Experimental infection of 3-week-old conventional colostrum-fed pigs with porcine circovirus type 2 and porcine parvovirus

This report describes an experimental infection with porcine circovirus type 2 (PCV2) in combination with porcine parvovirus (PPV) in 3-week-old conventional colostrum-fed pigs with maternal antibodies to both viruses. Two groups of four pigs each were inoculated with PCV2 and PPV. One of the groups received also a commercial inactivated vaccine against porcine pleuropneumonia to evaluate possible effects of the stimulation of the immune system of pigs on the infection. Another group of four pigs was kept as uninfected control. Clinical signs, rectal temperatures and body weights were recorded. Serum antibody titers to PCV2 and PPV were determined at weekly intervals. Pigs were killed 42 days after inoculation and tissue samples were examined for the presence of gross and microscopic lesions. Tissues were also analyzed for the presence of PCV2 and PPV DNA by PCR, and for the presence of PCV2 antigen by immunohistochemistry (IHC). All the pigs had serum antibodies to PCV2 and PPV at the beginning of the trial. None of them developed clinical symptoms or pathological lesions typical of post-weaning multisystemic wasting syndrome (PMWS), a disease associated to PCV2 infection. However, IHC and/or PCR analyses showed that clinically silent PCV2 infection developed in five of the eight inoculated pigs, regardless of the administration of the vaccine. In particular, PCV2 DNA and/or antigen were detected in most of the tissues examined in the two pigs with the lowest titer of maternal PCV2 antibodies at the beginning of the trial. PPV DNA was not detected in any of the samples examined. The five pigs with PCR and/or IHC evidence of PCV2 infection had a mean weight gain during the experiment lower than that of the inoculated PCR-negative pigs considered together and that of the control pigs. In conclusion, it would appear that passive immunity against PCV2 can play a role in preventing the development of PMWS, but is not able to prevent the establishing of clinically silent PCV2 infections. The dissemination and persistence of the virus in the tissues may depend on the level of PCV2 antibodies at the time of inoculation.     

Blood lipids, fecal fat and chymotrypsin excretion in the dog: influence of age, body weight and sex

Effects of physiological variables (age, body weight and sex) on lipemia (total lipids, phospholipids, triglycerides and NEFA), fecal fat and chymotrypsin excretion were examined in dogs. On comparing various ages and body weights, they found statistically significant differences, while only total lipids showed a statistically significant difference between the two sexes. Moreover, there was a significant correlation between body weight and fecal fat and chymotrypsin excretion. The results obtained contribute to the evaluation of small intestine functionality, especially in relation to some diseases, as malabsorption, maldigestion and steatorrhea in the dog.     

Effect of body position on the 6-lead ECG of dogs

ECGs recorded from dogs show characteristic morphology and changes in morphology with various disease states. These changes are determined by comparing individual recordings to reference ranges established from recordings obtained from normal dogs in right lateral (RL) recumbency. Using these reference ranges for ECGs recorded from dogs in other positions may not be valid. We compared ECG complexes from 39 normal dogs obtained in RL, left lateral (LL), and standing (ST) body positions. ECGs from dogs in ST position showed increased Q-wave and R-wave amplitudes in leads I and II, increased R-wave and S-wave amplitudes in leads aVR and aVL, and decreased R-wave and S-wave amplitudes in lead III when compared with recordings obtained in RL position. ECGs from dogs in LL position showed increased R-wave amplitude in leads II, III, and aVF and S-wave amplitude in lead aVL but decreased R-wave amplitude in lead aVR when compared with recordings obtained in RL position. The mean electrical axis (MEA) shifted to the left in ST position but remained within the normal range in LL position. We determined that both a change in the relative position of the recording electrodes with respect to the heart as well as a change in intrathoracic cardiac position contributed to these changes. P-wave amplitude, P-R and S-T intervals, and QRS complex durations remained unaltered by changes in body position. Our findings indicate that ECGs of dogs recorded in RL, LL, and ST positions yield dramatically different results, and investigators should use position-specific reference ranges to minimize potential misinterpretation of ECG results.     

Comparative studies on the pathogenicity and tissue distribution of three virulence variants of classical swine fever virus,two field isolates and one vaccine strain,with special regard to immunohistochemical investigations

Background

The aim of this study was to compare the tissue distribution and pathogenicity of three virulence variants of classical swine fever virus (CSFV) and to investigate the applicability of various conventional diagnostic procedures.

Methods

64 pigs were divided into three groups and infected with the highly virulent isolate ISS/60, the moderately virulent isolate Wingene''93 and the live attenuated vaccine strain Riems, respectively. Clinical signs, gross and histopathological changes were compared in relation to time elapsed post infection. Virus spread in various organs was followed by virus isolation, by immunohistochemistry, applying monoclonal antibodies in a two-step method and by in situ hybridisation using a digoxigenin-labelled riboprobe.

Results

The tissue distribution data are discussed in details, analyzing the results of the various diagnostic approaches. The comparative studies revealed remarkable differences in the onset of clinical signs as well as in the development of the macro- and microscopical changes, and in the tissue distribution of CSFV in the three experimental groups.

Conclusion

The present study demonstrates that in the case of highly and moderately virulent virus variants the virulence does not affect the pattern of the viral spread, however, it influences the outcome, the duration and the intensity of the disease. Immunohistochemistry has the advantage to allow the rapid detection and localisation of the virus, especially in cases of early infection, when clinical signs are still absent. Compared to virus isolation, the advantage of this method is that no cell culture facilities are required. Thus, immunohistochemistry provides simple and sensitive tools for the prompt detection of newly emerging variants of CSFV, including the viruses of very mild virulence.     

Limited fluid volume resuscitation (LFVR) in severe shock unresponsive to initial fluid challenge: A pilot study in 10 cats

Objective

To evaluate the effect of limited fluid volume resuscitation (LFVR) administration in cats with severe shock that was unresponsive to initial conventional resuscitation (CR) with isotonic crystalloids.

Clinicopathologic features and outcome predictors of Leptospira interrogans Australis serogroup infection in dogs: a retrospective study of 20 cases (2001-2004)

BACKGROUND AND HYPOTHESIS: We retrospectively evaluated the clinicopathologic findings and outcome predictors in dogs with Leptospira interrogans Australis serogroup infections. ANIMALS AND METHODS: The medical records of 159 dogs that had a leptospiral microscopic agglutination test (MAT) performed between 2001 and 2004 were reviewed. RESULTS: Twenty dogs met serologic criteria for either symptomatic (16 dogs) or asymptomatic (4 dogs) infection caused by Leptospira interrogans Australis serogroup. Seven of 16 symptomatic dogs died or were euthanized and 9/16 recovered. Systemic inflammatory response syndrome (SIRS) was observed in 9/16 dogs. The presence of SIRS did not affect prognosis (P = .357). C-reactive protein (CRP) and haptoglobin (Hpt) concentrations were altered in all symptomatic dogs, but results did not differ significantly between survivors and nonsurvivors (P = .08 and P = .055, respectively). Conversely, the CRP to Hpt ratio (CRP/Hpt) was significantly increased in nonsurvivors. Disseminated intravascular coagulation (DIC) was diagnosed in 7/16 dogs. DIC did not significantly affect outcome (P = .126). Multiple organ involvement was present with renal failure in 16/16, liver damage in 12/16, cardiac damage in 11/16, and muscular damage in 8/16 dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: Among the evaluated clinicopathologic biomarkers, serum albumin, cardiac troponin I, CRP/Hpt, urinary albumin, and urinary total protein to creatinine ratio were found to predict outcome and warrant evaluation in larger prospective studies.     

Paraneoplastic alopecia associated with hepatocellular carcinoma in a cat

A 15-year-old spayed female domestic shorthair cat presented with alopecia associated with hepatocellular carcinoma. Clinical signs, which had commenced 6 months previously, included loss of appetite, loss of weight, and depression. As reported by the owner, the cat developed alopecia a week before referral. The hair loss was localized to the ventral aspect of the thorax and abdomen, medial aspect of front and hind limbs, and ventral aspect of the tail, and was associated with histological features consistent with paraneoplastic alopecia. At necropsy, multiple hepatic nodules were observed, and subsequent histopathological investigation showed cords and sheets of hepatocyte-like neoplastic cells positive for the hepatocyte marker (Hep Par 1), thereby demonstrating the hepatocellular origin of the tumour, which was diagnosed as a hepatocellular carcinoma. This is the first report of feline paraneoplastic alopecia associated with hepatocellular carcinoma confirmed by the Hep Par 1 marker.