Page 125 - Canine Lameness

7.5 ­quipment 97

Table 7.1 Supplies required for performing arthrocentesis.

Arthrocentesis supplies

Sedation ● Sedation and monitoring supplies and equipment
Site preparation ● Hair clippers
Sterile scrub solution and alcohol
●
Sterile gauze
●
Sterile gloves
●
Needles ● Small dogs and cats = 25–22 g needles; 5/8″ to 1″ length
Medium to large dogs = 22–20 g needles; 1–1.5″ length
●
Giant‐breed dogs = may require spinal needle; 2.5″ length
●
Syringes ● Sterile disposable syringes
○ Small dogs and cats = 1–3 ml
○ Medium‐ to Giant‐breed dogs = 3–6 ml
Sample submission supplies ● Glass slides (and slide mailer) for
○ submission of freshly prepared smears
Pediatric blood culture flasks for
●
○ obtaining bacterial culture and sensitivity a
Ethylenediaminetetraacetic acid (EDTA) blood tubes (purple or
●
b
lavender top tubes) for
○ total nucleated cell count
○ cytology
○ total protein (if not underfilled)
c
Sterile, no additive blood tubes (red top glass tubes) for
●
○ biochemical analytes (lactate, glucose, and total protein)
○ mucin clot test (rarely indicated)
○ obtaining bacterial culture and sensitivity a
b,c
Heparin blood tubes (green top) for
●
○ mucin clot test (rarely indicated)
○ total nucleated cell count
○ total protein (if not underfilled)
a Pediatric blood culture flasks are preferred (over culturette swabs or red top tubes) particularly if >0.5 ml of
synovial fluid is available to increase the chances of obtaining a successful culture result. If large amounts of
sample are available, cultures should be submitted in blood culture flasks and red top tubes (Chapter 9).
b Small volume (pediatric) heparin and EDTA tubes are recommended to reduce dilutional effects that may lead to
testing errors.
c Unless EDTA blood tubes are unavailable, heparin blood tubes are generally not utilized. Please note that heparin
tubes cannot be used for cytology.

not only be appropriate to the animal and joint, but also chosen with care to minimize the potential
for iatrogenic trauma, to permit easy collection of joint fluid in as few attempts as necessary, and
to ensure samples are free of blood contaminant.
The use of spinal needles with the stylet inserted is controversial (e.g. for hip and shoulder joint
aspiration in large dogs), since some studies have suggested that it may result in increased con-
tamination due to the hairs getting stuck in between the space of the stylet and needle (Adams
et al. 2010; Wahl et al. 2012). To reduce the risk of contamination with arthrocentesis, Wahl et al.
(2012) recommend using regular, disposable hypodermic needles. However, the tip of these nee-
dles is more oblique than the tip of a spinal needle (Wahl et al. 2012) and thus may not enter the
lumen of the joint completely in smaller joints. For this reason, some authors recommend using a
spinal needle for small joints (Degner 2014).