The index herd with PMWS in Sweden: Presence of serum amyloid A,circovirus 2 viral load and antibody levels in healthy and PMWS-affected pigs

Background

Postweaning Multisystemic Wasting Syndrome (PMWS) is an emerging disease in pigs of multifactorial origin, but associated to porcine circovirus type 2 (PCV2) infection. PMWS was first diagnosed in Sweden at a progeny test station that received pigs aged five weeks from 19 different nucleus herds on the day after weaning. The objective of this study was to examine, for the first time in an index outbreak of PMWS, the relationship between PCV2 virus, antibodies to PCV2 and serum amyloid a (SAA) in sequentially collected serum samples from pigs with and without signs of PMWS.

Methods

Forty pigs of the last batch that entered the station at a mean age of 37.5 days were monitored for signs of PMWS during the first 55 days after arrival. Serum was collected on six occasions and analysed for presence of PCV2 DNA and antibodies to PCV2, as well as for levels of SAA.

Results

Four of the pigs (10%) were concluded to have developed PMWS, with necropsy confirmation in three of them. These pigs displayed low levels of maternal antibodies to PCV2, more than 10⁷ PCV2 viral DNA copies per ml serum and failed to mount a serological response to the virus. Starting between day 23 and 34 after arrival, an increase in PCV2 viral load was seen in all pigs, but PCV2 did not induce any SAA-response. Pigs that remained healthy seroconverted to PCV2 as the viral load was increased, regardless of initially having low or high levels of PCV2-antibodies.

Conclusion

In this index case of PMWS in Sweden, pigs affected by PMWS were not able to mount a relevant serum antibody response which contributed to the disease progression. The maximal PCV2 virus load was significantly higher and was also detected at an earlier stage in PMWS-affected pigs than in healthy pigs. However, a viral load above 10⁷ PCV2 DNA copies per ml serum was also recorded in 18 out of 34 pigs without any clinical signs of PMWS, suggesting that these pigs were able to initiate a protective immune response to PCV2.     

Laminin receptor 1 is differentially expressed in thoracic and limb wounds in the horse

Healing of wounds located on the distal limbs of horses is often complicated by retarded epithelialization and the development of exuberant granulation tissue (proud flesh). Treatments that definitively resolve this pathological process are still unavailable. Molecular studies of the repair mechanism might contribute to the development of new therapeutic strategies. The study presented herein aimed to clone the full length cDNA and to study the spatio-temporal expression profile of mRNA and protein for LAMR1, previously attributed a role in wound epithelialization, during the repair of body and limb wounds in the horse. Cloning was achieved by screening a cDNA library previously derived from 7-day wound biopsies. Expression was studied in unwounded skin and in samples from 1-, 2-, 3-, 4- and 6-week-old wounds of the body and limb. Temporal gene expression was determined by real time polymerase chain reaction (RT-PCR) while protein expression was mapped immunohistochemically. Full-length cDNA for equine LAMR1 was shown to be highly similar to that of other species. The mRNA expression of LAMR1 was significantly up-regulated only in thoracic wounds, 4 and 6 weeks following wounding (upon epithelialization). Cutaneous wounding induced protein expression at both locations. Our data suggest that up-regulation of LAMR1 protein might favour epithelialization during wound healing. However, its interaction with ligands other than laminin complicates data interpretation. Future studies should quantitatively verify the temporal expression of this protein in order to provide the basis for targeted therapies that might enhance epithelialization.     

A review of allergen-specific immunotherapy in human and veterinary medicine

This article reviews allergen-specific immunotherapy in human and veterinary medicine. Current hypotheses of possible mechanisms of actions are outlined. Indications, success rates, adverse effects and factors influencing outcome of therapy are discussed in humans, dogs, cats and horses.     

Parenteral nutrition in neonatal foals: clinical description, complications and outcome in 53 foals (1995-2005)

This retrospective study describes the use of and complications associated with parenteral nutrition (PN) administration to 53 equine neonates at the University of California Veterinary Medical Teaching Hospital. Medical records were examined and information obtained on signalment, physical examination, clinical diagnosis, outcome, total hospitalization time, insulin administration, microbiology culture results, other complications (i.e. thrombophlebitis) and necropsy findings. Complete blood count and serum biochemistry analytes, venous blood gas, serum electrolyte and glucose concentrations, and blood lactate concentration results were compared before and during PN administration in all foals. Seventeen foals (32%) developed hypertriglyceridemia (>200mg/dL). Triglyceride concentrations >200mg/dL were significantly (P=0.049) associated with non-survival. Forty-seven foals (89%) developed hyperglycemia (blood glucose >120mg/dL) and eight (15%) developed catheter-related complications (thrombosis or local sepsis). Packed cell volume, total protein, creatinine, blood urea nitrogen, and sorbitol dehydrogenase concentrations decreased while foals were on PN, while serum chloride concentration increased. This study highlighted that hypertriglyceridemia during the acute phase of neonatal illness may be detrimental to outcome, and that the safety of lipid-containing solutions in foals warrants further study.     

Vincristine overdose in a cat: clinical management, use of calcium folinate, and pathological lesions

A 6-year-old female neutered Burmese cat received a 10 times overdose (5mg/m(2)) of vincristine, administered in error. Supportive therapy, including administration of calcium folinate, was instigated within 8h. Despite treatment, the patient exhibited deterioration in renal and respiratory function and died 72 h after overdose. Necropsy was performed within 24h of death. Gross examination revealed pulmonary oedema and a pale brown liver with a prominent lobular pattern. Histological examination revealed marked apoptosis and necrosis of the bone marrow myeloid series, and mild to moderate apoptosis and necrosis of the erythroid and megakaryocyte series. Multifocal necrosis of the renal tubules, hepatocytes, and small intestinal crypt epithelium was also observed. Use of calcium folinate as a rescue therapy following vincristine overdose in humans has been previously documented. If treatment is to be successful in cases of vincristine overdose in cats, then a more complete understanding of the pathogenesis of vincristine toxicity in companion animal species is required.     

Metabolic characterization of rumen epithelial tissue from dairy calves fed different starter diets using 1H NMR spectroscopy

The metabolic profile of calf rumen epithelial tissue was for the first time characterized by ¹H NMR spectroscopy of chloroform/methanol extracts. The metabolite profiles comprised a number of amino acids, creatine, taurine, short-chain fatty acids and triglycerides. The effects of two dietary interventions; i) four levels of milk allowance with a concomitant different uptake of starter concentrate, and ii) two diets with varying content of starch and fibre in the concentrate, were elucidated. Partial least square regression analysis revealed that the intensity of NMR signals assigned to leucine, isoleucine and valine (0.90  ppm), propionate (1.06 and 2.18  ppm), lactate (1.32  ppm), butyrate (1.56  ppm), acetate (1.93  ppm), glutamine/glutamate (2.18, 2.35 and 3.75  ppm), creatine (3.04 and 3.94  ppm) and glycine (3.55  ppm) decreased with increasing milk allowance. In addition, the analysis revealed that the main difference between the two diets was the content of propionate in the epithelia tissue extracts. Previous morphological analyses of the same rumen epithelia were not able to detect any significant effects of either milk allowance or dietary starch content. Accordingly, the present study demonstrated that ¹H NMR spectroscopy applied on extracts is a useful tool for metabolite profiling of epithelial tissue and for following the development of epithelia tissue in young calves, and that the technique may be more sensitive to dietary effects than morphological studies.     

Salt-induced changes in pork myofibrillar tissue investigated by FT-IR microspectroscopy and light microscopy

FT-IR microspectroscopy and light microscopy were used to investigate pork muscle musculus semitendinosus samples, taken from three animals, that were subjected to brine salting at different concentrations (0.9, 3, 6, and 9% NaCl). Differences in spectral characteristics and in microstructure were observed in meat from animals differing in initial pH and varying salt concentrations. The FT-IR data displayed changes in the amide I region from 1700 to 1600 cm(-1). This spectral range was analyzed by principal component analysis (PCA) and partial least-squares regression (PLSR). These methods revealed correlations between the spectral data and the different animals, salt content, moisture content, pH value, and myofiber diameter. A shrinking share of alpha-helical components was related to an increase in salt concentration in the muscle. At the same time, a greater share in nonhydrogenated C=O groups (1668 cm(-1)) was related to an increase in salt concentration in the meat. The share of aggregated beta-strands differed with respect to the different animals but was not influenced by salt concentration. The meat at higher pHs (>6) had less aggregated beta-strands than that at lower pHs (5.6-5.7). It could be demonstrated that simultaneous with changes in microstructure, pH value, salt, and moisture content were alterations in the protein amide I region as measured by FT-IR microspectroscopy, revealing a relationship between these biophysical and chemical parameters and secondary protein structure attributes.     

Transtracheal wash from a puppy with respiratory disease

A 4-month-old, intact male Boxer puppy was presented to the Animal Emergency and Critical Care Services of South Florida because of nasal discharge, dehydration, dyspnea, and coughing. The dog had been diagnosed with intestinal parasites and kennel cough approximately 10 days before presentation. Lateral and ventrodorsal radiographs of the thorax revealed an increased bronchointerstitial pattern throughout the lungs. A transtracheal wash was performed. On cytologic examination of direct, Wright-Giemsa-stained smears, small basophilic coccoid structures (0.3-0.9 microm in diameter) were observed in low to moderate numbers within neutrophils and adherent to epithelial cells. The small size of the organisms raised suspicion for Mycoplasma. Culture of the transtracheal wash fluid resulted in growth of a Mycoplasma sp. The patient was treated with enrofloxacin and amoxicillin/clavulanate and made a full recovery. Recognizing Mycoplasma in transtracheal washes could aid in recommending the appropriate culture media or immunologic techniques, which could result in an accurate diagnosis of mycoplasmosis.     

Neospora caninum: Serological follow-up in dairy cows during pregnancy

We conducted a longitudinal study to follow-up the anti-Neospora caninum serologic status in 30 initially seropositive and 83 initially seronegative cows during their pregnancy. Study cows were blood-sampled every other month during pregnancy until parturition. Blood serum samples were screened for anti-N. caninum antibodies by ELISA. Cows that seroconverted were re-tested by immunoblot as a confirmation test. Among 30 seropositive cows, 28 cows remained seropositive during the whole pregnancy, whereas 2 cows transiently tested negative at least once during pregnancy. Among 83 seronegative cows, 82 cows remained seronegative and 1 cow tested positive three times during the sixth, eighth and last month of pregnancy. As only 2 out of 30 seropositive animals and 1 out of 83 animals changed their serologic status during pregnancy, the study results indicate that there is only a minor temporal instability of anti-N. caninum antibody reactivity in adult cattle.     

Wildlife translocation: the conservation implications of pathogen exposure and genetic heterozygosity

Background  

A key challenge for conservation biologists is to determine the most appropriate demographic and genetic management strategies for wildlife populations threatened by disease. We explored this topic by examining whether genetic background and previous pathogen exposure influenced survival of translocated animals when captive-bred and free-ranging bighorn sheep (Ovis canadensis) were used to re-establish a population that had been extirpated in the San Andres Mountains in New Mexico, USA.