Broadly reactive pan-paramyxovirus reverse transcription polymerase chain reaction and sequence analysis for the detection of Canine distemper virus in a case of canine meningoencephalitis of unknown etiology

Despite the immunologic protection associated with routine vaccination protocols, Canine distemper virus (CDV) remains an important pathogen of dogs. Antemortem diagnosis of systemic CDV infection may be made by reverse transcription polymerase chain reaction (RT-PCR) and/or immunohistochemical testing for CDV antigen; central nervous system infection often requires postmortem confirmation via histopathology and immunohistochemistry. An 8-month-old intact male French Bulldog previously vaccinated for CDV presented with multifocal neurologic signs. Based on clinical and postmortem findings, the dog's disease was categorized as a meningoencephalitis of unknown etiology. Broadly reactive, pan-paramyxovirus RT-PCR using consensus-degenerate hybrid oligonucleotide primers, combined with sequence analysis, identified CDV amplicons in the dog's brain. Immunohistochemistry confirmed the presence of CDV antigens, and a specific CDV RT-PCR based on the phosphoprotein gene identified a wild-type versus vaccinal virus strain. This case illustrates the utility of broadly reactive PCR and sequence analysis for the identification of pathogens in diseases with unknown etiology.

Native shrub reestablishment in exotic annual grasslands: do ecosystem processes recover?

The impacts of exotic plant species on ecosystem processes are well established, motivating numerous efforts to facilitate native-species recovery. Nonetheless, how the return of native species influences ecosystem processes and how these changes feed back to influence the recovery process are poorly understood. We examined these questions in exotic annual grasslands on Santa Cruz Island, California, USA, where the removal of nonnative herbivores has led to the recovery of the native shrubs Artemisia californica and Eriogonum arborescens. To examine the influence of shrub colonization on nutrient cycling, and the mechanisms by which these changes arise, we measured available nitrogen and phosphorus, and quantified nitrogen mineralization and litterfall rates under shrubs and grasses in the field and in experimental monoculture plots. Both native shrubs altered nitrogen cycling as they colonized the grassland, but they did so in opposite directions. Eriogonum depressed nitrogen pools and mineralization rates via large inputs of nitrogen-poor litter. In contrast Artemisia increased nitrogen and phosphorus pools and nitrogen mineralization rates. Last, to determine if shrub effects on soils favor shrubs or grasses, we conducted a nitrogen and phosphorus fertilization experiment in the field. Only the exotic grass was significantly limited by nitrogen. Thus the depressed nitrogen availability associated with Eriogonum colonization is more harmful to exotic grasses than to the native shrub. By contrast, the elevated nitrogen associated with recovering Artemisia favors grasses over the shrub, possibly hindering recovery of the native. Mechanistic studies of the ecosystem ,impacts of native-plant recovery are useful for managers wishing to predict which native species return ecosystem function, and whether such changes feed back to influence native recovery.

Arrhythmias and elevated troponin I in a dog with steroid-responsive meningitis-arteritis

A 10-month-old dog was presented with clinical signs of fever, lethargy, inappetence, and cardiac arrhythmias. Computed tomography scan and cerebrospinal fluid analysis supported the diagnosis of steroid-responsive meningitis-arteritis. Echocardiography, electrocardiogram, and elevated serum troponin I supported a diagnosis of myocarditis. The arrhythmias resolved during treatment of the primary neurological disease, and they were considered as secondary to the meningitis.

Magnetic resonance imaging characteristics of necrotizing meningoencephalitis in Pug dogs

BACKGROUND

The magnetic resonance imaging (MRI) characteristics of necrotizing meningoencephalitis (NME) are not well documented.

OBJECTIVES

To describe common MRI features of NME, to compare the MRI features to histopathologic findings, and to determine whether or not MRI lesions are predictive of survival time.

ANIMALS

Eighteen Pugs with NME.

METHODS

Retrospective MRI case study of Pugs identified by a search of medical records at 6 veterinary institutions. Eighteen dogs met inclusion criteria of histopathologically confirmed NME and antemortem MRI exam. MRI lesions were characterized and compared with histopathology with the kappa statistic. Survival times were compared with MRI findings by use of Mann-Whitney U-tests and Spearman's rho.

RESULTS

Twelve of 18 lesions were indistinctly marginated with mild parenchymal contrast enhancement. Prosencephalic (17/18) lesion distribution included the parietal (16/18), temporal (16/18), and occipital (16/18) lobes. There were cerebellar (4/18) and brainstem (3/18) lesions. Asymmetric lesions were present in both gray and white matter in all dogs. Falx cerebri shift was common (11/18), and 6 dogs had brain herniation. Leptomeningeal enhancement was present in 9/18 dogs. A moderate positive association was found between parenchymal contrast enhancement and both necrosis (kappa= 0.45; P= .045) and monocytic inflammation (kappa= 0.48; P= .025). Higher MRI lesion burden was correlated with longer time from disease onset to MRI (P= .045). MRI lesion burden did not correlate to survival time.

CONCLUSIONS AND CLINICAL IMPORTANCE

Asymmetric prosencephalic grey and white matter lesions with variable contrast enhancement were consistent MRI changes in Pugs with confirmed NME. While not pathognomonic for NME, these MRI characteristics should increase confidence in a presumptive diagnosis of NME in young Pugs with acute signs of neurologic disease.

Direct and indirect effects of climate change on a prairie plant community

BACKGROUND

Climate change directly affects species by altering their physical environment and indirectly affects species by altering interspecific interactions such as predation and competition. Recent studies have shown that the indirect effects of climate change may amplify or counteract the direct effects. However, little is known about the the relative strength of direct and indirect effects or their potential to impact population persistence.

METHODOLOGY/PRINCIPAL FINDINGS

We studied the effects of altered precipitation and interspecific interactions on the low-density tiller growth rates and biomass production of three perennial grass species in a Kansas, USA mixed prairie. We transplanted plugs of each species into local neighborhoods of heterospecific competitors and then exposed the plugs to a factorial manipulation of growing season precipitation and neighbor removal. Precipitation treatments had significant direct effects on two of the three species. Interspecific competition also had strong effects, reducing low-density tiller growth rates and aboveground biomass production for all three species. In fact, in the presence of competitors, (log) tiller growth rates were close to or below zero for all three species. However, we found no convincing evidence that per capita competitive effects changed with precipitation, as shown by a lack of significant precipitation x competition interactions.

CONCLUSIONS/SIGNIFICANCE

We found little evidence that altered precipitation will influence per capita competitive effects. However, based on species' very low growth rates in the presence of competitors in some precipitation treatments, interspecific interactions appear strong enough to affect the balance between population persistence and local extinction. Therefore, ecological forecasting models should include the effect of interspecific interactions on population growth, even if such interaction coefficients are treated as constants.

Effect of mannitol and hypertonic saline on cerebral oxygenation in patients with severe traumatic brain injury and refractory intracranial hypertension

BACKGROUND

The impact of osmotic therapies on brain oxygen has not been extensively studied in humans. We examined the effects on brain tissue oxygen tension (PbtO(2)) of mannitol and hypertonic saline (HTS) in patients with severe traumatic brain injury (TBI) and refractory intracranial hypertension.

METHODS

12 consecutive patients with severe TBI who underwent intracranial pressure (ICP) and PbtO(2) monitoring were studied. Patients were treated with mannitol (25%, 0.75 g/kg) for episodes of elevated ICP (>20 mm Hg) or HTS (7.5%, 250 ml) if ICP was not controlled with mannitol. PbtO(2), ICP, mean arterial pressure, cerebral perfusion pressure (CPP), central venous pressure and cardiac output were monitored continuously.

RESULTS

42 episodes of intracranial hypertension, treated with mannitol (n = 28 boluses) or HTS (n = 14 boluses), were analysed. HTS treatment was associated with an increase in PbtO(2) (from baseline 28.3 (13.8) mm Hg to 34.9 (18.2) mm Hg at 30 min, 37.0 (17.6) mm Hg at 60 min and 41.4 (17.7) mm Hg at 120 min; all p<0.01) while mannitol did not affect PbtO(2) (baseline 30.4 (11.4) vs 28.7 (13.5) vs 28.4 (10.6) vs 27.5 (9.9) mm Hg; all p>0.1). Compared with mannitol, HTS was associated with lower ICP and higher CPP and cardiac output.

CONCLUSIONS

In patients with severe TBI and elevated ICP refractory to previous mannitol treatment, 7.5% hypertonic saline administered as second tier therapy is associated with a significant increase in brain oxygenation, and improved cerebral and systemic haemodynamics.

Cervical spinal locking plate in combination with cortical ring allograft for a one level fusion in dogs with cervical spondylotic myelopathy

OBJECTIVE

To evaluate use of a surgical technique commonly used in humans for treatment of cervical spondylotic myelopathy (CSM) in dogs.

DESIGN

Prospective case series.

ANIMALS

Dogs with CSM (n=10).

METHODS

Dogs weighing >30 kg that had CSM at 1 vertebral articulation were eligible for inclusion. Dogs had vertebral column distraction/fusion performed using a cortical ring allograft, cancellous autograft, and a spinal locking plate. Dogs were evaluated temporally by repeat neurological examinations and by client perception of postsurgical outcome, determined by telephone interview.

RESULTS

Nine dogs survived the immediate postoperative period. Seven of 8 dogs had moderate to complete improvement without recurrence (mean follow-up, 2.48 years). The most common postsurgical complications were screw loosening (n=4) and plate shifting (2), neither of which required surgical revision. One dog had pseudoarthrosis that may have negatively impacted outcome.

CONCLUSION

Treatment of single level CSM in dogs with ring allograft and a spinal locking plate system may lead to successful outcomes. The major problems encountered with included cost of the implants and adjusting the system designed for humans to fit the vertebral column of a dog.

CLINICAL RELEVANCE

For dogs with CSM at a single level, the use of a spinal locking plate in combination with a cortical ring allograft can be an effective surgical treatment. Costs of the implants as well as anatomic differences in dogs make this type of surgery less appealing.

Immunohistochemical features of a feline spinal cord gemistocytic astrocytoma

A gemistocytic astrocytoma is described in the spinal cord of a 3-year-old, spayed, female, Domestic Shorthair cat. The neoplasm was tested for glial fibrillar acidic protein (GFAP), epidermal growth factor receptor (EGFR), and p53 protein expression. On histologic examination, the neoplastic cells were pleomorphic, with distinct cell borders and abundant cytoplasm that frequently extended into variably sized fibrillar processes. Neoplastic cells were strongly positive for GFAP and negative for EGFR. Eight percent (mean percentage) of neoplastic cells were p53 positive. Only 1 p53-positive cell was found in the normal spinal cord. The increased expression of p53 in the neoplasm was suggestive of an abnormal biological behavior of the p53 protein and its possible involvement in the neoplastic process of feline astrocytoma.

Associations of sex, breed, and age with cervical vertebral compressive myelopathy in horses: 811 cases (1974-2007)

OBJECTIVE

To determine sex, breed, and age distributions in a population of horses with cervical vertebral compressive myelopathy (CVCM), compared with contemporaneous control horses.

DESIGN

Retrospective case-control study.

ANIMALS

811 horses with CVCM and 805 control horses.

PROCEDURES

The Veterinary Medical Database was searched to identify horses with CVCM and contemporaneous control horses registered between July 1974 and August 2007. Admission date, admitting institution, sex, breed, age at the time of registration in the database, weight, and discharge status (alive, died, or euthanized) were recorded for each case and control horse.

RESULTS

On the basis of results of multivariable logistic regression analysis, geldings and sexually intact males had a significantly higher likelihood of having CVCM than females (odds ratio [OR], 2.0 [95% confidence interval, 1.5 to 2.6]; and OR, 2.4 [95% confidence interval, 1.8 to 3.2], respectively). Thoroughbreds, Tennessee Walking Horses, and Warm-bloods were overrepresented in the CVCM group, compared with Quarter Horses. Horses that ranged from < 6 months to < 7 years of age had significantly higher odds of having CVCM, compared with horses > or = 10 years of age.

CONCLUSIONS AND CLINICAL RELEVANCE

Sex, breed, and age predilections were detected in horses with CVCM. Improved understanding of these factors will aid clinical recognition of the disease in groups that may have a high prevalence of CVCM or were previously not recognized to be commonly affected. The results may also stimulate future investigations to further delineate etiopathogenesis, such as breed-related genetic causality.

Epidemiology of necrotizing meningoencephalitis in Pug dogs

Background: Although the histopathologic features of necrotizing meningoencephalitis (NME) have been described previously, little information is available concerning the signalment, geographic distribution, seasonal onset, treatment, and survival of affected dogs.

Animals: Sixty Pugs with NME and 14 contemporaneous control Pugs with other intracranial diseases (non‐NME group).

Methods: Pugs that were euthanized or died because of intracranial disease were prospectively obtained. All dogs had necropsy, histopathology, and testing for various infectious diseases and were subsequently divided into NME and non‐NME groups. Signalment, geographic distribution, seasonal onset, treatment, and survival were compared between groups.

Results: In Pugs with NME, median age at onset of clinical signs was 18 months (range, 4–113 months). A greater proportion of female dogs were present in the NME group (40/60) compared with the control group (6/14). Pugs with NME had a significantly lower mean weight (7.81 kg) than control Pugs (9.79 kg) (P= .012). Mean survival in Pugs with NME was 93 days (range, 1–680 days), with dogs receiving any form of treatment living significantly longer than those that were not treated (P= .003). Anticonvulsive drugs were the only treatment significantly associated with longer survival (P= .003).

Conclusions and Clinical Importance: NME appears to be a common cause of intracranial signs in Pugs, based on the high proportion of NME dogs reported in this population. Pugs with NME are most commonly young adult female dogs. Although further investigation is needed to determine the optimal treatment of NME, anticonvulsive drugs appear to beneficially affect duration of survival.

Evaluation of a questionnaire for obtaining owner-perceived, weighted quality-of-life assessments for dogs with spinal cord injuries

OBJECTIVE

To evaluate a questionnaire for obtaining owner-perceived, weighted quality-oflife assessments for dogs with spinal cord injuries.

DESIGN

Evaluation study. Animals-100 dogs with spinal cord injuries and 48 healthy control dogs.

PROCEDURES

The questionnaire was adapted from a questionnaire (the schedule for the evaluation of individual quality of life-direct weighting) used for human patients. Specifically, owners were asked to identify 5 areas or activities they believed had the most influence on their dogs' quality of life, assess their dogs' current status in each of those areas, and provide a weighting for the importance of each area. Results were used to construct a weighted quality-of-life score ranging from 0 to 100 for each dog. Owners were also asked to provide a quality-of-life score with a visual analog scale (VAS).

RESULTS

A good correlation was found between weighted and VAS quality-of-life scores. Dogs with spinal cord injuries had weighted quality-of-life scores that were significantly lower than scores for control dogs. Quality-of-life areas and activities provided by owners of dogs with spinal cord injuries were similar to areas and activities provided by owners of healthy control dogs and could mostly be encompassed by 5 broader domains: mobility, play or mental stimulation, health, companionship, and other.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that the questionnaire could be used to obtain owner-perceived, weighted quality-of-life assessments for dogs with spinal cord injuries. Obtaining owner-perceived quality-of-life assessments for individual dogs should allow veterinarians to better address quality-of-life concerns and expectations of owners.

Owner-perceived, weighted quality-of-life assessments in dogs with spinal cord injuries

OBJECTIVE

To evaluate changes over time in owner-perceived, weighted quality-of-life assessments in dogs with spinal cord injuries and determine whether scores were associated with underlying etiology or with veterinarian-assigned scores for severity of neurologic dysfunction.

DESIGN

Cohort study.

ANIMALS

100 dogs with spinal cord injury.

PROCEDURES

Duration of dysfunction, modified Frankel neurologic injury score, and etiology were recorded. At initial and recheck (4- to 6-week) evaluations, owners were asked to identify 5 areas or activities they believed had the most influence on their dogs' quality of life, assess their dogs' current status in each area, and provide a weighting for the importance of each area; results were used to construct a weighted quality-of-life score. Owners were also asked to provide a quality-of-life score with a visual analog scale (VAS).

RESULTS

At initial and recheck evaluations, weighted quality-of-life scores were higher for ambulatory than for nonambulatory dogs. However, scores did not differ among groups when dogs were grouped on the basis of underlying etiology or duration of injury. Dogs with an increase in Frankel score between the initial and recheck evaluations had a significant increase in weighted quality-of-life score, whereas for dogs that did not have any change in Frankel score, initial and recheck weighted quality-of-life scores were not significantly different.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that owner-assigned, weighted quality-of-life scores for dogs with spinal cord injuries did not vary significantly on the basis of underlying etiology or duration of injury but were higher for ambulatory than for nonambulatory dogs.

Relationship between glaucoma and selenium levels in plasma and aqueous humour

AIM

The aim of the study was to compare selenium levels in plasma and aqueous humour in subjects with and without primary open-angle glaucoma (POAG).

METHODS

Forty-seven POAG cases and 54 controls in this case-control study were recruited from surgery patients at the University Physician's Ophthalmology Clinic in Tucson, Arizona, USA. Aqueous humour and plasma selenium were determined by high-performance liquid chromatography ion channel plasma mass spectrometry (HPLC ICP-MS). Potential confounders were assessed via a questionnaire. Biological samples were collected and processed at surgery and analysed for selenium content after collection was complete. Outcome measures included the odds of glaucoma in relationship to plasma selenium, aqueous humour selenium, and the ratio of levels of aqueous humour selenium to plasma selenium.

RESULTS

Tertile of selenium and its relationship to POAG was examined. After adjustment for common glaucoma risk factors, the odds of glaucoma in the highest tertile of plasma selenium (OR = 11.3; p = 0.03) and the middle tertile of aqueous humour selenium (OR = 0.06; p = 0.02) was significantly associated with glaucoma.

CONCLUSION

Although a causal pathway cannot be inferred from our analysis, our data, added to that of others, suggest that the pathology is selenium-related.

Confirmed and presumptive cervical vertebral compressive myelopathy in older horses: a retrospective study (1992-2004)

BACKGROUND

Cervical vertebral compressive myelopathy (CVCM) is a common cause of myelopathy in horses aged 6 months to 4 years. Little information is available regarding the types of lesions, treatment, and outcomes in horses with CVCM that are > or =4 years old.

ANIMALS

Twenty-two affected horses (10 with a confirmed diagnosis of CVCM and 12 presumptive cases) and 210 contemporaneous control horses.

METHODS

Horses > or =4 years old that were diagnosed with CVCM between January 1992 and January 2004 were identified from medical records at Texas A&M University and the University of Florida. Data analyzed included history, signalment, neurologic examination findings, lesion location, treatment, and outcome. Signalment was also recorded in a population of contemporaneous controls.

RESULTS

Horses identified had a median age of 8.4 years, and there was a greater percentage of male horses among the cases than among the controls. The most common breeds represented were warmblood (n=6) and quarter horse (n=5) types; warmbloods were significantly (P < .05) overrepresented relative to control horses. The caudal cervical vertebral column was the most common site of CVCM lesions, and the C5-C6 (4/9) and C6-C7 (3/9) articulations were most often identified as abnormal via myelography. The most common lesions seen with radiography and myelography were articular process osteophytes. Of the 22 affected horses, 8 were euthanized and a diagnosis of CVCM was confirmed by necropsy for all; 5 of 8 of these horses had spinal cord compression caused, entirely or in part, by articular process osteophytes. Medical management was the therapy chosen in all horses, and administration of corticosteroids and nonsteroidal anti-inflammatory drugs resulted in improvement in the greatest number of horses.

CONCLUSIONS AND CLINICAL IMPORTANCE

CVCM should be a differential diagnosis in older horses with cervical myelopathy. Articular process osteophytes are the most frequently identified cause of spinal cord compression in this group. Male horses and horses of warmblood or Tennessee Walking Horse breeds may be predisposed to this condition.