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.

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.

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Felinehyperthyroidism is the most common endocrine disease of older cats and radioiodine is considered to be the gold standard treatment. Isolation periods following treatment vary depending on both individual treatment facilities and the relevant legislation of the country; therefore, there is no recognised standardised protocol defining the length of isolation. This work describes how our institution validated that its owner restrictions met dose constraints by using a model of iodine retention to calculate the required duration and nature of owner restrictions. Materials and MethOds:The retained radioactivity of cats at the point of discharge was used to simulate the radiation dose to owners in the 90 days following release. The model created was used to calculate the minimum duration of isolation for a range of administered activities and owner restrictions.results: Using the model, it was found that when injected with the maximum dose used, 222 MBq radioiodine, it was possible to release cats after 14 days of isolation and keep owner doses below 0.30 mSv (whole-body effective dose constraint for a single radiation source) with some restrictions. It was possible to release after 23 days with no restrictions.clinical significance: The present study provides clinicians with a consistent and verified method in which they can calculate the isolation periods for radioiodine-treated cats.