Randomised clinical trial evaluating the effect of a single preappointment dose of gabapentin on signs of stress in hyperthyroid cats.

OBJECTIVES: The aim of this study was to evaluate the efficacy of gabapentin as an anxiolytic in hyperthyroid cats. METHODS: Cats (n = 47) with confirmed hyperthyroidism were successfully enrolled. The cat owner allocated a temperament score and a transport stress score at their first visit. For the second visit the cat owner (blinded to treatment) administered either liquid gabapentin 20 mg/kg (n = 22) or an indistinguishable placebo solution (n = 25) 1 h prior to leaving home. A second transport score was allocated by the cat owner at this visit. Upon admission a compliance score was independently assigned by two veterinary nurses blinded to treatment. Excess blood from routine blood draw was analysed for gabapentin plasma concentration from cats in the gabapentin group. RESULTS: There were no significant differences in baseline transport score between groups (P = 0.13), but significant differences were noted in the second visit transport score between cats medicated with gabapentin compared with placebo (P = 0.018). Mean compliance scores were significantly different between cats in the treatment group compared with placebo (P = 0.019). Further sedation was required to complete the procedures in 24% of cats in the placebo group compared to 9% in the gabapentin group (P = 0.25). Mean plasma gabapentin concentrations were 10.1 mg/l (range 1.7-22.7) in the gabapentin group within a 1-3 h time frame post-administration. CONCLUSIONS AND RELEVANCE: Hyperthyroid cats medicated with 20 mg/kg gabapentin 1 h prior to leaving home were more relaxed during transport and more compliant with veterinary procedures than cats administered a placebo solution.

Establishing levels of retained radioactivity in cats receiving radioactive iodine treatment.

BACKGROUND: Radioactive iodine (RAI) is considered the gold standard treatment for feline hyperthyroidism. Currently exposure limits to radiation are regulated by national legislation, therefore the length of the isolation period in hospital for cats receiving radioactive treatment varies according to the place where the radioactive facility is located. The aim of this study was to establish when retained radioactivity decreases in cats receiving subcutaneous I-131 to a level that would allow discharge of cats from the hospital while being compliant with current United Kingdom legislation. METHODS: Clinical records of cats treated with subcutaneous I-131 were retrospectively reviewed. Radioactive emission rates were measured using an external probe. Retained radioactivity below 11 MBq at the point of discharge was required by the initial risk assessment to ensure that a 0.3 mSv dose constraint was maintained for owners following standard cat-owner contact restrictions. Average retained activity for each treatment regimen at the time of discharge was calculated. The biological half-life for iodine retention was also calculated. RESULTS: Overall, an end activity below 11 MBq was reached at day 11 in 49% of cats, and at day 13 in 91% of cats. These cats were allowed to be discharged according to UK legislation, as long as contact restrictions were applied at home for 2 weeks. CONCLUSION: Based on our study, an isolation period of 13 days before allowing discharge of cats treated with subcutaneous RAI (I-131) is compliant with current UK legislation.