Dilution of maropitant (Cerenia) in lactated Ringer solution prolongs subcutaneous drug absorption and reduces maximum plasma concentration.

OBJECTIVE: The aim of this study was to determine whether the pharmacokinetics of maropitant, administered SC as a commercially available maropitant-containing injectable product (Cerenia Injectable), differ when combined with lactated Ringer solution prior to administration. ANIMALS: We used 6 adult spayed female Beagle dogs between 3 and 6 years of age, with a mean weight of 9.58 kg. PROCEDURES: In this randomized crossover study, the dogs underwent 2 treatment protocols separated by a 14-day washout period: (1) an SC injection of 1 mg/kg of Cerenia Injectable (maropitant citrate; 10 mg/mL) and (2) 1 mg/kg of Cerenia Injectable diluted in 10 mL/kg of lactated Ringer injectable solution (LRS) given SC. Plasma maropitant concentrations were assessed by mass spectrometry. Pharmacokinetic analysis was performed using pharmacokinetic and pharmacodynamic data-analysis software to determine maximum plasma concentration (Cmax), time to reach maximum concentration, half-life, total exposure to the drug, mean residence time, clearance rate per fraction absorbed, and absorption and elimination kinetic parameters. RESULTS: Cmax was reduced by 26% (P = .002), the absorption rate constant decreased 80% (P = .031), and the absorption half-life increased when Cerenia was administered diluted in LRS. CLINICAL RELEVANCE: Administration of maropitant (Cerenia) diluted in LRS had a pharmacokinetic impact, resulting in a significantly reduced Cmax and slower absorption. Clinical efficacy was not assessed in this study.

Pandemic H1N1 influenza virus infection in a Canadian cat.

A cat was presented for necropsy after being found dead at home. Histologic findings suggested viral pneumonia. Polymerase chain reaction and viral typing revealed influenza A(H1N1)pdm09. This is the first report of influenza in a Canadian cat and highlights the importance of considering influenza virus in the differential diagnosis for feline respiratory distress.

Infection par le virus de l'influenza H1N1 pandémique chez un chat canadien. Un chat a été présenté pour une nécropsie après avoir été trouvé mort à son domicile. Les résultats histologiques ont suggéré une pneumonie virale. Une amplification en chaîne par polymérase et un typage viral ont révélé l'influenza A(H1N1) pdm09. Il s'agit du premier rapport de l'influenza chez un chat canadien et il souligne l'importance de considérer le virus de l'influenza dans le diagnostic différentiel lors de détresse respiratoire féline.(Traduit par Isabelle Vallières).

Moderate exercise during pregnancy in Wistar rats alters bone and body composition of the adult offspring in a sex-dependent manner.

Exercise during pregnancy may have long-lasting effects on offspring health. Musculoskeletal growth and development, metabolism, and later-life disease risk can all be impacted by the maternal environment during pregnancy. The skeleton influences glucose handling through the actions of the bone-derived hormone osteocalcin. The purpose of this study was to test the effects of moderate maternal exercise during pregnancy on the bone and body composition of the offspring in adult life, and to investigate the role of osteocalcin in these effects. Groups of pregnant Wistar rats either performed bipedal standing exercise to obtain food/water throughout gestation but not lactation, or were fed conventionally. Litters were reduced to 8/dam and pups were raised to maturity under control conditions. Whole body dual-energy x-ray absorptiometry, and ex vivo peripheral quantitative computed tomography scans of the right tibia were performed. At study termination blood and tissue samples were collected. Serum concentrations of fully and undercarboxylated osteocalcin were measured, and the relative expression levels of osteocalcin, insulin receptor, Forkhead box transcription factor O1, and osteotesticular protein tyrosine phosphatase mRNA were quantified. Body mass did not differ between the offspring of exercised and control dams, but the male offspring of exercised dams had a greater % fat and lower % lean than controls (p=0.001 and p=0.0008, respectively). At the mid-tibial diaphysis, offspring of exercised dams had a lower volumetric bone mineral density than controls (p=0.01) and in the male offspring of exercised dams the bone: muscle relationship was fundamentally altered. Serum concentrations of undercarboxylated osteocalcin were significantly greater in the male offspring of exercised dams than in controls (p=0.02); however, the relative expression of the measured genes did not differ between groups. These results suggest that moderate exercise during pregnancy can result in lasting changes to the musculoskeletal system and adiposity in offspring, in a sex-specific manner.

Comparison of the levels of Equus caballus papillomavirus type 2 (EcPV-2) DNA in equine squamous cell carcinomas and non-cancerous tissues using quantitative PCR.

Equus caballus papillomavirus type 2 (EcPV-2) infection has been associated with equine genital squamous cell carcinomas (SCCs). However, quantitative PCR (qPCR) has not been performed to determine viral copy numbers within these lesions. Additionally, the frequency with which EcPV-2 can be detected in other common sites of equine SCC development remains uncertain. The aim of this study was to develop a qPCR assay to estimate the viral load in a variety of equine tissue samples. These included 40 SCC lesions, 19 penile non-SCC or precursor disease lesions, and 222 tissues without observable lesions from SCC-prone sites on clinically normal horses. EcPV-2 DNA was present significantly more frequently, and in higher copy numbers, in equine penile SCC lesions than in either healthy penile mucosa or non-SCC penile lesions. This supports the hypothesis that EcPV-2 is involved in development of penile SCCs and suggests that penile EcPV-2 infection is rare in the absence of SCCs. Samples of normal vulval mucosa rarely contained EcPV-2 DNA and none of the nictitating membrane samples contained EcPV-2 DNA, indicating that asymptomatic EcPV-2 infection is uncommon at these sites. EcPV-2 DNA was detected in a proportion of both SCCs and normal samples from the oral cavity or pharynx, although there were no significant differences in the rate of infection or viral copy number between the SCCs and the normal mucosal samples. As such, the role of EcPV-2 in development of SCCs in this location remains to be established.

Persistent, widespread papilloma formation on the penis of a horse: a novel presentation of equine papillomavirus type 2 infection.

A 9-year-old gelding presented with approximately 100 papillomas that covered about 75% of the distal penis. Biopsy was performed, and histology showed evidence of viral cytopathic change and koilocytosis. Polymerase chain reaction using DNA extracted from biopsied tissue amplified equine papillomavirus type 2 (EcPV-2) DNA sequences. Sixteen months later, the horse was re-examined and the appearance of the papillomas was unchanged. Equine papillomavirus type 2 DNA sequences were again amplified from both biopsied tissue and swabs of the penis. Papillomavirus was localized to the lesions by immunohistochemistry and in situ hybridization. An examination 2 years after the initial presentation revealed no detectable change in the appearance of the penis. The large number of papillomas and their failure to regress over an extended period support a clinical classification of papillomatosis. To the authors' knowledge, this is the first report of papillomatosis of the equine penis. This novel clinical manifestation suggests that persistent EcPV-2 infection is possible in horses. As there is evidence that EcPV-2 may promote development of equine penile squamous cell carcinoma, understanding the natural history of EcPV-2 infections may be important in preventing equine penile neoplasia.

Voluntary exercise in pregnant rats positively influences fetal growth without initiating a maternal physiological stress response.

The effects of increased physical activity during pregnancy on the health of the offspring in later life are unknown. Research in this field requires an animal model of exercise during pregnancy that is sufficiently strenuous to cause an effect but does not elicit a stress response. Previously, we demonstrated that two models of voluntary exercise in the nonpregnant rat, tower climbing and rising to an erect bipedal stance (squat), cause bone modeling without elevating the stress hormone corticosterone. In this study, these same models were applied to pregnant rats. Gravid Wistar rats were randomly divided into three groups: control, tower climbing, and squat exercise. The rats exercised throughout pregnancy and were killed at day 19. Maternal stress was assessed by fecal corticosterone measurement. Maternal bone and soft tissue responses to exercise were assessed by peripheral quantitative computed tomography and dual-energy X-ray absorptiometry. Maternal weight gain during the first 19 days of pregnancy was less in exercised than in nonexercised pregnant control rats. Fecal corticosterone levels did not differ between the three maternal groups. The fetuses responded to maternal exercise in a uterine position-dependent manner. Mid-uterine horn fetuses from the squat exercise group were heavier (P < 0.0001) and longer (P < 0.0001) and had a greater placental weight (P = 0.001) than those from control rats. Fetuses from tower-climbing dams were longer (P < 0.0001) and had heavier placentas (P = 0.01) than those from control rats, but fetal weight did not differ from controls. These models of voluntary exercise in the rat may be useful for future studies of the effects of exercise during pregnancy on the developmental origins of health and disease.

Short-term voluntary exercise in the rat causes bone modeling without initiating a physiological stress response.

Recent research has revealed a neuroendocrine connection between the skeleton and metabolism. Exercise alters both bone modeling and energy balance and may be useful in further developing our understanding of this complex interplay. However, research in this field requires an animal model of exercise that does not cause a physiological stress response in the exercised subjects. In this study, we develop a model of short-term voluntary exercise in the female rat that causes bone modeling without causing stress. Rats were randomly assigned to one of three age-matched groups: control, tower climbing, and squat exercise (rising to an erect bipedal stance). Exercise for 21 days resulted in bone modeling as assessed by peripheral quantitative computed tomography. Fecal corticosterone output was used to assess physiological stress at three time points during the study (preexercise, early exercise, and late in the exercise period). There were no differences in fecal corticosterone levels between groups or time points. This model of voluntary exercise in the rat will be useful for future studies of the influence of exercise on the relationship between skeletal and metabolic health and may be appropriate for investigation of the developmental origins of those effects.

Omasal dilation and displacement in 4 Holstein dairy cows.

Cases of omasal dilation and displacement in 4 dairy cows are described. The disease was initially diagnosed by a combination of history and clinical signs that included right-sided abdominal distension, rectal palpation, and decreased milk production. The condition was confirmed by laparotomy or necropsy.