Objective—To characterize the computed tomographic (CT) and cross-sectional anatomic features of myofascial compartments and soft tissue spaces in the manus of cadavers of dogs without forelimb disease.
Animals—33 cadavers of adult medium- to large-breed dogs without forelimb disease.
Procedures—Forelimbs were removed from the cadavers within 4 hours after euthanasia or within 6 hours after thawing from initial freezing. Specimens were then frozen for variable periods and thawed for approximately 16 hours before use. Each manus of 60 forelimbs underwent CT before and after injection of a radiopaque, blue-staining contrast medium into locations where soft tissue spaces and myofascial compartments were predicted (on the basis of pilot study data [6 forelimbs]). Two veterinary radiologists reviewed CT images and recorded the presence or absence of a discrete space or compartment at each injection site. Each manus was subsequently dissected or sectioned transversely. Locations of blue-staining contrast medium accumulation were compared with locations of contrast enhancement in CT images. Anatomic structures within each soft tissue space or myofascial compartment were described.
Results—13 soft tissue spaces and 5 myofascial compartments were identified in the manus. Three myofascial structures that were examined were determined not to be compartments.
Conclusions and Clinical Relevance—Knowledge of soft tissue spaces and myofascial compartments are used to map the likely spread of disease in the hands and feet of humans. Thus, understanding the locations and extent of similar structures in the canine manus may improve the effectiveness of surgical interventions in dogs with injury or inflammation of this region of the forelimb.
Objective—To determine whether the pattern of extension of modeled infection from the interdigital web spaces in dogs is predictable and whether the distribution differs among initial injury sites.
Sample Population—Thawed frozen forelimbs from 23 cadavers of previously healthy adult medium- to large-breed dogs.
Procedures—The manus of each forelimb was evaluated by use of computed tomography (CT) before and after injection of radiopaque blue-staining contrast medium into the interdigital web spaces. Two veterinary radiologists reviewed the CT images and recorded the extent of contrast medium from each site. Each manus was dissected or sectioned transversely after imaging, and the extent of contrast medium accumulation was recorded and compared with locations of CT contrast enhancement. The Fisher exact test was performed to determine whether the pattern of contrast medium extension differed by injection site.
Results—Injections made in the interdigital web spaces of the canine manus led to unique and predictable patterns of extension into the surrounding soft tissues. That pattern of extension primarily involved the soft tissues of the digits.
Conclusions and Clinical Relevance—In humans, knowledge of common extension patterns from infected soft tissue spaces is used to predict the spread of disease within the hand and develop surgical plans that will minimize patient illness. Identification of the common sites of disease spread from the interdigital web spaces in dogs may help improve surgical planning and treatment for infection in the manus.
Objectives—To evaluate computed tomography (CT)
densitometry as a technique for quantifying contrast
enhancement of compressive soft tissues in the
canine lumbosacral vertebral canal and to determine
whether the degree of contrast enhancement can be
used to help predict tissue type or histopathologic characteristics.
Animals—29 large breed dogs with lumbosacral
Procedure—Contrast-enhanced CT of L5-S3 was performed
by use of a previously described protocol. At
each disk level, CT densities of a water-filled syringe,
epaxial muscles, and 4 vertebral canal locations were
measured. Mean tissue enhancement was calculated
by vertebral canal location, using water-filled syringe
enhancement as a correction factor. Corrected CT
enhancement was compared with tissue type,
degree of tissue inflammation, and degree of tissue
Results—Intravenous contrast administration of contrast
medium significantly increased CT densities of
water-filled syringes and epaxial muscles. Corrected CT
enhancement of vertebral canal soft tissues at stenotic
sites was greater than at nonstenotic sites. There was
no association between enhancement and tissue type
for any vertebral canal location. There was no correlation
between enhancement and degree of tissue inflammation.
There was a correlation between enhancement
and tissue activity in the dorsal vertebral canal only.
Conclusions and Clinical Relevance—A water-filled
syringe is a useful calibration tool for CT density measurements.
The degree of tissue contrast enhancement,
measured by CT densitometry, can be helpful for
predicting the location of compressive soft tissues in
dogs with lumbosacral stenosis. However, it is of limited
value for predicting compressive soft-tissue types or
histopathologic characteristics. (Am J Vet Res
Case Description—An 8-year-old male Golden Retriever was evaluated because of an 8-week history of intermittent diarrhea with melena and hematochezia that were not responsive to medical treatment and resulted in severe anemia.
Clinical Findings—Exploratory celiotomy with intestinal and colonic biopsy revealed mild enterocolitis but did not result in diagnosis of the cause of melena and hematochezia. Endoscopy of the upper portion of the gastrointestinal tract and colonoscopy were performed. Multifocal areas of coalescing, tortuous mucosal blood vessels were observed in the cecum and all regions of the colon. A diagnosis of vascular ectasia (VE) was made on the basis of the endoscopic and histologic appearance of the lesions.
Treatment and Outcome—An ileorectal anastamosis was performed. Melena and hematochezia resolved within 3 days after surgery, and the anemia resolved within 6 weeks after surgery. Surgical resection of the cecum and colon and feeding of a highly digestible diet resulted in long-term (22 months) resolution of clinical signs.
Clinical Relevance—Initial exploratory celiotomy with intestinal and colonic biopsy failed to reveal the VE lesions responsible for the melena, hematochezia, and anemia. Endoscopic evaluation was necessary for detection of the colonic VE lesions. Surgical resection of the cecum and colon and feeding of a highly digestible diet may result in a favorable outcome in affected dogs.
To compare the elution characteristics of amikacin-impregnated calcium sulfate (CaSO4) beads based on different drug concentrations and bead size configurations.
Six groups of amikacin-impregnated CaSO4 beads and one negative control group.
Amikacin-impregnated CaSO4 beads were formed with either 500 mg (low-concentration) or 1 g (high-concentration) of amikacin per 15 g CaSO4 hemihydrate powder. The number of beads necessary to approximate 150 mg of amikacin for each of the 3 bead sizes (3 mm, 5 mm, and 7 mm) at both low and high concentrations were placed in 6 mL of phosphate-buffered saline. The saline was sampled at 14 time points over 28 days. Amikacin concentrations were determined using liquid chromatography-mass spectrometry.
Smaller beads reached higher mean peak concentrations than larger beads (P < .0006). Peak concentrations for the low- and high-concentration groups were 20.5 mg/mL and 27.4 mg/mL, 13.1 mg/mL and 14.0 mg/mL, and 8.85 mg/mL and 6.75 mg/mL for the 3 mm, 5 mm, and 7 mm beads, respectively. Bead size also affected the length of therapeutic duration, lasting 6 days for the 3 mm and 5 mm beads and 9 days for the 7 mm beads. However, this was only statistically evident among the high-concentration beads (P < .044). Antimicrobial concentration within the same bead sizes did not affect elution.
Amikacin-impregnated CaSO4 beads achieved extreme supratherapeutic eluent concentrations. While additional studies are needed, bead size significantly affected elution with smaller beads reaching higher peak concentrations and 7 mm, high-concentration beads demonstrating a longer therapeutic duration than smaller beads.