The Effect of Season on Semen Characteristics and Freezability in Bos indicus and Bos taurus Bulls in the Southeastern Region of Brazil

The objectives of this study were to evaluate the effects of season in southeast of Brazil comparing genotypes on semen characteristics, freezability and peripheral plasma concentrations of testosterone. Ejaculates of five Bos indicus bulls and six Bos taurus bulls were evaluated over a period of 27 months, which was divided into winter (July, August, September), spring (October, November, December), summer (January, February, March) and autumn (April, May, June). Semen was evaluated according to standard procedures for ejaculate volume, sperm concentration, gross-motility, progressive motility and sperm morphology. After preparing and freezing the ejaculates according to commercial procedures, the straws were stored in liquid N₂ until post-thaw evaluation. Ejaculate volume, sperm concentration, gross-motility, progressive sperm motility, vigor and morphological sperm defects were significantly influenced by season and genotype (p < 0.05). Heat tolerance was better in B. indicus bulls than in B. taurus bulls characterized by lower values of sperm abnormalities throughout the observation period. The highest values were recorded for abnormal heads followed by cytoplasmatic droplets in B. taurus bulls. The proportion of ejaculates which were eliminated before freezing for reasons of bad quality was lower in the B. indicus bulls. Temporal changes in peripheral plasma testosterone concentrations were higher in B. indicus bulls than in B. taurus bulls not revealing seasonal influences. The results of this study show clear genotype differences regarding semen quality. Freezability of B. taurus semen varies considerably throughout the year, leading to a high proportion of eliminated ejaculates. Collecting semen from B. taurus bulls during the summer in an artificial insemination centre may not be profitable.     

Partial Right Ventriculectomy Using the Incised Patch Technique to Treat Double Chambered Right Ventricle and Chylothorax in a Cat

Objective— To report successful surgical treatment of double chambered right ventricle (DCRV) in a cat.
Study Design— Clinical report.
Animals— Cat with DCRV.
Methods— DCRV was diagnosed in a 5-month-old male Maine Coon cat using echocardiography and angiocardiography. At 2 years, despite medical therapy, chylothorax developed. A section of the right ventricular free wall that spanned the fibromuscular obstruction was excised under total venous inflow occlusion (TVIO) using the incised pericardial patch technique.
Results— Short-term recovery was complicated by return of chylothorax but this resolved after thoracocentesis and diuretic therapy. Three years after surgery, the cat is free of clinical signs and no longer on any medical therapy.
Conclusions— Partial right ventriculectomy can be performed under TVIO through an incised pericardial patch.
Clinical Relevance— DCRV in cat can be successfully treated by partial right ventriculectomy performed under TVIO through an incised pericardial patch.     

Docosahexaenoic acid and neurologic development in animals

Feeding dams a diet enriched with DHA during gestation and lactation has been associated with improvements in neurologic development of their puppies. Also, feeding diets or supplements containing DHA may improve memory or learning in young dogs.     

Prevalence of <Emphasis Type="Italic">Toxoplasma gondii</Emphasis> and <Emphasis Type="Italic">Neospora caninum</Emphasis> infections in sheep from Federal District,central region of Brazil

Serum samples from 1028 sheep were collected from 32 herds within Federal District, in the central region of Brazil. The samples were examined by indirect fluorescent antibody test (IFAT) using sera diluted 1:64 and 1:50 as cut-off values for the detection of antibodies against Toxoplasma gondii and Neospora caninum, respectively. The observed prevalence for T. gondii infection was 38.22% (26.81%<CI 0.95<49.62%), and the titers ranged from 64 to 65536. The observed prevalence for N. caninum infection was 8.81% (7.08%<CI 0.95<10.53%). The titers ranged from 50 to 51200. The reactant sera to both pathogens corresponded to 4.67% of the samples. The risk factors were not determined because of the absence of negative herds for T. gondii and the high proportion of positive herds for N. caninum (87.50%). The prevalence for T. gondii infection was significantly higher among males than in females. The present work is the first report on seroprevalence of T. gondii and N. caninum in sheep from Federal District and shows that infection by both parasites is widespread in the ovine population from this region.     

RELATIONSHIP AMONG BASILAR ARTERY RESISTANCE INDEX, DEGREE OF VENTRICULOMEGALY, AND CLINICAL SIGNS IN HYDROCEPHALIC DOGS

Forty-four transcranial Doppler ultrasound studies were performed in 36 dogs. The ratio of the height of the ventricle to the height of the brain (VB ratio) was calculated to determine the severity of ventriculomegaly. Resistance index (RI) was calculated from Doppler measurements of the blood flow velocity in the basilar artery and neurologic signs were scored on a scale of 0 to 3. Based on clinical and ultrasonographic findings, dogs were divided into four groups (normal controls, asymptomatic hydrocephalus, symptomatic hydrocephalus, and other intracranial disease). RI and VB ratio were compared between the groups of dogs and compared with neurologic signs in hydrocephalic dogs. RI ranged from 0.50 to 0.81 (mean, 0.68). Resistance index was significantly higher in dogs with symptomatic hydrocephalus and other intracranial disease when compared with the other two groups. The degree of ventriculomegaly was significantly higher in dogs with symptomatic hydrocephalus than the other groups, but there was substantial overlap between asymptomatic and symptomatic hydrocephalus groups. Combining measurements of VB ratio and RI allowed detection of symptomatic hydrocephalus with a sensitivity of 77% and a specificity of 94%. The severity of neurological signs was significantly correlated with RI and with VB ratio in hydrocephalic dogs, and in dogs evaluated on more than one occasion, changes in neurologic status were accompanied by changes in RI but not in VB ratio. All asymptomatic hydrocephalic dogs with a VB ratio of greater than 60% eventually developed neurologic signs. Our results suggest that ultrasonographic measurement of VB ratio and basilar artery RI may allow identification of dogs with symptomatic hydrocephalus or dogs that are at risk of developing symptomatic hydrocephalus. Repeated RI measurements are a useful means of monitoring dogs with a variety of intracranial diseases.     

Comparison of diazepam–ketamine and thiopentone for induction of anaesthesia in healthy dogs

Objective To compare the anaesthetic and cardiopulmonary effects of a diazepam–ketamine combination with thiopentone for induction of anaesthesia in dogs. Animal population Twenty healthy dogs of various breeds weighing between 3.8 and 42.6 kg undergoing major orthopaedic or soft tissue surgery. Materials and methods Pre‐anaesthetic medication in all cases was intramuscular acepromazine and methadone given 30 minutes before induction of anaesthesia. Each animal was then randomly assigned to receive either thiopentone or diazepam and ketamine. Quality of conditions for, and time to tracheal intubation were recorded. Anaesthesia was maintained with halothane in oxygen and nitrous oxide. Heart rate, respiratory rate, systolic blood pressure, end tidal carbon dioxide tensions and oxygen saturation were recorded at 10 minute intervals throughout surgery. The quality of recovery from anaesthesia was assessed. Results The quality of induction in both groups was satisfactory. The total mean time (± SD) to tracheal intubation (162 ± 84 seconds) was significantly longer in dogs receiving diazepam and ketamine compared to dogs receiving thiopentone (62 ± 28 seconds). Heart rate, systolic blood pressure and end tidal carbon dioxide concentration were not significantly different between groups. Respiratory rate was significantly higher in the diazepam–ketamine group between 0 and 30 minutes. The quality of recovery was similar in each group. Conclusions There appear to be fewer differences between the induction agents examined in this study than was previously believed. No pressor, or other cardiovascular stimulating effects were detected in the dogs that received diazepam and ketamine. Clinical relevance The absence of obvious differences between groups suggests that pre‐anaesthetic medication, inhaled anaesthetics and the physiological effects of surgery itself probably had a greater effect on the variables studied than the induction agent used. Further studies are required to determine whether diazepam and ketamine offers significant advantages over other induction agents in the unhealthy dog.     

Acute Necrotizing Pancreatitis and Acute Suppurative Pancreatitis in the Cat

Medical records and histologic sections of 40 cats with acute pancreatitis were reviewed. Two distinct groups of cats with pancreatitis were established by histologic analysis of tissue. Group I (32 cats) had acute pancreatic necrosis (APN). Group 2 (8 cats) had suppurative pancreatitis. Ages of affected cats ranged from 3 weeks to 16 years. l h e majority consisted of indoor cats of the Domestic Short-Haired breed but Siamese cats were over-represented relative to the general population ( P > 0.05). Twenty-two percent of cats were obese and 57%were underweight. Thirty-eight percent of cats had acute disease. In the other cats, two stages in the progression of the disease were evident: (1) anorexia. weight loss, and lethargy, followed by (2) acute deterioration, development of shock, and a moribund state, despite fluid therapy. The most common clinical signs were severe lethargy (100%), reduced appetite (97%), dehydration (92%), and hypothermia (68%). The initial hemogram occasionally showed a neutrophilia (30%) and anemia (2670)but packed cell volume (PCV) decreased markedly to the extent that 555% of cats were anemic terminally. Serum biochemical abnormalities included increased activities of A1, T (68%) and ALP (50%). and increased conrentrations of bilirubin (64%) and cholesterol (64%).Cats with APN were hyperglycemic (64%)), glycosuric (60%) and ketonuric (20%), whereas cats with suppurative pancreatitis tended to be hypoglycemic (7%). Renal failure and electrolyte abnormalities were mild or infrequent escept for hypokalemia (56%)).This study characterizes a severe necrotizing pancreatitis in the cat similar to that reported in other species, and a histologically distinct suppurative pancreatitis.     

Effect of Melatonin Implantation to Sperm Donor Rams on Post-thaw Viability and Acrosomal Integrity of Sperm Cells in the Breeding and Non-breeding Season

The influence of melatonin administration to sperm donors on the freezability of ram semen and enzyme leakage through sperm cells during different steps of the cryopreservation process were evaluated in the breeding and non-breeding season. Melatonin implantation to rams in the breeding season improved post-thaw sperm viability and intact acrosome rates without influencing the motility rate (p   < 0.05). Likewise, the post-thaw alkaline phosphatase release through sperm cells was significantly lower in the melatonin-treated group in comparison with untreated controls (p   < 0.05). In the non-breeding season, melatonin administration enhanced intact acrosome rates (p   < 0.05) and reduced aspartate aminotransferase activity (p   < 0.05) post-thaw in the offseason ejaculates. Melatonin implantation twice in the breeding and non-breeding season did not produce any further improvement in the post-thaw sperm parameters in the non-breeding season ejaculates. It was concluded that melatonin administration to sperm donors improved freezability of ram semen collected from these rams and reduced enzyme leakage through sperm cells during cryopreservation.