B Article Effects of short-term oral administration of propranolol on tear secretion in clinically normal dogs Masoud Selk Ghaffari, Vahid Arzani, Nargess Khorami, Seyed Mehdi Rajaei Abstract — This study evaluated the effects of short-term oral administration of propranolol on tear secretion in 15 clinically normal crossbreed dogs. The treatment group (n = 8) received propranolol (2 mg/kg q8h) orally for 7 days. The control group (n = 7) received placebo during the study. Schirmer I tear tests were performed on both eyes 1 d prior to drug administration (T 0 ), at 1 (T 1 ), 3 (T 3 ), and 7 (T 7 ) days of treatment. Tear production in dogs, measured by STT, was not significantly reduced in both groups. Résumé — Effets de l’administration orale à court terme du propranolol sur la sécrétion de larmes chez les chiens. Cette étude a évalué les effets de l’administration orale à court terme de propranolol sur la sécrétion de larmes chez 15 chiens normaux de race croisée. Le groupe de traitement (n = 8) a reçu du propranolol (2 mg/kg q8h) par voie orale pendant 7 jours. Le groupe témoin (n = 7) a reçu le placebo durant l’étude. Des tests de larmes de Schirmer I (TLS) ont été réalisés dans les deux yeux 1 jour avant l’administration du médicament (T 0 ) et après 1 jour (T 1 ), 3 jours (T 3 ) et 7 jours (T 7 ) de traitement. La production de larmes chez les chiens, mesurée par le TLS n’a pas été significativement réduite dans les deux groupes. Can Vet J 2011;52:875–877 Introduction eta-adrenergic blocking drugs are useful for treating both supraventricular and ventricular tachyarrhythmias. Two primary drugs in use in veterinary medicine are propranolol and atenolol (1). Propranolol is a nonselective agent that blocks both b 1 - and b 2 -receptors. The most common adverse events related to beta-blockers are bradycardia, hypotension, depres- sion, and precipitation of congestive heart failure. Hypoglycemia in diabetics and bronchospasm in patients with pre-existing lung disease are less likely to develop when selective B 1 -adrenergic blocking agents are used (2). Numerous studies have investigated possible side effects of systemic and topical beta-blockers on the ocular lacrimal system in humans, but the results are controver- sial. Some authors reported a decrease in tear production (3,4), whereas others observed no changes in tear secretion after appli- cation of beta-blockers (5). In the dog, however, there have been no studies on the effects of oral propranolol on tear secretion. Department of Clinical Sciences, School of Veterinary Medicine, Islamic Azad University-Karaj Branch. Karaj, Iran (Ghaffari, Arzani, Rajaei); Iran Veterinary Organization, Tehran, Iran (Khorami). Address all correspondence to Dr. Masoud Selk Ghaffari; Use of this article is limited to a single copy for personal study. Anyone interested in obtaining reprints should contact the CVMA office for additional copies or permission to use this material (Traduit par Isabelle Vallières) The purpose of the present investigation was to evaluate the effects of propranolol on tear secretion in clinically normal dogs. Materials and methods Fifteen healthy, intact crossbreed dogs (10 males; 5 females) between 2 and 4 years old, with a mean weight of kg [standard deviation (s)] were included in the study. Prior to the study, complete physical examinations, complete blood (cell) counts (CBC) and ophthalmic examinations including, Schirmer I tear test, biomicroscopy, and indirect ophthalmoscopy of both eyes were performed. Throughout the study period the dogs were maintained on a 12-h light/dark cycle in a temperature–controlled environment. A commercial dry food was offered once daily throughout the study. Water was given ad libitum. The dogs were randomly assigned to a treatment or control group. Dogs in the treatment group (n = 8) received propranolol (2 mg/kg q8h) orally for 7 d. Dogs in the control group (n = 7) received gelatin capsule placebo during the study. Schirmer tear tests were performed on both eyes 1 d prior to drug administra- tion (T 0 ), at 1 (T 1 ), 3 (T 3 ), and 7 (T 7 ) days of treatment. All measurements were taken between 12 pm and 1 pm. The Schirmer I tear test was performed by inserting a stan- dard sterile Schirmer tear test strip (Ophtechnics, Carson City, Nevada, USA) in the ventral conjunctival fornix for 60 s. Tearing rate was reported as the length of strip wetted in 1 min. Statistical analysis The data were analyzed using the Statistical Package Social Sciences (SPSS) software and presented in the form of descriptive statistics of means 6 standard deviations (s). An independent CVJ / VOL 52 / AUGUST