Self-expanding nitinol stents for the treatment of tracheal collapse in dogs: 12 cases (2001-2004)

OBJECTIVE: To evaluate long-term outcome following nitinol stent placement in dogs with tracheal collapse. DESIGN: Retrospective case series. ANIMALS: 12 client-owned dogs with endoscopically diagnosed tracheal collapse refractory to medical management. PROCEDURES: Medical records were reviewed for 12 dogs in which 1 or more self-expanding nitinol stents were placed for the treatment of endoscopically diagnosed tracheal collapse. A total of 17 stents were placed. RESULTS: Survival times after stent placement ranged from 1 to 48 months. Three of 12 dogs died within 6 months after stent placement. Nine dogs survived > 1 year after stent placement, and 7 dogs survived > 2 years. Of the deceased dogs, 5 of 9 succumbed to tracheal disease. Other causes of death included congestive heart failure, cerebral neoplasia, cerebrovascular accident, and renal failure. Material failure (stent fracture) was a common complication (5/12 dogs). Other complications reported included excessive granulation tissue within the stent lumen, tracheitis, and pneumonia. CONCLUSIONS AND CLINICAL RELEVANCE: Placement of an intraluminal stent with self-expanding nitinol stents was a successful palliative treatment for tracheal collapse in dogs that did not respond to medical management. Disease progression is inevitable, but substantial improvement in respiratory function may be achieved for a period of months to years.     

Massive transfusion in dogs: 15 cases (1997-2001)

OBJECTIVE: To determine clinical characteristics of dogs that received massive transfusion and identify the underlying diseases, complications, and outcomes. DESIGN: Retrospective study. ANIMALS: 15 dogs. PROCEDURE: Medical records of dogs receiving a massive blood transfusion were evaluated for transfusion volume, underlying disease process or injury, benefits and complications of transfusion, and outcome. A massive transfusion was defined as transfusion of a volume of blood products in excess of the patient's estimated blood volume (90 ml/kg [40 ml/lb]) in a 24-hour period or transfusion of a volume of blood products in excess of half the patient's estimated blood volume in a 3-hour period. RESULTS: Six dogs had intra-abdominal neoplasia resulting in hemoabdomen, 3 had suffered a traumatic incident resulting in hemoabdomen, and 6 had non-traumatic, non-neoplastic blood loss. Mean volumes of packed RBC and fresh-frozen plasma administered were 66.5 ml/kg (30 ml/lb) and 22.2 ml/kg (10 ml/lb), respectively. All dogs evaluated developed low ionized calcium concentrations and thrombocytopenia. Transfusion reactions were recognized in 6 dogs. Four dogs survived to hospital discharge. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that massive transfusion is possible and potentially successful in dogs. Predictable changes in electrolyte concentrations and platelet count develop.     

Congenital portosystemic shunts in dogs: 46 cases (1979-1986)

Congenital portosystemic shunts (CPSS) were diagnosed in 46 dogs. The historic, physical, and laboratory findings were tabulated. Half of the affected males were cryptorchid. Urolithiasis was detected in 20% of the dogs. The biochemical tests with the best sensitivity for the diagnosis of CPSS were sulfobromophthalein retention, fasting serum ammonia concentration, and serum alkaline phosphatase activity. The survival time and quality of life were assessed by physical and biochemical reevaluation of the dogs and by means of a questionnaire that was completed by the owners. Five dogs were treated medically. Thirty-three dogs were treated surgically. Dogs that had complete surgical occlusion of the CPSS became normal, and quality of life was excellent. Dogs that had partial occlusion of the CPSS improved, and some became clinically normal. Dogs that did not have surgical correction of the CPSS had continuation of signs, but several survived for years.     

Association of magnetic resonance imaging findings and histologic diagnosis in dogs with nasal disease: 78 cases (2001-2004)

OBJECTIVE-To determine whether magnetic resonance imaging (MRI) features correlated with histologic diagnosis in dogs with nasal disease. DESIGN-Retrospective case series. ANIMALS-78 Dogs undergoing MRI for evaluation of nasal disease. PROCEDURES-Medical records and MRI reports of dogs were reviewed to identify MRI features associated with histologic diagnosis. Features evaluated were presence of a mass effect, frontal sinus involvement, sphenoid sinus involvement, maxillary recess involvement, nasopharyngeal infiltration by soft tissue, nasal turbinate destruction, vomer bone lysis, paranasal bone destruction, cribriform plate erosion, and lesion extent (ie, unilateral vs bilateral). RESULTS-33 Dogs had neoplastic disease, 38 had inflammatory rhinitis, and 7 had fungal rhinitis. Lesion extent was not significantly associated with histologic diagnosis. Absence of a mass effect was significantly associated with inflammatory disease. However, presence of a mass was not specific for neoplasia. In dogs with evidence of a mass on magnetic resonance (MR) images, nasal turbinate destruction, frontal sinus invasion, and maxillary recess invasion were not useful in distinguishing neoplastic from nonneoplastic disease, but cribriform plate erosion, vomer bone lysis, paranasal bone destruction, sphenoid sinus invasion, and nasopharyngeal invasion were. CONCLUSIONS AND CLINICAL RELEVANCE-Results suggested that in dogs with nasal disease, the lack of a mass effect on MR images was significantly associated with inflammatory disease. In dogs with a mass effect on MR images, vomer bone lysis, cribriform plate erosion, paranasal bone destruction, sphenoid sinus invasion by a mass, and nasopharyngeal invasion by a mass were significantly associated with a diagnosis of neoplasia.     

Taurine deficiency in dogs with dilated cardiomyopathy: 12 cases (1997-2001)

OBJECTIVE: To determine signalment, history, clinical signs, blood and plasma taurine concentrations, electrocardiographic and echocardiographic findings, treatment, and outcome of dogs with low blood or plasma taurine concentrations and dilated cardiomyopathy (DCM). DESIGN: Retrospective study. ANIMALS: 12 client-owned dogs with low blood or plasma taurine concentrations and DCM. PROCEDURE: Medical records were reviewed, and clinical data were obtained. RESULTS: All 12 dogs were being fed a commercial dry diet containing lamb meal, rice, or both as primary ingredients. Cardiac function and plasma taurine concentration improved with treatment and taurine supplementation. Seven of the 12 dogs that were still alive at the time of the study were receiving no cardiac medications except taurine. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that consumption of certain commercial diets may be associated with low blood or plasma taurine concentrations and DCM in dogs. Taurine supplementation may result in prolonged survival times in these dogs, which is not typical for dogs with DCM. Samples should be submitted for measurement of blood and plasma taurine concentrations in dogs with DCM, and taurine supplementation is recommended while results of these analyses are pending.     

Liver lobe torsion in dogs: 13 cases (1995-2004)

OBJECTIVE: To determine history, results of diagnostic testing, surgical findings, complications, and outcome for dogs with liver lobe torsion (LLT). DESIGN: Retrospective case series. ANIMALS: 12 dogs (1 with 2 episodes). PROCEDURE: Signalment, clinical signs, clinicopathologic findings, radiographic and ultrasonographic findings, surgical and histologic findings, complications, and hospitalization time were evaluated. RESULTS: The most common clinical signs were nonspecific abnormalities (eg, vomiting, lethargy, and anorexia) of acute or chronic duration. All dogs were large-breed dogs (median body weight, 37.2 kg [82 lb]). Biochemical abnormalities included high alanine amino-transferase (n = 12) and aspartate aminotransferase (11) activities. Results of abdominal ultrasonography were supportive of the diagnosis in 5 of 8 cases. Affected lobes included the left medial lobe (n = 4), left lateral lobe (3), papillary process of the caudate lobe (2), caudate lobe (1), and right lateral lobe (1). Exploratory celiotomy and liver lobectomy were performed in 12 of 13 cases, and in 11 of those 12 cases, the dog survived. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that development of nonspecific clinical signs of vomiting, lethargy, and anorexia in conjunction with high serum hepatic enzyme activities and mature neutrophilia in a medium-sized or large-breed dog should increase the index of suspicion for LLT. Abdominal ultrasonography with Doppler assessment may be useful in establishing the diagnosis. The long-term outcome for dogs that survive the hospitalization period is excellent.     

Bone marrow necrosis in dogs: 34 cases (1996-2004)

OBJECTIVE: To identify the incidence, potential causes, and clinical and clinicopathologic features of bone marrow necrosis in dogs. DESIGN: Retrospective study. ANIMALS: 34 client-owned dogs. PROCEDURES: Reports of cytologic examinations of bone marrow specimens performed between 1996 and 2004 were reviewed. All reports that indicated the presence of necrosis, stromal disruption, phagocytic macrophages, individual cell necrosis, or myelofibrosis were evaluated further. RESULTS: Of 609 reports of bone marrow evaluations performed during the study period, 34 (5.6%) had evidence of bone marrow necrosis. Nine dogs had no evidence of associated diseases or drug or toxin exposure, and 25 dogs had associated disease conditions or drug exposures. All 9 dogs with idiopathic bone marrow necrosis were anemic (mean Hct, 14%), but only 3 had neutropenia, and 3 had thrombocytopenia. All 9 had myelofibrosis. Of the 25 dogs with associated disease conditions or drug exposures, only 14 (56%) had anemia (mean Hct, 33%). In addition, 14 (56%) had neutropenia and 18 (72%) had thrombocytopenia. Only 10 (40%) had myelofibrosis. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that bone marrow necrosis may be common in dogs with hematologic disorders. In most dogs, bone marrow necrosis was associated with an underlying disease condition or drug exposure, but idiopathic bone marrow necrosis was also identified. Disease conditions that should increase suspicion of possible bone marrow necrosis include sepsis, lymphosarcoma, and systemic lupus erythematosus; drug exposures that should increase suspicion of possible bone marrow necrosis include chemotherapeutic agents, phenobarbital, carprofen, metronidazole, and mitotane.     

Results of transthoracic esophagotomy retrieval of esophageal foreign body obstructions in dogs: 14 cases (2000-2004)

The records of 14 consecutive cases of esophageal foreign body obstruction in dogs that had undergone transthoracic esophagotomy for foreign body retrieval were reviewed. Clinical results were considered successful in 13 of 14 dogs. One dog was euthanized at surgery because of the severity of associated thoracic lesions. Clinical signs resolved in the remaining 13 dogs. Two dogs had postoperative complications. One dog developed a pyothorax, and one dog developed a subcutaneous seroma. The overall recovery rate was 93%.     

Diagnostic value of cytologic examination of gastrointestinal tract tumors in dogs and cats: 83 cases (2001-2004)

OBJECTIVE: To determine results of cytologic examination of fine-needle aspirates and impression smears of gastrointestinal tract tumors in dogs and cats. DESIGN: Retrospective case series. ANIMALS: 38 dogs and 44 cats with histologically confirmed gastrointestinal tract tumors. PROCEDURES: Results of cytologic examination of fine-needle aspirates (n = 67) or impression smears (31) were compared with the histologic diagnosis, and extent of agreement was classified as complete, partial, none, or undetermined. RESULTS: For 48 of the 67 (72%) fine-needle aspirates, there was complete or partial agreement between the cytologic and histologic diagnoses. For 12 (18%) aspirates, the extent of agreement could not be determined because the cytologic specimen was considered unsatisfactory. For 29 of the 31 (94%) impression smears, there was complete agreement between the cytologic and histologic diagnoses, and for 2 (6%), there was partial agreement. None of the impression smears were considered unsatisfactory. Proportion of samples with complete agreement and proportion of samples with complete or partial agreement were significantly higher for impression smears than for fine-needle aspirates. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that there was moderate agreement between results of cytologic examination of fine-needle aspirates from dogs and cats with gastrointestinal tract neoplasia and the definitive histologic diagnosis. The agreement between results of cytologic examination of impression smears and the histologic diagnosis appeared to be higher.     

Comparison of classic hypoadrenocorticism with glucocorticoid-deficient hypoadrenocorticism in dogs: 46 cases (1985-2005)

OBJECTIVE: To compare dogs with glucocorticoid-deficient hypoadrenocorticism (GDH) with those with mineralocorticoid- and glucocorticoid-deficient hypoadrenocorticism (MGDH) and determine prevalence, historical and clinicopathologic markers, and outcome of dogs with GDH. DESIGN: Retrospective case series. ANIMALS: 46 dogs with hypoadrenocorticism. PROCEDURES: Records in the veterinary medical database at Purdue University were searched for dogs in which hypoadrenocorticism had been diagnosed at the Veterinary Teaching Hospital from 1985 to 2005. Data pertaining to signalment, history, a minimum clinicopathologic database, treatment, and outcome were collected. Dogs with hypoadrenocorticism were classified as having MGDH if hyponatremia, hyperkalemia, or both were detected and as having GDH if hyponatremia and hyperkalemia were absent. Dogs were excluded if they had ever been treated with mitotane or had been treated with > 1 dose of corticosteroids within a month prior to the ACTH-stimulation test. RESULTS: 35 dogs with MGDH and 11 dogs with GDH met the inclusion criteria. Dogs with GDH were older at the time of diagnosis and had a longer duration of clinical signs prior to diagnosis than those with MGDH. Dogs with GDH were more likely to be anemic, hypoalbuminemic, and hypocholesterolemic than dogs with MGDH. CONCLUSIONS AND CLINICAL RELEVANCE: GDH was more common than reported in a referral hospital population of dogs with primary hypoadrenocorticism. Definitive diagnosis of GDH remains a clinical challenge. Absence of a stress leukogram in dogs with signs of illness (especially relating to the gastrointestinal tract) warrants further investigation. Most dogs with primary cortisol deficiency do not develop mineralocorticoid deficiency.     

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.     

Surgery alone or in combination with radiation therapy for treatment of intracranial meningiomas in dogs: 31 cases (1989-2002)

OBJECTIVE: To compare, for dogs with intracranial meningiomas, survival times for dogs treated with surgical resection followed by radiation therapy with survival times for dogs treated with surgery alone. DESIGN: Retrospective study. ANIMALS: 31 dogs with intracranial meningiomas. PROCEDURE: Medical records of dogs with histologic confirmation of an intracranial meningioma were reviewed. For each dog, signalment, clinical signs, tumor location, treatment protocol, and survival time were obtained from the medical record and through follow-up telephone interviews. RESULTS: Dogs that underwent tumor resection alone and survived > 1 week after surgery had a median survival time of 7 months (range, 0.5 to 22 months). Dogs that underwent tumor resection followed by radiation therapy had a median survival time of 16.5 months (range, 3 to 58 months). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that in dogs with intracranial meningiomas, use of radiation therapy as a supplement to tumor resection can significantly extend life expectancy.     

Surgical management of cricopharyngeal dysphagia in dogs: 14 cases (1989-2001)

OBJECTIVE: To determine outcome of and complications associated with cricopharyngeal myotomy or myectomy for treatment of cricopharyngeal dysphagia (CPD) in dogs. DESIGN: Retrospective study. ANIMALS: 14 dogs. PROCEDURE: Medical records of dogs with CPD that underwent cricopharyngeal myotomy or myectomy were examined. Follow-up information was obtained through telephone interviews with owners and referring veterinarians and clinical examinations when feasible. RESULTS: 16 surgical procedures were performed on the 14 dogs. Dysphagia was completely resolved immediately after surgery in 1 dog, and clinical signs did not recur (follow-up time of 8 years); a second dog also had immediate complete resolution of dysphagia, but follow-up time was only 10 days. Three dogs had transient complete resolution with a mean time to recurrence of dysphagia of 12.3 weeks (range, 2 to 36 weeks). Three dogs had permanent partial resolution. Six dogs had no improvement after surgery. Eight of the 14 dogs were euthanatized because of problems related to CPD, including persistent dysphagia (n = 8) and aspiration pneumonia (5). CONCLUSIONS AND CLINICAL RELEVANCE: The failure rate for dogs undergoing surgical treatment of CPD may be high, particularly if concurrent aspiration pneumonia or malnutrition is not addressed prior to surgery. For those dogs with concurrent diseases, more aggressive medical management, such as enteral tube feeding, may be warranted rather than surgery. In dogs with CPD complicated by other anatomic or functional conditions, such as myasthenia gravis, laryngeal paralysis, and esophageal stricture, surgery may also not be indicated.     

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.     

West Nile virus encephalomyelitis in horses: 46 cases (2001)

OBJECTIVE: To determine signalment, clinical findings, results of diagnostic testing, outcome, and postmortem findings in horses with West Nile virus (WNV) encephalomyelitis. DESIGN: Retrospective study. ANIMALS: 46 horses with WNV encephalomyelitis. PROCEDURE: Clinical data were extracted from medical records of affected horses. RESULTS: On the basis of clinical signs and results of serologic testing, WNV encephalomyelitis was diagnosed in 46 of 56 horses with CNS signs. Significantly more males than females were affected. Increased rectal temperature, weakness or ataxia, and muscle fasciculations were the most common clinical signs. Paresis was more common than ataxia, although both could be asymmetrical and multifocal. Supportive treatment included anti-inflammatory medications, fluids, antimicrobials, and slinging of recumbent horses. Results of the IgM capture ELISA and the plaque reduction neutralization test provided a diagnosis in 43 horses, and only results of the plaque reduction neutralization test were positive in 3 horses. Mortality rate was 30%, and 71% of recumbent horses were euthanatized. One horse that had received 2 vaccinations for WNV developed the disease and was euthanatized. Follow-up communications with 19 owners revealed that most horses had residual deficits at 1 month after release from the hospital; abnormalities were resolved in all but 2 horses by 12 months after release. CONCLUSIONS AND CLINICAL RELEVANCE: Our findings were similar to those of previous WNV outbreaks in horses but provided additional clinical details from monitored hospitalized horses. Diagnostic testing is essential to diagnosis, treatment is supportive, and recovery rate of discharged ambulatory horses is < 100%.     

Cardiac lymphoma and pericardial effusion in dogs: 12 cases (1994-2004)

OBJECTIVE: To determine clinical characteristics and clinicopathologic findings, including results of pericardial fluid analysis, and determine the outcome associated with pericardial effusion caused by cardiac lymphoma in dogs. DESIGN: Retrospective case series. ANIMALS: 12 dogs. PROCEDURE: Medical records of affected dogs were reviewed for echocardiographic findings, radiographic findings, results of pericardial fluid analysis, clinicopathologic findings, treatment protocols, and outcomes. RESULTS: Pericardial effusion was detected by echocardiography in all 12 dogs, and lymphoma was detected by cytologic examination of the effusion (11/12 dogs) or histologic examination of pericardium (3/12). Large-breed dogs were overrepresented; median weight was 40.5 kg (89.1 lb). Most hematologic and biochemical changes were mild and non-specific. Survival time for dogs treated with combination chemotherapeutic agents was 157 days and for dogs that did not receive chemotherapy survival time was 22 days. This difference was not significant, but several dogs had long-term survival. CONCLUSIONS AND CLINICAL RELEVANCE: Cardiac lymphoma is an uncommon cause of pericardial effusion, and results suggest that cardiac lymphoma does not always warrant the poor prognosis of other stage V, substage b lymphomas.