Contributions of biogenic material to the atmospheric ice-nucleating particle population in North Western Europe.

A minute fraction of atmospheric particles exert a disproportionate effect on the phase of mixed-phase clouds by acting as ice-nucleating particles (INPs). To understand the effects of these particles on weather and climate, both now and into the future, we must first develop a quantitative understanding of the major INP sources worldwide. Previous work has demonstrated that aerosols such as desert dusts are globally important INPs, but the role of biogenic INPs is unclear, with conflicting evidence for their importance. Here, we show that at a temperate site all INPs active above -18 °C at concentrations >0.1 L-1 are destroyed on heating, consistent with these INPs being of biological origin. Furthermore, we show that a global model of desert dust INPs dramatically underestimates the measured INP concentrations, but is consistent with the thermally-stable component. Notably, the heat sensitive INPs are active at temperatures where shallow cloud layers in Northern Europe are frequently observed to glaciate. Hence, we suggest that biogenic material is important for primary ice production in this region. The prevalence of heat sensitive, most likely biogenic, INPs in this region highlights that, as a community, we need to quantify the sources and transport of these particles as well as determine their atmospheric abundance across the globe and at cloud altitudes.

Evaluation of toxicities from combined metronomic and maximal-tolerated dose chemotherapy in dogs with osteosarcoma.

OBJECTIVE: To evaluate the tolerability of a piroxicam and cyclophosphamide metronomic treatment protocol combined with carboplatin alone or carboplatin and doxorubicin at maximal-tolerated doses. METHODS: Retrospective study of 30 dogs diagnosed with osteosarcoma. All dogs underwent amputation and chemotherapy treatment with one of the two maximal-tolerated dose protocols. Metronomic chemotherapy was administered in conjunction with these protocols, and continued subsequently. The protocols included 0 · 3 mg/kg piroxicam and 10 to 12 mg/M(2) cyclophosphamide with 300 mg/M(2) carboplatin alone, or 300 mg/M(2) carboplatin alternating with 30 mg/M(2) doxorubicin. RESULTS: Fourteen dogs were treated with the carboplatin and metronomic protocol and 16 were treated with the carboplatin alternating with doxorubicin and metronomic protocol. Grades 3 and 4 toxicities overall were significantly (P = 0 · 018) more common in the former group. The disease-free interval of the carboplatin and metronomic group was 192 days, which was not significantly different (P = 0 · 916) to the 182 days for the carboplatin alternating with doxorubicin and metronomic group. The median survival times of the two groups were 217 and 189 days, respectively. CLINICAL SIGNIFICANCE: Piroxicam and cyclophosphamide metronomic protocols can be safely administered in combination with maximal-tolerated dose chemotherapy protocols. A significantly higher frequency of toxicities was observed in dogs treated with the carboplatin and metronomic protocol.

A retrospective analysis of the efficacy of Oncept vaccine for the adjunct treatment of canine oral malignant melanoma.

Oral malignant melanoma (OMM) in the dog is often locally aggressive with a high metastatic potential and there are few treatment options that have been demonstrated to improve outcome of this disease. The purpose of this study was to determine whether adjunctive treatment with the Oncept melanoma vaccine affected the outcome of dogs with OMM that had achieved loco-regional cancer control. Medical records from 45 dogs that presented to the Animal Cancer and Imaging Center were reviewed, including 30 dogs with stage II and III disease. Dogs that received the vaccine did not achieve a greater progression-free survival, disease-free interval or median survival time than dogs that did not receive the vaccine.

Esophageal duplication cyst in a dog.

A cranial cervical mass was surgically removed from a dog. On histologic examination, the mass was consistent with an esophageal duplication cyst, a condition rare in humans and not reported in the dog.

Mandibular and sublingual sialocoeles in the dog: a retrospective evaluation of 41 cases, using the ventral approach for treatment.

AIMS: To review results of the ventral approach for mandibular and sublingual sialoadenectomy for the treatment of sialocoeles associated with the mandibular and sublingual salivary glands in the dog, and to determine rates of recurrence and complication following this procedure. METHODS: Thirty-nine dogs with 41 sialocoeles that underwent surgical intervention were retrospectively evaluated with respect to signalment, aetiology, location of sialocoeles, duration of clinical signs, treatment prior to referral, post-operative use of antibiotics and drains, complications, and recurrence. RESULTS: The mean age at the time of surgery was 5.1 (SD 3.8) years, and duration of clinical signs 6.6 (SD 10.6) months. Long-term follow-up was available for 31 dogs; the minimum was 8 months and mean 47.7 (SD 25.8) months post-surgery. There was no recurrence of sialocoeles following the ventral approach for mandibular and sublingual sialoadenectomy. Postoperatively, 6/35 (17%) cases developed a seroma at the surgical site. No breed or sex predisposition was determined. The cause of the sialocoele was unknown in 36/41 (88%) cases. CONCLUSIONS AND CLINICAL RELEVANCE: Excellent clinical results were achieved with a low rate of complications using the ventral approach for mandibular and sublingual sialoadenectomy. The ventral approach is recommended to minimise the risk of recurrence of sialocoeles.

A urethropexy technique for surgical treatment of urethral prolapse in the male dog.

Urethral prolapse is an uncommon condition affecting young male dogs, most commonly English bulldogs. Current described techniques for surgical treatment of urethral prolapse involve manual reduction of prolapsed mucosa and placement of a temporary purse-string suture at the penile tip, or resection of the prolapsed tissue and apposition of urethral and penile mucosa. The incidence of recurrence of urethral prolapse following resection of the prolapse is not known. This report describes a technique for surgical treatment of urethral prolapse in the male dog that minimizes surgical and anesthetic time, is simple to perform, requires minimal equipment, is effective, and is not associated with significant complications or recurrence. Three cases are described.

Intracellular magnesium concentrations in dogs with gastric dilatation-volvulus.

OBJECTIVE: To quantify and compare intracellular magnesium concentrations (Mgi) in clinically normal dogs (control dogs) and dogs that have gastric dilatation-volvulus (GDV dogs) and to determine whether there is a difference in Mgi and serum magnesium concentrations (Mgs) between GDV dogs with and without cardiac arrhythmias. ANIMALS: 41 control dogs and 21 GDV dogs. PROCEDURE: Rectus abdominis muscle specimens were obtained from control and GDV dogs for determination of Mgi. Blood samples were obtained from GDV dogs for determination of Mgs, and dogs were monitored for 48 hours for cardiac arrhythmias. Muscle specimens were frozen at -40 C, oven dried at 95 C, and digested with concentrated nitric acid. Multielemental analyses were performed by simultaneous/sequential inductively coupled plasma-atomic emission spectroscopy with fixed-cross flow nebulization. The Mg, was standardized to sulfur content to correct for the amount of fat and fascia in the muscle specimen. Mean (+/- SEM) values were recorded in parts per million (ppm). Results-There were no significant differences in Mgi between control (627 +/- 11.1 ppm) and GDV (597 +/- 20.5 ppm) dogs, in Mgi between GDV dogs with (590 +/- 34 ppm) and without (584 +/- 29 ppm) cardiac arrhythmias, and in Mgs between GDV dogs with (1.77 +/- 0.26 ppm) and without (1.51 +/- 0.09 ppm) cardiac arrhythmias. There was no correlation between Mgs and Mgi (R2 = 0.0001). CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate that Mg depletion is not pathophysiologically important in dogs with GDV and does not play a role in the cardiac arrhythmias detected in these patients.

Evaluation of a free vascularized medial tibial bone graft in dogs.

OBJECTIVE: To develop a free vascularized tibial bone graft based on the periosteal saphenous blood supply. STUDY DESIGN: Preliminary anatomic study of medial tibial blood supply. In vivo comparison of a vascularized and avascular tibial bone graft. ANIMALS: Nine canine cadavers; 14 healthy adult dogs that weighed 25 to 32 kg. METHODS: An anatomic study of the vascular supply of the medial aspect of the tibia was performed using the Spalteholz technique. A bone graft consisting of the medial aspect of the tibia was transferred to a mandibular defect as a vascularized graft in 7 dogs and as an avascular graft in 7 dogs. Bone scans were performed to evaluate graft perfusion. Radiographic evaluation of the mandibles and tibias was performed. The dogs were killed after 60 days, five mandibles from each group were examined histologically, and two from each group were evaluated using the Spalteholz technique. RESULTS: The saphenous vascular pedicle provides vascular perfusion to the medial tibial cortex. Bone scans and radiographic evaluations were consistent with viable bone in the vascularized grafts, and nonviable bone in the avascular grafts. Histological examination revealed live, healing bone in vascular grafts and necrotic bone in avascular grafts. Spalteholz evaluation revealed many small arborizing vessels in the vascular grafts and no organized vasculature in the avascular grafts. CONCLUSIONS: The vascularized medial tibial cortical bone graft survived and proceeded to bony union in the mandibular body defect more readily than the avascular graft in this experimental model. CLINICAL RELEVANCE: A vascularized medial tibial bone graft is a suitable free graft for use in reconstructing bone defects in dogs.

Microvascular free tissue transfer: results in 57 consecutive cases.

OBJECTIVE: To evaluate the outcomes and complications in a consecutive series of animals undergoing microvascular reconstructive procedures at two veterinary institutions. STUDY DESIGN: Retrospective study. ANIMALS OR SAMPLE POPULATION: A total of 44 client-owned dogs and one red-necked wallaby. METHODS: The medical records of all animals undergoing reconstructive microsurgical procedures at the Western College of Veterinary Medicine and Michigan State University were reviewed. Microvascular flap survival and related complications were described. Statistical analysis was performed to determine the significance of relationships between operative factors and outcome. RESULTS: A total of 57 microvascular procedures were performed on 55 animals. Reconstruction was required after trauma in 42 animals, after ablative cancer surgery in 11 animals and for correction of congenital tissue aplasia in I animal. Donor tissues included the superficial cervical cutaneous, medial saphenous fasciocutaneous or musculofasciocutaneous, caudal superficial epigastric cutaneous, trapezius muscle or musculocutaneous, caudal sartorius muscle, latissimus dorsi muscle or musculocutaneous, cranial abdominal myoperitoneal, carpal footpad, digital footpad, and vascularized ulnar bone flaps. A total of 53 of 57 flaps (93%) survived. There was a significant relationship between flap failure and level of assistant surgeon experience (P < .05). Latissimus dorsi flaps were significantly more likely to fail when compared with pooled data from all other flap types (P < .01). CONCLUSIONS: The success of microvascular tissue transfer in this case series compares favorably with those reported in human reconstructive microsurgery. Both the primary and assistant surgeon should be practiced in microsurgical technique. Failure of latissimus dorsi flaps was not likely caused by an inherently deficient flap design, but was more likely attributed to the location and severity of trauma at the recipient site, the difficulty in isolating suitable recipient vessels for anastomosis or the absence of a trained assistant surgeon during these procedures. Clinical Relevance-This retrospective study documents the successful application of microvascular technique in a series of clinical cases requiring tissue reconstruction.

Surgical correction of late-onset Budd-Chiari-like syndrome in a dog.

An 18-month-old dog was examined because of ascites of 1 month's duration. Typical causes of ascites, including hepatic failure, heart failure, and protein-losing enteropathy, were ruled out. The dog's history included being hit by a car 6 months earlier, and the caudal vena cava had an S shape on thoracic radiographs. In addition, the abdominal fluid had a high protein concentration and low cellular content. These findings were all consistent with a diagnosis of postsinusoidal hypertension secondary to obstruction of hepatic venous outflow (Budd-Chiari-like syndrome). During exploratory thoracotomy, the pericardium appeared to have been torn from the heart and was partially wrapped around the caudal vena cava, causing a constriction. The pericardium was removed and the dog recovered without any further complications. Blunt trauma has been previously reported to cause kinking of the caudal vena cava and Budd-Chiari-like syndrome in dogs; but in these dogs, clinical signs of ascites developed a few days to several weeks after the traumatic incident. It appears that, depending on the cause of the hepatic venous outflow obstruction, onset of Budd-Chiari-like syndrome may be delayed for months.

Evaluation of the sensitivity and specificity of diagnostic criteria for sepsis in dogs.

OBJECTIVE: To evaluate the ability of various individual criteria and grouped criteria to diagnose sepsis in dogs. STUDY DESIGN: Prospective acquisition of clinical data. ANIMALS OR SAMPLE POPULATION: Client-owned dogs; 30 septic and 320 nonseptic. METHODS: Rectal temperature, heart rate, respiratory rate, white blood cell (WBC) count with percent bands, platelet count, and serum glucose concentration were obtained on day 0. True sepsis was determined on days 0 to 3 according to the following criteria: (1) histological, microbiological, and/or gross confirmation of infection, and (2) systemic illness caused by infection. Data were analyzed by the Mann-Whitney U test and multiple logistic regression. Sensitivity and specificity were calculated. RESULTS: The mean temperature, heart rate, WBC count, and percent bands were greater, whereas the mean platelet count was less in septic compared with nonseptic dogs. There was no difference in respiratory rate or glucose concentration. WBC/bands were the best individual criterion for the diagnosis of sepsis (sensitivity 87%; specificity 69%). The sensitivity and specificity of the grouped criteria (> or = two of four; temperature, heart rate, respiratory rate, WBC) varied according to ranges of normal used. Multiple logistic regression resulted in little improvement in the sensitivity/specificity of these diagnostic criteria for the diagnosis of sepsis. CONCLUSIONS: These criteria are useful for the diagnosis of sepsis when limits are used that result in a high sensitivity (e.g., 97%). The high sensitivity was associated with a low false-negative and a high false-positive rate; sepsis was overdiagnosed with these grouped criteria. CLINICAL RELEVANCE: These criteria may be used for a sensitive, but nonspecific, diagnosis of sepsis in dogs.

Medial saphenous fasciocutaneous and myocutaneous free flap transfer in eight dogs.

Skin defects on the distal extremity (n = 7) or face (n = 1) of eight dogs were repaired using a medial saphenous fasciocutaneous or myocutaneous flap. The cause of the wounds were ablative oncological surgery (n = 4), trauma (n = 3), or radiation burn (n = 1). The flap was removed from the medial femorotibial region, and transferred to the wound bed. The vascular supply to the flap was reestablished via microvascular anastomosis of the medial saphenous vessels of the flap to recipient vessels isolated adjacent to the wound. Three flaps incorporated the distal half of the caudal head of the sartorius muscle to form a myocutaneous free flap. All flaps survived completely. The medial saphenous fasciocutaneous and myocutaneous free flaps were found to be reliable and cosmetically acceptable for repair of skin defects in dogs.

Association of perianal fistula and colitis in the German shepherd dog: response to high-dose prednisone and dietary therapy.

Twenty-seven German shepherd dogs with perianal fistulas and histological evidence of colitis were entered in a prospective clinical study to investigate the association between perianal fistula and colitis. Additionally, the response of perianal fistula disease to immunosuppressive doses of prednisone and an alternative protein diet was evaluated. All 27 cases completed the treatment protocol, and perianal fistulas completely resolved in nine (33.3%) cases, improved in nine cases, and remained unchanged in nine cases.

Myoperitoneal microvascular free flaps in dogs: an anatomical study and a clinical case report.

The purpose of the anatomical study was to identify potential myoperitoneal microvascular free flaps, in dogs, that are based on a single artery and vein. The angiosomes of the right deep circumflex iliac artery and left phrenicoabdominal (cranial abdominal) artery were evaluated in six medium-sized canine cadavers. The right deep circumflex iliac artery and left phrenicoabdominal (cranial abdominal) artery were injected with a mixture of barium and latex (equal parts). The entire right and left transversus abdominis muscles were dissected from the abdominal wall and radiographed. The angiograms of the deep circumflex iliac artery showed poor arborization of the vessels within the transversus abdominis muscle in all six cadavers. The angiograms of the phrenicoabdominal (cranial abdominal) artery showed consistent filling of the vascular bed of the cranial half of the transversus abdominis muscle flap in all six dogs. The vascular pedicle lengths and the diameter of the arteries and veins of both the deep circumflex iliac and phrenicoabdominal (cranial abdominal) myoperitoneal free flaps were found to be acceptable for microvascular anastomosis. The deep circumflex iliac flap was unacceptable because of inadequate vascular perfusion. The cranial abdominal artery had a consistent, large branch that supplied the cranial half of the transversus abdominis muscle, thereby making a myoperitoneal flap supplied by this vessel a potentially useful free flap. An 8-year-old male, neutered, mixed-breed dog was evaluated for possible repair of a large defect of the hard palate. Previous operations, using local tissue flaps, had been unsuccessful. A myoperitoneal free flap, based on the right cranial abdominal artery, and consisting of the cranial portion of the transversus abdominis muscle, was used successfully to reconstruct the hard palate. Migrating epithelium from the edges of the wound covered the myoperitoneal flap by 10 weeks after surgery. Therefore, the cranial abdominal myoperitoneal free flap can be considered for reconstruction of intra-oral defects that cannot be repaired using conventional local flap techniques.

Evaluation of the cranial rectus abdominus muscle pedicle flap as a blood supply for the caudal superficial epigastric skin flap in dogs.

This study evaluates the cranial rectus abdominus muscle pedicle flap as the sole blood supply for the caudal superficial epigastric skin flap. This flap was composed of a cranially based rectus abdominus muscle pedicle flap that was attached to the caudal superficial epigastric island skin flap (including mammary glands 2 to 5) via the pudendoepigastric trunk. Selective angiography of the cranial epigastric artery in eight cadaver dogs proved that the arterial vasculature in the cranial rectus abdominus was contiguous with that in the caudal superficial epigastric skin flap. In the live dog study, three of six of the flaps failed because of venous insufficiency. Necrosis of mammary gland 2 occurred in two of six flaps. One of six flaps survived with the exception of the cranial most aspect of mammary gland 2. Angiography of the cranial epigastric artery proved that arterial blood supply to these flaps was intact. Histological evaluation of the failed flaps showed full-thickness necrosis of the skin and subcutaneous tissues, the presence of severe congestion, and venous thrombosis. Retrograde venous blood flow through the flap was inconsistent, and hence resulted in failure of this myocutaneous flap. Use of this flap for clinical wound reconstruction cannot be recommended.

The medial saphenous fasciocutaneous free flap in dogs.

The purpose of this study was to identify the angiosome of the medial saphenous artery and vein and to evaluate the use of this cutaneous angiosome as a free skin flap in the dog. In phase 1 of this study, selective angiography of the medial saphenous artery performed in six canine cadavers showed that the skin covering the entire medial femorotibial area, the distal half of the caudal head of the sartorius muscle, and the gracilis muscle were perfused by the medial saphenous artery. In phase 2, a medial saphenous fasciocutaneous island flap was raised and sutured back to the skin edges of the donor wound in three dogs. One hundred percent survival of all of the flaps occurred. In phase 3, a medial saphenous fasciocutaneous microvascular free flap was transferred to a wound that was created over the dorsal metacarpal (n = 3) or metatarsal region (n = 3). The mean length +/- SD of the medial saphenous vascular pedicle was 80 +/- 13 mm (n = 5); the mean diameter +/- SD of the medial saphenous artery was 2.8 +/- 0.2 mm (n = 5) and the mean diameter +/- SD of the medial saphenous vein was 4.2 +/- 0.2 mm (n = 5). One hundred percent of all flaps survived (n = 6). Selective angiography or the distal cranial tibial artery (metatarsal wounds, n = 3) and the median artery (metacarpal wound, n = 3) was performed 3 weeks after surgery. All of the vascular anastomoses were patent and neovascularization of the wound beds was present. This free flap was found to be acceptable for cosmetic reconstruction of wounds located on the distal extremity.

Healing responses of the lower urinary tract.

Healing of the urinary tract follows a series of events similar to other epithelial surfaces. This process, however, occurs more rapidly in the urinary tract. A variety of factors that can affect the healing response of the urinary tract are presented in this article. It is important for the veterinarian to be aware of these factors so that the appropriate surgical or medical treatment can be provided to the patient to optimize the healing processes.

Gastric dilatation-volvulus after splenic torsion in two dogs.

Two dogs developed gastric dilatation-volvulus 2 and 17 months, respectively, after splenectomy for treatment of splenic torsion. Splenic displacement and torsion may stretch the gastric ligaments, allowing increased mobility of the stomach. After splenectomy, an anatomic void may be created in the cranioventral part of the abdomen, contributing to the mobility of the stomach. Veterinarians treating dogs with isolated splenic torsion may wish to consider prophylactic gastropexy at splenectomy, to reduce the chance of future gastric dilatation-volvulus. Prophylactic gastropexy should be done only if the dog's hemodynamic status is stable enough to allow for performance of the additional surgery.