Objective-To evaluate the effect of dietary supplementation with the probiotic strain Lactobacillus acidophilus DSM13241 in healthy adult cats. Animals-15 adult cats. Procedures-Cats were fed a nutritionally complete dry food for 5 weeks. Fecal character was assessed daily, and a single fecal sample and 3-mL blood sample were collected for bacterial enumeration and hematologic analysis, respectively. Cats were then fed the same diet supplemented with L acidophilus DSM13241 (2 X 10(8) CFU/d) for 4.5 weeks. Repeat fecal and hematologic measurements were taken prior to the return to control diet for a 4-week period. Results-The probiotic species was recovered from feces, demonstrating survival through the feline gastrointestinal tract. Probiotic supplementation was associated with increased numbers of beneficial Lactobacillus and L acidophilus groups in feces and decreased numbers of Clostridium spp and Enterococcus faecalis, indicating an altered bacterial balance in the gastrointestinal tract microflora. Fecal pH was also decreased suggesting a colonic environment selective for the beneficial lactic acid bacterial population. Systemic and immunomodulatory effects were associated with administration of L acidophilus DSM13241 including altered cell numbers within WBC subsets and enhanced phagocytic capacity in the peripheral granulocyte population. In addition, plasma endotoxin concentrations were decreased during probiotic feeding, and RBCs had a decreased susceptibility to osmotic pressure. Conclusions and Clinical Relevance-Probiotic strain L acidophilus DSM13241 fed at 2 X 10(8) CFU/d can alter the balance of gastrointestinal microflora in healthy cats. Furthermore, administration of this probiotic results in beneficial systemic and immunomodulatory effects in cats.

Objective-To use in vitro assays to evaluate the effects of a novel immunosuppressive agent, FTY720, on biological functions (migration, phagocytosis, and production of reactive-oxygen species ROS) of feline peripheral neutrophils and determine the cytotoxic effects of FTY720 on feline peripheral neutrophils. Sample Population-Peripheral neutrophils obtained from 8 healthy cats. Procedure-Peripheral neutrophils were isolated from blood samples obtained from the 8 cats and exposed to the phosphorylated form of FTY720 (FTY720-P). A fluorescence-based in vitro evaluation of migration was performed. Phagocytosis of microbes and production of ROS were evaluated by use of a 2-color flow cytometry system. Samples of whole blood obtained from the cats were incubated with various concentrations of FTY720-P, fluorescein-labeled Staphylococcus aureus, and dihydroethidium. Cytotoxic effects were evaluated by use of propidium iodide staining. Results-Addition of FTY720-P caused a slight nonsignificant decrease in phagocytosis and production of ROS by feline peripheral neutrophils. Migration activity of feline peripheral neutrophils was significantly increased by the addition of FTY720-P. Addition of FTY720-P at concentrations considered for clinical use did not increase the death rate of feline peripheral neutrophils. Conclusions and Clinical Relevance-FTY720 does not inhibit critical functions of feline peripheral neutrophils in vitro.