Arrhythmias and transient changes in cardiac function after topical administration of one drop of phenylephrine 10% in an adult cat undergoing conjunctival graft.

HISTORY: A 2-year-old, entire female, Somali cat weighing 3.8 kg was admitted for a conjunctival graft on the right eye, for treatment of an acute descemetocele. Medetomidine 4.2 µg kg(-1) and methadone 0.2 mg kg(-1) were administered by intramuscular injection as preanaesthetic medication. Anaesthesia was induced using diazepam 0.26 mg kg(-1) and propofol 4 mg kg(-1) administered by intravenous (i.v.) injection. Following endotracheal intubation, anaesthesia was maintained with isoflurane delivered in oxygen (1 L minute(-1)) and nitrous oxide (2 L minute(-1)) via a non-rebreathing system. Twenty minutes after induction of anaesthesia, one drop of a 10% phenylephrine hydrochloride solution was administered topically to the right eye. PHYSICAL EXAMINATION: After phenylephrine administration, a decrease in heart rate (from 95 to 80 beats minute(-1)) and an increase in arterial blood pressure occurred. The pulse then became difficult to palpate manually and multifocal ventricular premature contractions were observed on the electrocardiogram. MANAGEMENT: Nitrous oxide was discontinued and the isoflurane vaporizer setting was decreased from 1.5% to 0.5%. Lidocaine 1 mg kg(-1) i.v. was administered, this resulted in ventricular bigeminy. The quality of the femoral pulse improved and was regular in rhythm and character. Surgery was completed as fast as possible. The bigeminy progressively disappeared and before disconnecting the cat from the breathing system, there was a normal sinus rhythm with a heart rate of 85 beats minute(-1). FOLLOW-UP: Echocardiography was performed during recovery and showed mitral and aortic valve insufficiency and dilation of the left ventricle, suggesting a reduction in systolic function. Echocardiography was repeated the following day and was normal. CONCLUSIONS: In order to diminish the potential for cardiovascular sequelae associated with systemic absorption of ocular phenylephrine, less concentrated solutions, smaller drop size or different instillation techniques should be considered for topical use in small patients.

Stress associated with road transportation in desert sheep and goats, and the effect of pretreatment with xylazine or sodium betaine.

The present work investigates some clinical, endocrinological, biochemical and haematological variables in desert sheep and goats stressed in the course of individual road transportation, and the influence thereon of pretreatment with an established anti-stressor drug, xylazine HCl, and a test compound, sodium betaine (trimethylglycine). Road transportation for 2h resulted in variable and statistically insignificant increases in heart, pulse and respiratory rates in both control and experimental animals. Transportation stress significantly increased the concentrations of plasma cortisol, and glucose, and decreased that of magnesium. The endogenous thiocyanate concentration was unaffected. The stress also insignificantly decreased the haematocrit (PCV), and the number of lymphocytes, and increased the concentration of haemoglobin. Pretreatment of sheep and goats with xylazine at a single dose of 0.01 mg/kg by the intravenous route significantly ameliorated the effects induced by the stressful stimulus. The effects of pretreatment of the two species with sodium betaine (10 mg/kg) produced variable and insignificant effects.

Determinants of weak femoral artery pulse in dogs with mitral valve prolapse.

In three substudies encompassing 247 dogs from two breeds predisposed to myxomatous mitral valve disease (MMVD), femoral artery pulse strength was palpated and related to potential explanatory factors, including quantitative echocardiographic measures of MMVD, aortic and femoral artery diameter and wall thickness and blood pressure. In addition, in 109 Cavalier King Charles Spaniels (of which 61 were included in the three substudies mentioned above), the relation between femoral artery pulse strength and presence of thrombocytopenia was investigated. In 26% of the dogs, a pulse

Chemical restraint of fishers (Martes pennanti) with ketamine and medetomidine-ketamine.

We chemically restrained fishers (Martes pennanti) as part of a captive-management protocol designed to facilitate veterinary evaluation and treatment, and conditioning on a high-calorie diet before reintroduction in Pennsylvania. We compared the safety and efficacy of ketamine (KET) and medetomidine-ketamine (MED-KET) by monitoring immobilization intervals (induction time, down time, alert time, and recovery time) and physiologic responses (pulse rate, respiration rate, rectal temperature, blood pressure, oxygen saturation, and mean arterial pressure) during restraint. We administered MED-KET at 0.4 mg MED combined with 20.0 mg KET to males and at 0.2 mg MED combined with 10.0 mg KET to females. The x +/- SD dosages were MED 0.07 +/- 0.008 mg/kg + KET 3.7 +/- 0.5 mg/ kg for males and MED 0.07 +/- 0.007 mg/kg + KET 3.6 +/- 0.3 mg/kg for females. KET alone was administered at 100.0 mg to males and at 50.0 mg to females. resulting in x +/- SD dosages of 18.7 +/- 1.8 mg/kg for males and 19.2 +/- 2.2 mg/kg for females. Mean induction time did not differ between fishers restrained with MED-KET (4.6 min) and KET (4.5 min). However, compared with KET, MED-KET resulted in longer mean down time (36.2 vs. 142.2 min), alert time (40.8 vs. 146.8). and recovery time (81.1 vs. 199.4 min). Fishers that received MED-KET were mildly bradycardic and hypertensive compared with those that received KET. Although KET resulted in increased muscle tension and labored respiration, it would be effective for performing brief, noninvasive procedures for fishers because induction was rapid, recovery was short and calm, anesthesia was not profound, and physiologic response was generally expected on the basis of known drug pharmacology. Medetomidine-ketamine also immobilized fishers effectively, providing rapid induction, physiologic response typical to alpha2 agonism, calm recovery, and possibly a plane of anesthesia adequate for invasive procedures such as tooth removal or surgery.

Acute phase response in naturally occurring coliform mastitis.

Changes in the activities of serum cytokines and in acute phase response were observed in dairy cows with naturally occurring coliform mastitis. Seven cows with severe mastitis showed systemic and mammary inflammatory response throughout the observation period, and 11 cows with mild mastitis recovered and were able to be milked within 3 days of onset of mastitis. Serum interleukin (IL)-I and tumor necrosis factor (TNF) activities were higher in the severe group than in the mild group at the first appearance of symptoms. Elevated IL-1 activity was evident in the severe group throughout the observation period. Serum alpha-1-acidglycoprotein (alpha1AG) concentration began to rise with the beginning of mastitis in the severe group, and peaked at 9 days. Serum haptoglobin (Hp) concentrations peaked at 3 days, and decreased gradually after 3 days in the severe group. These results showed that there are dynamic changes in serum IL-1 activity and in serum alpha1AG and Hp concentrations in cows with severe coliform mastitis.

[The use of memoprint in the cat]. / Utilisation du Memoprint chez le chat.

In this study, done in the context of normal veterinary practice, the possibilities of using Memoprint have been evaluated. The values of systolic arterial pressure (SAP), diastolic arterial pressure (DAP) and pulse rate (PR) in healthy cats (n = 72) have been determined, as well as the values of SAP, DAP and PR before (n = 26), during (n = 40) and after (n = 16) an anaesthesia for routine surgery. The results show that Memoprint allows a quick, convenient and correct determination of SAP (average: 122.7 mmHg) and DAP (88.5), but an imprecise determination of the PR. The measures are not highly repeatable with conscious cats (SAP: 0.68, DAP: 0.51), unlike that obtained before (0.90, 0.86), during (0.96, 0.90) and after (0.88, 0.58) the anaesthesia, indicating once again the importance of the cats' familiarity and cooperation with the veterinarian. An analysis of the variance of the values of blood pressure shows their direct relationship with age, sex, breed and style of life of the cats and an increase in pressure in those over ten years of age.

Changes in rectal temperature and hematologic, biochemical, blood gas, and acid-base values in healthy Labrador Retrievers before and after strenuous exercise.

OBJECTIVE: To measure changes in rectal temperature and hematologic, biochemical, blood gas, and acid-base values before and after exercise. ANIMALS: 14 healthy adult Labrador Retrievers. PROCEDURE: Dogs exercised continuously for 10 minutes by repeatedly retrieving a dummy thrown approximately 40 to 50 yards on land. The ambient temperature during each exercise period was recorded. Rectal temperature, pulse, and respiratory rate were measured; CBC and serum biochemical profile were determined; and arterial blood gas tensions, acid-base status, and plasma lactate and pyruvate concentrations were measured at rest and immediately after exercise. Rectal temperature, pulse, respiratory rate, and lactate and pyruvate concentrations were evaluated at intervals up to 120 minutes after exercise. RESULTS: Immediately after exercise, rectal temperature increased markedly; ambient temperature did not affect rectal temperature. Arterial blood pH and PaO2 were significantly increased after exercise, and PaCO2 and bicarbonate concentration were significantly decreased after exercise. Also, statistically, but not clinically, significant increases were observed in RBC, WBC, and segmented neutrophil counts; hemoglobin, total protein, and serum sodium and potassium concentrations; PCV; anion gap; and creatine kinase activity. Plasma lactate and pyruvate concentrations increased significantly after exercise, but there was no change in the lactate-to-pyruvate ratio. CONCLUSION AND CLINICAL RELEVANCE: Reference values for healthy Laborador Retrievers during a standardized exercise protocol were established to compare data obtained from Laborador Retrievers with exercise intolerance and collapse. Important characteristics of lactate and pyruvate metabolism were documented that will enable more precise evaluation of exercise intolerance in this breed.