Karen M. Tobias

Portosystemic vascular anomalies.

Portovascular anomalies are most commonly seen as congenital communications in dogs and cats. Fixation, whether surgical or interventional, should be considered in all cases for which it is possible to improve perfusion to the liver, and ultimately liver function. Medical management before fixation is always recommended. If surgery is not recommended or not possible, long-term medical management can be successful in approximately 30% of cases. New modalities, such as percutaneous transjugular coil embolization or glue embolization, facilitate treatment of more complicated conditions, such as intrahepatic portosystemic shunts and hepatic arteriovenous malformations.

Adrenal Response to Adrenocorticotropic Hormone in Dogs before and after Surgical Attenuation of a Single Congenital Portosystemic Shunt

BACKGROUND Dogs with single congenital portosystemic shunts (CPSS) often develop postoperative hypoglycemia and prolonged anesthetic recovery. These abnormalities could be attributable to inadequate adrenal response. However, adequacy of adrenal response after CPSS surgery is unexplored. HYPOTHESIS Dogs with CPSS have inadequate postoperative adrenal response. ANIMALS Eight nonoperated, 8 ovariohysterectomy (OHE), and 16 CPSS dogs. METHODS Consecutive day ACTH stimulation tests were performed on nonoperated healthy dogs, healthy dogs before and after OHE, and CPSS dogs before and after surgery. Adequate response was defined as >50% or >30 ng/mL increase in cortisol after ACTH administration. Blood glucose (BG) was monitored before and after surgery. Prolonged anesthetic recovery and refractory hypoglycemia episodes were recorded. RESULTS Results of consecutive day ACTH stimulation tests did not vary in normal dogs. Results of preoperative ACTH stimulation tests of CPSS and OHE dogs were not significantly different. Dogs with CPSS had higher postoperative baseline cortisol concentrations (median, 329 ng/mL) than OHE dogs (median, 153 ng/mL). Postoperative cortisol increase after ACTH in CPSS was < or =50% in 10/16 and < or =30 ng/mL in 6/16. After surgery, BG was < or =60 mg/dL in 7/16 CPSS dogs. Cortisol concentrations were not correlated with BG. Two CPSS dogs had refractory hypoglycemia and 4 had delayed recovery; all improved with dexamethasone administration (0.1-0.2 mg/kg/IV). CONCLUSIONS AND CLINICAL IMPORTANCE Contrary to previous reports, baseline cortisol concentrations in CPSS and healthy dogs are similar. Many CPSS dogs have postoperative hypercortisolemia. Response to ACTH does not correlate with postoperative hypoglycemia or prolonged anesthetic recovery.

Disposition of deracoxib in cats after oral administration.

The pharmacokinetics of deracoxib in seven healthy cats were determined following a single oral (1 mg/kg) dose. Minimal variability among cats was found for all estimated pharmacokinetic variables. Terminal half-life (t(1/2)) was 7.9 hours. The mean maximum concentration (C(max)) was 0.28 microg/mL and was measured 3.64 hours after drug administration. Deracoxib was not detectable in the plasma after 60 hours. The compounded liquid formula was accepted readily, and no adverse effects were observed. Further studies are needed to determine the efficacy and safety of deracoxib after acute and chronic use in the cat.

Modified proximal perineal urethrostomy technique for treatment of urethral stricture in goats

OBJECTIVE To report a modified procedure for perineal urethrostomy (PU) in goats. STUDY DESIGN Case series. ANIMALS Adult castrated male pet goats (n = 11) that had recurrence of urinary tract obstruction after one or more surgical procedures for obstructive urolithiasis. METHODS Medical records (May 2008-February 2011) of goats that had a modified proximal PU were reviewed for history, signalment, and intraoperative and postoperative complications. Follow up was obtained through clinical examination or by telephone interview of owners or referring veterinarians. RESULTS Ten goats survived to discharge. Postoperative complications included hemorrhage (n = 7), misdirected urine stream (3), obstructive urolithiasis (2), and bladder atony, dysuria, dehiscence, or delayed healing (1 each). One goat died acutely 15 hours after surgery from peritonitis, pleuritis, hemorrhagic cystitis, and hepatic lipidosis, and 1 goat was euthanatized 14 months after surgery because of renal failure and persistent cystitis. Urethrostomy sites were patent and functional in 9 goats available for long-term follow-up (>12 months). CONCLUSIONS Transection of penile body attachments from the pelvis and careful mucocutaneous apposition may decrease the risk of postoperative urethral stricture formation in goats after PU. Hemorrhage is common after the procedure but does not affect clinical outcome.Objective To report a modified procedure for perineal urethrostomy (PU) in goats. Study Design Case series. Animals Adult castrated male pet goats (n = 11) that had recurrence of urinary tract obstruction after one or more surgical procedures for obstructive urolithiasis. Methods Medical records (May 2008–February 2011) of goats that had a modified proximal PU were reviewed for history, signalment, and intraoperative and postoperative complications. Follow up was obtained through clinical examination or by telephone interview of owners or referring veterinarians. Results Ten goats survived to discharge. Postoperative complications included hemorrhage (n = 7), misdirected urine stream (3), obstructive urolithiasis (2), and bladder atony, dysuria, dehiscence, or delayed healing (1 each). One goat died acutely 15 hours after surgery from peritonitis, pleuritis, hemorrhagic cystitis, and hepatic lipidosis, and 1 goat was euthanatized 14 months after surgery because of renal failure and persistent cystitis. Urethrostomy sites were patent and functional in 9 goats available for long-term follow-up (>12 months). Conclusions Transection of penile body attachments from the pelvis and careful mucocutaneous apposition may decrease the risk of postoperative urethral stricture formation in goats after PU. Hemorrhage is common after the procedure but does not affect clinical outcome.

CEFOVECIN (CONVENIA) FOR THE TREATMENT OF SEPTIC PERITONITIS IN A FEMALE LION (PANTHERA LEO)

An 8-yr-old intact female African lion (Panthera leo) presented with a 3-day history of lethargy, anorexia, and vomiting. Hematologic and biochemical abnormalities included a leukocytosis, 41,700/microl (4,700-15,300) with a neutrophilia (37,530/microl; 2,000-9,200) and a left shift (1,250/microl bands; 0-300), and mild hypokalemia of 2.1 mEq/L (2.8-4.8). Abdominal radiographs revealed evidence of intestinal ileus, peritonitis, and the presence of effusion. An exploratory laparotomy was performed, and septic peritonitis due to a pyometra was diagnosed. The lion was treated with an ovariohysterectomy, abdominal lavage, fluid therapy, and a subcutaneous injection of cefovecin. The lion recovered, and clinical signs associated with septic peritonitis resolved within 36 hr. It was returned to conspecifics 3 wk later. Three months postoperatively, the lion showed no residual signs of septic peritonitis.

Head and neck swelling due to a circumferential cicatricial scar in a dog.

A 4-year-old, castrated male, mixed-breed dog was evaluated because of progressive head swelling, exercise intolerance, and increasing respiratory effort of 1 months duration. Physical examination and radiographs revealed severe edema of the head and face that was cranial to a circumferential, midcervical constriction caused by scarring related to previous removal of a foreign body. Surgical en bloc resection of the cicatricial tissue was performed, and clinical signs resolved completely after 2 months. Histopathology showed ongoing inflammation and hairs within a fibrous band. This case emphasizes that incomplete wound debridement may lead to excessive fibrous tissue proliferation and that thorough wound examination and debridement should be performed after removing circumferential cervical foreign bodies to ensure complete healing.

Urethral prolapse in dogs: a retrospective study.

OBJECTIVE To evaluate the signalment, clinical signs, treatment, and outcome of dogs with urethral prolapse and identify risk factors associated with prolapse or treatment. STUDY DESIGN Retrospective case series. ANIMALS Dogs (n = 48) with urethral prolapse. METHODS Medical records (May 1995-June 2010) from 2 referral centers were reviewed. Retrieved data included signalment, clinical signs, laboratory findings, treatment, complications, results of long-term follow-up. Records from Veterinary Medical Data Base (VMDB) were evaluated to determine odds ratios. RESULTS Odds ratio for urethral prolapse in English bulldogs compared to all breeds was 366.99 (95% CI: 265.83, 506.65). Of 48 affected dogs, 46 had either resection and anastomosis (43 dogs) or urethropexy (3 dogs). The most common early postoperative complication was hemorrhage (39%); postoperative hemorrhage was less common when a simple continuous pattern was used for resection and anastomosis. Prolapse recurred in 57% of dogs available for long-term follow-up; recurrence was less common in dogs that were administered postoperative butorphanol or acepromazine. Gender was not associated with urethral prolapse or postoperative complications. CONCLUSIONS Urethral prolapse occurs most commonly in English bulldogs. Postoperative hemorrhage and prolapse recurrence may be reduced with use of a simple continuous pattern for urethral anastomosis and by administration of postoperative sedation, respectively. Castration status did not appear to affect prolapse development or outcome.Objective To evaluate the signalment, clinical signs, treatment, and outcome of dogs with urethral prolapse and identify risk factors associated with prolapse or treatment. Study Design Retrospective case series. Animals Dogs (n = 48) with urethral prolapse. Methods Medical records (May 1995–June 2010) from 2 referral centers were reviewed. Retrieved data included signalment, clinical signs, laboratory findings, treatment, complications, results of long-term follow-up. Records from Veterinary Medical Data Base (VMDB) were evaluated to determine odds ratios. Results Odds ratio for urethral prolapse in English bulldogs compared to all breeds was 366.99 (95% CI: 265.83, 506.65). Of 48 affected dogs, 46 had either resection and anastomosis (43 dogs) or urethropexy (3 dogs). The most common early postoperative complication was hemorrhage (39%); postoperative hemorrhage was less common when a simple continuous pattern was used for resection and anastomosis. Prolapse recurred in 57% of dogs available for long-term follow-up; recurrence was less common in dogs that were administered postoperative butorphanol or acepromazine. Gender was not associated with urethral prolapse or postoperative complications. Conclusions Urethral prolapse occurs most commonly in English bulldogs. Postoperative hemorrhage and prolapse recurrence may be reduced with use of a simple continuous pattern for urethral anastomosis and by administration of postoperative sedation, respectively. Castration status did not appear to affect prolapse development or outcome.

Evaluation of a semiquantitative SNAP test for measurement of bile acids in dogs

Background. Serum bile acids (SBA) are used as a routine screening tool of liver function in dogs. Serum samples are usually shipped to a referral laboratory for quantitative analysis with an enzymatic chemistry analyzer. The canine SNAP Bile Acids Test (SNAP-BAT) provides an immediate, semi-quantitative measurement of bile acid concentrations in-house. With the SNAP-BAT, bile acids concentrations of 5–30 µmol/L are quantified, and results outside of that range are classified as <5 or >30 µmol/L. Agreement of the SNAP-BAT with the enzymatic method has not been extensively investigated. Objectives. The purposes of this prospective clinical study were to assess the precision of the SNAP-BAT and determine agreement of SNAP-BAT with results from an in-house chemistry analyzer. Methods. After verifying intra-assay precision of the SNAP-BAT, a prospective analysis was performed using blood samples collected from 56 dogs suspected to have liver disease. Each sample was analyzed with an enzymatic, in-house chemistry analyzer and the SNAP-BAT. Agreement between the two methods was statistically assessed using the κ index of agreement. Results. Intra-assay variability was minimal. The κ index for agreement between the SNAP-BAT and routine chemistry analyzer was between 0.752 and 0.819, indicating substantial to near perfect agreement. Conclusions. The SNAP-BAT is a highly accurate, semi-quantitative test that yields immediate results, and has very little intra-assay variability, particularly for results >30 µmol/L.

Protein C Activity in Dogs: Adaptation of a Commercial Human Colorimetric Assay and Evaluation of Effects of Storage Time and Temperature

Objectives of this study were to adapt a commercial human protein C (PC) colorimetric assay for use in dogs and to investigate effects of various storage conditions. The human assay was modified by using pooled canine plasma for calibration and by increasing the activation time. PC activity was measured in fresh canine plasma and in plasma stored under various conditions. PC activity of some stored samples was significantly different from that of fresh plasma; however, differences were small. No difference was detected in samples stored under similar conditions but analyzed in different laboratories using similar methodology. Results of this study indicate that the human colorimetric assay is suitable for canine samples if pooled canine plasma is used for calibration, that Clinical and Laboratory Standards Institute sample storage guidelines developed for testing in humans are appropriate for dogs, and that comparisons of results from laboratories using similar methodology are legitimate.

Ammonia concentrations in canine whole blood, EDTA-anticoagulated whole blood, and plasma measured by use of a point-of-care ammonia meter

OBJECTIVE To investigate the use of canine whole blood (WB) for measurement of ammonia concentration by use of a point-of-care ammonia meter and to compare results of measuring ammonia concentrations in WB, EDTA-anticoagulated WB, and plasma. ANIMALS 40 client-owned dogs. PROCEDURES A blood sample (2 mL) was obtained from each dog. One drop of WB was immediately applied to a test strip for evaluation with an ammonia meter. The remainder of the blood sample was placed in an EDTA-containing tube, and 1 drop of EDTA-anticoagulated WB was applied to a test strip. The remaining EDTA-anticoagulated WB sample was centrifuged, and the plasma was harvested and placed on ice. One drop of plasma was applied to a test strip; the remainder of the plasma sample was transported on ice and used for ammonia measurement with a reference laboratory instrument. All samples were tested within 1 hour after sample collection. Results were evaluated to detect significant differences in ammonia concentration. RESULTS Ammonia concentrations did not differ significantly between WB and EDTA-anticoagulated WB and between plasma samples measured with the meter and reference laboratory instrument. However, median ammonia concentration was significantly higher in plasma than in WB or EDTA-anti-coagulated WB. CONCLUSIONS AND CLINICAL RELEVANCE Anticoagulant-free WB was a valid sample for measurement by use of the ammonia meter. Plasma samples had higher ammonia concentrations than did WB samples. Results for each sample type should be interpreted by use of specimen- and method-specific reference intervals.