Most German Shepherd owners never think about their dog’s blood until something small refuses to stop bleeding. A nicked ear, for instance. A lost puppy tooth. A routine spay that turns into a phone call from the clinic.
Hemophilia A is the reason that occasionally happens, and it is worth understanding before you meet it. It is the most common inherited bleeding disorder in dogs (Merck Veterinary Manual, retrieved 2026-08-12). German Shepherds are one of the breeds it is tested for.
Here is the reassuring headline first, because a lot of what you will read online gets it wrong: most affected dogs live a normal lifespan. In other words, what they need is a diagnosis, a plan for surgery, and an owner who knows what to watch for.
What hemophilia A actually is
Hemophilia A is an inherited bleeding disorder caused by a deficiency of coagulation factor VIII, a protein your dog’s body needs to form a stable clot (UC Davis Veterinary Genetics Laboratory, retrieved 2026-08-12).
Clotting happens in two stages, however. First, platelets rush to the injury and form a soft plug. Then a chain of proteins called the coagulation cascade reinforces that plug into a firm clot that holds. In short, the cascade is the reinforcement stage, not the first response.
In hemophilia A, however, the first stage works perfectly. Platelets are normal. The problem is further along the cascade, where factor VIII is missing. So a clot starts to form and then fails to set, and bleeding carries on longer than it should.
Therefore that distinction matters practically. A dog with hemophilia A does not bleed from everything. It bleeds too long from the things that would normally stop.
Hemophilia A, hemophilia B, and von Willebrand disease
In fact, these three get muddled constantly, and they are not the same condition.
| Condition | What is missing | How common in dogs |
|---|---|---|
| Hemophilia A | Factor VIII | The most common inherited clotting disorder |
| Hemophilia B | Factor IX | Rare compared with A, and generally milder |
| Von Willebrand disease | Von Willebrand factor | A separate, common hereditary bleeding disorder |
VCA describes hemophilia B as tending “to be a milder disease than hemophilia A,” and notes it is “rare compared to hemophilia A” (VCA Animal Hospitals, retrieved 2026-08-12). Similarly, von Willebrand disease is a different mechanism again, and we cover it in our von Willebrand disease in German Shepherds article.
However, why care about the difference? Because the tests, the breeding advice and the transfusion products are not interchangeable. “My dog has a clotting problem” is not a diagnosis you can act on.
How it is inherited, and what that means for breeding
Hemophilia A is X-linked recessive. This is the single most useful fact for anyone breeding or buying, and most articles skip it entirely.
Males carry one X chromosome, so a single affected copy is enough to give them the disease. Females carry two. A carrier is a female with one normal and one affected copy. She shows no clinical signs at all (UC Davis VGL, retrieved 2026-08-12). Merck describes the same pattern: “usually females are subclinically affected carriers and males are affected.”
Thus, in a real litter, according to UC Davis: breed a carrier female to a normal male and every female puppy is clinically healthy, though half of them will be carriers. Among the male puppies, half will be normal and half will be affected.
Notably, in German Shepherds two separate mutations are known. UC Davis reports them as HEMA-1 and HEMA-2, and a single cheek-swab DNA test identifies both. Results can be filed with the Orthopedic Foundation for Animals. The same test applies to Shiloh Shepherds and White Shepherds.
One note for breeders, however: UC Davis recommends waiting until puppies are at least three weeks old before swabbing.
What the signs actually look like
However, there is no single dramatic symptom. That is exactly what makes this condition easy to miss.
Notably, UC Davis describes affected dogs as having a variable presentation with mild to moderate bleeding. The things owners actually notice:
- Bruising easily, including bleeding into the skin
- Prolonged bleeding after any trauma, out of proportion to the injury
- Frequent nosebleeds
- Stiffness or lameness from bleeding into muscles and joints
- Difficulty breathing or a swollen abdomen, if bleeding happens into the chest or belly (VCA, retrieved 2026-08-12)
In puppies, watch three specific moments
Merck names the points where an affected puppy usually gives itself away: prolonged bleeding from the umbilical vessels after birth, from the gums while the adult teeth are coming in, and after early procedures such as dewclaw removal (Merck Veterinary Manual, retrieved 2026-08-12).
Therefore, if you have a puppy that bled unusually long during teething, that is worth mentioning to your vet rather than filing away as bad luck.
How severe is it? The factor VIII percentage
In fact, severity tracks how much working factor VIII a dog has, expressed as a percentage of normal.
Merck gives a useful anchor. Dogs with 5 to 10% of normal activity often do not bleed spontaneously. However, they do bleed for a long time after trauma or surgery (retrieved 2026-08-12). Below that range, spontaneous bleeding becomes more likely.
Consequently, this is also why the condition hides for years. UC Davis puts it directly: variable presentation plus a lack of obvious bleeding incidents means hemophilia A “often results in this condition going undetected until a dog has a surgical procedure or severe trauma.”
In other words, plenty of affected dogs get diagnosed on an operating table. That is the outcome a DNA test exists to prevent.
How a vet diagnoses it
There are three layers. Each answers a different question.
- A screening clotting test. The aPTT, or activated partial thromboplastin time, is the screening test VCA names. It flags that something in the cascade is slow, without saying what.
- A factor VIII activity assay. This measures how much working factor VIII the dog actually has, which is what gives you the severity percentage.
- A DNA test. VCA confirms DNA tests are available for hemophilia A, and UC Davis runs the German Shepherd specific version. This is the one that identifies carriers, which no clotting test can do, because carrier females clot normally.
Importantly, that last point is worth sitting with. A carrier female will pass every clotting test you run on her. If you are breeding, the DNA test is not an optional extra, it is the only tool that sees her.
What the DNA test actually involves
In fact, people put this off because they imagine a blood draw and a big bill. It is neither.
In fact, the sample is a cheek swab. UC Davis sends cytology brushes by post, and you rub the bristles between your dog’s gums and cheek for about fifteen seconds, usually three brushes per dog. Do not collect drool, and do not swab a puppy that has just nursed, because the mother’s genetic material can contaminate the sample. Make sure the dog has not eaten or drunk anything for at least an hour first (UC Davis Veterinary Genetics Laboratory, retrieved 2026-08-12).
As of August 2026, UC Davis lists the hemophilia A test at $58 as a single test, or $27 when added to another health test on the same animal. The broader German Shepherd Health Panel, which bundles hemophilia A with the breed’s other screened conditions, is listed at $130 per animal. Turnaround is at least 15 business days. Check the current prices before ordering, since these change.
Hence the result comes back in one of five forms, and the wording differs by sex because males have only one X chromosome:
- N/N – normal female, no copies
- N/HEMA – carrier female, one copy, clinically healthy
- HEMA/HEMA – affected female, two copies
- N – normal male
- HEMA – affected male, one copy
Thus the report specifies whether the mutation found is HEMA-1 or HEMA-2. For a pet owner the practical value is simple: a clear result means you can stop wondering, and an affected result means every future surgery gets planned properly instead of discovered halfway through.
Treatment, and what to do during a bleed
However, be clear about the ceiling first: hemophilia A cannot be cured. VCA states it plainly, and there is no medication that makes a dog produce the missing factor.
In contrast, what treatment does exist is replacement. Following trauma or surgery, affected dogs may need transfusions of whole blood or of blood products that supply clotting factors (VCA, retrieved 2026-08-12). Merck describes the protocol as repeated transfusions of cryoprecipitate or fresh frozen plasma. The dose is 10 mL per kilogram every 8 to 12 hours, continued until the bleeding stops (retrieved 2026-08-12).
However, you do not need to memorise that. It is here so you recognise what a vet is describing to you. It also explains why an affected dog needs a clinic that stocks the products, not one improvising on the day.
As a result, if your dog is bleeding and will not stop, that is a vet visit rather than a home project. Apply gentle steady pressure with a clean cloth. Keep the dog quiet rather than letting it run around. Phone the clinic on your way so they can prepare. Do not give any medication on your own initiative.
Living with a dog that has hemophilia A
Meanwhile, day to day this is a manageable condition rather than a constant crisis. The management is mostly about anticipating the moments that matter.
- Tell every vet, every time. Put it on the file at your regular practice, and say it out loud at any emergency clinic. A team that knows before a procedure can plan blood products in advance.
- Plan surgery, never improvise it. Elective procedures including spay, neuter and dental work should be scheduled with the diagnosis on the table.
- Keep dental care routine. Gum disease means bleeding gums, and bleeding gums are worse in a dog that cannot reinforce a clot.
- Think about the surfaces and the games. High-impact leaping and rough wrestling create the blunt trauma that leads to joint and muscle bleeds.
- Learn your dog’s normal. Knowing the usual colour of the gums and how long a small scrape usually takes to stop makes an abnormal episode obvious early.
However, none of that means wrapping the dog in cotton wool. Most affected dogs have a normal lifespan, and a German Shepherd still needs exercise, work and a life. It means choosing which risks are worth taking.
Questions worth asking a breeder
In addition, hemophilia A is one of the conditions on the UC Davis German Shepherd health panel, so a breeder testing properly will have a result to show you.
- Have both parents been DNA tested for hemophilia A, and can I see the certificates?
- Is the dam a carrier? A normal clotting test on her does not answer this.
- Are the results filed with the OFA, where I can look them up?
- Has any puppy in previous litters bled unusually after dewclaw removal or during teething?
Notably, a breeder working inside a health-testing programme will answer all four without hesitating. For the wider picture on what to check before a deposit changes hands, see our guide to choosing a German Shepherd puppy.
Related health conditions in the breed
Hemophilia A is one of several inherited conditions German Shepherd owners should know by name. Others worth reading about include von Willebrand disease, another bleeding disorder, degenerative myelopathy, and hip dysplasia. Our German Shepherd care guide pulls the routine health picture together.
Final Thoughts
In summary, hemophilia A sounds frightening because the word carries a lot of human history with it. In dogs the everyday reality is narrower than the name suggests. Factor VIII is missing, clots do not hold, and bleeding lasts longer than it should.
In fact, the two things that change outcomes are both available to you. Know the diagnosis before a scalpel is involved, and make sure every vet who touches your dog knows it too.
Meanwhile, if you are choosing a puppy, simply ask for the test results. It is a cheek swab and a certificate number, and it is the difference between finding out now and finding out during surgery.
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