Pilot evaluation of a vacuum-assisted biopsy instrument for percutaneous renal biopsy in dogs.

Kidney biopsies in dogs are commonly obtained using automated spring-loaded biopsy instruments. Interpretation of biopsies from dogs with glomerular disease requires examination of at least 5-10 glomeruli, with at least two biopsies usually required for full evaluation. The purpose of this study was to compare quality and interpretability of renal biopsies obtained from healthy dogs with a large-gauge, vacuum-assisted biopsy instrument versus two biopsies obtained with a spring-loaded biopsy needle. Twenty dogs were randomized into two groups, and percutaneous, ultrasound-guided renal biopsies were evaluated using standard criteria. There were no significant differences in the number of biopsies that contained renal tissue, cortex, or medulla. Biopsies obtained with either instrument contained an adequate number of glomeruli and an equivalent number of arterioles and severity of tissue compression. Differences included easier penetration of the renal capsule and collection of sufficient tissue for interpretation with only one instrument pass when using the vacuum-assisted device (vs two passes required with the spring-loaded instrument). Before use in client-owned dogs, future studies should evaluate whether these differences are clinically relevant advantages in the diagnostic evaluation of dogs with kidney disease, and determine the prevalence and severity of complications when using this larger gauge device.

Consequences of intratumoral injection of a herbal preparation containing blood root (Sanguinaria canadensis) extract in two dogs.

CASE DESCRIPTION: 2 dogs were referred for surgical removal of cutaneous tumors that had previously been treated by intratumoral injection of a herbal preparation containing blood-root (Sanguinaria canadensis) extract. CLINICAL FINDINGS: 11 days following injection of bloodroot extract into a small dermal tumor, dog 1 developed a large, soft, fluctuant cutaneous mass at the site of injection. Ultrasonographic evaluation of the mass revealed a fluid-filled central cavity with increased echogenicity of the surrounding subcutaneous tissues. Dog 2 had a small dermal tumor under the left mandible that had been treated in similar fashion. However, an exuberant reaction was not observed following injection of bloodroot extract in this dog. TREATMENT AND OUTCOME: Both dogs underwent surgical excision of the cutaneous tumors. Histologic evaluation revealed severe necrosis and inflammation in the excised tissues from dog 1. This dog experienced postsurgical wound complications and had a prolonged postsurgical recovery. Similar, although less severe, histopathologic findings were apparent in the excised tissues from dog 2; this dog recovered without complications. CLINICAL RELEVANCE: Various products containing bloodroot are marketed on the Internet for topical and parenteral treatment of cutaneous neoplasms in domestic animals. However, the antineoplastic properties, therapeutic efficacy, and adverse effects of these products are poorly described in the veterinary literature. Clinicians should be aware of the potential for harm caused by the use of these products.

Feasibility of contrast-enhanced ultrasound-guided biopsy of sentinel lymph nodes in dogs.

Our goal was to develop and validate a technique to identify the sentinel lymph nodes of the mammary glands of healthy dogs with contrast-enhanced ultrasound, and evaluate the feasibility of obtaining representative samples of a sentinel lymph node under ultrasound guidance using a new biopsy device. Three healthy intact female adult hounds were anesthetized and each received an injection of octafluoropropane-filled lipid microspheres and a separate subcutaneous injection of methylene blue dye around a mammary gland. Ultrasound was then used to follow the contrast agent through the lymphatic channel to the sentinel lymph node. Lymph node biopsy was performed under ultrasound guidance, followed by an excisional biopsy of the lymph nodes and a regional mastectomy procedure. Excised tissues were submitted for histopathologic examination and evaluated as to whether they were representative of the node. The ultrasound contrast agent was easily visualized with ultrasound leading up to the sentinel lymph nodes. Eight normal lymph nodes (two inguinal, one axillary in two dogs; two inguinal in one dog) were identified and biopsied. Lymphoid tissue was obtained from all biopsy specimens. Samples from four of eight lymph nodes contained both cortical and medullary lymphoid tissue. Contrast-enhanced ultrasound can be successfully used to image and guide minimally invasive biopsy of the normal sentinel lymph nodes draining the mammary glands in healthy dogs. Further work is needed to evaluate whether this technique may be applicable in patients with breast cancer or other conditions warranting evaluation of sentinel lymph nodes in animals.