Microscopical Evaluation of Smears of the Leptomeninges to Predict Meningitis in Piglets.

Meningitis, caused by bacterial infections such as Streptococcus spp., is a frequently observed cause of death in pigs. In order to implement effective treatment and avoid further losses, it is important to establish this diagnosis quickly. However, this is often difficult because macroscopic lesions may not be visible, and additional laboratory testing may take several days. The present study investigated whether microscopical examination of impression smears of the leptomeninges taken during necropsy can help in establishing a presumptive diagnosis of meningitis in pigs more quickly. In total, 54 pigs suffering from neurological signs and/or (acute) mortality were examined. They were 3 to 10 weeks old and originated from 16 farms. From each pig, bacterial culture was performed on one half of the brain using a swab from the leptomeninges. From the other half, paired cytological impression smears of the leptomeninges were stained with a commercial quick stain dye (Hemacolor®) and Gram stain and microscopically evaluated for the abundance of neutrophils and the presence of short-chain coccoid bacteria. Bacterial culture of the leptomeninges was positive in 36/54 cases, in 28 of which Streptococcus spp. were found. The numbers of smears with low, moderate, or high abundance of neutrophils were 19, 17, and 18, respectively. Short-chain coccoid bacteria were detected successfully in 12 pigs in the Gram-stained smear. The positive predictive value of smears with moderate or high abundance of neutrophils for bacterial presence and, therefore, likely meningitis was 89%, whereas the negative predictive value of smears with low abundance of neutrophils was 74%. The positive predictive value of smears with short chains of coccoid bacteria for diagnosis of Streptococcus spp. was 100%, whereas the negative predictive value was 62%. In conclusion, microscopical examination of impression smears of the leptomeninges of piglets with neurological signs and/or (acute) mortality is a feasible procedure that can help swine practitioners in establishing a tentative diagnosis of meningitis more quickly, especially if neutrophils are abundant, and short chains of coccoid bacteria are present.

Dynamics of the Enteric Virome in a Swine Herd Affected by Non-PCV2/PRRSV Postweaning Wasting Syndrome.

A commercial pig farm with no history of porcine circovirus 2 (PCV2) or porcine reproductive and respiratory syndrome virus (PRRSV) repeatedly reported a significant reduction in body weight gain and wasting symptoms in approximately 20-30% of the pigs in the period between three and six weeks after weaning. As standard clinical interventions failed to tackle symptomatology, viral metagenomics were used to describe and monitor the enteric virome at birth, 3 weeks, 4 weeks, 6 weeks, and 9 weeks of age. The latter four sampling points were 7 days, 3 weeks, and 6 weeks post weaning, respectively. Fourteen distinct enteric viruses were identified within the herd, which all have previously been linked to enteric diseases. Here we show that wasting is associated with alterations in the enteric virome of the pigs, characterized by: (1) the presence of enterovirus G at 3 weeks of age, followed by a higher prevalence of the virus in wasting pigs at 6 weeks after weaning; (2) rotaviruses at 3 weeks of age; and (3) porcine sapovirus one week after weaning. However, the data do not provide a causal link between specific viral infections and the postweaning clinical problems on the farm. Together, our results offer evidence that disturbances in the enteric virome at the preweaning stage and early after weaning have a determining role in the development of intestinal barrier dysfunctions and nutrient uptake in the postweaning growth phase. Moreover, we show that the enteric viral load sharply increases in the week after weaning in both healthy and wasting pigs. This study is also the first to report the dynamics and co-infection of porcine rotavirus species and porcine astrovirus genetic lineages during the first 9 weeks of the life of domestic pigs.

Use of paracetamol in sows around farrowing: effect on health and condition of the sow, piglet mortality, piglet weight and piglet weight gain.

BACKGROUND: Pain and fever in the periparturient period can lead to prolonged farrowing and can slow down the recovery of the sow, which will have an effect on the vitality and survival of the piglets. This study investigated the use of orally administered Paracetamol (Pracetam- CEVA) in sows in the periparturient period. RESULTS: Mortality did not differ in piglets during the first week, or during total lactation (P > 0.10). No difference was found in weight or weight gain of the piglets during lactation. The coefficient of variation of piglet weight was smaller in the Paracetamol (Pm) group at day 7, day 14 and at weaning, but not at birth. So, the variation within litters was smaller in the Pm- treated sows, in comparison with the Control (C) litters. No difference in mean IgG concentration was found between treatments, but the coefficient of variation was too high (> 40) in 50% of the C litters and not in Pm litters. The Pm- treated sows lost less backfat than the C- sows. No effect was found on the body temperature of the sows, but fever was rare in both groups. CONCLUSION: Paracetamol results in less variation of body weight of piglets during lactation, seems to have a potential effect on the distribution of IgG within litters and has a positive effect on backfat loss. The effects of Paracetamol might be even more pronounced in farms with high piglet mortality (this farm only 8%) or with a high incidence of agalactia, fever after farrowing or piglet diarrhoea, which was not the case in this farm. Paracetamol is a promising product for increasing the welfare in lactating sows and optimising production in the farrowing stable.

Two novel porcine teschovirus strains as the causative agents of encephalomyelitis in the Netherlands.

BACKGROUND: Porcine teschovirus (PTV) circulates among wild and domesticated pig populations without causing clinical disease, however neuroinvasive strains have caused high morbidity and mortality in the past. In recent years, several reports appeared with viral agents as a cause for neurologic signs in weanling and growing pigs among which PTV and new strains of PTV were described. CASE PRESENTATION: On two unrelated pig farms in the Netherlands the weanling pig population showed a staggering gate, which developed progressively to paresis or paralysis of the hind legs with a morbidity up to 5%. After necropsy we diagnosed a non-suppurative encephalomyelitis on both farms, which was most consistent with a viral infection. PTV was detected within the central nervous system by qPCR. From both farms PTV full-length genomes were sequenced, which clustered closely with PTV-3 (98%) or PTV-11 (85%). Other common swine viruses were excluded by qPCR and sequencing of the virus. CONCLUSION: Our results show that new neuroinvasive PTV strains still emerge in pigs in the Netherlands. Further research is needed to investigate the impact of PTV and other viral agents causing encephalomyelitis within wild and domestic pig populations supported by the awareness of veterinarians.

Chronic allopurinol treatment during the last trimester of pregnancy in sows: effects on low and normal birth weight offspring.

Low-birth-weight (LBW) children are born with several risk factors for disease, morbidity and neonatal mortality, even if carried to term. Placental insufficiency leading to hypoxemia and reduced nutritional supply is the main cause for LBW. Brain damage and poor neurological outcome can be the consequence. LBW after being carried to term gives better chances for survival, but these children are still at risk for poor health and the development of cognitive impairments. Preventive therapies are not yet available. We studied the risk/efficacy of chronic prenatal treatment with the anti-oxidative drug allopurinol, as putative preventive treatment in piglets. LBW piglets served as a natural model for LBW. A cognitive holeboard test was applied to study the learning and memory abilities of these allopurinol treated piglets after weaning. Preliminary analysis of the plasma concentrations in sows and their piglets suggested that a daily dose of 15 mg.kg(-1) resulted in effective plasma concentration of allopurinol in piglets. No adverse effects of chronic allopurinol treatment were found on farrowing, birth weight, open field behavior, learning abilities, relative brain, hippocampus and spleen weights. LBW piglets showed increased anxiety levels in an open field test, but cognitive performance was not affected by allopurinol treatment. LBW animals treated with allopurinol showed the largest postnatal compensatory body weight gain. In contrast to a previous study, no differences in learning abilities were found between LBW and normal-birth-weight piglets. This discrepancy might be attributable to experimental differences. Our results indicate that chronic prenatal allopurinol treatment during the third trimester of pregnancy is safe, as no adverse side effects were observed. Compensatory weight gain of treated piglets is a positive indication for the chronic prenatal use of allopurinol in these animals. Further studies are needed to assess the possible preventive effects of allopurinol on brain functions in LBW piglets.

Neoplasms of the genital tract in a Vietnamese potbellied pig.

A 9-year-old, female potbellied pig showed loss of appetite and abdominal distension. After clinical examination and ultrasonography, a tumour was suspected. At laparotomy a large mass was present in the genital tract. Because the mass could not be excised, the pig was euthanized. Pathological examination revealed leiomyoma of the cervix and uterus wall in addition to multifocal adenocarcinomas of the uterus.

Addition of chromic oxide to creep feed as a fecal marker for selection of creep feed-eating suckling pigs.

OBJECTIVE: To determine whether the addition of chromic oxide (Cr(2)O(3)) to creep feed could be used as a visual marker in feces for selection of creep feed-eating suckling pigs. ANIMALS: 20 suckling pigs. PROCEDURES: Via syringe, 5 pigs (2 to 3 days old on day 0; 1 pig/treatment) from each of 4 litters received oral administrations of 10, 20, 30, or 40 g of creep feed containing 10 g of Cr(2)O(3)*kg(1) on each of 2 consecutive days (days 20 and 21) or 30 g of creep feed containing 10 g of Cr(2)O(3)*kg(1) on day 20 and 30 g of Cr(2)O(3)-free creep feed on day 21. On days 21 through 24, 6 fecal samples were collected from each pig at regular intervals between 8:00 AM and 6:00 PM. Green-colored feces were considered indicative of creep feed consumption (eaters). Data analyses were based on single and multiple fecal samples. RESULTS: On day 22, evaluation of 1 fecal sample/pig and multiple fecal samples per pig resulted in identification of as many as 40% and only 15% of the feed-treated pigs wrongly as noneaters, respectively. Repeated sampling over multiple days would identify 99% of eaters accurately. Pigs erroneously identified as noneaters were those administered either low amounts of Cr(2)O(3)-supplemented creep feed for 2 days or Cr(2)O(3)-supplemented creep feed on only 1 day. CONCLUSIONS AND CLINICAL RELEVANCE: Data suggest that addition of Cr(2)O(3) to creep feed enables selection of individual creep feed-eating suckling pigs via examination of feces, provided that repeated fecal samples are evaluated.