United States Department of Agriculture-Agricultural Research Service research on alternatives to methyl bromide: pre-plant and post-harvest

Methyl bromide is a widely used fumigant for both pre-plant and post-harvest pest and pathogen control. The Montreal Protocol and the US Clean Air Act mandate a phase-out of the import and manufacture of methyl bromide, beginning in 2001 and culminating with a complete ban, except for quarantine and certain pre-shipment uses and exempted critical uses, in January 2005. In 1995, ARS built on its existing programs in soil-borne plant pathology and post-harvest entomology and plant pathology to initiate a national research program to develop alternatives to methyl bromide. The focus has been on strawberry, pepper, tomato, perennial and nursery cropping systems for pre-plant methyl bromide use and fresh and durable commodities for post-harvest use. Recently the program has been expanded to include research on alternatives for the ornamental and cut flower cropping systems. An overview of the national research program is presented. Results from four specific research trials are presented, ranging from organic to conventional systems. Good progress on short-term alternatives is being made. These will be used as the foundation of integrated management systems which begin with pre-plant management decisions and continue through post-harvest processing.     

Endoscopic evaluation of the gastroduodenal mucosa to determine the safety of short-term concurrent administration of meloxicam and dexamethasone in healthy dogs

OBJECTIVE: To evaluate the safety, with respect to the development of gastric ulcers and erosions, of concurrent administration of meloxicam and dexamethasone for 3 days to healthy dogs. ANIMALS: 20 conditioned purpose-bred research Beagles. PROCEDURE: Seven days prior to treatment, dogs were anesthetized for endoscopic evaluation of the upper portion of the gastrointestinal tract (ie, the gastric and duodenal mucosa). Five regions of the gastroduodenal area were scored by 2 investigators. Dogs were randomly assigned to 1 of 4 treatment groups as follows: saline-saline, dexamethasone-saline, saline-meloxicam, and dexamethasone-meloxicam groups. On days 1, 2, and 3, dogs received either dexamethasone or saline (0.9% NaCl) solution injections SC twice daily. On days 2, 3, and 4, dogs received either meloxicam or saline solution injections SC once daily. On day 2, dogs were anesthetized for a sham surgery (ie, electrostimulation). On day 5, the gastroduodenal area of each dog was reevaluated by use of endoscopic evaluation and histologic examination of biopsy specimens. RESULTS: The total endoscopic score of the dexamethasone-meloxicam group was significantly greater than the scores of the other groups. The dexamethasone-saline group had a mean cumulative score that was significantly greater than the saline-meloxicam or saline-saline groups. Endoscopic scores of the saline-meloxicam group were not significantly different from scores of the saline-saline group. No significant differences in histologic findings were found between groups. CONCLUSIONS AND CLINICAL RELEVANCE: In healthy dogs, meloxicam appears to be safe with regard to adverse effects on the gastrointestinal tract. Concurrent administration of dexamethasone and meloxicam is more likely to cause gastric erosions than meloxicam administration alone.     

Clinical differentiation of acute necrotizing from chronic nonsuppurative pancreatitis in cats: 63 cases (1996-2001)

OBJECTIVE: To characterize clinical, clinicopathologic, radiographic, and ultrasonographic findings in cats with histologically confirmed acute necrotizing pancreatitis (ANP) or chronic nonsuppurative pancreatitis (CP) and identify features that may be useful in the antemortem differentiation of these disorders. DESIGN: Retrospective study. ANIMALS: 63 cats with histologically confirmed ANP (n = 30) or CP (33). PROCEDURE: Medical records were reviewed for signalment, clinical signs, concurrent diseases, clinicopathologic findings, and results of radiography and ultrasonography. RESULTS: Cats in both groups had similar nonspecific clinical signs, physical examination findings, and radiographic and ultrasonographic abnormalities. Abdominal ultrasonographic abnormalities, including hypoechoic pancreas, hyperechoic mesentery, and abdominal effusion, were found in cats in both groups and, therefore, were not specific for ANP. Cats with CP were significantly more likely to have concurrent diseases than were cats with ANP (100 and 83%, respectively). Clinicopathologic abnormalities were similar between groups; however, serum alanine aminotransferase and alkaline phosphatase activities were significantly higher in cats with CP. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that ANP and CP in cats cannot be distinguished from each other solely on the basis of history, physical examination findings, results of clinicopathologic testing, radiographic abnormalities, or ultrasonographic abnormalities.     

Effects of anesthesia and surgery on serologic responses to vaccination in kittens

OBJECTIVE: To determine the effects of anesthesia and surgery on serologic responses to vaccination in kittens. DESIGN: Prospective controlled trial. ANIMALS: 32 specific-pathogen-free kittens. PROCEDURES: Kittens were assigned to 1 of 4 treatment groups: neutering at 7, 8, or 9 weeks of age or no neutering. All kittens were inoculated with modified-live virus vaccines against feline panleukopenia virus (FPV), feline herpesvirus (FHV), and feline calicivirus (FCV) at 8, 11, and 14 weeks of age and inactivated rabies virus (RV) at 14 weeks of age. Serum antibody titers against FPV, FHV, and FCV were determined at 8, 9, 11, 14, and 17 weeks of age; RV titers were determined at 14 and 17 weeks of age. RESULTS: Serologic responses of kittens neutered at the time of first vaccination (8 weeks) were not different from those of kittens neutered 1 week before (7 weeks) or 1 week after (9 weeks) first vaccination or from those of kittens that were not neutered. In total, 31%, 0%, 69%, and 9% of kittens failed to develop adequate titers against FPV, FCV, FHV, and RV, respectively, by 17 weeks of age. CONCLUSIONS AND CLINICAL RELEVANCE: Neutering at or near the time of first vaccination with a modified-live virus vaccine did not impair antibody responses in kittens. Many kittens that were last vaccinated at 14 weeks of age had inadequate antibody titers at 17 weeks of age. Kittens may be vaccinated in the perioperative period when necessary, and the primary vaccination series should be extended through at least 16 weeks of age.     

Gastric Helicobacter species as a cause of feline gastric lymphoma: a viable hypothesis

Gastric Helicobacter spp. are associated with chronic inflammation and neoplastic transformation in humans as well as domestic and laboratory species. The present study examined the association of Helicobacter heilmannii (Hhe) infection in pet cats with feline gastric mucosa associated lymphoid tissue (MALT) lymphoma. Tissues were collected via gastric biopsy or at necropsy from 47 pet cats with clinical signs of gastrointestinal disease, including vomiting and inappetance, and classified as gastritis (14/47), lymphoma (31/37), or normal (2/47). Tissues positive for argyrophilic organisms with Warthin–Starry stain (29/47) were assessed by fluorescent in situ hybridization (FISH) for the presence of Hhe strains 1–4 as well as with a fifth probe that detected Helicobacter salomonis, Helicobacter bizzozeronii, or Helicobacter felis. A significant association of positive Warthin–Starry status with Hhe infection was found in cases of sick cats (22/29; p < 0.05 by Chi-square; χ² = 7.034). Interestingly, a significant association between Hhe status and a diagnosis of lymphoblastic or lymphocytic lymphoma was observed as well in a subset of 24 Warthin–Starry positive lymphoma cases: of lymphoblastic lymphoma cases, 13/17 were positive for Hhe (p < 0.05; χ² = 4.854). Hhe strains 2 and 4 were most commonly found (18/29 and 17/29, respectively) among sick cats, although a higher than expected number of cats was also positive for Hhe1, which initial reports have described as rare in cats and common in humans. The association found between a positive Hhe status with the presence of feline gastric lymphoma, especially lymphoblastic lymphoma, argues for the need to conduct prospective studies to better identify the frequency and strain distribution of Hhe infection in both healthy and clinically ill cats, particularly those cats with gastric lymphoma.     

An allogeneic hybrid-cell fusion vaccine against canine mammary cancer

Mammary cancer is among the most prevalent of canine tumors frequently resulting in death due to metastatic disease. Most tumors fail to raise an effective immune reaction making improving immune recognition a priority. Hybrid-cell fusion strategies have been employed to load dendritic cell populations with tumor cell antigens to stimulate immune recognition; however, recovery, heterogeneity and quality of primary cells from patients present enormous challenges. We employed allogeneic cell lines to develop an improved hybrid-cell fusion strategy and evaluated immune reactions in normal laboratory beagles. Such a strategy relies on enhanced immune recognition of allogeneic tumor cell antigens by antigen presenting cells. Optimized PEG-promoted fusions between uniquely stained canine mammary tumor CMT12 or CMT28 cells and a dendritic cell-like DH82 cell fusion partner resulted in greater than 40% hybrid-cell fusion populations by flow cytometry and fluorescence microscopy. Hybrid-cell fusions were delivered by direct ultrasound guided injection into popliteal lymph nodes of laboratory beagles. Only hybrid-cell fusions provided statistically significant enhancement of cell-mediated immunity ((51)Cr-release assay) compared to innate reactions in na?ve vehicle injected dogs while dogs vaccinated with either single cell component alone did not. Vaccination with hybrid-cell fusions enhanced IFN-gamma expression in sorted CD8+ and CD4+ cells but not in CD4-/CD8- cells consistent with a CTL response. Cell-mediated immune assays revealed strong reactions against matched (vaccine component) CMT cells and unmatched CMT cells indicative of an immune response to mammary cancer antigens common to both cell lines. These results provide proof of principle for development of an allogeneic vaccination strategy against canine mammary cancer.     

Connectivity of mule deer (Odocoileus hemionus) populations in a highly fragmented urban landscape

Context

Urbanization is a substantial force shaping the genetic and demographic structure of natural populations. Urban development and major highways can limit animal movements, and thus gene flow, even in highly mobile species. Characterizing varying species responses to human activity and fragmentation is important for maintaining genetic continuity in wild animals and for preserving biodiversity. As one of the only common and wide-ranging large wild herbivores in much of urban North America, deer play an important ecological role in urban ecosystems, yet the genetic impacts of development on deer are not well known.

Objectives

We assessed genetic connectivity for mule deer to understand their genetic response to habitat fragmentation, due to development and highway barriers, in an increasingly urbanized landscape.

Methods

Using non-invasive sampling across a broad region of southern California, we investigated genetic structure among several natural areas that were separated by major highways and applied least-cost path modelling to determine if landscape context and highway attributes influence genetic distance for mule deer.

Results

We observed significant yet variable differentiation between subregions. We show that genetic structure corresponds with highway boundaries in certain habitat patches, and that particular landscape configurations more greatly limit gene flow between patches.

Conclusions

As a large and highly mobile species generally considered to be well adapted to human activity, mule deer nonetheless showed genetic impacts of intensive urbanization. Because of this potential vulnerability, mule deer and other ungulates may require further consideration for effective habitat management and maintenance of landscape connectivity in human-dominated landscapes.

     

Multiple-scale prediction of forest loss risk across Borneo

Context

The forests of Borneo have among the highest biodiversity and also the highest forest loss rates on the planet.

Objectives

Our objectives were to: (1) compare multiple modelling approaches, (2) evaluate the utility of landscape composition and configuration as predictors, (3) assess the influence of the ratio of forest loss and persistence points in the training sample, (4) identify the multiple-scale drivers of recent forest loss and (5) predict future forest loss risk across Borneo.

Methods

We compared random forest machine learning and logistic regression in a multi-scale approach to model forest loss risk between 2000 and 2010 as a function of topographical variables and landscape structure, and applied the highest performing model to predict the spatial pattern of forest loss risk between 2010 and 2020. We utilized a naïve model as a null comparison and used the total operating characteristic AUC to assess model performance.

Results

Our analysis produced five main results. We found that: (1) random forest consistently outperformed logistic regression and the naïve model; (2) including landscape structure variables substantially improved predictions; (3) a ratio of occurrence to non-occurrence points in the training dataset that does not match the actual ratio in the landscape biases the predictions of both random forest and logistic regression; (4) forest loss risk differed between the three nations that comprise Borneo, with patterns in Kalimantan highly related to distance from the edge of the previous frontier of forest loss, while Malaysian Borneo showed a more diffuse pattern related to the structure of the landscape; (5) we predicted continuing very high rates of forest loss in the 2010–2020 period, and produced maps of the expected risk of forest loss across the full extent of Borneo.

Conclusions

These results confirm that multiple-scale modelling using landscape metrics as predictors in a random forest modelling framework is a powerful approach to landscape change modelling. There is immense immanent risk to Borneo’s forests, with clear spatial patterns of risk related to topography and landscape structure that differ between the three nations that comprise Borneo.

     

A pilot study examining a proprietary herbal blend for the treatment of canine osteoarthritis pain

Osteoarthritis is the most common joint disease in dogs. Despite the use of nonsteroidal anti-inflammatory drugs (NSAIDs), many owners seek natural therapies; either to augment the response to NSAIDs, or as a replacement. Substantial research has been directed to investigation of novel therapies. A randomized, double-blinded, controlled study was conducted to assess the efficacy of a herbal remedy for treatment of canine osteoarthritis pain. Client-owned dogs (N = 24) with osteoarthritis were enrolled between 2 veterinary hospitals. Each dog underwent veterinary and owner assessment at 0, 4, and 8 weeks, using the Canine Brief Pain Inventory and Hudson activity scale. Blood was collected for a complete blood (cell) count (CBC) and serum chemistry analysis. The product was deemed to be safe and well-tolerated at the manufacturer recommended dosage, with no significant changes seen in the CBC or serum biochemical analyses. Aside from1 dog that developed gastrointestinal upset, all other dogs tolerated the supplement without complication. The supplement did not statistically improve clinical signs in dogs based on veterinary or owner assessments of lameness. There was a treatment/time effect when assessing veterinary pain scores; however, post-hoc analysis suggests no observable benefit of treatment compared with the placebo group at any time point.