Indications, management, and outcome of long-term positive-pressure ventilation in dogs and cats: 148 cases (1990-2001)

OBJECTIVE

To determine outcome of positive-pressure ventilation (PPV) for 24 hours or longer and identify factors associated with successful weaning from PPV and survival to hospital discharge in dogs and cats.

DESIGN

Retrospective case series.

ANIMALS

124 dogs and 24 cats that received PPV for 24 hours or longer.

PROCEDURES

Medical records were reviewed for signalment, primary diagnosis, reason for initiating PPV, measures of oxygenation and ventilation before and during PPV, ventilator settings, complications, duration of PPV, and outcome. Animals were categorized into 1 of 3 groups on the basis of the reason for PPV.

RESULTS

Group 1 patients received PPV for inadequate oxygenation (67 dogs and 6 cats), group 2 for inadequate ventilation (46 dogs and 16 cats), and group 3 for inadequate oxygenation and ventilation (11 dogs and 2 cats). Of the group 1 animals, 36% (26/73) were weaned from PPV and 22% (16/73) survived to hospital discharge. In group 2, 50% (31/62) were weaned from PPV and 39% (24/62) survived to hospital discharge. In group 3, 3 of 13 were weaned from PPV and 1 of 13 survived to hospital discharge. Likelihood of successful weaning and survival to hospital discharge were significantly higher for group 2 animals, and cats had a significantly lower likelihood of successful weaning from PPV, compared with dogs. Median duration of PPV was 48 hours (range, 24 to 356 hours) and was not associated with outcome.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that long-term PPV is practical and successful in dogs and cats.

Cardiovascular involvement in 8 dogs with blastomyces dermatitidis infection

BACKGROUND

Blastomycosis is a common systemic fungal infection in dogs.

HYPOTHESIS

Dogs with cardiovascular involvement may have abnormalities in electrical conduction and valvular function, and may have a worse prognosis.

ANIMALS

Eight client-owned animals.

METHODS

Dogs with cardiovascular lesions caused by blastomycosis were identified from retrospective evaluation of medical records.

RESULTS

Five dogs had de novo infections and 3 had recurrences of previously treated infections. Harsh labored breathing, lethargy, and anorexia were the most common historic complaints. Three dogs had syncope. Physical examination and clinicopathologic data were typical of blastomycosis and included dyspnea, increased lung sounds, and lethargy. In addition, 3 dogs had heart murmurs and 1 had a third-degree atrioventricular block. Four dogs had myocarditis and 2 had pericarditis or epicarditis. Two dogs had cardiac signs attributed to extracardiac compression by fungal granulomas and clinical signs were relieved by treatment. Half of the remaining 6 dogs were euthanized; 2 of these were not treated. Of the remaining 3 dogs, 1 dog died acutely while sleeping; the second died intraoperatively during an attempt to place an epicardial pacemaker; and the third had Blastomyces-induced endocarditis and died of heart failure.

CONCLUSIONS AND CLINICAL IMPORTANCE

Blastomycosis should be considered in the differential diagnosis of dogs from endemic areas with inflammatory myocarditis, heart block, heart base or intracardiac mass lesions, syncope, or endocarditis.

Retrospective Comparison of Surgical Ligation and Transarterial Catheter Occlusion for Treatment of Patent Ductus Arteriosus in Two Hundred and Four Dogs (1993?2003)

OBJECTIVE

To compare procedure time, complications, mortality, and short-term outcome in dogs with patent ductus arteriosus (PDA) treated by surgical ligation (SL) or transarterial coil occlusion (TCO).

STUDY DESIGN

Retrospective study.

ANIMALS

Dogs with PDA (n=204).

METHODS

Medical records of dogs treated for PDA were reviewed. Dogs treated by SL when it was the primary method used for PDA treatment (1993-1998) were compared with dogs treated by TCO when it was the primary method used for PDA treatment (1999-2003). Dogs treated during the transition between techniques, dogs treated with SL (1999-2003) and dogs treated with TCO before 1999, as well as dogs with pulmonary hypertension, or bidirectional or reversed (right-to-left) flow through the PDA were excluded from analysis.

RESULTS

Age, weight, gender distribution, and procedure times (P=.43) were similar for both groups. Major complications were more common with SL (12% versus 4.3%; P=.035) whereas minor complications were more common with TCO (12% versus 26%; P=.015). Initial success rate was higher for SL (94%) compared with TCO (84%; P=.027). There was no significant difference in mortality between SL (5.6%) and TCO (2.6%; P=.27).

CONCLUSIONS

Both SL and TCO are acceptable PDA treatments with comparable mortality; however, SL was associated with a higher risk of major complications and TCO was associated with a lower initial success rate.

Protothecosis in 17 Australian dogs and a review of the canine literature

Systemic protothecosis was diagnosed in 17 Australian dogs between 1988 and 2005. There was a preponderance of young-adult (median 4 years), medium- to large-breed dogs. Females (12/17 cases) and Boxer dogs (7 cases, including 6 purebreds and one Boxer cross) were over-represented. Sixteen of 17 dogs died, with a median survival of four months. A disproportionate number of cases were from coastal Queensland. In most patients, first signs were referable to colitis (11/17 cases), which varied in severity, and was often present for many months before other symptoms developed. Subsequent to dissemination, signs were mostly ocular (12 cases) and/or neurologic (8 cases). Two dogs had signs due to bony lesions. Once dissemination was evident, death or euthanasia transpired quickly. Prototheca organisms had a tropism for the eye, central nervous system (CNS), bone, kidneys and myocardium, tissues with a good blood supply. Microscopic examination and culture of urine (5 cases), cerebrospinal fluid (CSF;1 case), rectal scrapings (4 cases), aspirates or biopsies of eyes (5 cases) and histology of colonic biopsies (6 cases) as well as skin and lymph nodes (2 cases) helped secure a diagnosis. Of the cases where culture was successful, P wickerhamii was isolated from two patients, while P zopfii was isolated from five. P zopfii infections had a more aggressive course. Treatment was not attempted in most cases. Combination therapy with amphotericin B and itraconazole proved effective in two cases, although in one of these treatment should have been for a longer duration. One surviving dog is currently still receiving itraconazole. Protothecosis should be considered in all dogs with refractory colitis, especially in female Boxers.

Risk factors associated with outcome in dogs with tetanus: 38 cases (1987–2005)

OBJECTIVE

To assess the clinical course of disease and risk factors associated with outcome in dogs with tetanus.

DESIGN

Retrospective case series.

ANIMALS

38 dogs with tetanus.

PROCEDURES

Data were collected from medical records of dogs with tetanus, including signalment; wound characteristics; initial clinical signs; severity of worst clinical signs; time to wound management, antimicrobial treatment, and antitoxin administration; and 28-day survival rate. Statistical analyses were performed to evaluate relationships between the potentially predictive variables and disease progression and outcome.

RESULTS

The 28-day survival rate was 77% (among 35 uncensored dogs). The most common initial clinical signs in affected dogs were ocular (n = 18) and facial (11) abnormalities. Nineteen dogs progressed to recumbency with severe muscle spasms, and 14 dogs had high or low heart rate or blood pressure values. Eight dogs died or were euthanized because of complications of tetanus. There was a significant association between younger age and development of more severe clinical signs. Furthermore, a significant inverse relationship between development of severe clinical signs and survival was identified. There was no association between earlier initiation of wound management, antimicrobial administration, or antitoxin administration and either progression of signs or 28-day survival rate. Wound type was not associated with 28-day survival rate.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that younger dogs with tetanus may be more likely to develop severe clinical signs. The prognosis for survival in dogs with tetanus is good if abnormalities in heart rate or blood pressure values do not develop.

Results of pacemaker implantation in 104 dogs

OBJECTIVES

To document the outcome, survival and complications involved in pacemaker implantation in dogs in a retrospective study.

METHODS

Case records for all dogs in which pacemaker implantation was performed were reviewed.

RESULTS

A total of 104 dogs underwent pacemaker implantation. Dogs were presented with atrioventricular (AV) block (71), sick sinus syndrome (25) or vasovagal syncope (eight). Age at presentation varied from six months to 13 years with a median age of seven years and two months. The Labrador was the most commonly represented breed (17 cases). All but one dog survived pacemaker implantation, with 93 showing resolution of their clinical signs while 10 dogs showed intermittent residual signs. One-, three- and five-year survival estimates were 86, 65 and 39 per cent, respectively. Major complications after implantation were documented in 15 dogs and three of these led to fatalities. Minor complications were noted in 23 dogs. Sudden death occurred in six dogs three to 55 months following successful pacemaker implantation.

CLINICAL SIGNIFICANCE

Transvenous pacemaker implantation was successful in reducing or eliminating clinical signs in over 90 per cent of dogs with third-degree atrioventricular (AV) block or sick sinus syndrome. In dogs with vasovagal syncope, six of eight dogs had greatly reduced frequency of collapse and two became asymptomatic. Although the procedure was associated with complications, these were rarely life threatening and good survival was documented in the majority of cases.

Risk factors associated with short-term outcome and development of perioperative complications in dogs undergoing surgery because of gastric dilatation-volvulus: 166 cases (1992–2003)

OBJECTIVE

To evaluate risk factors associated with death and development of perioperative complications in dogs undergoing surgery for treatment of gastric dilatation-volvulus (GDV).

DESIGN

Retrospective case series.

ANIMALS

166 dogs.

PROCEDURES

Records of dogs with confirmed GDV that underwent surgery were reviewed. Logistic regression was performed to identify factors associated with development of complications (ie, hypotension, arrhythmias, gastric necrosis necessitating gastrectomy, disseminated intravascular coagulation, peritonitis, sepsis, postoperative dilatation, postoperative vomiting, and incisional problems) and with short-term outcome (ie, died vs survived to the time of suture removal).

RESULTS

Short-term mortality rate was 16.2% (27/166). Risk factors significantly associated with death prior to suture removal were clinical signs for > 6 hours prior to examination, combined splenectomy and partial gastrectomy, hypotension at any time during hospitalization, peritonitis, sepsis, and disseminated intravascular coagulation. Partial gastrectomy was not a significant risk factor for death but was for peritonitis, disseminated intravascular coagulation, sepsis, and arrhythmias. Age, gastrectomy, and disseminated intravascular coagulation were risk factors for development of hypotension. Use of a synthetic colloid or hypertonic saline solution was associated with a significantly decreased risk of hypotension.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that the prognosis for dogs undergoing surgery because of GDV is good but that certain factors are associated with an increased risk that dogs will develop perioperative complications or die.

Factors influencing the short-term outcome following thoracic surgery in 98 dogs

OBJECTIVES

To evaluate the factors influencing the short-term (<14 days) outcome of thoracic surgery in dogs.

METHODS

A retrospective review of 98 dogs undergoing thoracotomy over a five-year period was undertaken.

RESULTS

A pre-operative diagnosis was achieved in 69 per cent of cases. Intrathoraic neoplasia had the lowest pre-operative diagnosis rate (5.5 per cent). Mortality rates of 21 per cent were recorded and were significantly higher for intrathoracic neoplasia (50 per cent) and significantly lower for persistent ductus arteriosus (7.4 per cent) and vascular ring anomaly (0 per cent). Median sternotomy was the preferred approach for pyothorax (85 per cent) and penetrating thoracic injuries (66 per cent). Intercostal thoracotomy was the preferred approach for all other diseases. Postoperative complications occurred in 39 per cent of cases. Wound complications were more common for pyothorax (45 per cent) and following median sternotomy (71 per cent). Thoracic drains were placed in 77 per cent of cases and complications were recorded in 23 per cent. Pyothorax and chylothorax had thoracic drains maintained for significantly longer periods of time. Longer thoracic drain duration was correlated significantly with increased complication rates.

CLINICAL SIGNIFICANCE

The short-term outcome following thoracic surgery is influenced by diagnosis. The thoracic approach is determined by intrathoracic disease, but may influence outcome by affecting the incidence of postoperative wound complications. The risk of thoracic drain complications increases with drain duration, which is influenced by the underlying disease. Drains should be maintained for the minimal amount of time possible.

Combined cytosine arabinoside and prednisone therapy for meningoencephalitis of unknown aetiology in 10 dogs

OBJECTIVES

The differential diagnosis for young to middle-aged dogs with progressive neurological signs, focal or multifocal computed tomography/magnetic resonance imaging lesions, mononuclear cerebrospinal fluid pleocytosis and negative infectious titres includes granulomatous meningoencephalomyelitis, breed-specific meningoencephalitis, infectious meningoencephalitis of unknown origin and central nervous system neoplasia. The terminology meningoencephalitis of unknown aetiology may be preferable for cases that lack histopathological diagnoses. The safety and efficacy of a combination of cytosine arabinoside and prednisone protocol is evaluated, in this study, for the treatment of meningoencephalitis of unknown aetiology in 10 dogs.

METHODS

Cases were selected based on neuroanatomical localisation, negative regional infectious disease titres, cerebrospinal fluid pleocytosis and brain imaging. Clinical response was gauged through follow-up examinations, owner and referring veterinarian surveys and review of medical records.

RESULTS

Partial or complete remission was achieved in all dogs; the median survival time for the 10 dogs was 531 days (range 46 to 1025 days), with five of the 10 dogs alive at the time of writing.

CLINICAL SIGNIFICANCE

Prednisone/cytosine arabinoside is a safe empirical therapy for dogs with meningoencephalitis of unknown aetiology; this drug combination may prolong survival time.

Cyanide poisoning deaths in dogs

In 2005, the deaths of three dogs were reported in Erdek, Turkey. Examining appropriate historical and clinical signs, postmortem findings and the discovery of cyanide in their stomachs and intestinal contents and livers supported a diagnosis of cyanide poisoning.

Long-term survival and risk factors associated with biliary surgery in dogs: 34 cases (1994–2004)

OBJECTIVE

To determine factors associated with long-term survival after biliary surgery in dogs.

DESIGN

Retrospective case series.

ANIMALS

34 dogs that underwent biliary surgery.

PROCEDURES

Data extracted from medical records included sex, breed, body weight, age at surgery, history and clinical examination findings, preoperative and postoperative CBC, serum biochemical panel and coagulation profiles results, abdominal ultrasonographic findings, results of bacteriologic culture and histologic examination, surgical findings, postoperative complications, and survival time. Follow-up information was obtained from medical records or phone conversations with owners and referring veterinarians.

RESULTS

Primary biliary findings included gallbladder mucocele (n = 20 dogs), inflammatory diseases (4), trauma (3), and neoplasia (1). Secondary biliary diseases included pancreatitis (n = 4), pancreatic neoplasia (1), and duodenal perforation (1). One- and 2-year survival rates were both 66%. Increasing age; gamma-glutamyltransferase activity; preanesthetic heart rate; BUN, phosphorus, and bilirubin concentrations; and the use of biliary diversion procedures were risk factors for death, although pancreatitis was not. However, poor long-term survival was associated with pancreatitis.

CONCLUSIONS AND CLINICAL RELEVANCE

Long-term prognosis was guarded after biliary surgery in dogs. However, dogs that survived the early postoperative period had good long-term prognosis. Dogs with pancreatitis had poor prognosis. Overall, the prognosis was worse for dogs that underwent a biliary diversion, compared with dogs that did not.

Radiation Therapy for Incompletely Excised Grade II Canine Mast Cell Tumors

Forty-five dogs with incompletely excised grade II mast cell tumors were treated with radiation using a cobalt 60 teletherapy unit (15 fractions of 3.2 Gy for a total of 48 Gy). Twenty-four of the dogs underwent prophylactic regional lymph node irradiation. Three (6.7%) dogs had tumor recurrence, two (4.4%) dogs developed metastasis, and 14 (31%) dogs developed a second cutaneous mast cell tumor. No difference in overall survival rate was observed between the dogs receiving and not receiving prophylactic irradiation of the regional lymph node.

Heart disease as a cause of death in insured Swedish dogs younger than 10 years of age

BACKGROUND

Population-based information on disease occurrence is paramount in clinical decision making and in designing preventative measures, but such information is scarce.

HYPOTHESIS

The risk of cardiac death is higher in certain breeds and mortality varies by age and sex. DOGS: Dogs that were life insured by an animal insurance company between 1995 and 2002.

METHODS

The mortality pattern for heart disease in insured dogs up to 10 years of age was studied. The influences of sex, age, breed, month, and geographic location were investigated by means of incidence rates, proportions, and survival proportions. Cox proportional hazards regression was used to model time to heart disease.

RESULTS

405,376 dogs contributed to a denominator of 1,431,933 dog-years at risk (DYAR) and 3,049 dogs had been assigned a cardiac-related diagnosis as cause of death. The cardiac-related mortality for dogs <10 years of age, was 21.3 deaths per 10,000 DYAR. This mortality in males and females was 27.3 deaths and 15.4 deaths per 10,000 DYAR, respectively. Twelve of 54 breeds had a point estimate above the overall rate. The 3 breeds with the highest point estimates were: Irish Wolfhounds, Cavalier King Charles Spaniels, and Great Danes (rates of 356, 247, and 179 deaths per 10,000 DYAR, respectively).

CONCLUSIONS AND CLINICAL IMPORTANCE

Breed, age, and sex affect cardiac mortality in certain breeds of dogs, but no effects of month and geographic location were identified. These findings can assist clinicians in establishing diagnoses, and can assist breeders in defining priorities for preventative measures.

Clinical characteristics and predictors of mortality for Cryptococcus gattii infection in dogs and cats of southwestern British Columbia

Since 1999, Cryptococcus gattii has emerged as an important pathogen of humans and animals in southwestern British Columbia. Historically thought to be restricted to the tropics and subtropics, C. gattii has posed new diagnostic and treatment challenges to veterinary practitioners working within the recently identified endemic region. Clinical reports of canine and feline cryptococcosis caused by C. gattii diagnosed between January 1999 and December 2003 were included in this case series. The most common manifestations of disease were respiratory and central nervous system signs. Multivariate survival analysis revealed that the only significant predictor of mortality was the presence of central nervous system signs upon presentation or during therapy. Case fatality rates in both species were high. Further investigation into effective treatment regimes is warranted.

Capillary and venous Babesia canis rossi parasitaemias and their association with outcome of infection and circulatory compromise

This observational study of 100 dogs naturally infected with Babesia canis rossi determined whether severity of parasitaemia was associated with outcome of infection and documented the relative distribution of parasitised red blood cells (pRBC) in capillary and venous circulation. The association between increased parasitaemias and outcome with a clinically compromised circulation was also investigated. Outcome was defined as either hospitalisation with death, or hospitalisation with eventual recovery or treatment as an outpatient. Dogs were enrolled if large babesias were found on stained thin capillary blood smears made from an ear prick. Thin venous smears were prepared from jugular or cephalic blood. Parasitaemias were manually counted and expressed as the percent pRBC. Ten dogs died, 50 recovered after hospitalisation and 40 were treated as outpatients. Venous sampling site did not affect venous parasitaemia (P=0.6). Both capillary and venous parasitaemias of dogs that died were significantly higher than those of dogs that recovered after hospitalisation (P=0.002) and dogs that were treated as outpatients (P<0.0001). When assessing the whole group, capillary parasitaemia (median 0.61%, range <0.05-71.6%, interquartile range (IQR) 0.22-3.75%) was significantly higher than venous parasitaemia (median 0.14%, range 0-30.6%, IQR 0.046-0.52%) with P<0.0001. The 21 dogs with a clinically compromised circulation were more likely to die (P<0.0001) and had significantly higher capillary (median 5.98%, range 0.09-71.6%, IQR 2.44-19.41%) and venous (median 2.81%, range <0.05-30.6%, IQR 0.17-9.03%) parasitaemias than the 79 dogs with a clinically normal circulation (capillary median parasitaemia 0.38%, range <0.05-12.87%, IQR 0.16-1.42%; venous median parasitaemia 0.096%, range 0-6.13%, IQR <0.05-0.33%; P<0.0001). This study shows that high parasitaemia is significantly associated with death in B c rossi infected dogs. The previous clinical suspicion that capillary parasitaemias are usually higher than venous parasitaemias is confirmed. Thus capillary samples are the most appropriate diagnostic samples. Prior observations that a clinically compromised circulation is associated with death are confirmed. Despite the highly significant association between compromised circulation and higher parasitaemia, it is thought unlikely that parasite burden is the sole trigger for circulatory collapse.

Acute hepatic failure and coagulopathy associated with xylitol ingestion in eight dogs

CASE DESCRIPTION

8 adult dogs were evaluated for treatment of lethargy and vomiting after ingestion of xylitol, a sugar alcohol used as a sweetener in various products.

CLINICAL FINDINGS

In addition to vomiting and lethargy, 5 of the dogs had widespread petechial, ecchymotic, or gastrointestinal tract hemorrhages. Common clinicopathologic findings included moderately to severely high serum activities of liver enzymes, hyperbilirubinemia, hypoglycemia, hyperphosphatemia, prolonged clotting times, and thrombocytopenia. Necropsies were performed on 3 dogs and severe hepatic necrosis was found in 2. In the third dog, histologic examination revealed severe hepatocyte loss or atrophy with lobular collapse.

TREATMENT AND OUTCOME

Treatments varied among dogs and included IV administration of fluids; plasma transfusions; and, if indicated, administration of dextrose. Three dogs were euthanatized, 2 dogs died, 2 dogs made a complete recovery, and 1 dog was recovering but was lost to follow-up.

CLINICAL RELEVANCE

Although xylitol causes hypoglycemia in dogs, hepatic failure after ingestion has not previously been reported. Because an increasing number of consumer products contain xylitol, clinicians should be aware that ingestion of xylitol can have serious, life-threatening effects.

Evaluation of survival time in dogs with stage III osteosarcoma that undergo treatment: 90 cases (1985-2004)

OBJECTIVE-To assess survival time in dogs that underwent treatment for stage III osteosarcoma and evaluate factors affecting survival. DESIGN-Retrospective case series. ANIMALS-90 dogs with stage III osteosarcoma. PROCEDURES-Records in the osteosarcoma database at the Animal Cancer Center at Colorado State University from 1985 to 2004 were searched for dogs with metastatic disease at the time of evaluation. Dogs were included in the study if they had metastasis to any site and if treatment was initiated. A Kaplan-Meier survival analysis was performed, and the influences of age, sex, breed, primary tumor site, metastatic sites, and treatment on outcome were analyzed via log-rank analysis. RESULTS-Median survival time was 76 days, with a range of 0 to 1,583 days. No significant differences in survival times on the basis of age, sex, breed, or primary site were observed. Breeds and primary tumor sites were typical of those usually associated with osteosarcoma in dogs. Dogs treated palliatively with radiation therapy and chemotherapy had a significantly longer survival time (130 days) than dogs in all other treatment groups. Dogs treated with surgery alone had a significantly shorter survival time (3 days) than dogs treated with surgery and chemotherapy (78 days). Dogs with bone metastases had a longer survival time than dogs with soft tissue metastases. CONCLUSIONS AND CLINICAL RELEVANCE-Treatment of dogs with stage III osteosarcoma can result in various survival times. Dogs with metastasis to bone and dogs that were treated palliatively with radiation and chemotherapy had the longest survival times.

Subtotal intracapsular prostatectomy as a useful treatment for advanced-stage prostatic malignancies

OBJECTIVES

Palliative surgery for advanced-stage prostatic cancers was tested with regard to survival rate and complications in a prospective randomised clinical study of dogs. Currently, therapeutic approaches have a grave long-term prognosis in clinically significant prostatic cancer.

METHODS

Of 167 dogs with prostatic disorders, 24 were diagnosed with prostatic cancer. Eleven dogs underwent subtotal intracapsular prostatectomy, while in 10 dogs total prostatectomy was performed. The remaining three dogs were euthanased at their owner's request. Dogs treated by subtotal intracapsular prostatectomy and those treated by total prostatectomy were followed until their death.

RESULTS

It was found that dogs treated by subtotal intracapsular prostatectomy survived 5.63 times longer (mean [sd] 112.0 [63.03] days) than those treated by total prostatectomy (19.9 [10.67] days) (P<0.01). Moreover, a significant decrease in postoperative complications after subtotal intracapsular prostatectomy was recorded, especially with regard to urinary incontinence.

CLINICAL SIGNIFICANCE

It was concluded that, in the authors' facility, treatment of prostatic cancer by subtotal intracapsular prostatectomy was superior to that by total prostatectomy, with respect to both postoperative survival and serious complications.

Evaluation of factors associated with survival in dogs with untreated nasal carcinomas: 139 cases (1993-2003)

OBJECTIVE

To evaluate factors associated with survival in dogs with nasal carcinomas that did not receive treatment or received only palliative treatment.

DESIGN

Retrospective case series.

ANIMALS

139 dogs with histologically confirmed nasal carcinomas.

PROCEDURES

Medical records, computed tomography images, and biopsy specimens of nasal carcinomas were reviewed. Only dogs that were not treated with radiation, surgery, chemotherapy, or immunotherapy and that survived > or = 7 days from the date of diagnosis were included. The Kaplan-Meier method was used to estimate survival time. Factors potentially associated with survival were compared by use of log-rank and Wilcoxon rank sum tests. Multivariable survival analysis was performed by use of the Cox proportional hazards regression model.

RESULTS

Overall median survival time was 95 days (95% confidence interval [CI], 73 to 113 days; range, 7 to 1,114 days). In dogs with epistaxis, the hazard of dying was 2.3 times that of dogs that did not have epistaxis. Median survival time of 107 dogs with epistaxis was 88 days (95% CI, 65 to 106 days) and that of 32 dogs without epistaxis was 224 days (95% CI, 54 to 467 days).

CONCLUSIONS AND CLINICAL RELEVANCE

The prognosis of dogs with untreated nasal carcinomas is poor. Treatment strategies to improve outcome should be pursued.

Evaluation of intracranial meningioma resection with a surgical aspirator in dogs: 17 cases (1996-2004)

OBJECTIVE

To determine results of intracranial meningioma resection by use of a surgical aspirator and assess prognostic factors associated with intracranial meningiomas in dogs.

DESIGN

Retrospective case series.

ANIMALS

17 dogs.

PROCEDURES

Medical records of dogs that underwent resection of an intracranial meningioma by use of a surgical aspirator were reviewed. Information pertaining to signalment, imaging findings, clinical signs, duration of clinical signs, preoperative treatment, location of the tumor, results of histologic assessment, outcome, and necropsy results was obtained from the medical record. Clients and referring veterinarians were contacted via telephone for information on recurrence of clinical signs and postoperative survival time.

RESULTS

16 dogs were > 7 years of age, and all 17 dogs had seizures before surgery. The most commonly affected breed was the Golden Retriever, represented by 6 of the 17 dogs. Median survival time was 1,254 days. Of the data collected, only histologic subtype of the tumor was prognostic. Analysis of survival times according to histologic tumor subtypes indicated that the order from most brief to longest was as follows: anaplastic, 0 days; fibroblastic, 10 days; psammomatous, > 313 days; meningothelial, > 523 days; and transitional, 1,254 days.

CONCLUSIONS AND CLINICAL RELEVANCE

Use of a surgical aspirator to resect intracranial meningiomas in dogs was associated with longer survival times than those achieved with traditional surgery alone or traditional surgery combined with radiation therapy. Dogs with meningothelial, psammomatous, or transitional intracranial meningioma subtypes appeared to have a better prognosis than dogs with other subtypes of meningioma.

Evaluation of the relationship between causative organisms and clinical characteristics of infective endocarditis in dogs: 71 cases (1992-2005)

OBJECTIVE

To evaluate microbiologic findings in dogs with infective endocarditis (IE) and determine whether there were differences in clinical features of disease caused by different groups of infective agents.

DESIGN

Retrospective case series.

ANIMALS

71 dogs with suspected or definite IE.

PROCEDURES

Medical records were reviewed for results of bacterial culture and susceptibility testing, serologic assays for vector-borne disease, and PCR testing on vegetative growths. Cases were grouped by causative organism and relationships among infectious agent group, and various hematologic, biochemical, and clinical variables were determined. Survival analyses were used to determine associations between infecting organisms and outcome.

RESULTS

Causative bacteria were identified in 41 of 71 (58%) dogs. Gram-positive cocci were the causative agents in most (21/41; 51%) infections, with Streptococcus canis associated with 24% of infections. Gram-negative organisms were detected in 9 of the 41 (22%) dogs. Infection with Bartonella spp was detected in 6 of 31 (19%) dogs with negative results for microbial growth on blood culture. Aortic valve involvement and congestive heart failure were more frequent in dogs with endocarditis from Bartonella spp infection, and those dogs were more likely to be afebrile. Infection with Bartonella spp was negatively correlated with survival. Mitral valve involvement and polyarthritis were more frequent in dogs with streptococcal endocarditis.

CONCLUSIONS AND CLINICAL RELEVANCE

Streptococci were the most common cause of IE and were more likely to infect the mitral valve and be associated with polyarthritis. Dogs with IE secondary to Bartonella spp infection were often afebrile, more likely to develop congestive heart failure, rarely had mitral valve involvement, and had shorter survival times.

Signalment, clinical signs, and prognostic indicators associated with high-grade second- or third-degree atrioventricular block in dogs: 124 cases (January 1, 1997-December 31, 1997)

OBJECTIVE

To evaluate signalment, clinical signs, and prognosis associated with high-grade second- or third-degree atrioventricular block (AVB) in dogs.

DESIGN

Retrospective case series.

ANIMALS

124 dogs.

PROCEDURES

Data were gathered from ECGs, veterinarian questionnaires, echocardiograms, and radiographs submitted for review; compared with data from a large control group; and examined for association between variables and duration of survival. A new classification system for AVB was evaluated.

RESULTS

Afghan, Catahoula Leopard Dog, Chow Chow, Cocker Spaniel, German Wirehaired Pointer, and Labrador Retriever breeds were predisposed to high-grade second- or third-degree AVB. Heavier, older, and sexually intact female dogs were overrepresented in the study group. Weakness, lethargy, exercise intolerance, and syncope were the most common clinical signs. The presence of clinical signs was not associated with duration of survival. Dogs with high-grade second-degree AVB had a duration of survival similar to that of dogs with third-degree AVB. Dogs with high-grade second- or third-degree AVB were at high risk for sudden death in the first 6 months after diagnosis. High ventricular escape rhythm rate and narrow escape-complex QRS width were negatively associated with duration of survival. Pacemaker implantation had a significant positive association with survival.

CONCLUSIONS AND CLINICAL RELEVANCE

Pacemaker implantation should be strongly considered in all dogs with high-grade second- or third-degree AVB regardless of whether clinical signs are evident. If medical treatment is warranted, vagolytic medications may be the best choice. A new classification system for AVB may merit further investigation.

Clinical Efficacy of Pimobendan Versus Benazepril for the Treatment of Acquired Atrioventricular Valvular Disease in Dogs

Seventy-six dogs with clinical acquired atrioventricular valvular disease were evaluated to determine the efficacy of pimobendan (n=41) versus benazepril hydrochloride (n=35) in a randomized, positive-controlled, multicenter study. The study was divided into 56-day and long-term evaluation periods. In a subgroup of dogs with concurrent furosemide treatment (pimobendan [n=31], benazepril [n=25]), the Heart Insufficiency Score improved in favor of pimobendan (P=0.0011), equating to a superior overall efficacy rating (P&lt;0.0001) at day 56. Long-term median survival (i.e., death or treatment failure) for dogs receiving pimobendan was 415 days versus 128 days for dogs not on pimobendan (P=0.0022).

Vascular endothelial growth factor expression in canine intracranial meningiomas and association with patient survival

BACKGROUND

Vascular endothelial growth factor (VEGF) is a regulator of angiogenesis and vascular permeability. In human patients with meningiomas, increased VEGF expression is predictive of postsurgical recurrence. The objectives of this study were to evaluate VEGF expression in canine intracranial meningiomas and to determine whether an association between VEGF expression and patient survival existed.

METHODOLOGY

Tumor tissue from 17 dogs with histologically confirmed intracranial meningiomas was obtained surgically. All dogs then were treated with radiotherapy. Immunohistochemistry was performed on 5-microm sections of paraffin-embedded tumor tissue with rabbit anti-human VEGF polyclonal antibody. The extent, intensity, and distribution of VEGF staining for each section were assessed with light microscopy by means of a semiquantitative scale. Survival was analyzed by the Kaplan-Meier procedure. Survival rates among groups were compared by log-rank tests with the significance set at P < or = .05.

FINDINGS

VEGF expression was detected in all tumors, with >50% of cells staining positively in tissues from 15/17 dogs. Shorter survival times were associated with greater VEGF expression (P = .01).

CONCLUSIONS

VEGF expression can be measured in canine intracranial meningiomas and may be associated with poor outcome.

SIGNIFICANCE

The extent of VEGF expression in canine intracranial meningiomas may be used as a prognostic marker and suggests a potential future target for therapy.