Sentinel lymph node mapping in canine mast cell tumours using a preoperative radiographic indirect lymphography: Technique description and results in 138 cases

Several sentinel lymph node (SLN) mapping techniques, to detect nodal metastasis in canine tumours have been investigated in the last 10 years in veterinary oncology. The purpose of this prospective study was to describe a reliable, quick, and inexpensive technique for SLN mapping in canine patients affected by cutaneous and subcutaneous mast cell tumours (MCT). Eighty dogs were enrolled in this study for a total of 138 cytologically diagnosed MCTs. Sentinel lymph node mapping was performed by injecting iomeprole peritumorally followed by serial radiographs at 1, 3, 6 and 9-min post injection. A total of 168 SLNs were detected, 90% at first radiograph, 1 min after the peritumoral iomeprole injection, while in the rest of the cases SLN was identified at 3 min. Sentinel lymph nodes detected by the preoperative radiographic indirect lymphography with iomeprole (PRILI) differed from regional lymph nodes in 57% of cases. The PRILI technique detected simultaneously multiple SLNs in the 26% of cases and multiple lymph centers in the 31% of MCTs. To allow the surgical identification of the SLNs, a peritumoral injection of methylene blue was performed at the time of surgery. This study reports a widely available technique for SLN mapping using digital radiographs in combination with a water-soluble medium, representing a cost-effective alternative to other SLN mapping procedures. Based on our results, this technique can be effective for SLNs mapping in dogs with MCTs but further comparative studies are needed to assess its reliability and efficacy in different tumours.     

Clinical usefulness of intradermal fluorescein and patent blue violet dyes for sentinel lymph node identification in dogs

The first lymph node receiving drainage from a specific anatomic region is referred to as the sentinel lymph node (SLN). This study sought to evaluate the intradermal use of two dyes, patent blue violet (PBV) and fluorescein (FL), for SLN mapping in the dog. Multiple intradermal injections were performed in five healthy dogs using two dyes, PBV in 0.9% NaCl and FL in solutions of 0.9% NaCl and 6% hetastarch. Skin flaps were raised and followed to the first area of discrete stain uptake. Areas of uptake were identified as lymph nodes grossly and by cytology. Identification of a SLN for each area of intradermal injection was accomplished for 98% of the injection sites. Intradermal injections of both PBV and FL dyes produce readily visible staining of lymphatic vessels and SLNs in healthy dogs and are sufficient to allow ready identification of these structures during postmortem dissection.     

Incorporation of sentinel lymph node mapping in dogs with mast cell tumours: 20 consecutive procedures

The study hypothesis is that incorporation of sentinel lymph node (SLN) mapping in dogs presenting for mast cell tumour (MCT) removal would impact the recommended adjuvant therapy offered. Nineteen dogs were enrolled having either spontaneously occurring or incompletely excised MCTs. Staging included regional lymph node aspiration. SLN mapping was done with regional lymphoscintigraphy combined with intra‐operative lymphoscintigraphy and blue dye. Twenty MCTs in 19 dogs were excised with SLN mapping. Eight dogs had SLNs different from the closest node. Twelve dogs had metastasis in extirpated SLNs, seven occurred in MCTs with a MI ≤ 5. No correlation was noted between patient stage and the c‐KIT proto‐oncogene. Because of SLN staging, 8 of 19 dogs were offered additional therapy that would have otherwise been excluded. Anatomic sampling of lymph nodes in dogs with MCTs does not accurately reflect which lymph nodes are most likely to be receiving the draining tumour lymph.     

The role of sentinel lymph node mapping in small animal veterinary medicine: A comparison with current approaches in human medicine

The relevance of regional lymph node (LN) assessment to quantify the metastatic spread of cancer is well recognized in veterinary oncology. Evaluation of LNs is critical for tumour staging. However, sampling the correct LN may not be possible without sentinel lymph node (SLN) mapping. Methods for diagnostic imaging and intraoperative detection of SLNs are well established in human medicine, in particular, the combination of lymphoscintigraphy and intraoperative application of blue dyes. Nevertheless, alternative imaging techniques are available and have gained increasing interest. Successful implementation of these techniques in dogs have been reported in both clinical and experimental studies. This review aims to provide an overview of SLN mapping techniques in human and veterinary medicine.     

Sentinel lymph node mapping by near‐infrared fluorescence imaging and contrast‐enhanced ultrasound in healthy dogs

Sentinel lymph node (SLN) mapping is a valuable and crucial diagnostic procedure in staging malignancies. We compared two non‐invasive techniques, near‐infrared (NIR) fluorescence imaging and contrast‐enhanced ultrasound (CEUS), to identify the SLNs in three superficial anatomical regions in an animal model. Six healthy laboratory dogs were included in a proof‐of‐concept trial. A NIR fluorescent dye (Indocyanine Green) and microbubbles (Sonovue) were consecutively injected subdermally in the Inguinal, axillary and popliteal region to map the SLNs. Transcutaneous NIR fluorescence imaging identified SLNs in 17 out of a total of 18 occasions. CEUS identified SLNs in all regions (18/18). Whereas NIR fluorescence imaging performed better in the visualization of the afferent lymphatic tract, CEUS demonstrated different filling patterns of the SLNs, a feature potentially critical for the concept of SLN mapping in cancer patients. Both NIR fluorescence imaging and CEUS are safe, non‐invasive, practical and accurate methods to perform real‐time transcutaneous SLN mapping with potential in a clinical setting.     

ASSESSMENT OF SENTINEL LYMPH NODE METASTASIS IN CANINE MAMMARY GLAND TUMORS USING COMPUTED TOMOGRAPHIC INDIRECT LYMPHOGRAPHY

In the staging process of the breast cancer, demonstrating metastasis of the sentinel lymph node (SLN) has an important prognostic value, in both humans and animals. The aim of this prospective case‐control study was to determine the diagnostic value of computed tomographic indirect lymphography (CT‐LG) for detecting SLN metastasis in dogs with mammary cancer. Thirty‐three female dogs with tumors in the abdominal and inguinal mammary glands were prospectively selected and subjected to CT‐LG, 1 and 5 min after injection of 1 ml of contrast agent (iopamidol) in the subareolar tissue of the neoplastic and the contralateral normal mammary glands. The pattern of postcontrast opacification, degree of postcontrast enhancement, and size and shape were assessed in 65 SLNs in total and were correlated with histopathological findings. The absence of opacification or heterogeneous opacification 1 min after contrast medium injection showed the highest sensitivity, specificity, and accuracy (93%, 100%, and 98.4%, respectively). In images taken 1 min after injection, an absolute density value lower than 444 Hounsfield units (HU) in the center of the SLN also provided significant sensitivity and specificity (93.8% and 75%, respectively). The size and shape of the SLN (maximum and minimum diameter, maximum/minimum diameter ratio, maximum diameter/height of fifth thoracic vertebral body ratio) showed the lowest sensitivity and specificity. Results of this study support the hypothesis that CT‐LG could help in the assessment of SLN metastasis in cases of mammary gland tumors in dogs.     

THE EFFECT OF A COMBINATION OF MEDETOMIDINE-BUTORPHANOL AND MEDETOMIDINE, BUTORPHANOL, ATROPINE ON GLOMERULAR FILTRATION RATE IN DOGS

The effects of intramuscularly administered medetomidine and butorphanol (MB), and medetomidine, butorphanol, atropine (MBA) on glomerular filtration rate (GFR) were determined in six dogs as measured by 99m-Tc-labeled diethylenetriaminepentaacetic acid (99mTc-DTPA) nuclear scintigraphy. Direct systolic, diastolic, and mean arterial blood pressures and heart rate were measured at regular time intervals before, during, and after GFR calculations. The mean GFR measurement following MB was significantly greater (4.44 ml/min/kg) than following MBA (3.82 ml/min/kg) or saline treatment (3.41 ml/min/kg). There was no significant difference between the mean GFR measurements following MBA injection and following saline injection. Diastolic and mean arterial pressures following MBA injection were significantly higher than the values recorded after either MB or saline alone. Heart rate following MB administration was significantly lower than that recorded for dogs receiving MBA or saline alone. The results of this study indicate that the administration of medetomidine in combination with butorphanol significantly increases total GFR in healthy dogs, while the administration of the combination of medetomidine, butorphanol, and atropine does not.     

Sentinel lymph node mapping of the canine anal sac using lymphoscintigraphy: A pilot study

Sentinel lymph node mapping and biopsy are important parts of oncologic staging in human medicine. Sentinel lymph node mapping enables identification of the first lymph node to receive lymphatic drainage while avoiding unnecessary lymph node dissection. Anal sac adenocarcinoma is the most common malignant neoplasm of the canine perineal area. For dogs with anal sac adenocarcinoma, lympadenectomy and metastasis to the iliosacral lymphocentrum are negative prognostics indicators. The objectives of this prospective, two by two, crossover pilot study were to establish the feasibility of lymphoscintigraphy using Technetium‐99 sulfur colloid of the canine anal sac of healthy dogs, compare two injection techniques, and the time for identification of sentinel lymph nodes using each technique. We hypothesized that both intramural and perimural injections of the canine anal sac would identify similar sentinel lymph node drainage. The sentinel lymph node was identified in all dogs using either technique. Intramural injection of the canine anal sac showed radiopharmaceutical uptake faster than perimural injection technique (P = 0.040). There was concordance between intramual and perimural techniques for the sentinel lymph node identified in 50% of cases. A sacral lymph node was identified as sentinel in three of eight dogs (37.5%). Lymphoscintigraphy of the canine anal sac is safe and feasible in normal dogs; however, the method of injection technique seems to have a significant effect on the sentinel lymph node identified.     

Sentinel lymph node mapping with computed tomography lymphography for mast cell tumours and a comparison between regional and sentinel lymph node histological status: Sixty-two cases

It is known that the regional lymph node (RLN) may not correspond to the sentinel lymph node (SLN) (the first lymph node draining the tumour), and many diagnostic techniques have recently been aimed at its detection. Although lymphoscintigraphy is the gold standard in both human and veterinary medicine for SLN mapping, it is relatively unavailable in veterinary medicine due to costs and difficult management of the radiotracer. This prospective study evaluated, as a first aim, the feasibility and sensitivity of the computed tomography lymphography (CTL) in detecting the SLN in 62 mast cell tumours (MCTs). The second aim was to evaluate the accuracy of the CTL in identifying the most representative lymph node of the patient's lymphatic status; the histological status of the SNL was compared with that of the RLN, to see in how many cases the patient's stage would have changed according to the RLN. When the RLN turned out to be also the SLN it was decided to excise, as a control LN, the one localised in the neighbourhood of the MCT (neighbouring lymph node; NLN). The detection rate was 90%, with failure of SLN identification in six cases. In 18 (32%) of 56 MCTs with a diagnostic CTL, the SLN did not correspond to the RLN. Forty-five MCTs were surgically removed, together with their corresponding SLN and RLN/NLN. Since the clinical stage of the patient would have changed in only 7% of cases, CTL is a reliable method of detecting the SLN and, for staging purposes, there is no need to remove other LNs.     

Patterns of nodal metastases,biological behaviour and prognosis of canine mast cell tumours of the pinna: A multi-institutional retrospective study

Canine cutaneous mast cell tumours (cMCTs) of the pinna have been associated with an aggressive biological behaviour, although data remain scarce. The knowledge acquired over the past years on histologic gradings, and the value of lymph node (LN) staging, may help in better characterizing this anatomical presentation. The first aim was to describe the frequency, location, and histologic appearance of LN metastases in cMCT of the pinna. A second aim was to evaluate prognosis. Medical records of dogs with cMCT of the pinna, that underwent tumour and sentinel (SLN) or regional LN (RLN) excision, were reviewed. The influence of potential prognostic variables on time to progression (TTP) and tumour-specific survival (TSS) was investigated. Thirty-nine dogs were included: 19 (48.7%) had Kiupel high-grade (K-HG) and 20 (51.3%) had low-grade (K-LG) MCTs. Eighteen (46.1%) dogs underwent SLN mapping: the superficial cervical LN was at least one of SLN in 17 (94.4%) cases. Twenty-two (56.4%) dogs had LN metastases; the superficial cervical LN was always involved. On multivariable analysis, only K-HG was associated with increased risk of progression (p = .043) and tumour-related death (p = .021). Median TTP and TSS were 270 and 370 days in K-HG, respectively; these were not reached in dogs with K-LG tumours (p < .01). cMCTs of the pinna are often K-HG and are also associated with a higher frequency of LN metastasis; however, we confirmed the independent prognostic value of histologic grading. A multimodal treatment may lead to favourable long-term outcome. Moreover, the superficial cervical LN is most often the SLN.     

Popliteal and mesenteric lymph node injection with methylene blue for coloration of the thoracic duct in dogs

OBJECTIVE:To describe and compare the time of onset and intensity of thoracic duct coloration after injection of methylene blue into a mesenteric or popliteal lymph node. STUDY DESIGN: Experimental study. ANIMALS: Twenty adult dogs. METHODS: A right tenth intercostal thoracotomy, a right paracostal laparotomy, and an approach to the right popliteal lymph node were performed on each dog. Methylene blue (0.5 mg/kg of a 1% solution, maximum 10 mg) was injected into either a mesenteric (group M, 10 dogs) or popliteal (group P, 10 dogs) lymph node. Thoracic duct color was graded (0 to 3) every 5 minutes for 60 minutes. Statistical analysis was performed on mean thoracic duct color grade data, on number of successful outcomes between groups M and P, and between weight groups. RESULTS: Coloration of the thoracic duct occurred in all group M dogs and 6 group P dogs. Coloration was first recorded 0 to 10 minutes after injection in all dogs and persisted for 60 minutes in 15 dogs. Mean thoracic duct color grade was significantly increased postinjection compared with preinjection at all times in group M. More successful outcomes occurred in group M (P =.03). CONCLUSIONS: Methylene blue injected into mesenteric or popliteal lymph nodes was successful in coloring the thoracic duct, but both mean grade and number of successful outcomes were significantly higher after mesenteric injection. CLINICAL RELEVANCE: Thoracic duct coloration after lymph node injection occurred within 10 minutes and persisted for 60 minutes. This information is useful in planning thoracic duct ligation in cases of chylothorax when observation of the duct is desired. Injection of both lymph node sites was successful, but mesenteric node injection was a more reliable technique.     

Acanthomatous ameloblastoma in dogs treated with intralesional bleomycin

Acanthomatous ameloblastoma (AA) is a benign gingival tumour that often invades bone. This retrospective study evaluated the efficacy of intralesional (IL) bleomycin as a treatment for AA. Six dogs received weekly or bimonthly IL bleomycin injections (dose range, 10–20 U m^?2). A seventh dog presented with advanced, nonresectable AA was treated palliatively. One to sixteen treatments were administered (median, 5). Six of the seven dogs had a complete response within 4 months from initial IL injection (median, 1.5 months), whereas the palliative case had approximately 25% decrease in tumour volume 14 days from initial injection. Local recurrence was not observed during the study period, with a median follow‐up time of 842 days. Adverse effects were limited to wound formation with bone exposure (n = 4), mild tissue reactions (n = 3), local swelling (n = 2) and local infection (n = 1). The conclusions of this study show IL bleomycin is an effective treatment for canines with AA.     

Effect of Chemical or Electrical Activation of Bovine Oocytes on Blastocyst Development and Quality

Activation of in vitro‐matured (IVM) oocytes is essential for successful embryo production following nuclear transfer (NT) or intracytoplasmic sperm injection (ICSI). This study was designed to compare the rates of blastocyst production and embryo quality (as measured by numbers of viable cells) following parthenogenetic activation with electrical pulse or the use of two different calcium ionophores, A23187 (CA) or ionomycin (IO), with or without the addition of bovine serum albumin (BSA). IVM oocytes with a first polar body were randomly allocated to five treatment groups: CA (5 μm CA, 5 min; n = 88), CA + BSA (5 μm CA, 5 min; BSA, 5 min; n = 90), IO (5 μm IO, 5 min; n = 91), IO + BSA (5 μm IO, 5 min; BSA, 5 min; n = 86) and EL (two pulses of 1.5 kV/cm, 20 μs; n = 120). Blastocyst rates were higher (p < 0.05) for CA (54.4%), IO (51.4%) and EL (54.5%) than for IO + BSA (18.3%). Treatment CA + BSA (39.8%) did not differ from the others. There was no difference (p > 0.05) among treatments in total number of cells. However, the percentage of viable cells was reduced in CA (49.9%), CA + BSA (45.8%), IO (64.9%), IO + BSA (50.9%) compared with EL (82.7%). In summary, the addition of BSA to the IO treatment had an adverse effect on blastocyst production rates. Although there was no difference between electrical stimulation and chemical activation on blastocyst production rates, electrical activation resulted in blastocysts with a higher percentage of viable cells.     

Comparison of mesenteric lymphadenography performed via surgical and laparoscopic approaches in dogs

OBJECTIVE: To determine whether injection of a mesenteric lymph node with iodinated aqueous contrast medium results in radiographic delineation of the thoracic duct and its branches, ascertain the ideal interval between injection and radiographic imaging, and evaluate mesenteric lymphadenography performed via laparoscopic and surgical approaches in dogs. ANIMALS: 10 adult dogs. PROCEDURE: In each dog, a right paracostal laparotomy or a right laparoscopic approach was performed to identify a mesenteric lymph node for injection of an iodinated aqueous contrast agent (0.22 mL/kg [81.4 mg of iodine/kg]). Lateral radiographic views were obtained at 60, 120, 180, 240, and 300 seconds after injection. RESULTS: A mesenteric lymph node was identified and injected with contrast medium in each dog. Via paracostal laparotomy, lymph node injection resulted in successful lymphangiographic evaluation in 4 of 5 dogs, whereas via the laparoscopic approach, lymph node injection resulted in successful lymphangio-graphic evaluation in 2 of 5 dogs. In successful radiographic evaluations, injected lymph nodes, mesenteric lymphatics, and the thoracic duct and its branches were delineated. Radiographs obtained at 60 and 120 seconds after injection of contrast medium provided the most detail. CONCLUSIONS AND CLINICAL RELEVANCE: Injection of a mesenteric lymph node directly with contrast medium appears to be a feasible technique for delineation of the thoracic duct and its branches in dogs and might be useful in small animals in which mesenteric lymphatic catheterization can be difficult and lymphangiography is more likely to fail. Refinement of the laparoscopic technique may provide a minimally invasive approach to lymphadenography.     

EFFECTS OF FUROSEMIDE ON URETERAL DIAMETER AND ATTENUATION USING COMPUTED TOMOGRAPHIC EXCRETORY UROGRAPHY IN NORMAL DOGS

One of the limitations of computed tomographic excretory urography (CTEU) for diagnosis of ureteral disease in dogs is that normal ureteral peristalsis can cause intermittent and inconsistent filling. The aims of this study were to determine if the addition of furosemide to a standard CTEU protocol would increase identification of the ureteral segments, increase ureteral attenuation and increase ureteral diameter in normal dogs. Standard and furosemide‐enhanced CTEU scans were acquired in 14 healthy dogs 3 and 10 minutes postcontrast. Ureteral diameters, attenuation values, and percent ureteral filling scores were recorded without the knowledge of furosemide treatment. Comparisons were made between treatments for each postcontrast scan time. The addition of furosemide to the CTEU protocol improved visualization of the ureters by significantly increasing the number of ureteral segments that were able to be identified, as well as their diameter when imaging the patient 3 min following contrast injection (P = 0.012). No major side effects were observed at the dose of 4 mg/kg. There was no advantage to imaging dogs 10 min following contrast administration as the ureteral segments were less attenuating and a smaller percentage of the ureter could be identified. We conclude that the addition of furosemide to canine CTEU studies is safe and may help improve visualization of the ureters.     

Adverse haematological effects of vinblastine, prednisolone and cimetidine treatment: a retrospective study in fourteen dogs with mast cell tumours

Vinblastine toxicity is poorly documented in dogs. The aim of this study was to investigate the haematological alterations in dogs treated with vinblastine and prednisolone. Fourteen dogs with mast cell tumours (MCT) were selected on at least one of the following criteria: lymph node infiltration, surgical margin infiltration, grade II MCTs with Ki-67 >10%, and grade III MCTs. Starting 15 days after surgery, the dogs were given vinblastine (2 mg/m2 i.v. four times weekly, then twice monthly for 2 months) and prednisolone (2 mg/kg/day p.o.). An EDTA blood sample was collected weekly for complete blood count (CBC). A total of 98 doses of vinblastine were given to the 14 dogs and 114 CBC were performed. Abnormal haematological findings were observed in 12 CBCs from five dogs, which represent a prevalence of 20% of the total CBCs performed in these animals. The most prevalent abnormal finding was thrombopenia (9/12) most often with grade I toxicity (6/9). In conclusion, the risk of occurrence of adverse haematological effects resulting from vinblastine-prednisolone treatment seems limited in dogs with MCT and it should not be overestimated.     

Evaluation of the Palmaz Stent in the Trachea and Mainstem Bronchi of Normal Dogs

Objective — This study evaluates the efficacy of the Palmaz balloon expandable intraluminal stent in the trachea and mainstem bronchi of normal dogs. Study Design — Effects of the stent were evaluated by physical examination, thoracic radiography, respiratory tract fluoroscopy and endoscopy, tracheal diameter measurement, postmortem examination, and airway histomorphometry. Animals or Sample Population — Ten normal beagle dogs. Methods — Stent size was estimated from thoracic radiographs in awake dogs. Group I dogs (n = 4) had two stents placed: one in the thoracic trachea (TT) plus a randomly chosen mainstem bronchus (MB). Group II dogs (n = 3) had stents placed in the MB (one stent), TT (one stent), and mid- or proximal cervical trachea (CT) (one or two stents). Three dogs were used as sham-operated controls (group III). Temperature, pulse, respiration, and cough were measured twice daily. Dogs were evaluated at 21 and 49 to 56 days after stent placement, euthanatized, and tissues were collected for histomorphometric analysis of stent integration and epithelial pathology. Results — Mean tracheal diameters of awake (10.5 ±1.7 mm) and anesthetized dogs before stent implantation (13.9 ± 2.0 mm) were significantly different (P <.01). Complications associated with stent placement included acute pulmonary edema (n = 2), stent migration (n = 7), stent collapse (n = 4 CT, 2 TT, and 1 MB), and positive tracheal culture (n = 10). Group II dogs coughed more at rest, exercise, and with tracheal palpation than dogs in other groups (P <.01). Group I dogs coughed more at rest than group III dogs (P <.01). Stent integration ranged from 0 to 91.3%. Squamous metaplasia and epithelial ulceration associated with stents ranged from 0 to 57.5% and 0 to 32.7%, respectively. Conclusions — Determination of stent size should be based on measurements taken on anesthetized dogs because use of inappropriately sized stents may promote stent migration, squamous metaplasia, and/or ulceration. Epithelialization over stent struts may occur if the stent is closely associated with tracheal epithelium. Clinical Relevance — Palmaz stents do not appear to be appropriate for placement in the CT of dogs; however, with technical modifications, application in the TT and MB may be feasible.     

Use of laparotomy in a staged approach for resolution of bilateral or complicated perineal hernia in 41 dogs

OBJECTIVE: To evaluate the value of laparotomy as the initial step in the treatment of bilateral or complicated perineal hernia (PH) in dogs. STUDY DESIGN: Retrospective study. ANIMALS OR SAMPLE POPULATION: Forty-one dogs with PH. METHODS: Dogs with bilateral or complicated PH treated by a 2-step approach between November 1997 and December 2001 were studied. Inclusion criteria for complicated PH were: recurrence of PH, unilateral PH with a major rectal dilatation, PH with a concurrent surgical prostatic disease, and PH with retroflexed bladder. Colopexy, vas deferens pexy, cystopexy, and prostatic omentalization were performed during laparotomy as needed. Later, PH was performed by internal obturator muscle flap (IOMF) or if there was a perineal rent or weakness on the contralateral side, appositional herniorrhaphy was performed. Outcome was followed for >/=6 months. RESULTS: PH were bilateral (20 dogs) or unilateral (21). Twenty-one (51%) dogs had prostatic disease (clinical or ultrasonography diagnosis; 17 confirmed histologically) and 12 (29%) had urinary bladder retroflexion. Forty-one colopexies, 32 vas deferens pexies, 6 cystopexies, and 9 prostatic surgeries (omentalization or perineal cyst resection) were performed. PH was performed 2-20 days (median, 6 days) later: 61 IOMF transpositions, 13 appositional. Mean follow-up time was 26.6 months (range, 6-54 months, median, 27 months). PH was resolved in 37 (90%) dogs; 4 dogs had recurrence, and all occurred within 6 months. Thirty-eight (92%) dogs had an improved quality of life (good in 34 dogs, fair in 4 dogs). Wound complications occurred in 7 dogs (17%). Postoperative urine dribbling occurred in 15 dogs (37%) and was irreversible in 7 dogs (17%). Postoperative fecal straining persisted in 18 dogs (44%), and was permanent in 4 dogs (10%). Fecal incontinence did not occur. CONCLUSIONS: In bilateral or complicated PH, fixation of the urinary bladder and colon, and treatment of prostatic disease increase the chances of resolution. Emptying of the perineal space by organ pexy allows improved observation during herniorrhaphy. Despite a 90% clinical resolution, dogs with complicated PH treated by a 2-step protocol may have persistent urinary and fecal disorders. CLINICAL RELEVANCE: To improve the prognosis of bilateral or complicated PH, investigation and treatment of concomitant lesions (rectal, prostatic, bladder) should be part of a rational surgical strategy using a 2-step protocol.     

Bupivacaine 0.25% and methylene blue spread with epidural anesthesia in dog

ObjectiveTo evaluate the extent sensory and motor blocks produced by the epidural injection of different volumes of 0.25% bupivacaine (Bu) with methylene blue (MB), in dogs.Study designProspective experimental trial.AnimalsTwenty healthy adult mongrel dogs, weighing 9.9 ± 1.9 kg.MethodsDogs were randomly allocated into one of four groups that received 0.2, 0.4, 0.6 or 0.8 mL kg^?1 of an epidural solution containing 0.25% Bu and MB. Sensory block was evaluated against time by pinching the tail, hind limb interdigital web, toenail bases and the skin over the vertebral dermatomes. Motor block was assessed by ataxia, hind limb weight-bearing ability and by loss of muscle tone of the tail and pelvic limbs. Data were collected at 2, 5, 10, 15 and 30 minutes after the end of epidural injection. After the final time point, dogs were euthanatized and laminectomies were conducted to expose the extent of the dural dye staining.ResultsThe volumes 0.2, 0.4, 0.6 and 0.8 mL kg^?1 of 0.25% Bu and MB blocked a mean of 5, 14.2, 20.2 and 21 dermatomes, respectively. The extent of the senory block increased up to a volume of 0.6 mL kg^?1. Motor block was longer-lasting and more intense than sensory block. Complete dyeing of the spinal cord with MB was achieved in some dogs at 0.4 mL kg^?1 and all dogs at 0.6 mL kg^?1.ConclusionsThe volume of anesthetic injected into the epidural space plays an important role in the quality of the epidural anesthesia. At 0.25%, bupivacaine provided an efficient sensory block at 0.6 mL kg^?1.Clinical relevanceRelatively high volumes (0.6 mL kg^?1) of 0.25%, BU and MB were needed to produce an effective sensory and motor block caudal to the umbilicus, but all spinal cord segments were reached by MB at this dose.