Epidemiology and significance of chicken infectious anemia virus infections in broilers and broiler parents under nonvaccinated European circumstances

A serologic survey in unvaccinated broiler parent and broiler progeny flocks demonstrated seroconversion against chicken infecrious anemia virus (CIAV) in all parent flocks before or around point of lay and in 38% of the broiler flocks examined at slaughter age. The presence of CIAV antibodies at slaughter of broilers was positively correlated with slaughterhouse condemnation rates. Results indicate that CIAV infections are highly prevalent in both broiler parent and broiler flocks and that CIAV infections in broilers are associated with increased slaughterhouse condemnation.     

Induction of sexual activity of male creole goats in subtropical northern Mexico using long days and melatonin

The aim of this study was to determine whether the sexual activity of local male Creole goats in subtropical Mexico can be induced during the non-breeding season by a long-day treatment followed by insertion of two melatonin implants. The experiment was carried out in the Laguna region in the State of Coahuila, Mexico (26 degrees N). Fourteen male goats were allocated to two balanced groups (n = 7 each) according to body and testicular weights. Males were kept together in two separate groups and fed lucerne hay for ad libitum intake and 300 g of commercial concentrate and had free access to water and mineral blocks. The control group remained in open sheds under natural photoperiod and ambient temperature conditions. The experimental group was placed in a light-proof building and exposed to 2.5 mo of long days (16 h of light/d) from November 1 to January 15. On January 16, each male received two s.c. melatonin implants and was exposed to natural photoperiodic changes in an open shed. In the control group, testicular weight exhibited seasonal variations; the highest value occurred on May 30 (146 +/- 10 g). Treated males reached maximum testicular weight earlier (March 15; 147 +/- 11 g), and sperm quality from January to March was higher than that observed in the control group (P < 0.05). Treatment caused an increase in LH pulse frequency (2.0 +/- 0.5 vs 0.3 +/- 0.2 pulse/8 h in February, 4.6 +/- 1.1 vs 0.1 +/- 0.1 pulse/8 h in March; experimental vs control group, respectively). In the control group, plasma testosterone remained low until mid-June and increased thereafter to remain elevated until the end of the study. In the experimental group, elevated plasma testosterone was observed from February to April and from July to November. Treating male goats in subtropical latitudes with artificial long days and melatonin can induce an intense sexual activity during the natural nonbreeding season.     

Diagnosis of cerebellar cortical degeneration in a Scottish terrier using magnetic resonance imaging

Primary cerebellar cortical degeneration (CCD), also termed abiotrophy, is the spontaneous premature degeneration of fully differentiated neurological tissue. Cerebellar hypoplasia shares many morphological features with primary CCD, both conditions being characterised by decreased cerebellar size, with reduced numbers of Purkinje and granular cells. CCD has been identified in many canine breeds. This is the first report of the syndrome in a Scottish terrier. The patient presented with mild, gradually progressive ataxia. Survey radiographs of the cervical spine and cerebrospinal fluid (CSF) analysis were normal. CSF distemper and Toxoplasma titres were negative. A diagnosis of cerebellar atrophy was made based on magnetic resonance imaging. The progressive clinical signs suggested cerebellar degeneration rather than hypoplasia. On necropsy, the cerebellum showed macroscopic and microscopic changes consistent with primary CCD.     

Hepatic cirrhosis in a five-month-old dog

The clinicopathological features of an unusual case of a five-month-old male Spanish mastiff, which was presented with clinical signs indicative of severe hepatic failure, are reported. Fluid replacement therapy, colloid plasma expanders, antibiotics and diuretic drugs were unsuccessful in improving the animal's general condition, and euthanasia was elected by the owner. On necropsy, ascites and severe cirrhosis, with extensive periacinar necrosis, was found. Cirrhosis is a rare lesion in young dogs. The most common causes are circulatory disturbances, hereditary metabolic disorders or poisoning, such as aflatoxicosis and anticonvulsant therapy. The possible involvement of canine adenovirus in this case is discussed.     

Morphological and quantitative study of the Leydig cells of pigs fed with anabolic doses of clenbuterol

The effects of clenbuterol administered at anabolic doses on the testicular interstitium were studied in 30 pigs allocated to three experimental groups. The diet of two groups was supplemented with clenbuterol (Clb) (1 ppm), but whereas in the Clb+ group the treatment was given until slaughter (treatment period: 3 months), in the Clb- group the clenbuterol was withdrawn 2 weeks before slaughter (treatment period: 2-5 months); in the control group, the pigs were fed without clenbuterol. For histological procedures, a fractional sampling scheme was applied and routine techniques for light and transmission electron microscopy were used. The results of subjective morphology and morphometrics showed slight differences between the treated and the control groups. Conversely, the stereological results identified a prominent hyperplasia of the Leydig cells and ultrastructural analysis of these cells revealed a conspicuous increase in the organelles related to testosterone production, suggesting a functional activation of the interstitial cells in response to the clenbuterol treatment.     

Determination of hematologic and blood chemical reference values in fattening pigs of different ages

In swine medicine, the determination of hematology and blood chemistry parameters is of primary interest in connection with the detection of herd problems. For the evaluation of laboratory results the availability of reference values is a prerequisite. So far, no reference values of fattening pigs have been available in Switzerland. For this reason, in the present study reference values for hematology and blood chemistry were determined for two bodyweight categories, 40-60 kg (group 1) and 85-110 kg (group 2). Hematocrit, hemoglobin and RBC counts were lower in animals in group 1. The number of segmented neutrophils was markedly higher in group 1. Lymphocyte counts exceeded neutrophil values in both groups. Concentrations of total bilirubin, AST, CK and LDH partly reached very high levels due to hemolysis or contamination of the blood samples with muscle tissue.     

Evidence for the transmission of scrapie to sheep and goats from a vaccine against Mycoplasma agalactiae

An accidental infection from a vaccine was suggested as the explanation for the sudden increase in outbreaks of scrapie in Italy in 1997 and 1998. This paper describes a recent outbreak of scrapie in sheep and goats which were exposed to the same vaccine. No ewes or goats had been imported into the herd since 1992, but a vaccine against Mycoplasma agalactiae had been administered twice, in 1995 and 1997. High rates of crude mortality and scrapie incidence were experienced by both species, all birth cohorts were involved and a large proportion of aged animals was affected. A pattern of brain lesions was observed, with slight differences between the sheep and goats, which was very similar to the pattern observed in animals previously exposed to the same vaccine but clearly different from that observed in the brains of sheep with scrapie in a flock not exposed to the vaccine. Regardless of their exposure status, genotype analysis of the sheep showed the presence of polymorphism only at codon 171. The patterns of both incidence and brain lesions provide evidence that the epidemic of scrapie was due to the use of the vaccine.