Long-term effect of oral cannabidiol administration to healthy adult dogs on tear production, intraocular pressure, and tear concentrations.

OBJECTIVE: To determine the chronic effects of oral cannabidiol (CBD) use on tear production, intraocular pressure (IOP), and concentration of CBD in tears of healthy dogs. ANIMALS STUDIED: Eighteen healthy research Beagles. PROCEDURES: This was a masked, placebo-controlled, randomized prospective study. Eighteen dogs were randomly assigned to three groups (six dogs per group) based on daily dosage of oral MCT oil (placebo), CBD 5 mg/kg, and CBD 10 mg/kg. Schirmer tear test (STT-1) and IOP were measured twice daily (7 am and 7 pm) every 4 weeks for 36 weeks. Week 36 tears were collected and analyzed for CBD concentrations (ng/mL) using liquid chromatography/mass spectrometry. A mixed linear model was used as the statistical method and p-value <.05 was considered significant. RESULTS: No significant differences were found between placebo vs. 5 mg/kg vs. 10 mg/kg for STT-1 or IOP (AM and PM). CBD was detected in 10 out of 11 (91%) viable tear samples receiving 5 mg/kg or 10 mg/kg dosages. One sample in the 5 mg/kg group had inadequate tear volume for analysis. The CBD concentration in tears was at or below the lower limit of quantification in placebo group, 4.12-11.2 ng/mL for the 5 mg/kg group, and 6.22-152 ng/mL for the 10 mg/kg group. CONCLUSIONS: Long-term administration of oral CBD in healthy research beagles demonstrates a favorable safety profile regarding ocular tolerability. Oral CBD administration does not appear to affect tear production or IOP over a 36-week period. This is the first canine study positively identifying concentrations of CBD in tears following oral administration.

Galactoligosaccharide and a prebiotic blend improve colonic health and immunity of adult dogs.

This study aimed to evaluate the effects of two prebiotics in different concentrations on nutrient digestibility, fermentative products and immunological variables in adult dogs. Twenty-four adult dogs were randomly divided into six blocks according to their metabolic body weights (BW0.75); within these groups, dogs were randomized to four treatments: control without prebiotics (CO); inclusion of 0.5% prebiotic blend Yes-Golf (B1); inclusion of 1.0% galactooligosaccharide (GOS); and inclusion of 1.0% prebiotic blend Yes-Golf (B2). The experiment lasted 30 days, with 20 days adaptation and 10 days stool and blood collection. Results were analyzed for normality and means were separated by ANOVA and adjusted by the Tukey test at the significance level of 5.0%. Prebiotic supplementation had no effect on apparent digestibility coefficients (ADC), total stool production and fecal scores (p > 0.05). Prebiotics evaluated also did not alter fecal pH, nor the concentrations of ammonia, lactic acid, short chain fatty acids (SCFA) and most fecal branched chain fatty acids (BCFA) (p > 0.05). The addition of GOS decreased the concentration of iso-valeric acid (p = 0.0423). Regarding immunological variables, concentrations of fecal IgA were not influenced by the treatments. Treatments GOS and B2 increased the total number of polymorphonuclear cells, as well as the oxidative burst in relation to treatments B1 and CO (p < 0.0001). Treatment B2 improved the rate of S. aureus phagocytosis in relation to CO (p = 0.0111), and both the GOS and B2 treatments had a better index for E. coli phagocytosis than the CO treatment (p = 0.0067). In conclusion, there was indication that both prebiotics GOS and B2 at 1.0% inclusion improved the immunity of healthy dogs.

Nutritional inadequacies in commercial vegan foods for dogs and cats.

The objective of this study was to evaluate the macronutrients composition, fatty acid and amino acid profiles, and essential minerals content of all vegan foods for dogs and cats available in the Brazilian market, and to compare results with FEDIAF (2019) and AAFCO (2019) recommendations. Four vegan pet foods were assessed (three for dogs and one for cats). The comparisons were made in a descriptive manner. All foods met the minimum recommendations for macronutrients. Arachidonic acid was not reported in any food label. Regarding the FEDIAF recommendations, one food for dogs had low calcium, another had low potassium and a third had low sodium. The cat food presented potassium content lower than recommended. The Ca:P ratio did not meet the minimum recommendation of FEDIAF (2019) and AAFCO (2019) in any of the dog's foods analyzed, and the cat food also did not present the minimum recommendation based on FEDIAF (2019). Copper concentrations exceeded the legal limit in all foods. Zinc concentrations exceeded this limit in two foods (one for dogs and one for cats) and iron levels exceeded the legal limit in one dog food. One of the dog foods did not meet the minimum recommendation for methionine and the cat food did not meet the minimum recommendation for arginine. In addition, when the amount of nutrients consumed by animals with low energy requirements was simulated, in addition to the same non-conformities described above, it was observed that the cat food does not meet the minimum recommended of protein and taurine in unit/Kg0.67. It was concluded that all foods analyzed had one or more nutrients below the recommended levels and some presented zinc and copper excess, therefore, these foods should not be recommended for dogs and cats, because dietary deficiencies found may lead to health risks for dogs and cats. Furthermore, manufacturers should review their formulations to ensure the nutritional adequacy of these foods.

Comparison of four digestibility markers to estimate fecal output of dogs.

Twelve adult beagle dogs (10.6 ± 1.4 kg) were fed extruded dog diets in which the starch sources were whole sorghum, sorghum flour, sorghum mill-feed, or an equal combination of rice, corn, and wheat. The experiment was conducted as a replicated Latin square design digestibility study. Estimates of fecal organic matter (OM), crude protein (CP), crude fat (CF), and gross energy (GE) outputs were determined by four methods: total fecal collection (TFC), chromic oxide (Cr2O3), titanium dioxide (TiO2), and acid insoluble ash (AIA). The correlation among the fecal output estimates by the four methods by partial correlation coefficients from the Error SSCP Matrix (Pearson) were considered significant at P < 0.05. The external markers, Cr2O3 and TiO2, had a higher (P < 0.05) OM fecal output Pearson correlation to TFC than the intrinsic marker AIA (R = 0.931 for Cr2O3 vs. TiO2; R = 0.559 for TFC vs. Cr2O3; R = 0.592 for TFC vs. TiO2; R = 0.291 for AIA vs. TFC). Interestingly, TiO2 highly correlated (P < 0.05) to Cr2O3 (R = 0.93 for OM), and was also correlated highly to TFC and AIA. The study suggests that TiO2 may be a preferred marker to estimate fecal output in dogs vs. Cr2O3. The use of AIA represents a potential option for determining digestibility for diets in which external markers are impractical.

The Effect of Feed Form on Diet Digestibility and Cecal Parameters in Rabbits.

Fifteen New Zealand rabbits were randomly assigned to one of 3 dietary treatment groups of 5 animals each and fed pelleted, extruded, or muesli diets in a completely randomized design experiment. Rabbits were placed in individual cages with ad libitum access to water and food for 45 days acclimation followed by 30 days experimental period. Feed intake of rabbits fed pelleted and extruded diets was greater (p < 0.05) than rabbits fed the muesli diet (125.6 and 130.4 vs. 91.9 g/d), but weight change and feed efficiency were not affected by treatment. Diet digestibility among the treatments was inconsistent when comparing results obtained from total fecal collection and AIA (please define) as an internal marker. Rabbits fed extruded and pelleted diets had lower (p < 0.05) cecal pH (6.42 and 6.38 vs. 7.02, respectively), and higher (p < 0.05) production of SCFA (18.5 and 19.0 vs. 11.7 mM, respectively) than those fed muesli. The fermentation products from rabbits fed pelleted and extruded diets had a greater proportion of butyrate and less propionate than rabbits fed muesli. The results of this study indicate that the basal dietary composition had a greater impact on diet utilization and cecal fermentation than food form.