| Comparative Coagulation |
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Clinical Topics - Bleeding Time
Tests
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Buccal Mucosal Bleeding Time: |
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Supplies: |
Stopwatch or timer-
muzzle gauze
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filter paper or gauze sponges
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bleeding time template device
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- Surgicutt, International Technidyne Corp., Edison, NJ or
- Simplate, Organon Teknika, Durham, NC
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(optional) anesthetic or tranquilizer: do not use narcotic drugs,
acceptable drugs include xylazine, propofol, barbiturates or inhalant
gas anesthesia.
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Procedure: |
- The dog is positioned in sternal or lateral recumbency. The
upper lip is everted and secured using a strip of gauze wrapped
snugly around the muzzle. The template device is placed on the
buccal mucosa and triggered as the timer or stopwatch is started.
Simplate incisions are made parallel and Surgicutt incision is
made perpendicular to the lip margin. Blood flow from the incision(s)
is blotted using filter paper held directly below, but not touching
the wounds. The time from triggering the device until blood no
longer appears on the paper is recorded as the bleeding time.
The muzzle gauze is removed and pressure applied to the wounds
until active bleeding ceases. If needed, topical tissue adhesive
(cyanoacrylate) can be applied to prevent rebleeding.
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Normal Range: |
- Two to four minutes.
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Interpretation: |
- Lip bleeding time is expected to be prolonged in patients with
severe acquired or inherited platelet dysfunction or severe von
Willebrand disease. There is a variable response in dogs with
DIC or mild forms of vWD. Dogs with even severe coagulation factor
deficiencies usually have normal lip bleeding time.
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The upper lip is everted and held in place with muzzle
gauze that encircles the upper and lower jaw. The gauze must be tied
snugly. The buccal bleeding time is not inherently painful, but dogs
must remain quiet and in position for up to 10 to 12 minutes. Sedation
may be required for adequate restraint. |
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The Simplate device is triggered parallel to the lip
margin. Blood flowing from the wounds is then gently blotted below
the incisions. Do not wipe or disturb the wounds. The time from incision
to cessation of blood flow is recorded as the buccal mucosal bleeding
time. |
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Cuticle Bleeding Time (Toenail Bleeding Time): |
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Supplies: |
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timer or stopwatch
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guillotine type toenail clippers
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silver nitrate cautery sticks
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anesthetic or tranquilizer: (dogs must be anesthetized or heavily
sedated to prevent movement and discomfort during this procedure)
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do not use narcotic drugs, acceptable drugs include xylazine,
propofol, barbiturates or inhalant gas
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Technique: |
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The dog is positioned in lateral recumbency.
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Remove any hair that covers the nails.
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The guillotine clipper is used to sever the apex of the nail cuticle.
A clean transection of the nail is made just into the quick, to
produce a free flow of blood. An arterial pulse indicates that
the cut was too high, and only two or three drops of blood means
the cut was too low. Several nails can be cut at one time to ensure
appropriate technique.
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A stopwatch is started simultaneously with the cut, and the nail
is left to bleed freely. The time until bleeding stops is recorded
as the bleeding time.
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The nail is cauterized with silver nitrate sticks to prevent rebleeding.
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Normal Range: |
- Two to eight minutes.
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Interpretation: |
- Toenail bleeding time is expected to be prolonged in patients
with acquired or inherited platelet dysfunction, coagulation factor
deficiency, severe von Willebrand disease, or the hemorrhagic
phase of DIC.
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The nail cuticle is exposed. Cuticle bleeding time
can be performed simultaneously on several nails. The cuticle bleeding
time wound is painful, dogs should be sedated or anesthetized for
this procedure. |
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Transection at appropriate site for steady flow from
the cuticle. Discrete drops of blood should fall from the wound for
at least the first 30 to 60 seconds after transection. A steady stream
or arterial pulse indicates that the wound is too far into the cuticle.
That nail should be cauterized and the test repeated using a different
nail. |
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Bleeding Time References: |
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American Journal of Veterinary Research 1987;48:1337-42
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Canadian Veterinary Journal 1989;30:344-5
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Thrombosis and Haemostasis 1993; 70:777-80.
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