EFFECT OF BOLUS SIZE ON DEGLUTITION AND ESOPHAGEAL TRANSIT IN HEALTHY DOGS

Contrast videofluoroscopy is the gold standard procedure for evaluating dysphagia in humans, but quantitative measures vary depending on bolus size and consistency. We hypothesized that quantitative measures made during videofluoroscopy of swallowing in dogs would differ between bolus sizes and consistencies. Ten healthy adult dogs were enrolled a prospective, crossover experimental study and underwent contrast videofluoroscopy while swallowing liquid (5, 10, and 15 ml) and canned food (3, 8, and 12 g) boluses. Maximum pharyngeal contraction occurred significantly later with medium solid boluses than with medium liquid boluses, with a mean difference of 0.021 s (adjusted P = 0.042). Upper esophageal sphincter opening occurred significantly earlier with large solid boluses than with medium solid boluses, with a mean difference of 0.018 s (adjusted P = 0.025). Thoracic esophageal transit time was significantly longer with small solid boluses than with small liquid boluses, with a mean difference of 0.68 s (adjusted P = 0.004). Odds of primary esophageal peristalsis occurring were significantly (18.5 times) higher with large solid vs. large liquid boluses (adjusted P = 0.031). No other statistical comparisons reached significance. Based on these results, we recommend a standardized approach to videofluoscopy in dogs with determination of quantitative measures using medium liquid and soft food boluses to minimize effects of size. Furthermore, we conclude that measurements made on liquid swallows should not be directly compared to measurements made on soft food boluses.     

Soil Disinfestation with Steam: A Review of Economics,Engineering, and Soil Pest Control in California Strawberry

ABSTRACT

Increasingly stricter fumigant regulations will limit their use and require effective non-fumigant treatments if large-scale strawberry production is to continue in California. Steam has long been used for soil disinfestation in greenhouse soils where it controls most soil pests. The challenge of field-scale soil disinfestation with steam in place of fumigants is availability of machinery capable of treating a large acreage in a timely manner while making the most efficient use of fuel and water. Steam can be a component within an integrated set of fumigant and non-fumigant practices. Steam used together with other practices may permit technically and economically sustainable strawberry production into the future by allowing growers to adapt to more stringent fumigant use restrictions. It may be possible to overcome some of the limitations of steam because steam generator technology has advanced in recent years as well as recent developments in co-applications with steam, including exothermic compounds co-applied with steam and mustard seed meal co-applied with steam. Regarding steam generator technology, direct-fire steam generators are more energy efficient than traditional steam boilers and avoid the hazards of steam pressure vessels. Steam is arguably the most effective non-fumigant method of soil disinfestation and it likely has a role in a future California strawberry production system that is forced to use much less fumigant than it does at present.     

Use of an axial pattern flap and nictitans to reconstruct medial eyelids and canthus in a dog

A 10-year-old male neutered Boxer presented with recurrence of a mast cell tumor at the right medial canthal area. Following excision including 2 cm margins, the medial one-half of the upper and lower eyelids and the medial canthus were reconstructed using an axial pattern flap based on the cutaneous branch of the superficial temporal artery. The bulbar conjunctiva of the nictitans was preserved and sutured to the medial flap edge, thus creating a conjunctival lining to the deep aspect of the flap, protecting corneal epithelium. This is a valuable surgical technique for closing a large skin defect and reconstructing the medial eyelids, thus preserving the globe.     

Exploring relationships between body condition score,body fat,activity level and inflammatory biomarkers

Obesity is associated with inflammatory disorders in humans, including degenerative joint disease. While obesity is endemic in horses, its relationship to equine degenerative joint disease has not been explored. The current study sought to describe relationships between: body weight (BW), body condition score (BCS), lameness grade (AAEP), total body fat mass (kg; FM) and fat per cent (FP) [multifrequency bioelectrical impedance analysis (mfBIA)], age, gender, activity level (AL), synovial fluid (SF) and plasma (PL) PGE₂ and glycosaminoglycan (GAG) in horses. During this field investigation, the BCS (of nine) of 54 horses at multiple farms in southern Ontario, Canada, was determined. Horses were categorized as thin (BCS=3/9; n = 6), moderate (BCS=4 or 5/9; n = 18), overweight (BCS=6 or 7/9; n = 19) or obese (BCS=8 or 9/9; n = 11). Total fat mass (kg) and body fat% was measured using mfBIA, lameness was assessed (AAEP lameness scale) and synovial fluid was collected via aseptic arthrocentesis from the left intercarpal joint for assessment of inflammatory biomarkers (PGE₂, GAG). Means were compared with a one‐way ANOVA; correlation coefficients were calculated using a Spearman Rank Order Correlation to reveal correlations between variables. BCS was positively correlated with BW, FM, FP, AL and PL‐PGE₂. BW was also significantly positively correlated with PL‐PGE₂. It is concluded that BCS is significantly correlated with PL‐PGE₂, due in part to the combined effect of AL and body condition. Net inflammatory effects of body fat on risk for joint disease require further study.     

The prevalence of dynamic pharyngeal collapse is high in brachycephalic dogs undergoing videofluoroscopy

The aim of this retrospective study was to determine the frequency of pharyngeal collapse in a large group of brachycephalic dogs undergoing videofluoroscopic assessment of swallowing or airway diameter. We hypothesized that brachycephalic dogs would have pharyngeal collapse more frequently than dolichocephalic or mesocephalic dogs with or without airway collapse. The medical records database was searched for brachycephalic dogs undergoing videofluoroscopy of swallowing or airway diameter between January 1, 2006 and December 31, 2015. A cohort of dolichocephalic/mesocephalic dogs with videofluoroscopically confirmed airway collapse was age and time matched for comparison. A control group of dolichocephalic/mesocephalic dogs that did not have documented airway collapse was also evaluated. All fluoroscopic studies were assessed by a board certified veterinary radiologist for the presence and degree of pharyngeal collapse. Results demonstrate that pharyngeal collapse was significantly more common in brachycephalic dogs (58/82; 72%) than in nonbrachycephalic dogs with (7/25; 28%) and without (2/30; 7%) airway collapse. Pharyngeal collapse is more prevalent in brachycephalic dogs undergoing videofluoroscopy than in dolichocephalic/mesocephalic dogs with or without airway collapse.     

An investigation into the bacterial contamination of goniolenses in use in clinical practice

Objectives To report the incidence and evaluate the clinical significance of goniolens bacterial contamination in clinical use in dogs with three different usage protocols and one with an added cleaning protocol. Animals Studied and Methods Three groups of twenty dogs undergoing gonioscopy at a private practice in the UK had the goniolenses swabbed for bacteriology culture and identification prior to placement on the cornea. Three protocols of lens use, with 2 different types of goniolens, were studied. One protocol was then repeated with 21 dogs with a lens cleaning protocol prior to storage. Results Low levels of bacterial contamination were found in all 3 initial groups (10‐15%). No correlation was found between usage protocol used and rate of contamination and no correlation was found between length of storage between use and contamination. All bacteria cultured were considered naturally occurring commensals for the canine eye and environment. The group with a cleaning protocol had a 4.7% contamination rate. This was not statistically different from the non‐cleaning groups. Conclusions The rate of bacterial contamination of goniolenses in clinical practice is low and the bacterial contaminants consist of commensal bacteria, unlikely to be of detriment to the eye. Minimal contamination of the goniolenses was found and this did not appear to be of clinical significance. The introduction of a simple cleaning protocol did not produce a statistically significant reduction in bacterial contamination.     

Xylem exudate concentrations of cofactor nutrients in grapevine are correlated with exudation rate

Xylem exudates collected from the cut canes of Vitis vin‐ifera L. var. Waltham Cross for 10 weeks around the time of budburst were analyzed for nutrient concentrations. The seasonal variations of the inorganic constituents examined [phosphorus (P), calcium (Ca), potassium (K), magnesium (Mg), manganese (Mn), zinc (Zn), iron (Fe), copper (Cu), sodium (Na), and chlorine (Cl)] are presented and discussed with respect to the metabolic needs of the plant as it breaks dormancy. Of particular interest was the observation that some of the nutrients (Ca, K, Mg, Mn, Zn, and Fe) showed similar seasonal variations in their concentrations. These variations were significantly correlated with the rate of xylem exudate flow. Other essential nutrients which are not enzyme cofactors did not show this variation. We propose that these variations, similar to the previously noted variation of organic acids in grapevine xylem exudate, reflect a flow‐dependent uptake and/or remobilization of nutrients to facilitate budburst through the provision of cofactors in large quantities at the critical time.     

Variations in the secondary metabolite camptothecin in relation to tissue age and season in Camptotheca acuminata

We investigated variation in concentration of the secondary metabolite, camptothecin (CPT), in relation to leaf, branch and tree age, season, and leaf drying method in Camptotheca acuminata Decaisne saplings. Younger leaves contained higher CPT concentrations than older leaves. Within a branch, there was a linear decline in CPT concentration from leaves at the apex of the branch down to Leaf 7. Comparing leaves of similar age, those from younger trees had higher CPT concentrations than those from older trees. Over the course of the growing season, there was a steady decline of 11% per month in leaf CPT concentration. Branches showed a similar seasonal decline in CPT concentration to leaves; however, the rate of decline was threefold greater in leaves than in branches. Freeze-dried tissues had a 27% higher CPT concentration than oven- or air-dried tissues, suggesting that oven- and air-drying caused degradation of CPT. The decline in CPT concentration with tissue aging may reflect a genetically determined mechanism whereby, in young trees, chemicals serve as a first line of defense against attacks by herbivores and pathogenic microorganisms until other mechanisms are developed and deployed. We hypothesize that chemical defense mechanisms are programmed for early ontogenic stages, whereas they are induced by biotic and abiotic factors during later ontogenic stages.