A standardized extract of the traditional herb ginkgo biloba was added to the diet of older dogs that presented with chronic geriatric conditions related to the cognitive dysfunction syndrome.
The multi-component extract contains various active constituents such as terpene lactones and flavonoids that influence peripheral and cerebral blood circulation. In man, ginkgo leaf is used in cerebral insufficiency, peripheral arterial occlusive disease and disturbance of vestibular origin, namely dizziness, equilibrium related problems and tinnitus.
Thirty-nine dogs were enrolled in the study after pet owners signed informed consent forms. They were examined by the veterinary investigator after 0,1,4 and 8 weeks. At the beginning of treatment, each canine patient - of various pedigrees - was at a unique stage of the chronic geriatric condition and exhibited its own individual combination of clinical signs, each expressed at different degrees of severity.
The severity of canine geriatric conditions, judged by the investigator, was significantly reduced after 8 weeks of supplementation (p=0.02). Rather unexpectedly in these chronic conditions 29% of the dogs were free of clinical signs at study-end. Accordingly also clinical sign scores "sleepy and activity change" (Sleeps more during the day, sleeps less during the night, awakening in the night and walk about, awakening in the night and barking/yowling without an apparent motive) and "general behavior" (Apathic, nervous, agitated, general condition) improved significantly. Due to the age prerequisite in the inclusion criteria certain animals were suffering from associated age-related diseases that necessitated euthanasia. Fifteen adverse events were recorded. A possible relationship to the investigated product, was suspected in two cases, diarrhea with vomiting and deterioration of housetraining, both brief and reversible events.
It was shown that oral administration of a ginkgo leaf extract in the dosage of 20-40 mg/10 kg body weight once daily for 8 weeks appears to be both safe and efficacious in geriatric conditions and age-related behavioral changes of dogs.