Increased sacral screw purchase minimizes screw loosening in canine triple pelvic osteotomy

OBJECTIVE: To determine if screw loosening in triple pelvic osteotomies (TPO) is minimized when screws cranial to the ilial osteotomy had maximal sacral purchase. STUDY DESIGN: Prospective study. ANIMALS: Forty-six dogs with decreased acetabular coverage of the femoral head and minimal degenerative joint changes. METHODS: TPOs were performed where screws cranial to the ilial osteotomy were inserted to maximally engage sacral bone. Data collected were: use of ilial and ischial cerclage wire, screw length, ventrodorsal radiographic sacral width (most caudal aspect), pelvic canal diameter, and sacral penetration of the 3 cranial screws. On all subsequent radiographs, changes in screw position, pelvic canal diameter, and sacral purchase were noted. RESULTS: For 69 TPOs, 414 screws were used. Mean radiographic cranial screw length was 34.54 mm. Combined sacral depth of all 3 screws was 93.3% of sacral width. All osteotomies healed uneventfully. Twenty-four screws (6%) loosened with 12 being in the most cranial positions. Use of ischial or ilial cerclage wires did not statistically influence screw loosening. Pelvic diameter decreased by a mean of 7.79% from postoperative radiographs to the last radiographic recheck. CONCLUSIONS: By sufficiently engaging the sacrum with screws cranial to the ilial osteotomy, implant failures can be avoided and screw loosening minimized when a 6-hole TPO plate is used. CLINICAL RELEVANCE: To minimize screw-loosening in TPO, screws inserted cranial to the ilial osteotomy should be inserted to maximum sacral depth without penetrating the vertebral canal.     

Early detection and treatment of screw loosening in triple pelvic osteotomy

OBJECTIVE: To detect early screw loosening in triple pelvic osteotomy (TPO) and to evaluate the efficacy of retightening using fluoroscopic guidance and minimally invasive surgery to maintain acetabular alignment and achieve bone healing. STUDY DESIGN: Prospective clinical study. SAMPLE POPULATION: Sixteen dogs that had TPO. METHODS: Dogs (16) had TPO (21) by using pre-angled plates secured with 3.5 and 4.0 mm screws, with ischiatic or iliac cerclage, for osteosynthesis. In all but 1 TPO at least 1 screw was inserted into the sacral body (43 screws). The mean radiographic screw length inserted in the sacrum was 10.2 mm, and the mean percent sacral engagement was 22%. Dogs were examined clinically and radiographically immediately postoperatively, and at 10, 30, 60, and 90 days to evaluate screw position. Loose screws were retightened through stab incisions using fluoroscopy to locate the screw. RESULTS: TPO was performed without operative complications. At 10 days, 12 TPOs (57%; 11 dogs) had loose screws primarily located in the cranial aspect of the plate. This represented 20% (25) of the inserted screws. In 5 dogs, screw loosening resulted in medial rotation of the acetabular segment. All loose screws were retightened; 3 screws loosened again in 2 dogs and were detected at 60 days. However, the osteotomies healed with the planned acetabular rotation without further intervention. Screw tightening corrected the acetabular segment displacement. Screws correctly seated at 10 days did not subsequently loosen. Clinical and radiographic outcome was judged excellent in all dogs. CONCLUSION: Loose screws in TPO plates can be identified by 10 days postoperatively and retightened using fluoroscopic guidance to achieve acetabular realignment and healing without need for further surgery. CLINICAL RELEVANCE: Postoperative radiographic evaluation of screw position at 10 days after TPO is recommended to detect loose screws. Retightening loose screws should be considered as an alternative to TPO revision or confinement, especially in immature dogs.     

Results of single-session bilateral triple pelvic osteotomy with an eight-hole iliac bone plate in dogs: 95 cases (1996-1999)

OBJECTIVE: To evaluate feasibility of single-session bilateral triple pelvic osteotomy with 8-hole iliac bone plates in dogs with bilateral hip dysplasia. DESIGN: Retrospective study. ANIMALS: 95 dogs with bilateral hip dysplasia. PROCEDURE: Medical records were reviewed, and information was obtained on signalment; body weight; angles of subluxation and reduction prior to surgery; durations of surgery and hospitalization; postoperative mobility; severity of lameness, radiographic grade of hip dysplasia, Norberg angle, and femoral head coverage before and after surgery; time required for radiographic evidence of iliac healing; change in pelvic diameter; implant integrity; and complications. RESULTS: Mean age at the time of surgery was 10.8 months, and mean weight was 35.2 kg (77.4 lb). Prior to surgery, mean angles of subluxation were 2.2 degrees on the right and 2.6 degrees on the left; mean angles of reduction were 25.9 degrees on the right and 27.3 degrees on the left. Mean surgical time was 95 minutes. All but 1 dog were able to walk on their own by the fourth day after surgery. Mean hospitalization time was 7.5 days. Clinical signs of lameness and radiographic grade of hip dysplasia were significantly improved during follow-up examinations. Mean time for radiographic iliac healing was 8 weeks. None of the plates and only 7 of the 1,520 (0.5%) screws loosened after surgery. Nineteen dogs had complications, but all complications were minor. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that single-session bilateral triple pelvic osteotomy with 8-hole iliac bone plates is effective for treatment of dogs with bilateral hip dysplasia.     

Risk factors for screw migration after triple pelvic osteotomy

The objective of this retrospective study was to identify risk factors for screw migration after triple pelvic osteotomy (TPO) in clinical patients. The medical records, radiographs made immediately after surgery, and follow-up radiographs documenting a healed osteotomy were reviewed for 52 dogs treated with unilateral TPO and 38 dogs treated with bilateral TPO. Signalment, surgeon expertise, length of surgery, sequence of surgery in dogs treated bilaterally, use of ischial or ilial wires or both, screw depth in the sacrum, and screw migration were documented for each of the 128 pelvic osteotomies. Screws placed in the first and second plate hole, securing the cranial portion of the plate, loosened most frequently. Factors associated with decreased screw migration included use of an ischial hemicerclage wire and increased depth of sacral purchase with the first and second cranial screws.     

Acetabular ventroversion with double pelvic osteotomy versus triple pelvic osteotomy: a cadaveric study in dogs

Objective: To determine which of 3 different plate angles (20°, 25°, 30°) used in double pelvic osteotomy (DPO) would result in the most similar acetabular angle (AA) achieved with a 20° triple pelvic osteotomy (TPO) technique in dogs. Study Design: Experimental anatomic study. Animals: Cadaveric canine pelves (n=8). Methods: Transverse plane computed tomographic images of cadaveric pelves with intact sacroiliac joints, mounted in a custom jig, were made (baseline) and again after DPO (20°, 25°, 30°) and TPO (20°) and pelvic angles measured in 6 transverse planes. Pelvic angles of the 3 DPO techniques were compared with TPO using concordance correlation to determine which DPO angle resulted in an acetabular ventroversion angle closest to TPO. Results: Mean ± SD AAs were 32.89 ± 2.23 (baseline), 47.39 ± 4.39 (20° DPO), 51.43 ± 5.06 (25° DPO), 54.75 ± 4.38 (30° DPO), and 50.20 ± 5.76 (20° TPO). Concordance correlations for the AA compared with 20° TPO were 0.027 (baseline), 0.721 (20° DPO), 0.902 (25° DPO), and 0.593 (30° DPO). A concordance correlation of ≥0.8 indicates good correlation. Conclusions: A 25° DPO is most similar in acetabular ventroversion to 20° TPO (concordance correlation, 0.902).     

Zinc intoxication in dogs: 19 cases (1991-2003)

OBJECTIVE: To determine physical examination findings, clinicopathologic changes, and prognosis in dogs with zinc toxicosis. DESIGN: Retrospective case series. ANIMALS: 19 dogs with zinc toxicosis. PROCEDURES: Medical records from 1991 through 2003 were searched for animals with a diagnosis of zinc toxicosis. Information concerning signalment, body weight, historical findings, initial owner complaints, physical examination findings, clinicopathologic findings, blood zinc concentrations, source of zinc, treatments given, duration of hospital stay, and outcome was collected. RESULTS: Records of 19 dogs with zinc toxicosis were reviewed.The most common historical findings were vomiting (n = 14) and pigmenturia (12). The most common clinicopathologic findings were anemia (n = 19) and hyperbilirubinemia (12). Median age was 1.3 years, and median weight was 5.6 kg (12.3 lb). The prognosis was favorable, with 17 dogs surviving after a median hospital stay of 2 days. CONCLUSIONS AND CLINICAL RELEVANCE: Hemolytic anemia as a result of zinc toxicosis appeared to affect young small-breed dogs more frequently than older large-breed dogs. The prognosis with treatment is good, and most affected dogs had a short hospital stay.     

Nonhealing corneal ulcers in cats: 29 cases (1991-1999)

OBJECTIVE: To compare mean healing times after debridement, debridement with grid keratotomy, and superficial keratectomy in cats with nonhealing corneal ulcers. DESIGN: Retrospective study. ANIMALS: 29 cats with 36 nonhealing corneal ulcers. PROCEDURE: Medical records of cats with nonhealing corneal ulcers were reviewed. Signalment, duration of clinical signs, ophthalmic abnormalities, and response to various treatment protocols were recorded. RESULTS: Mean age of affected cats was 7 years, 8 months. Affected breeds included domestic shorthair (17 cats), Persian (9), Himalayan (2), and Siamese (1). Clinical signs were evident for approximately 2 weeks prior to referral. Both eyes were affected in 4 cats. Mean healing time of ulcers treated with superficial debridement was 30 days. Mean healing time of ulcers treated with superficial debridement and grid keratotomy was 42 days. Superficial keratectomy was performed on 2 eyes and resulted in a healing time of 2 weeks. Formation of a corneal sequestrum was evident in 2 of 21 eyes treated with superficial debridement. Formation of a corneal sequestrum was evident in 4 of 13 eyes treated with superficial debridement and grid keratotomy. CONCLUSIONS AND CLINICAL RELEVANCE: Brachycephalic cats appear to be predisposed to developing nonhealing corneal ulcers. The combination of superficial debridement and grid keratotomy did not decrease mean healing time of nonhealing ulcers, compared with superficial debridement alone. Grid keratotomy may predispose cats with corneal ulcers to develop a corneal sequestrum.     

Evaluation of primary re-excision after recent inadequate resection of soft tissue sarcomas in dogs: 41 cases (1999-2004)

OBJECTIVE: To determine the efficacy of primary re-excision alone for treatment of soft tissue sarcomas after recent incomplete resection, the frequency and clinical importance of detecting residual tumor in resected scars, and prognostic factors associated with the procedure. DESIGN: Retrospective case series. ANIMALS: 41 dogs. PROCEDURES: Medical records of dogs that had undergone recent incomplete excision of a soft tissue sarcoma at a referring veterinary practice and subsequent re-excision of the scar at the Colorado State University Veterinary Medical Center were reviewed. Owners and referring veterinarians were contacted for follow-up information. Slides from re-excised specimens were reviewed. Dogs that underwent radiation therapy after the re-excision procedure were excluded. RESULTS: 41 dogs met the inclusion criteria, and long-term follow-up information was available for 39 dogs. Median follow-up time was 816 days. Local recurrence of tumor developed in 6 of 39 (15%) dogs, and distant metastasis occurred in 4 of 39 (10%) dogs. Healthy tissue margins of 0.5 to 3.5 cm were achieved at re-excision. Residual tumor was identified in 9 of 41 (22%) resected scars. No tumor-, patient-, or treatment-related variables were associated with local recurrence except for the presence of liposarcoma or fibrosarcoma or whether fine-needle aspiration had been performed prior to surgery. CONCLUSIONS AND CLINICAL RELEVANCE: After incomplete resection of soft tissue sarcomas, resection of local tissue should be performed, even if excisable tissue margins appear narrow. A long-term favorable prognosis is achievable without radiation therapy or amputation. The presence of residual tumor in resected scar tissue should not be used to predict local recurrence.     

Lung lobe torsion in dogs: 22 cases (1981-1999)

OBJECTIVE: To identify breed disposition, postoperative complications, and outcome in dogs with lung lobe torsion. DESIGN: Retrospective study. ANIMALS: 22 client-owned dogs. PROCEDURE: Information on signalment; history; clinical findings; results of clinicopathologic testing, diagnostic imaging, and pleural fluid analysis; surgical treatment; intra- and postoperative complications; histologic findings; and outcome were obtained from medical records. RESULTS: All 22 dogs had pleural effusion; dyspnea was the most common reason for examination. Fifteen dogs were large deep-chested breeds; 5 were toy breeds. Afghan Hounds were overrepresented, compared with the hospital population. One dog was euthanatized without treatment; the remaining dogs underwent exploratory thoracotomy and lung lobectomy. Eleven dogs recovered from surgery without complications, but 3 of these later died of thoracic disease. Four dogs survived to discharge but had clinically important complications within 2 months, including chylothorax, mediastinal mesothelioma, gastric dilatation, and a second lung lobe torsion. Six dogs died or were euthanatized within 2 weeks after surgery because of acute respiratory distress syndrome, pneumonia, septic shock, pneumothorax, or chylothorax. Chylothorax was diagnosed in 8 of the 22 dogs, including 4 Afghan Hounds. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that lung lobe torsion is rare in dogs and develops most frequently in large deep-chested dogs, particularly Afghan Hounds. Other predisposing causes were not identified, but an association with chylothorax was evident, especially in Afghan Hounds. Prognosis for dogs with lung lobe torsion was fair to guarded.     

5-Hydroxytryptophan toxicosis in dogs: 21 cases (1989-1999)

OBJECTIVE: To determine epidemiologic characteristics, clinical findings, and treatment outcome of 5-hydroxytryptophan (5-HTP) toxicosis in dogs. DESIGN: Retrospective study. ANIMALS: 21 dogs with evidence of accidental 5-HTP ingestion. PROCEDURE: Information was retrieved from the National Animal Poison Control Center database. Records of dogs ingesting 5-HTP between January 1989 and February 1999 were reviewed for information on signalment, dose ingested, clinical signs (onset, severity, duration), treatments administered, and outcome. RESULTS: Clinical signs of toxicosis developed in 19 of 21 (90%) dogs. Neurologic signs included seizures (9 dogs), depression (6), tremors (5), hyperesthesia (5), and ataxia (4). Gastrointestinal tract signs included vomiting or diarrhea (12 dogs), signs of abdominal pain (3), and hypersalivation (2). Other clinical signs were hyperthermia (7 dogs) and transient blindness (3). Three dogs died. No important clinical laboratory or necropsy findings were reported. The doses of 5-HTP ingested ranged from 2.5 to 573 mg/kg (1.1 to 260 mg/lb) of body weight; the minimum toxic dose reported in our study was 23.6 mg/kg (10.7 mg/lb), and the minimum lethal dose was 128 mg/kg (58.1 mg/lb). Onset of signs ranged from 10 minutes to 4 hours after ingestion, and signs lasted up to 36 hours. Of 17 dogs with clinical signs of toxicosis that received treatment, 16 recovered; treatment consisted of decontamination, seizure control, thermoregulation, fluid therapy, and supportive care. CONCLUSIONS AND CLINICAL RELEVANCE: Ingestion of 5-HTP in dogs can result in a potentially life-threatening syndrome resembling serotonin syndrome in humans, which requires prompt and aggressive care.     

Mammary duct ectasia in dogs: 51 cases (1992-1999)

OBJECTIVE: To evaluate the clinical and pathologic characteristics of mammary duct ectasia in dogs. DESIGN: Retrospective study. ANIMALS: 51 dogs with mammary duct ectasia. PROCEDURE: Information regarding body condition, history, number and location of affected mammary glands, appearance of lesions, surgical treatment, nonsurgical treatment, and evidence of recurrence or development of mammary neoplasia was obtained from surveys sent to referring veterinarians. Results of information from examination of histologic sections and referring veterinarians were evaluated for all mammary duct ectasia biopsies performed between 1992 and 1999. RESULTS: Duct ectasia was the primary diagnosis in 51 of 1,825 (2.8%) mammary biopsy specimens and comprised 48% of nonneoplastic mammary diseases. Affected dogs were evenly distributed over a range of 1 to 13 years of age, with a mean age at the time of diagnosis of 6.1 +/- 3.1 years. All dogs were female (31 sexually intact, 20 spayed); 10 of 26 had whelped. Duct ectasia was described as nodular (26 dogs), cystic (13), and multiglandular (11) and located in caudal (31) more often than cranial (14) or middle glands (10). Ectasia recurred in 3 dogs. One dog had a history of previously excised mammary adenocarcinoma; another subsequently developed mammary carcinoma. CONCLUSIONS AND CLINICAL RELEVANCE: Duct ectasia affected mature, sexually intact and spayed female dogs over a wide age range. Certain breeds were affected more commonly than expected. Increased risk for mammary neoplasia was not evident. Duct ectasia should be considered as a cause for mammary enlargement, especially in young dogs or when its cystic nature is evident. Mastectomy is usually curative, and neoplasia should be ruled out in dogs with ectasia.     

Effect of triple pelvic osteotomy on the proximal femoral geometry in dysplastic dogs

Triple pelvic osteotomy (TPO) is one of the surgical procedures for use to try to reduce subsequent degenerative joint disease or modify the progress of hip dysplasia in young dogs. Joint force and pressure distribution were changed by this procedure. Therefore, the aim of this study was to find out whether the remodeling of proximal femur exists or not after TPO in dysplastic dogs. Ten femora from five young dysplastic mongrel dogs, treated unilaterally with TPO using 20° canine pelvic osteotomy plates, were used. One year after TPO, neck-proximal shaft angle, femoral head, neck, diaphyseal and mid-shaft diameters, total femoral, femoral neck axis, and intertrochanteric, femoral head offset lengths as well as the lengths from head center to lateral margin of greater trochanter and to proximal femoral axis were measured from the bone. The significant differences between treatment and control side were determined in Norberg angle, neck-proximal shaft angle, neck diameter, diaphyseal diameter, mid-shaft diameter, length from head center to proximal femoral axis and femoral head offset length. In conclusion, although small number of cases was used, it was determined that the aforementioned variables are affected by TPO. So, these variables may be supply additional information about the changes to the joint following TPO in dysplastic dogs.     

Evaluation of risk factors for development of secondary glaucoma in dogs: 156 cases (1999-2004)

OBJECTIVE: To determine the immediately antecedent cause of secondary glaucoma and the prevalence of secondary glaucoma with anterior uveitis or lens dislocation in dogs. DESIGN: Retrospective case series. ANIMALS: 156 dogs with secondary glaucoma. PROCEDURES: Cause of glaucoma was determined from records. Breed, age, sex, and neuter status of all dogs with secondary glaucoma were compared with the general hospital population. The prevalence of secondary glaucoma in dogs with a primary diagnosis of lens dislocation or anterior uveitis during the same period was determined. RESULTS: Secondary glaucoma was diagnosed in 156 of 2,257 (6.9%) dogs examined because of ophthalmic disease and was bilateral in 33 (21.2%) of those dogs. In 31 (94%) bilaterally affected dogs, the antecedent cause was the same in both eyes. Common causes of secondary glaucoma were non-surgical anterior uveitis (44.9%), anterior uveitis associated with prior phacoemulsification (15.8%), and lens dislocation (15.2%). Parson Russell Terriers, Poodles, Boston Terriers, Cocker Spaniels, Rhodesian Ridgebacks, and Australian Cattle Dogs had diagnoses of secondary glaucoma more often than expected, compared with the reference population. Age, sex, neuter status, and laterality were not associated with secondary glaucoma. The prevalence of secondary glaucoma in dogs with lens dislocation or uveitis was 15% or 17%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Glaucoma develops secondary to many intraocular diseases, particularly uveitis and lens dislocation. Diagnosis of these diseases should prompt frequent monitoring of intraocular pressure, regardless of signalment.     

Ventilatory failure, ventilator management, and outcome in dogs with cervical spinal disorders: 14 cases (1991-1999)

OBJECTIVE: To determine the incidence of and risk factors for ventilatory failure in dogs undergoing surgery for treatment of cervical spinal disorders and to document ventilator management, clinical course, and long-term outcome of dogs that experienced ventilatory failure in association with cervical spinal disorders or their management. DESIGN: Retrospective study. ANIMALS: 14 dogs. PROCEDURE: Dogs with cervical spinal disorders that required positive-pressure ventilation (PPV) were identified, and signalment, concurrent diseases, neurologic status at initial examination, clinical course, pulmonary function before, during, and after PPV, management techniques, complications, and outcome were recorded. Dogs that underwent surgery and required PPV were compared with dogs that underwent cervical spinal surgery during the same period that did not require PPV. RESULTS: 14 dogs with cervical spinal disorders required PPV to treat hypoventilation, including 13 of 263 (4.9%) dogs that underwent surgery for cervical spinal disorders. Lesions between the second and fourth cervical vertebrae and treatment by means of a dorsal decompressive laminectomy were associated with a significantly increased risk of perioperative hypoventilation. Pulmonary gas exchange function was normal or nearly normal throughout the course of PPV in dogs that survived. Ten dogs survived, and 9 of the 10 regained neurologic function. All 9 dogs that regained neurologic function had deep pain perception on initial examination at the veterinary teaching hospital. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that a small percentage of dogs with cervical spinal disorders may require perioperative ventilatory support. With prolonged PPV and aggressive management, a good outcome may be achieved in dogs similar to those described in the present study.     

Surgical correction of brachycephalic syndrome in dogs: 62 cases (1991-2004)

OBJECTIVE: To assess results of surgical correction of brachycephalic syndrome (including stenotic nares, elongated soft palate, and everted laryngeal saccules) in dogs and determine whether dogs with hypoplastic trachea have a less favorable long-term outcome. DESIGN: Retrospective case series. ANIMALS: 62 dogs with brachycephalic syndrome. PROCEDURES: Medical records from 1991 to 2004 were reviewed for information regarding signalment, clinical signs, diagnosis, surgery, and long-term outcome. Surgical outcome was rated by owners as excellent, good, fair, or poor. Common abnormalities, treatments, and long-term outcomes among the 62 dogs were assessed. RESULTS: Predominantly affected breeds included English Bulldog, Pug, and Boston Terrier. Elongated soft palate was the most common abnormality (54/62 [87.1%] dogs); the most common combination of abnormalities was elongated soft palate, stenotic nares, and everted saccules (16/62 [25.8%] dogs). The English Bulldog was the most common breed for all abnormalities, including elongated soft palate (27/54 [50%] dogs), stenotic nares (14/36 [38.9%] dogs), everted saccules (20/36 [55.6%] dogs), hypoplastic trachea (7/13 [53.9%] dogs), and laryngeal collapse (2/5 [40%]). No dogs had everted saccules alone. Outcome did not differ between dogs under-going staphylectomy by use of laser or scissor resection. Follow-up information was obtained for 34 dogs; 16 (47.1%) had an excellent outcome, and 16 (47.1%) had a good outcome. Overall treatment success rate was 94.2%, and overall mortality rate was 3.2%. CONCLUSIONS AND CLINICAL RELEVANCE: Surgical treatment of brachycephalic syndrome in dogs appeared to be associated with a favorable long-term outcome, regardless of age, breed, specific diagnoses, or number and combinations of diagnoses.     

Bilateral cavernous sinus syndrome in dogs: 6 cases (1999-2004)

OBJECTIVE: To determine clinical features, diagnostic imaging abnormalities, underlying disease, disease progression, and outcome in dogs with bilateral cavernous sinus syndrome. DESIGN: Retrospective study. ANIMALS: 6 dogs. PROCEDURE: Dogs were included if clinical signs consistent with bilateral cavernous sinus syndrome (i.e., deficits of the third, fourth, and sixth cranial nerves and at least 1 of the first 2 branches of the fifth cranial nerve) were present and a lesion of the cavernous sinus was identified by means of diagnostic imaging or postmortem examination. RESULTS: 5 dogs were evaluated because of problems referable to abnormal ocular motility or pupillomotor dysfunction, and 1 dog was evaluated because of partial motor seizures involving the face and bilateral mydriasis. Four dogs had neurologic signs referable to an extrasinusoidal lesion at the time of initial examination, and the remaining 2 dogs eventually developed extrasinusoidal signs. Besides neuroanatomic location, the only consistent neuroimaging feature was variably intense, heterogeneous enhancement of cavernous sinus lesions. Neoplasia was histologically confirmed as the underlying cause in 5 of the dogs and was suspected in the remaining dog. Median survival time for the 4 dogs that were treated was 199 days (range, 16 to 392 days). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that bilateral cavernous sinus syndrome is rare in dogs but should be suspected in dogs with compatible clinical signs. Affected dogs have a poor prognosis, and dogs with clinical signs of bilateral cavernous sinus syndrome should be systematically evaluated for neoplastic disease.     

Surgical management of gallbladder mucoceles in dogs: 22 cases (1999-2003)

OBJECTIVES: To describe preoperative, surgical, and postoperative findings and determine prognostic indicators and treatment recommendations in dogs treated surgically for gallbladder mucocele. DESIGN: Retrospective study. ANIMALS: 22 client-owned dogs. PROCEDURES: Medical records of dogs with gallbladder mucoceles that were treated surgically were reviewed. History, clinical signs, results of selected clinicopathologic analyses and abdominal ultrasonography, surgical procedure performed, results of histologic examination of a liver biopsy specimen, and survival time were recorded. Follow-up information was obtained via telephone interview with owners and referring veterinarians. RESULTS: Dogs were 7 to 15 years of age and had non-specific clinical signs (vomiting, anorexia, and lethargy). Physical examination findings included icterus, signs of depression, and signs of discomfort on palpation of the abdomen. Sixteen dogs had a definitive diagnosis and 6 dogs were strongly suspected of having a gallbladder mucocele on the basis of results of abdominal ultrasonography. Fifteen dogs survived after surgery; 3 of these dogs had bile-induced peritonitis, and 4 had pancreatitis. One dog was euthanatized as a result of severe pancreatitis, and 1 was euthanatized because of acute renal failure; 5 dogs died as a result of pancreatitis, cholecystitis, or bile-induced peritonitis. Hepatic abnormalities were detected histologically in all dogs. CONCLUSIONS AND CLINICAL RELEVANCE: No predictors of survival were identified. No associations between outcome of surgical treatment (survival vs nonsurvival) and preoperative findings, biliary rupture, surgical procedure performed, results of histologic examination of the liver, or development of pancreatitis were found. Cholecystoduodenostomy and cholecystectomy appear to be acceptable treatments for gallbladder mucocele.     

Trigeminal neuropathy in dogs: a retrospective study of 29 cases (1991-2000)

The medical records of 29 dogs unable to close their mouths due to flaccid paralysis or paresis of the muscles innervated by the mandibular branch of the trigeminal nerve, were reviewed. Idiopathic trigeminal neuropathy was diagnosed in 26 dogs based on complete resolution of clinical signs and lack of any long-term neurological disease. Of these dogs, golden retrievers were overrepresented. No age, sex, or seasonal predispositions were identified. Trigeminal sensory innervation deficits were observed in 35% (9/26), facial nerve deficits were observed in 8% (2/26), and Horner's syndrome was observed in 8% (2/26) of dogs. Electromyographic examination of the muscles of mastication revealed abnormalities in seven of nine dogs. Results of cerebrospinal fluid analysis were abnormal in seven of eight dogs. Corticosteroid therapy did not affect the clinical course of the disease. Mean time to recovery was 22 days. Lymphosarcoma, Neospora caninum infection, and severe polyneuritis of unknown origin were diagnosed in three of 29 dogs at necropsy.     

Medical and surgical treatment of pyothorax in dogs: 26 cases (1991-2001)

OBJECTIVE: To compare outcomes of dogs with pyothorax treated medically versus surgically and to identify prognostic indicators for dogs with pyothorax. DESIGN: Retrospective study. ANIMALS: 26 dogs. PROCEDURE: Medical records were reviewed to obtain information regarding signalment, results of physical and laboratory evaluations at the time of initial examination, results of bacterial culture of pleural fluid, radiographic abnormalities, treatment (surgical vs medical), complications, whether the disease recurred, disease-free interval, survival time, and cause of death. RESULTS: Calculated proportions of dogs free from disease 1 year after treatment were 25 and 78%, respectively, for dogs treated medically and surgically. Treatment was 5.4 times as likely to fail in dogs treated medically as in dogs treated surgically. Two regression models relating treatment group (medical vs surgical) to disease-free interval were found to be significant. The first contained terms for medical treatment and isolation of Actinomyces spp from pleural fluid; the second contained terms for medical treatment and radiographic detection of mediastinal or pulmonary lesions at the time of initial examination. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that surgical treatment is associated with a better outcome than medical treatment in dogs with pyothorax. In addition, surgery should be considered if radiographic evidence of mediastinal or pulmonary lesions is detected or if Actinomyces spp is isolated from the pleural fluid.