Objective—To evaluate the efficacy of the probiotic Lactobacillus rhamnosus strain GG for the alleviation or prevention of clinical signs of atopic dermatitis (AD) in genetically predisposed dogs.
Animals—2 adult Beagles with severe AD and 16 puppies.
Procedures—The 2 adult Beagles were bred twice, with a year between breedings. Lactobacillus rhamnosus GG was administered to the bitch during the second pregnancy and to the puppies of the second litter from 3 weeks to 6 months of age. Both litters were epicutaneously sensitized to Dermatophagoides farinae. Blood samples were collected from puppies every 6 weeks to measure serum titers of allergen-specific IgE. At 6 months of age, all puppies underwent intradermal allergen testing and environmental challenge with D farinae. Clinical signs were scored.
Results—In the first litter, at 6 months of age, 7 of 7 puppies were strongly seropositive for IgE against D farinae, 6 had a positive reaction to intradermal testing, and 7 developed severe clinical signs of AD after the environmental challenge. In the second litter, 7 of 9 puppies were seropositive, 3 had a positive reaction to intradermal testing, and 6 developed dermatitis and pruritus after the challenge. The second litter had a significantly lower serum titer of allergen-specific IgE and milder reaction to intradermal testing, compared with the first litter. Clinical scores did not differ between litters.
Conclusions and Clinical Relevance—Administration of L rhamnosus GG to puppies appeared to reduce immunologic indicators of AD, although no significant decrease in clinical signs was detected.
Objective—To evaluate the pharmacokinetics of pentoxifylline
(PTX) and its 5-hydroxyhexyl-metabolite,
metabolite 1 (M1), in dogs after IV administration of a
single dose and oral administration of multiple doses.
Procedure—A crossover study design was used so
that each of the dogs received all treatments in random
order. A drug-free period of 5 days was allowed
between treatments. Treatments included IV administration
of a single dose of PTX (15 mg/kg of body
weight), oral administration of PTX with food at a
dosage of 15 mg/kg (q 8 h) for 5 days, and oral administration
of PTX without food at a dosage of 15 mg/kg
(q 8 h) for 5 days. Blood samples were taken at 0.25,
0.5, 1, 1.5, 2, 2.5, and 3 hours after the first and last
dose of PTX was administered PO, and at 5, 10, 20, 40,
80, and 160 minutes after PTX was administered IV.
Results—PTX was rapidly absorbed and eliminated
after oral administration. Mean bioavailability after
oral administration ranged from 15 to 32% among
treatment groups and was not affected by the presence
of food. Higher plasma PTX concentrations and
apparent bioavailability were observed after oral
administration of the first dose, compared with the
last dose during the 5-day treatment regimens.
Conclusions and Clinical Relevance—In dogs, oral
administration of 15 mg of PTX/kg results in plasma
concentrations similar to those produced by therapeutic
doses in humans, and a three-times-a-day dosing
regimen is the most appropriate. (Am J Vet Res 2000;61:631–637)
Our thinking about the skin disease in dogs currently called AD has undergone immense changes in the past 75 years. First called eczema in dogs by Schnelle1 in 1933, it was later termed canine allergic inhalant dermatitis and then canine atopy. The skin disease associated with atopy in dogs is now referred to as canine AD.
Since the first description of this condition, huge strides have been made in human medicine, particularly in the biomedical sciences, with regard to how the immune system works. Basic scientific knowledge has crossed over into the field of clinical medicine, resulting in
Objective—To determine serum pharmacokinetics of pentoxifylline and its 5-hydroxyhexyl metabolite in horses after administration of a single IV dose and after single and multiple oral doses.
Animals—8 healthy adult horses.
Procedures—A crossover study design was used with a washout period of 6 days between treatments. Treatments were IV administration of a single dose of pentoxifylline (8.5 mg/kg) and oral administration of generic sustained-release pentoxifylline (10 mg/kg, q 12 h, for 8 days). Blood samples were collected 0, 1, 3, 6, 12, 20, 30, and 45 minutes and 1, 2, 4, 6, 8, and 12 hours after IV administration. For oral administration, blood samples were collected 0, 0.25, 0.5, 0.75, 1, 2, 4, 8, and 12 hours after the first dose and 0, 0.25, 0.5, 0.75, 1, 2, 4, 8, 12, and 24 hours after the last dose.
Results—Elimination of pentoxifylline was rapid after IV administration. After oral administration, pentoxifylline was rapidly absorbed and variably eliminated. Higher serum concentrations of pentoxifylline and apparent bioavailability were observed after oral administration of the first dose, compared with values after administration of the last dose on day 8 of treatment.
Conclusions and Clinical Relevance—In horses, oral administration of 10 mg of pentoxifylline/kg results in serum concentrations equivalent to those observed for therapeutic doses of pentoxifylline in humans. Twice daily administration appears to be appropriate. However, serum concentrations of pentoxifylline appear to decrease with repeated dosing; thus, practitioners may consider increasing the dosage if clinical response diminishes with repeated administration.
Improved understanding of the pathogenesis of atopic dermatitis in dogs has led to more effective treatment plans, including skin barrier repair and new targeted treatments for management of allergy-associated itch and inflammation. The intent of this review article is to provide an update on the etiologic rationale behind current recommendations that emphasize a multimodal approach for the management of atopic dermatitis in dogs. Increasing knowledge of this complex disease process will help direct future treatment options.