Biopsies Of Dogs Research Articles

Using a three-dimensional-printed device with the patient's maxillary dental impression allows to perform minimally invasive brain biopsies in dogs and cats: a preliminary study.

To develop an innovative process for stereotactic brain biopsies in dogs and cats that would provide a definitive diagnosis and optimize the management of patients with brain lesions. 4 dogs and 1 cat diagnosed with 1 or more brain lesion(s) underwent brain biopsies between March 24, 2023, and October 25, 2023. Based on trajectories selected on images of MRI and CT scan performed on each patient, a computerized software program was used to design a 3-D-printed patient-specific device with maxillary dental impression located on a baseplate to secure the patient's head and with insertion ports for the biopsy instrumentations located on a C-arm. As proof of concept, the device was successfully used in 2 cadavers before being used on clinical patients. All biopsy samples were submitted for histopathological examination. Histological diagnosis was obtained in 80% (4/5) of the cases (choroid plexus tumor, astrocytoma, meningioma, and chronic meningoencephalitis of unknown origin). In 1 patient, the results of biopsy were nondiagnostic; postmortem diagnosis was consistent with a low-grade oligodendroglioma. All the patients were discharged within 24 hours after the procedure without complications. This novel stereotactic system allows the surgeon to perform safe, easy-to-use, inexpensive, and minimally invasive precise brain biopsies in dogs and cats, without complications. This unique technique could be applied to any size and type of skull and for any type of brain lesions and would provide diagnostic information that would be valuable for future treatment planning and prognosis.

Intestinal full-thickness needle-core biopsy via laparotomy is safe, rapid, and effective and less invasive than standard incisional biopsy in dogs and cats.

To describe the intestinal full-thickness needle-core biopsy technique via abdominal laparotomy outcomes and compare the histopathological and immunohistochemical diagnosis with standard incisional intestinal biopsy technique in dogs and cats. 3 dogs and 17 cats. Client-owned dogs and cats were prospectively enrolled if intestinal full-thickness biopsies were indicated for the diagnosis of diffuse chronic intestinal diseases following ultrasonography. The study period extended from June 2021 to December 2022. All animals underwent intestinal biopsies with both techniques (needle-core biopsy and standard incisional biopsy) via abdominal laparotomy. Data collected included clinical signs, biopsy collection times, complications, and histopathologic and immunohistochemical findings. A minimum follow-up of 14 days was required. The main clinical sign at presentation was chronic vomiting (65%). Mean needle-core biopsy collection time (262 seconds) was significantly shorter than standard incisional biopsy collection time (599 seconds; P < .000001). The incidence of minor complications was 10% (inflammation of the skin surgical site secondary to licking). One catastrophic complication occurred on a standard incisional biopsy site in 1 cat in a context of bile peritonitis (5% of all cases). There were no complications associated with the needle-core biopsy. All but 1 cat were discharged, with a median of 2 days (range, 1 to 4 days) after surgery. The diagnoses resulting from both techniques were 100% concordant for the distinction between inflammatory bowel disease and intestinal lymphoma via histopathology and immunochemistry. Needle-core biopsy is safe, rapid, and effective and is less invasive than standard incisional biopsy.

Ultrasound-guided core needle biopsy in dogs with thyroid carcinoma.

Currently, a histological diagnosis of highly vascularized canine (c) thyroid carcinoma (TC) is primarily obtained following excisional biopsy (EB) through thyroidectomy. Non-EBs are contraindicated in unresectable invasive cTCs due to their highly vascularized nature, which subsequently, lack histological diagnosis. We hypothesised ultrasound-guided core needle biopsy (UGCNB) to be a safe biopsy technique to obtain an accurate histological diagnosis in unresectable TCs. Nine client-owned dogs with suspected naturally occurring TC, presented for surgical excision, were included. First, a UGCNB was taken from the cervical tumour, followed by EB. Haemorrhage following UGCNB was evaluated preoperatively and once the tumour was surgically exposed by visual inspection and ultrasonography. Histological analysis, including cell organisation, tumour capsular and vascular invasion, and immunohistochemistry were performed and compared between both biopsy specimens (i.e., UGCNB and EB) of the same dog. Pre- and peroperative visual inspection revealed minor, localised haemorrhage, subsequent to the UGCNB, in 7/9 dogs. Histology of the EBs confirmed TC in 8/9 dogs and was inconclusive in 1/9 dogs. Histology of the UGCNBs revealed neoplastic thyroid tissue in 7/9 UGCNBs and was inconclusive in 1/9 UGCNBs. The remaining UGCNB contained no mass related tissue and was, therefore, excluded. Histological parameters (i.e., cell organisation, tumour capsular and vascular invasion) were not concordant between 6/8 included UGCNBs and their respective EB. Immunolabelling for thyroglobulin and calcitonin was concordant between all eight included UGCNBs and their respective EB. The remaining evaluated immunohistochemical markers (i.e., cyclooxygenase-2 [COX-2], P-glycoprotein and vascular endothelial growth factor [VEGF]) were concordant between the included UGCNBs and the EBs in 6/8 dogs. To conclude, UGCNBs can be safely obtained in suspected cTCs and enable a reliable diagnosis of the thyroid origin, thyroid cell origin and potential therapeutic markers such as COX-2, P-glycoprotein and VEGF. Subsequently, UGCNB enables clinicians to establish an individually tailored treatment plan in dogs with unresectable TC.

Evaluation for Postoperative Infections Following Cutaneous Punch Biopsies in Dogs and Cats: 154 Cases (2013-2018).

Antimicrobial stewardship is becoming more important every day with increasing bacterial resistance and limitations on antibiotics. Prophylactic antibiotics are not necessary with all procedures, which has been shown previously with a variety of human and veterinary surgeries. Medical records were retrospectively evaluated for cases who had a cutaneous punch biopsy performed between 2013 and 2018 including the following information: species, signalment, concurrent diseases, concurrent medications, location of biopsy, histopathologic diagnosis, and bacterial infections postoperatively. The prevalence of secondary infections, due to punch biopsies in all animals, was 1.9% and further divided into 2.3% (3/128) of dogs and 0% (0/26) of cats. It was determined that the relative risk of developing complications from punch biopsy was 0.06 (0.01-0.93) when diagnosing a dermatologic disease versus a cutaneous mass (neoplastic and nonneoplastic), which was statistically significant. The risk increased 2.16 (0.16-59.91) times if the biopsy site was the trunk, which includes the neck, thorax, and abdomen. These results indicate that in veterinary medicine, postoperative complications are uncommon with cutaneous punch biopsies. The administration of prophylactic antibiotics in dogs and cats is unnecessary when performing a punch biopsy when there is no infection present at the time of biopsy.

Sentinel Lymph Node Biopsy Is Feasible in Dogs with Scars from Prior Local Excision of Solid Malignancies.

Simple SummarySentinel lymph node (SLN) excision is gaining relevance in the management of various canine malignancies due to its recognized impact on staging and treatment choices. However, the technologies to perform SLN mapping are only available to a few referral centers, and there is increasing demand for secondary nodal staging after prior tumor excision at the primary care institution. This retrospective study investigated the feasibility and usefulness of SLN biopsy in dogs with surgical scars resulting from the removal of various solid tumors referred for further staging and/or adjuvant treatment options. Thirty-three dogs with 34 scars underwent SLN biopsy at a median of 50 days after primary tumor excision. An SLN was identified for 31/34 scars, translating to a detection rate of 91.2%. Metastases were identified with histopathology in 13/31 dogs (41.9%) and they all had an excision of a mast cell tumor. SLN biopsy should be suggested in dogs presenting with scars from prior solid tumor excision, considering the observed detection rate and the importance of knowing the metastatic status of the SLN in oncological diseases.Sentinel lymph node (SLN) biopsy is a well-established staging tool in canine oncology. This study aims to explore the feasibility of SLN biopsy in dogs with scars from prior excised solid malignancies that were referred for further tumor staging and/or adjuvant treatment options. Mapping was either performed using radiopharmaceutical, methylene blue, and/or near-infrared fluorescent (NIRF) imaging. Thirty-three dogs with 34 scars from prior excision of the mast cell tumor (MCT) (n = 29), soft tissue sarcoma (n = 2), oral melanoma (n = 1), subungual melanoma (n = 1), and mammary adenocarcinoma (n = 1) were retrospectively enrolled. Primary treatment consisted of curative intent/wide tumor excisions in 50.0% of dogs and marginal excision in the remaining 50.0%. The median time between tumor excision and SLN biopsy was 50 days (range 17–110 days). The procedure was successful in 31/34 scars, translating to a detection rate of 91.2%. The SLN did not correspond to the regional lymph node in 19/31 scars (61.3%). SLN metastases were histologically identified in 13/31 (41.9%) dogs, all of them affected by MCT. Based on our results, SLN biopsy using lymphoscintigraphy/methylene blue and/or NIRF is feasible in dogs presenting with scars from the prior surgical excision of solid tumors, and should be suggested for accurate nodal staging.

Total lipid concentration of hairs increases after successful attenuation of extrahepatic portosystemic shunts in dogs.

Skin and coat quality can reflect nutritional deficiencies in humans and dogs with liver diseases. Determine skin and coat quality based on a scoring protocol and skin biopsies in dogs with an extrahepatic portosystemic shunt (EHPSS), and determine total lipid concentrations in hairs of dogs at time of surgery and 3 months after successful shunt closure. Ten client-owned dogs that underwent successful gradual attenuation of EHPSS, as defined by transsplenic portal scintigraphy, were included. A prospective cohort study was performed. All dogs underwent gradual attenuation of the EHPSS. Skin and coat scoring was performed at diagnosis, surgery, and 1 and 3 months postoperatively. Hair was plucked from the lumbar region for total lipid analysis and an 8 mm punch skin biopsy was taken at time of surgery and 3 months postoperatively, when the dogs underwent transsplenic portal scintigraphy to determine EHPSS closure. No significant differences were observed in skin and coat scoring over time. Total lipid concentrations of hairs increased significantly from surgery to 3 months postoperatively [30 μg/mg hair (13-56 μg/mg hair) to 47 μg/mg hair (25-63 μg/mg hair); p= 0.005]. Skin biopsies showed the presence of significantly more scales 3 months postoperatively (p= 0.018). A significant increase in total lipid concentrations in hairs suggests that successful surgical attenuation of EHPSS improves either intestinal absorption of lipids, fat metabolism in the liver, or a combination of both.

Assessing the Risk of Nodal Metastases in Canine Integumentary Mast Cell Tumors: Is Sentinel Lymph Node Biopsy Always Necessary?

Simple SummaryMast cell tumor (MCT) is the most common integumentary neoplasm in dogs. The draining lymph node (LN) is the first site of histologically detectable metastasis, even if not clinically altered. The recent literature showed the discrepancy between the regional LN and the truly draining LN (the so-called sentinel lymph node—SLN) in dogs with integumentary MCT. However, the mapping and biopsy of SLN include additional anesthesiologic, diagnostic and surgical procedures, and additional cost. The study aimed to assess the possible association between clinicopathological variables and SLN status. Sixty-six cases of low-grade cutaneous and subcutaneous MCT in dogs admitted to the mapping and biopsy of SLN were included. An MCT dimension smaller than 3 cm seems to correlate less with occult or overt SLN metastasis, although further study should confirm the exclusion of cases with this variable to the mapping and biopsy of the SLN. In contrast, the high association of tumor ≥ 3 cm and subcutaneous MCT with overt SLN metastasis involves a solid suggestion for those procedures in the presence of one of these variables.The recent literature supports the sentinel lymph node (SLN) biopsy in dogs with MCT due to discrepancy with the regional lymph node and the high percentage of occult metastasis. However, the SLN biopsy includes additional anesthesiologic, diagnostic, and surgical procedures, and additional costs. The study aimed to assess the association between clinicopathological variables and SLN status, determining the identification of dogs at lower risk of SLN metastases. Dogs with integumentary MCT were admitted to the lymphoscintigraphic mapping and subsequent biopsy of SLN. The association between clinicopathological variables of MCT and SLN status was statistically tested, both considering occult and overt metastasis together (HN2-HN3) and overt metastasis (HN3) alone. Fifty low-grade cutaneous MCT and 16 subcutaneous MCT were included. A small to moderate association between integumentary MCT ≥ 3 cm and HN2-HN3 SLN was found. A strong association of integumentary MCT dimension and subcutaneous MCT with HN3 SLN occurred. Dimension of low-grade cutaneous and subcutaneous MCT seems to correlate with SLN status, but additional study should confirm this data before excluding small MCT to the SLN biopsy. On the contrary, the study results induce a solid suggestion for mapping and biopsy of the SLN in MCT > 3 cm and subcutaneous MCT.

Hemorrhage and complications associated with percutaneous ultrasound guided liver biopsy in dogs.

BackgroundLiver biopsy is often necessary to obtain a diagnosis in dogs with hepatobiliary disease. Hemorrhage after biopsy is a concern.ObjectiveTo describe the extent of hemorrhage and incidence of complications after percutaneous ultrasound guided liver biopsy (PUGLB) in dogs and to examine risk factors for hemorrhage or complications.AnimalsOne hundred two client owned dogs with suspected hepatobiliary disease that underwent PUGLB.MethodsMedical records were retrospectively reviewed. Using human guidelines, major hemorrhage was defined as an absolute decrease in the PCV (ΔPCV) 6%. Complications were defined separately as clinically relevant physiologic compromise that necessitated intervention or death. The relationship between ΔPCV and the occurrence of complications and the initial PCV, coagulation variables, serum activity of liver‐derived enzymes, serum bilirubin concentration, number of biopsies, biopsy needle gauge, radiologist experience, histological diagnosis, and ultrasound variables were compared.ResultsBefore PUGLB, most aberrations in coagulation variables were mild. After biopsy a decrease in PCV occurred in 87/102 (85.3%) dogs. The mean ΔPCV was −7.2% ± 4.5%. Major hemorrhage occurred in 43/102 (42.2%) dogs and complications in 2/102 (1.9%). ΔPCV was significantly positively correlated with PCV before biopsy (r = .47, P = .004). There was no correlation between ΔPCV or complications with any of the variables examined.Conclusion and Clinical ImportancePercutaneous ultrasound guided liver biopsy in the population of dogs in the current study, with normal or mild abnormalities in coagulation, results in a high incidence of clinically silent, major hemorrhage (42.5%), but few complications (1.9%).

Clinical utility of liver biopsies in dogs undergoing splenectomy.

To determine the prevalence of neoplasia detected on liver biopsy obtained at the time of splenectomy in dogs with splenic masses. Retrospective study of medical records of dogs with splenic masses from which liver biopsies were taken following splenectomy. Malignant splenic neoplasia was detected in 50 of 113 (44.2%) of the dogs undergoing splenectomy. Neoplastic liver disease was detected on biopsy from 1 of 40 (2.5%) dogs with a grossly normal liver and from 20 of 69 (28.9%) dogs with a grossly abnormal liver. Dogs with a grossly abnormal liver had a ~ 16 times (95% CI: 2.5-170) higher chance of being diagnosed with liver neoplasia on biopsy. Haemoabdomen was also associated with an increased likelihood of liver neoplasia on biopsy at the time of splenectomy. A liver biopsy taken from grossly normal liver is a low-yield diagnostic test but liver biopsy is recommended following splenectomy if the liver appears abnormal at surgery.

Risk factors for adverse events occurring after recovery from stereotactic brain biopsy in dogs with primary intracranial neoplasia.

BackgroundStereotactic brain biopsy (SBB) allows for histopathologic diagnosis of brain tumors. Adverse events (AE) occur in 5 to 29% of dogs after SBB, but risk factors associated with developing AE are poorly described.ObjectiveIdentify clinicopathologic, diagnostic imaging, or procedural variables that are associated with AE in dogs after SBB.AnimalsTwenty‐nine dogs with brain tumors.MethodsRetrospective, case‐control study. Dogs had laboratory investigations performed before SBB, as well as clinical examinations and diagnostic imaging of the brain before and after SBB. Cases experienced AE after SBB including transient exacerbation of preexisting neurologic deficits, transient new deficits, or permanent neurologic deficits. Controls had SBB performed without AE. Fisher's exact and Student's t tests were used to examine associations between the postulated risk factors and AE.ResultsAdverse events occurred in 8/29 (27%) dogs, and 7/8 AE (88%) were transient. Cases were significantly more likely to have T2W‐heterogenous tumors (88 versus 38%; P = .04) and lower platelet counts (194.75 ± 108.32 versus 284.29 ± 68.54 ×103/mm3, P = .006). Dogs with gradient echo signal voids present on baseline imaging were significantly more likely to have hemorrhage present after biopsy, and 7/8 (88%) of cases had hemorrhage on imaging after SBB.Conclusion and Clinical ImportanceTwenty‐seven percent of dogs undergoing SBB experience AE, with the majority of AE resolving with 1 week. Platelet counts should be ≥185 000/mm3 to minimize risk of SBB‐associated AE. Observation of intracranial hemorrhage after biopsy can have important clinical implications, as this was observed in 88% of dogs with AE.

Abstract A58: Advancing blood biopsy through the canine comparative model

Abstract Pet dogs are a powerful spontaneous model for human cancers. Dogs develop the same cancers that humans do, with striking similarities at the clinical, histopathologic, and genomic levels. These cancers have an accelerated clinical course compared with their human counterparts, and canine patients undergo many of the same interventions and treatments as human patients. The dog model thus offers the opportunity to implement rapid clinical trials informative for human medicine. We are developing liquid biopsy in dogs to further refine its clinical use by addressing questions that are difficult to assess in human patients. We have four ongoing pilot studies examining several different aspects of blood biopsy in canine patients. (1) We characterized the yield and tumor fraction of cell-free DNA (cfDNA) in nine canine cancer histologies using prospectively collected and banked plasma samples. (2) We tested the correlation between large-scale somatic copy number aberrations (SCNAs) in 24 osteosarcoma tumor samples and matched plasma samples and are now preparing to perform whole-exome sequencing (WES) of these samples to assess the concordance of SNVs and INDELs. (3) We investigated the use of cfDNA as a biomarker for response to therapy in four dogs with multicentric lymphoma treated with L-asparaginase via longitudinal blood biopsy. (4) We are optimizing phlebotomy techniques and characterizing short-term cfDNA dynamics by testing the effect of blood draw site and time of day on yield and tumor fraction. Samples from three sites (jugular, saphenous, and cephalic veins) were collected in a cohort of ten patients, and collection of samples at three time points throughout the day in a separate cohort is ongoing. (1) The majority (93%) of plasma samples yielded or were projected to yield sufficient DNA (&amp;gt;2ng) for ultra-low-pass whole-genome sequencing, and 37% had a tumor fraction ≥10%, allowing for WES given sufficient input DNA. (2) We found a strong correlation (Spearman coefficient of 0.74) between SCNAs in 13 tumor/plasma pairs with tumor fraction ≥10%. We are moving forward with WES of these cfDNA samples to examine simple somatic mutations. (3) Longitudinal cfDNA yield and tumor fraction correlated with response to therapy in three of four lymphoma patients. (4) Sample collection and sequencing are under way for the studies on the effect of blood draw site and time of day. Our studies demonstrated the feasibility of blood biopsy in dogs, the high concordance between cfDNA and tumor samples, and suggested that blood biopsy is a promising method for monitoring response to therapy. Emerging results will help to optimize phlebotomy protocols and characterize cfDNA dynamics over short time scales, as well as assessing in more detail the concordance between cfDNA and matched tumor samples. Further development of blood biopsy in dogs has the potential to improve and accelerate clinical application of this technology in human medicine and to facilitate further high-impact comparative translational studies in the dog model. Citation Format: Kate Megquier, Kan Xiong, Heather L. Gardner, Justin Rhoades, Viktor Adalsteinsson, Cheryl A. London, Elinor K. Karlsson. Advancing blood biopsy through the canine comparative model [abstract]. In: Proceedings of the AACR Special Conference on Advances in Liquid Biopsies; Jan 13-16, 2020; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(11_Suppl):Abstract nr A58.

Evaluation of minimally invasive small intestinal exploration and targeted abdominal organ biopsy with use of a wound retraction device in dogs: 27 cases (2010-2017).

To describe surgical technique, biopsy sample quality, and short-term outcome of minimally invasive small intestinal exploration and targeted abdominal organ biopsy (MISIETB) with use of a wound retraction device (WRD) in dogs. 27 client-owned dogs that underwent MISIETB with a WRD at 1 of 4 academic veterinary hospitals between January 1, 2010, and May 1, 2017. Medical records were retrospectively reviewed, and data collected included signalment; medical history; findings from physical, ultrasonographic, laparoscopic, cytologic, and histologic evaluations; surgical indications, procedures, duration, and complications; and short-term (14-day) outcomes. The Shapiro-Wilk test was used to evaluate the normality of continuous variables, and descriptive statistics were calculated for numeric variables. Laparoscopic exploration was performed through a multicannulated single port (n = 18), multiple ports (5), or a single 6-mm cannula (4). Median length of the incision for WRD placement was 4 cm (interquartile [25th to 75th percentile] range, 3 to 6 cm). All biopsy samples obtained had sufficient diagnostic quality. The 2 most common histologic diagnoses were lymphoplasmacytic enteritis (n = 14) and intestinal lymphoma (5). Twenty-five of 27 (93%) dogs survived to hospital discharge, and 3 (12%) dogs had postsurgical abnormalities unrelated to surgical technique. Results indicated that MISIETB with WRD was an effective method for obtaining diagnostic biopsy samples of the stomach, small intestine, pancreas, liver, and mesenteric lymph nodes in dogs. Prospective comparison between MISIETB with WRD and traditional laparotomy for abdominal organ biopsy in dogs is warranted.

Nasal discharge in dogs - are microbiological and histopathological examinations clinically useful?

Retrospective evaluation of the diagnostic value of bacterial culture of nasal mucosal swabs and histopathologic assessment of nasal mucosal biopsies in dogs with nasal discharge. Medical records of dogs with the predominant clinical sign of nasal discharge that were referred to the ENT Unit of the Small Animal Department between January 2015 and December 2016 were reviewed. Data of 85 dogs were evaluated. On the basis of the results of computed tomography (CT), rhinoscopy, bacterial culture of a nasal mucosal swab and histopathologic examination of nasal mucosal biopsies, dogs were assigned to one of six groups of primary nasal diseases: nasal neoplasia (24/85, 28 %), oronasal defect (22/85, 26 %), idiopathic chronic rhinitis (17/85, 20 %), foreign body (8/85, 10 %), sinonasal aspergillosis (7/85, 8 %) and diseases of the planum nasale (7/85, 8 %). In brachycephalic dogs (14/85, 17 %), oronasal defects (8/14, 57 %) were the most frequent cause of nasal discharge. No cases of a primary bacterial infection of the nasal cavity were observed and, therefore, antibiotic treatment had not been successful. Nevertheless, 72 % of the dogs in this study had received prior antibiotic treatment. Secondary bacterial infec tions diagnosed via nasal mucosal swabs were not diagnostic for the underlying primary nasal diseases. Targeted biopsies of tumors obtained under endoscopic visualization may lead to a definitive diagnosis, whereas biopsies of the nasal mucosa and the type of the inflammatory infiltrate were not diagnostic. Nasal discharge in dogs is frequently an indicator of an underlying severe primary nasal disease possibly leading to mortality of the affected dogs. Further diagnostics under anesthesia should be performed early in the diagnostic evaluation. Rhinoscopy as the central diagnostic is supported by CT and biopsy. Bacterial culture of the nasal discharge does not provide a diagnosis for the primary nasal disease process. Without further diagnostics, antibiotic treatment of dogs presenting with nasal discharge is considered as not appropriate and can be harmful in dogs with nasal tumors or sinonasal aspergillosis. When an intranasal malignant neoplasia is suspected, endoscopic-guided biopsies of the nasal mass should be obtained, because blind nasal biopsies are associated with a high rate of false-negative results.

Correlation between Endoscopic and Histopathological Findings in Dogs with Chronic Gastritis.

IntroductionChronic gastritis is a common diagnosis in dogs with signs of chronic vomiting. However, there is no data concerning endoscopic and histopathological agreement in dogs with chronic gastritis. Thus, a question should be raised whether taking gastroduodenal biopsies in dogs with chronic gastritis is necessary or not. Consequently, the purpose of the study was to compare the endoscopic and histopathological agreement in dogs with chronic gastritis.Material and MethodsA total of 22 non-pregnant client-owned dogs with the signs of chronic gastritis were enrolled in this prospective study. Procedures including clinical examination, blood analysis, and diagnostic imaging were performed before anaesthesia. Biopsies obtained from gastroduodenal sites were histopathologically evaluated. A total of 110 gastroduodenal samples were examined.ResultsSixty-eight samples had abnormal histopathology and endoscopy while 11 showed normal histopathological and endoscopic evidence.ConclusionThe obtained data demonstrated that it is not necessary to take extra gastroduodenal biopsies in dogs with evidence of endoscopic gastroduodenitis. We also believe that further prospective studies, including cost and time effectiveness and more specific comparison between endoscopic appearance and histopathology, are necessary to make final recommendations regarding the need of using both procedures for definitive diagnosis.

Novel MRI and CT compatible stereotactic brain biopsy system in dogs using patient-specific facemasks.

The objective of this pilot study was to describe the application and first preliminary data of a novel MRI and CT compatible patient-specific facemask for stereotactic brain biopsy of intracranial lesions in dogs. Five client-owned dogs presenting for neurological deficits consistent with forebrain disease were included in the study. All dogs had MRI findings consistent with an intracranial lesion. Using images obtained from either MRI or CT, a virtual three-dimensional model of each dog's face was generated. The contact surface of each dog's face was selected for facemask design and a target point for biopsy was chosen using specialised software and toolkits. A patient-specific facemask with an attached biopsy port with premeasured and preselected trajectory was then fabricated by a 3D printer. The facemasks were sterilised and used intraoperatively to obtain biopsy samples. Biopsy samples were submitted for both cytological and histopathological evaluation. The diagnostic yield based on specific histological diagnosis was 80%. The one case in which a histological diagnosis could not be confirmed had a cytological interpretation consistent with meningioma. No major complications were observed during or immediately after brain biopsy and all dogs were discharged from the hospital within 72 hours postprocedure. In conclusion, patient-specific facemasks appear to be a safe and effective method of brain biopsy in dogs, with minimal complications observed.

The incidence of surgical site dehiscence following full-thickness gastrointestinal biopsy in dogs and cats and associated risk factors.

The objectives of this study were to: (1) document the incidence of surgical site dehiscence after full-thickness gastrointestinal biopsy in dogs and cats and (2) identify potential risk factors. Data relating to dogs and cats undergoing full-thickness gastrointestinal biopsy were reviewed retrospectively following submission of a completed questionnaire by 12 referral institutions. Outcome measures were definite dehiscence, possible dehiscence (clinical records suggestive of dehiscence but not confirmed), suspected dehiscence (definite and possible combined) and death within 14 days. Logistic regression was planned for analysis of association of dehiscence with low preoperative serum albumin, biopsy through neoplastic tissue, biopsy alongside another major abdominal surgical procedure and biopsy of the colon. Of 172 cats, two (1·2%) had definite dehiscence, and four (2·3%) had possible dehiscence. Low preoperative serum albumin was significantly associated with definite dehiscence in univariable analysis and with suspected dehiscence and death within 14 days in univariable analysis, but all odds ratios had wide 95% confidence intervals. A histopathological diagnosis of neoplasia was significantly associated with death within 14 days in univariable analysis. Of 195 dogs, two (1·0%) had definite dehiscence, and three (1·5%) had possible dehiscence. In dogs, there was no association between any outcome measure and the putative risk factors. Incidence of dehiscence following full-thickness gastrointestinal biopsy was low in this study. When determining the appropriateness of biopsy in individual cases, this information should be balanced against the potentially life-threatening consequences of dehiscence.

Histological Findings in Ultrasound-Guided Hepatic Biopsies in Dogs

Histological Findings in Ultrasound-Guided Hepatic Biopsies in Dogs

Laparoscopic kidney biopsy in dogs: Comparison of cup forceps and core needle biopsy

To investigate the feasibility of laparoscopic kidney biopsy with cup biopsy forceps in dogs (CupBF), and to compare to the use of a core biopsy needle (CoreBN). Experimental; randomized, controlled design. Eight healthy, adult Beagle dogs. Dogs were randomized to undergo laparoscopic biopsy of the right kidney using either 5 mm CupBF or a 16 gauge CoreBN. Intraoperative hemorrhage of the biopsy site was monitored. Biopsy quality was evaluated for tissue fragmentation and crushing, presence of renal cortex with or without medulla, and number of glomeruli. Postoperative packed cell volume, urinalysis, and ultrasonographic appearance of the biopsy site were evaluated. Biopsy specimens were obtained by both techniques and reliable hemostasis was achieved with direct compression in all dogs. The histologic score for CupBF biopsies was not significantly different from CoreBN biopsies. One CoreBN biopsy contained both renal cortex and medullar, while all CupBF biopsies contained cortex only. The mean (SD) number of glomeruli was significantly higher in CupBF biopsies [60 (9.1)] than CoreBN biopsies [26 (4.3)]. There was no gross hematuria, perirenal hematoma, or hydronephrosis in any dog postoperative. Laparoscopic kidney biopsy in dogs using 5 mm cup biopsy forceps is feasible with minimal risk and more glomeruli obtained compared to laparoscopic kidney biopsy using 16 gauge core biopsy needles.

Complication rates of ultrasound-guided liver biopsies in dogs and cats

Purpose: The interpretation of ultrasound detectable liver changes is very difficult. The diagnosis can be made after examination of a liver specimen which could be taken by ultrasound guidance. There are some known complications associated with ultrasound-guided biopsies. The most common complication after sampling is bleeding which could lead to death. The aim of the study is to prove the correlation of observable ascites and changes in coagulation parameters.

Diagnostic Laparoscopic Biopsy in Dogs and Cats

Se-Jin Park, Seung-Yong Lee, So-Young Jin, Min-Hyang Kim, Seong-Hoon Seok, Young-Ki Kim, Hee-Chun Lee, Dong-In Jung, Il-Hwa Hong, Seong-Chan Yeon. J Vet Clin 2016;33:21-4. https://doi.org/10.17555/jvc.2016.02.33.1.21