Long-Term Efficacy of a Percutaneously Adjustable Hydraulic Urethral Sphincter for Treatment of Urinary Incontinence in Four Dogs

Objective— To evaluate the efficacy of a surgically placed, static hydraulic urethral sphincter (SHUS) for treatment of urethral sphincter mechanism incompetency (USMI).
Study Design— Prospective study.
Animals— Spayed female dogs (n=4) with acquired USMI.
Methods— Urinary incontinence was assessed using a subjective continence score before and after implantation of an SHUS on the proximal urethra via ventral median celiotomy. Dogs were assessed for urinary continence, urinary tract infections, and implant-associated complications for 30 months. Residual incontinence was treated with percutaneous inflation of the SHUS with sterile saline solution through a biocompatible subcutaneous administration port.
Results— At last follow-up (26–30 months after surgery), continence scores improved from a median preoperative score of 3/10 to a median postoperative score of 10. One dog developed wound drainage over the subcutaneously placed administration port but remained continent after port removal. Three occluders were percutaneously filled with additional saline (median, 0.18 mL; mean, 0.16 mL) to improve continence after surgery.
Conclusions— Application and adjustment of an SHUS provided sustained improvements in continence score in all dogs.
Clinical Relevance— In this pilot study, 3 of 4 dogs with hydraulic urethral sphincter implantation had successful percutaneous adjustment and maintained improved continence scores for 2 years after surgery. Continence was maintained in the 4th dog even after administration port removal. Based on this pilot study, the SHUS warrants further clinical evaluation for treatment of dogs with USMI unresponsive to medical management.     

Effect of oral administration of unfractionated heparin (UFH) on coagulation parameters in plasma and levels of urine and fecal heparin in dogs

The effects of heparin administration, by the oral route, were evaluated in dogs. In single and multiple dose studies (single 7.5 mg/kg, multiple 3 × 7.5 mg/kg per 48 h), plasma, urine, and fecal samples were collected at various times up to 120 h after oral administration of unfractionated heparin. Changes in plasma and urine anti-Xa activity, plasma and urine anti-IIa activity, plasma activated partial thromboplastin time (APTT) and antithrombin (ATIII), and chemical heparin in urine and feces were examined with time. There was support for heparin absorption, with significant differences in APTT, heparin in plasma as determined by anti-Xa activity (Heptest) in the single dose study and plasma anti-Xa activity, anti-IIa activity and ATIII; and chemical heparin in urine in the multiple dose study. No clinical evidence of bleeding was detected in any dog during the studies. Oral heparin therapy may be applicable for thromboembolic disease in animals. Further studies are warranted to determine the effects of oral heparin at the endothelial level in the dog.     

Complications associated with the use of vascular access ports in dogs receiving external beam radiation therapy

OBJECTIVE: To assess the perioperative and postoperative complications associated with use of vascular access ports (VAPs) in the jugular and lateral saphenous veins of dogs requiring frequent anesthetic episodes for radiation therapy. DESIGN: Cohort study. ANIMALS: 40 dogs referred to a veterinary teaching hospital. PROCEDURES: VAPs were used in 23 dogs, and intravenous catheters inserted in a peripheral vein were used in 17 dogs. The frequency of perioperative and postoperative complications associated with VAP use and the frequency of infection associated with intravenous catheter use were recorded. Results of bacterial culture of VAP tips and amount of time required for VAP placement and removal and for anesthetic induction were also recorded. RESULTS: VAP-associated perioperative complications included malposition of the catheter tip in 4 of 23 (17.4%) dogs. The VAP-associated postoperative complications included seroma formation in 7 (30.4%) dogs, breakage of port-anchoring sutures in 3 (13.0%) dogs, suspected fatal catheter-related septicemia in 1 (4.3%) dog, and temporary partial withdrawal occlusion in 18 of 255 (7.1%) anesthetic episodes. CONCLUSIONS AND CLINICAL RELEVANCE: Placement of VAPs provided ready access in dogs receiving radiation therapy. Most complications were minor and self-limiting; however, a low risk of serious complications existed. Use of fluoroscopy to assess position of the catheter tip is recommended to decrease the risk of malposition. Immediate removal of a VAP is recommended when clinical signs of infection develop. Removal of a VAP at the completion of radiation therapy should be performed unless the benefit of continued vascular access outweighs the risks.     

Presumptive hepatotoxicity and rhabdomyolysis secondary to phenazopyridine toxicity in a dog

Objective – To describe a rare, but potential clinical manifestation of phenazopyridine (PAP) toxicity in a dog. Case Summary – A 6‐year‐old spayed female Chihuahua was evaluated for ataxia and dysphagia after ingestion of 200 mg (66 mg/kg) of PAP hydrochloride. The dog was presented to the hospital with shifting leg lameness involving all 4 limbs, which progressed to reluctance to walk and severe diffuse muscle hyperesthesia. Clinical laboratory abnormalities included marked increases in serum alanine aminotransferase, aspartate aminotransferase, creatine kinase, mild increases in alkaline phosphatase, and increased c‐Tnl‐troponin concentration. Treatment included administration of intravenous fluids, muscle relaxants, pain medications, and hepatoprotectants for 5 days in the hospital, and medical management at home for an additional 5 days. Follow‐up examinations performed 1 and 6 months after initial presentation revealed the dog to be clinically healthy with serum biochemical profiles within reference intervals. New or Unique Information Provided – The purpose of this report is to describe an unusual manifestation of PAP toxicosis in a dog, which has not been previously reported in the literature. A review of the ASPCA Animal Poison Control Center database revealed 347 cases of PAP exposure in dogs during 2000–2009 underscoring the importance of being aware of this toxicity in the dog.     

Anesthesia and perioperative management of a pneumonectomized dog

Although left- or right-sided pneumonectomy is tolerated by normal dogs, complications impacting the respiratory, cardiovascular, and gastrointestinal systems are not uncommon. Pneumonectomy in dogs results in secondary changes in the remaining lung, which include: decreased compliance and vital capacity; and increased pulmonary vascular resistance potentially leading to right ventricular hypertrophy. Such alterations make the anesthetic management of an animal with one lung particularly challenging. This report describes a dog with a history of left pneumonectomy due to Aspergillus fumigatus pneumonia 3 yr before presentation. The dog presented with a vaginal wall prolapse, and surgical resection of the protruding vaginal wall, ovariectomy, and prophylactic gastropexy were performed. Anesthesia was induced with midazolam, fentanyl, and propofol and was maintained with isoflurane using intermittent positive pressure ventilation and a constant rate infusion of fentanyl. Epidural anesthesia was also used. Recovery and postoperative management were uncomplicated. Intensive hemodynamic and respiratory monitoring and appropriate response and treatment of any detected abnormalities, taking into consideration the pathophysiologic alterations occurring in a pneumonectomized animal, are required for successful perianesthetic management.     

Bilateral intracorporeally sutured inguinal herniorrhaphy using 3-dimensional laparoscopy in a dog

A 7-month-old, intact male, mixed breed dog with bilateral inguinal hernias underwent general anesthesia for laparoscopic bilateral inguinal herniorrhaphy via a 3-port approach. A 3-dimensional laparoscopic system was used to perform the procedure immediately following prescrotal open castration. Intracorporeal suturing with polypropylene was performed, and 2 cruciate sutures were placed to close each inguinal ring. The caudal aspect of each inguinal ring was left slightly open so as not to disrupt the passage or patency of vessels and nerves. No intra- or post-operative complications occurred. One year after surgery, the dog has no evidence of recurrence of the inguinal hernias.Key clinical message:This case report demonstrates a novel minimally invasive approach to inguinal herniorrhaphy in a dog with no reported complications and a good long-term outcome. Intracorporeally sutured inguinal herniorrhaphy is feasible in dogs with good results, although additional cases are needed to gain experience with this technique in dogs with varying presentations of inguinal hernias.     

Development of hypoparathyroidism after excision of laryngeal rhabdomyosarcoma in a dog

An uncommon neoplasm of the larynx, rhabdomyosarcoma, was diagnosed in a 6-year-old 14-kg neutered female Spitz. In addition to the progressive onset of expected clinical signs of the tumor (exercise intolerance, respiratory stridor, inability to bark), the dog experienced hyperthermic crisis. Laryngectomy was successful in eradicating the local neoplastic tissue; however, unusual postoperative complications developed and included acute complications of pharyngotracheal fistula and hypoparathyroidism, and long-term complications of periodic collapse of the tracheal stoma and intolerance to heat. Probable causes and successful management of these complications are described. At 22 months after laryngectomy, the dog was admitted for a solitary hepatic metastasis. While hospitalized, the dog died of apparent asphyxiation attributable to stoma collapse.     

Implantation of permanent transvenous endocardial pacemaker in a dog with atrioventricular block

A 10-year old male mongrel dog was presented to the University Veterinary Teaching Hospital with a two-month history of episodic syncope. Twenty-four hr Holter electrocardiographic (ECG) recording revealed frequent episodes of advanced atrioventriculer block with long periods of ventricular asystole. The cause of syncope was determined to be Adams-Stokes syndrome exhibited bradyarrhythmia. After the animal failed to respond to medical therapy, permanent transvenous pacemaker implantation was performed. Postoperative Holter ECG showed 100 beat per min programmed pacemaker rhythm, which indicated successful capture of the artificial pacing. The dog recovered smoothly from the operation and syncopal episodes completely disappeared. Six months after the surgery, no complications were observed and the dog's quality of life has dramatically improved.     

Thoracoscopic Subphrenic Pericardectomy Using Double‐Lumen Endobronchial Intubation for Alternating One‐Lung Ventilation

Objective— To report the technique, complications, and effectiveness of thoracoscopic subphrenic pericardectomy (SPP) using double‐lumen endobronchial intubation for alternating 1‐lung (OLV) in healthy dogs. Study Design— Prospective cohort study. Animals— Mature purpose‐bred dogs (n=7). Methods— Bronchoscope‐assisted placement of a left‐sided double‐lumen endobronchial tube, immediately before surgery, allowed intraoperative alternation of ventilation between lung fields. A camera portal was established in a subxyphoid location. Two instrument portals were established at the 4th–6th intercostal spaces on the right and left sides. A vessel‐sealing device was used to create the subphrenic pericardectomy. After termination of the procedure, dogs were humanely euthanatized under anesthesia and necropsy performed. In each dog, the extent of pericardectomy and any complications were evaluated. Results— Technical difficulties with tube placement occurred in 4 dogs, but alternating OLV was achieved in all dogs and SPP completed successfully. Median surgical time was 87.5 minutes (range, 80–105 minutes). At necropsy, 0.5–2 cm of pericardial tissue remained ventral to the intact phrenic nerve in 6 dogs; in 1 dog, the phrenic nerve was transected on the left side only. Conclusions— Thoracoscopic subphrenic pericardectomy is a technically feasible procedure in healthy dogs. Double‐lumen endobronchial intubation allowed alternating OLV without intraoperative bronchoscopically guided tube manipulation in all but 1 dog. Clinical Relevance— Thoracoscopic subphrenic pericardectomy could potentially be used for management of conditions where relief of pericardial constriction or access to intrapericardial structures is desired.     

Severe haemoptysis associated with seizures in a dog

CASE HISTORY: A 7-year-old, sterilised male German Shepherd dog was presented with a history of three episodes of severe haemoptysis and associated dyspnoea within a 3-week period. A generalised tonic-clonic seizure was witnessed preceding the third episode. CLINICAL FINDINGS: Thoracic radiographs revealed a severe bilateral alveolar lung pattern of the caudodorsal lung fields; extension into the left cranial lung lobe was present but pulmonary vessels were within normal size limits. Frank blood was the only abnormality present at bronchoscopy. A coagulation profile, parasitological screening, thoracic and brain computed tomography (CT), and cerebrospinal fluid (CSF) cytological analysis did not identify any abnormalities. DIAGNOSIS: Haemoptysis due to either severe neurogenic pulmonary oedema or rupture of the pulmonary capillaries secondary to seizures was considered a possible diagnosis. The primary generalised seizures were attributed to late-onset idiopathic epilepsy diagnosed by exclusion of other causes. CLINICAL RELEVANCE: This is the first known case report describing severe haemoptysis associated with seizures in a dog.     

Anticoagulant effects of repeated subcutaneous injections of high doses of unfractionated heparin in healthy dogs.

OBJECTIVE: To evaluate s.c. administration of unfractionated heparin (UFH) in accordance with a dosing regimen for high-dose treatment in dogs. ANIMALS: 10 healthy adult Beagles. PROCEDURES: Two groups of dogs (5 dogs/group) were given 6 injections of heparin (500 units of UFH/kg of body weight, s.c.) at intervals of 8 (experiment 1) and 12 (experiment 2) hours. Blood samples were collected before and 4 hours after heparin injections to determine amidolytic heparin activity, activated partial thromboplastin time (APTT), thrombin time, antithrombin activity, platelet count, and Hct. RESULTS: For experiments 1 and 2, mean +/- SD heparin activities before (experiment 1, 1.32 +/- 0.20 U/ml; experiment 2, 0.69 +/- 0.174 U/ml) and 4 hours after the last heparin injection (experiment 1, 1.71 +/- 0.30 U/ml; experiment 2, 1.10 +/- 0.30 U/ml) were higher than values calculated for the regimen used in experiment 1. Results of the investigated thrombin time test system with low thrombin activity were frequently beyond the measurement range, even with UFH activities > or = 0.6 U/ml. Moreover, a severe decrease of antithrombin activity became evident during both experiments (eg, in experiment 2 from 95.6 +/- 4.8 to 59.2 +/- 6.6%). In each treatment group, 2 dogs developed hematomas. CONCLUSIONS AND CLINICAL RELEVANCE: Calculations of the course of heparin activity after a single injection do not result in a reliable dosing regimen for high-dose heparin treatment in dogs. High-dose treatment must be monitored for each dog. Thrombin time measured with low thrombin activity is unsuitable for this purpose.     

Pulmonary embolization of vascular occlusion coils in dogs with patent ductus arteriosus

Transcatheter coil embolization of patent ductus arteriosus (PDA) was performed in 206 dogs between 1994 and 2003 at Texas A&M University, of which 7 (3%) had embolization of coils to the pulmonary vasculature. Thoracic radiographs indicated that coils were located in the right pulmonary artery in 6 of the 7 dogs. Pulmonary perfusion scans were available for review in 5 dogs, and moderate perfusion defects were observed in the right caudal lung lobe in 4 dogs within 24 hours of embolization. Perfusion deficits observed initially in 2 of the dogs resolved on perfusion scans performed at 6 months and 3.1 years. One dog did not have evidence of focal perfusion defects on a perfusion scan performed 4.5 months after embolization. All pulmonary embolizations occurred during the procedure. Attempts at retrieval of coils were unsuccessful in the 2 dogs in which it was attempted. No short- or long-term clinical complications were observed in any of the dogs with pulmonary embolization. We conclude that pulmonary embolization of vascular occlusion coils is an uncommon event and is not typically associated with adverse clinical effects in dogs with PDA.     

Severe carpal and tarsal shearing injuries treated with an immediate arthrodesis in seven dogs

The medical records of seven dogs with severe, grade 3, open shearing wounds of the carpus or tarsus that were treated with an immediate arthrodesis were reviewed. Six dogs were managed with a transarticular external skeletal fixator (ESF), and one dog was treated with plate fixation. The soft tissues were managed simultaneously along with the definitive joint stabilization in all cases. Minor complications occurred in four dogs: one dog that required a skin graft, one dog in which a skin graft was recommended but not performed, one dog in which a secondary skin closure was performed, and one dog in which a delayed cancellous bone graft was placed. Major complications occurred in three dogs: two dogs that required restabilization of the arthrodesis and one dog that required implant (i.e., plate) removal due to infection. All dogs healed with acceptable functional and cosmetic results. Further long-term evaluation of five dogs revealed that all but one dog had either excellent or good functional outcomes, and the remaining dog had a fair outcome. Similarly, five dogs had either excellent or good cosmetic outcomes, with the remaining dog having a fair outcome. All owners were very satisfied with the overall results. This clinical study demonstrated that an immediate, definitive management technique, in which bone fusion and wound management are undertaken as simultaneous objectives, is a viable technique of managing severe periarticular shearing injuries. Transarticular stabilization with an ESF is the technique recommended.     

Bronchial stent placement in a dog with bronchomalacia and left atrial enlargement

A 13‐year‐old neutered male Maltese was referred for paroxysms of coughing and cyanosis, with radiographic evidence of bronchial disease and cardiomegaly. Investigation with echocardiography, bronchoscopy, fluoroscopy and bronchoalveolar lavage led to a diagnosis of myxomatous mitral valve degeneration with insufficiency, ISACHC class II heart failure and bronchomalacia with severe left mainstem bronchial collapse. Persistence of intractable cough despite medical therapy prompted placement of a stent in the left mainstem bronchus. Immediately after stent placement, severe pulmonary oedema developed, thought to be due to compression of the left atrium by the stent or acute lung injury related to stent placement. The dog recovered over a 3‐day period with diuretic therapy and positive end expiratory pressure ventilation. Subsequently, the dog died from congestive heart failure 102 days after stent placement, during which time occasional, self limiting coughing episodes occurred .     

Pneumopericardium associated with a pulmonary-pericardial communication in a dog

A 6-year-old 18-kg (39-lb) spayed female Standard Poodle was referred for treatment of pneumopericardium. The dog did not have severe clinical signs relating to the pneumopericardium, and the diagnosis was made incidentally while investigating the cause of a cough. Computed tomography revealed an air-filled structure consistent with a bulla to the right of the heart base that appeared to communicate with the pericardial cavity Because spontaneous resolution of the pneumopericardium seemed unlikely and cardiac tamponade was a possibility, exploratory thoracotomy was performed. A lobulated bulla was found at the hilus of the right middle lung lobe adhered to the underlying pericardial sac, and a 4-cm-diameter communication from the pericardium to the pulmonary bulla was found. Right middle lung lobectomy was performed, and the pericardiotomy and pericardial opening were sutured. The dog recovered without complications. In previously reported cases of pneumopericardium involving a cat and a dog, the condition resolved spontaneously. In this dog, in contrast, surgical resection of the affected lung lobe with pericardial reconstruction was required for resolution of the pneumopericardium.     

Immune-mediated thrombocytopenia associated with angiostrongylus vasorum infection in a Jack Russell terrier

A twenty-month-old Jack Russell terrier was presented with a four-day history of thrombocytopenia, echymotic inguinal haemorrhages, coughing and reduced exercise tolerance. Clinical examination revealed several petechial haemorrhages on the gingivae and small echymotic haemorrhages in the inguinal region, along with mild bilateral epistaxis. Haematology confirmed a platelet count of 1.0 × 10/L. Thoracic radiographs revealed a wide-spread mixed alveolar-interstitial lung pattern, apparent throughout the entire lungfield, but particularly marked within the left lung lobes. A presumptive diagnosis of immune-mediated thrombocytopenia was made and the dog was treated with vincristine and immunosuppressive doses of prednisolone. Initially anaemia developed following gastrointestinal haemorrhage; however, after symptomatic treatment the dog showed a marked clinical improvement. Evaluation for an underlying cause of the disease revealed Angiostrongylus vasorum L1 larvae on faecal analysis and treatment with fenbendazole was commenced. The dog made a full clinical recovery with all treatment was withdrawn within five weeks of diagnosis. This is the second report of immune-mediated thrombocytopenia associated with Angiostrongylus vasorum infection and it is the first to be successfully managed. The report highlights that Angiostrongylus vasorum should be considered in young dogs presented with thrombocytopenia.     

Bronchogenic cyst in a German shepherd dog

Intermittent episodes of fever, severe dyspnoea and cyanosis were observed in a two-and-a-half-year-old male German shepherd dog. The clinical signs were of sudden onset but disappeared within eight hours, in five almost identical episodes over a period of 40 days. Radiological examination of the thorax revealed a large rounded area of radiolucency surrounded by a thin radiopaque structure. The lesion increased in volume between examinations, but otherwise remained similar in appearance. It could not be confirmed from the radiographs whether the structure was situated in lung tissue or mediastinum. Bronchoscopic examination revealed no abnormal findings and there was no bacterial growth from samples taken 30 days after the onset of symptoms. A large, vesicular structure, partly adherent to the mediastinum, was surgically removed from the left cranial lung lobe. The structure was 8 to 10 cm in diameter and partly filled with mucoid pink fluid. Histological examination revealed that the wall contained traces of bronchial epithelial cells. On bacteriological examination of the fluid, Gram-positive, mucus-forming bacteria were present. The definitive gross pathological and histopathological diagnosis was a bronchogenic cyst which had developed secondarily to bronchiectasis. Bronchitis and peribronchitis were also identified. The dog recovered well after surgery and, at the time of writing, was in active duty as a police dog, showing no signs of respiratory illness.     

The use of an implantable central venous (Hickman) catheter for long-term venous access in dogs undergoing bone marrow transplantation.

Methods were developed for the insertion and maintenance of long-term central venous catheters in dogs in order to provide reliable venous access during bone marrow transplantation. Single-lumen, 9.6 Fr Hickman catheters with a VitaCuff were used. The catheter was inserted into the jugular vein via a surgical cut-down, and tunnelled subcutaneously to exit over the thoracic spine. Fluoroscopic guidance was necessary to ensure proper positioning of the catheter tip in the right atrium. The catheter was secured at the venous entrance site with a grommet and at the cutaneous exit site with a finger-cuff suture. The exit site was bandaged; dressings were changed daily. Five dogs were studied. Catheter insertion and maintenance techniques were developed using two dogs. For the other three dogs, which developed 7 wk of profound myelosuppression induced by total body irradiation, the catheters were used for blood sampling and infusions of antibiotics, fluids, and blood products. For these three dogs there were 261 total catheter-days. Complete catheter obstruction did not occur. Partial obstruction (inability to withdraw blood) occurred for 13 days with one catheter. The tip of this catheter was in the cranial vena cava. One irradiated dog had a staphylococcal exit site infection for several days after catheter insertion, which resolved with antibiotic therapy. Infections of the subcutaneous tunnel, and catheter associated bacteremia, were not identified. Infectious and hemorrhagic complications of myelosuppression were less severe than in six other dogs where intermittent venipuncture was used for vascular access during radiation induced myelosuppression. In conclusion, long-term central venous catheterization is feasible in dogs during profound myelosuppression and markedly facilitates patient management.     

Pharmacokinetics and pharmacodynamics of a therapeutic dose of unfractionated heparin (200 U/kg) administered subcutaneously or intravenously to healthy dogs

BACKGROUND: Heparin treatment has been recommended for dogs in hypercoagulable states such as disseminated intravascular coagulation, however, potential benefits have to be balanced against the bleeding risk if overdosage occurs. A better understanding of the pharmacology of heparin and tests to monitor heparin therapy in dogs may help prevent therapeutic hazards. OBJECTIVES: The purpose of this study was to evaluate the effects of 200 U/kg of sodium unfractionated heparin (UFH) on coagulation times in dogs after intravenous (IV) and subcutaneous (SC) administration and to compare these effects with plasma heparin concentrations assessed by its antifactor Xa (aXa) activity. METHODS: 200 U/kg of UFH were administered IV and SC to 5 healthy adult Beagle dogs with a washout period of at least 3 days. Activated partial thromboplastin time (APTT), prothrombin time (PT), and plasma aXa activity were determined in serial blood samples. RESULTS: After IV injection, PT remained unchanged except for a slight increase in 1 dog; APTT was not measurable (>60 seconds) for 45-90 minutes, and then decreased gradually to baseline values between 150 and 240 minutes. High plasma heparin concentrations were observed (maximal concentration = 4.64 +/-1.4 aXa U/mL) and decreased according to a slightly concave-convex pattern on a semilogarithmic curve, but returned to baseline slightly more slowly (t240-t300 minutes) than did APTT. After SC administration, APTT was moderately prolonged (by a ratio of 1.55 +/-0.28 APTT t0, range 1.35-2.01) between 1 and 4 hours after administration. Plasma aXa activity reached a maximum of 0.56 +/-0.20 aXa U/mL (range 0.42-0.9 U/mL) after 132 +/-26.8 minutes; this lasted for 102 +/-26.8 minutes. Prolongation of APTTs of 120-160% corresponded to plasma heparin concentrations of 0.3-0.7 aXa U/mL. CONCLUSIONS: As in humans, the pharmacokinetics of UFH in dogs was nonlinear. Administration of 200 U/kg of UFH SC in healthy dogs resulted in sustained plasma heparin concentrations in accordance with human recommendations for thrombosis treatment or prevention, without excessively increased bleeding risks. In these conditions, APTT can be used as a surrogate to assess plasma heparin concentrations. These findings need to be confirmed in diseased animals.