike or a cold spell in the first week is enough to stop development.

For shipped eggs, add rough handling to the list. Jostled, scrambled air cells and temperature extremes in transit kill many embryos before or shortly after they start, which is why shipped hatching eggs often show more blood rings than eggs collected at home. Finally, some early death is simply genetic — an embryo with lethal genes or a weak start will quit no matter how perfect your incubator. This is why even excellent hatches lose a few eggs to blood rings and quitters; a small amount of early embryonic death is normal and expected, not a sign you did something wrong.

Why you should remove them promptly

A dead embryo is a warm, moist mass of tissue sitting in an incubator — ideal conditions for bacteria. Left in place, a blood-ring egg can rot, build up gas, and burst, spraying bacteria across the good eggs around it and putting the whole hatch at risk. That is the single biggest reason to candle: to find and pull clears, blood rings, and quitters before they spoil. When you are confident an egg is dead — a clear blood ring, no growth over two candlings, or an obvious stalled embryo — remove it from the incubator. If you are not certain, it is safer to leave it one more candling than to toss a slow but living embryo.

Blood rings and quitters are a candling call, not a health diagnosis. If you are seeing repeated flock-wide fertility or embryo-death problems and suspect breeder disease, that is a veterinary question — do not attempt to medicate hatching eggs or breeders on your own. See PoultryDVM (https://www.poultrydvm.com) for disease and flock-health information, and work with an avian veterinarian.

Common pitfalls

Calling a blood ring on the first candling too early — candle around day 7–10 so a slow-but-live embryo has time to show veining before you judge it.
Leaving a confirmed blood ring or quitter in the incubator, where it can rot and explode, contaminating good eggs.
Panicking over a normal loss rate — a few blood rings and quitters are expected even in strong hatches, especially with shipped eggs.
Blaming your incubator for shipped-egg deaths — scrambled air cells and transit temperature swings kill many embryos before incubation even starts.
Trusting the incubator's built-in thermometer; uncalibrated heat spikes are a leading cause of early embryonic death.

Frequently asked questions

What is a blood ring in a hatching egg?: A blood ring is a well-defined red or dark circle you see against the inside of the shell when you candle an egg. It means the embryo started to develop and then died — usually in the first week. When the embryo dies, the network of blood vessels that was feeding it stops being held in place and detaches from the embryo, drawing away toward the shell where it collapses into a ring or arc. So a blood ring is not a stage of healthy growth; it only appears after death. On a live, developing egg you would instead see a dark central embryo surrounded by a branching spider-web of vessels, often moving. Mississippi State University Extension describes the blood ring as deteriorating blood vessels forming a dark ring after an embryo has developed for several days and then died. Common causes include temperature swings or overheating, improper egg storage, rough handling of shipped eggs, bacterial contamination, and genetics. Remove blood-ring eggs from the incubator promptly, because a dead egg can rot and burst, spreading bacteria to the eggs you are trying to hatch.
What is the difference between a blood ring and a quitter?: A quitter is any embryo that started developing and then stopped. A blood ring is one specific kind of quitter — typically an early, first-week death whose detached vessels form a clean ring. Later quitters may instead candle as a dark, motionless shadow, smeared or broken-up vessels, or an embryo that looks stalled next to its clutch-mates.
What causes blood rings and early embryo death?: According to Mississippi State University Extension, the usual causes are incorrect incubation temperatures (often too high), temperature swings, improper egg storage, poor breeder-flock nutrition, inadequate ventilation, and bacterial contamination such as Salmonella. For shipped eggs, rough handling and transit temperature extremes add to the toll. Some early death is also simply genetic.
Should I remove a blood ring egg from the incubator?: Yes — promptly. A dead embryo can rot, build up gas, and burst, spraying bacteria across your good eggs. Once you are confident an egg is dead (a clear blood ring, or no growth over two candlings), pull it. If you are unsure, wait one more candling rather than discarding a slow-but-living embryo.
Is it normal to have some blood rings and quitters in a hatch?: Yes. Even well-run hatches lose a few eggs to early death from genetics or minor setbacks, and this is expected rather than a sign of failure. Shipped eggs typically show higher losses because their air cells and temperatures are disturbed in transit. Set more eggs than you need.
Could a blood ring mean my breeding birds are sick?: A single blood ring is a normal candling finding, not a diagnosis. But repeated, flock-wide fertility or embryo-death problems can point to breeder-flock disease or nutrition issues. That is a veterinary question — do not medicate hatching eggs or breeders on your own. See PoultryDVM (https://www.poultrydvm.com) and consult an avian veterinarian.

Sources

Trouble Shooting Failures with Egg Incubation (blood rings & dead embryos) — Mississippi State University Extension Service (University extension)
Testing Incubated Eggs for Embryo Development (candling) — Mississippi State University Extension Service (University extension)
Avian Embryology (embryo development & early death) — eXtension — Poultry (University extension)