A meta-analysis comparing the effect of PCV2 vaccines on average daily weight gain and mortality rate in pigs from weaning to slaughter

The aim of this investigation was, through a meta-analysis, to review the published literature concerning the effect of PCV2 vaccination on the average daily weight gain (ADG) and on the mortality rate in pigs from weaning to slaughter. The review was restricted to studies investigating the effect of vaccines against PCV2 published from 2006 to 2008, identified using computerised literature databases. Only studies that met the following criteria were included: commercial vaccines were used, pigs or pens were assigned randomly to vaccination versus control groups in herds naturally infected with PCV2, and vaccinated and non-vaccinated pigs were housed together. Furthermore, it was a requirement that sample size, age at vaccination, and production period were stated. The levels of ADG and mortality rate had to be comparable to those seen in modern intensive swine production. In total, 107 studies were identified; 70 were excluded because they did not fulfil the inclusion criteria and 13 were identical to results published elsewhere. A significant effect of PCV2 vaccination on ADG was found for pigs in all production phases. The largest increase in ADG was found for finishing pigs (41.5g) and nursery-finishing pigs (33.6g) with only 10.6g increase in the nursery pigs. Mortality rate was significantly reduced for finishing pigs (4.4%) and nursery-finishing pigs (5.4%), but not for nursery pigs (0.25%). Herds negative for PRRS had a significantly larger increase in ADG compared to herds positive for PRRS. The PRRS status had no effect on mortality rate.     

More than eating dirt: a review of avian geophagy‡

Geophagy, the ingestion of earth varying in particle size from stones to soils rich in clay, is a relatively widespread behaviour across avian taxa. We reviewed its occurrence in birds and its hypothesised adaptive functions in birds. Of the ～30 avian orders, 23 exhibit geophagy. However, it has only been documented in ～260 species (～2% of birds) and therefor is relatively uncommon. Ingestion of stones and other large particles (grit) is recorded in 54 extant families across the avian phylogeny and appears to be ancient in birds and has evolved several times. Clay ingestion is recorded in 14 phylogenetically scattered families and might have evolved repeatedly. Furthermore, at least nine families exhibit both clay and grit ingestion. Six hypothesised functions of avian geophagy involve digestion and nutrition. Ingested grit might provide (1) essential minerals, particularly sodium or calcium, but it appears to primarily (2) improve mechanical digestion of food in the gizzard, where ingested stones and sand particles are known as gastroliths. Consistent with this gastrolith hypothesis, ～86% of species ingesting grit consume “hard” food: seeds, leaves, insects or other animals. In contrast, ingested clay appears to be for sodium or other nutrient intake and/or protecting birds from ingested plant secondary compounds, by (3) protecting the digestive tract and (4) adsorbing these compounds. Consistent with this, ～88% of species ingesting clay eat fruit that is often rich in secondary compounds and low in sodium, and clay ingestion is associated with frugivory in a representative sample of genera of which many have been shown to source sodium. The other two hypotheses are buffering gastric pH (5) and acquiring antidiarrheal agents (6), but no documentation of this in birds was found. We suggest additional tests of these hypotheses and additional investigation of these proposed benefits of geophagy in birds.     

Bronek (Brian) Stein

Veterinary Virology, 2nd edition, FJ Fenner, EPJ Gibbs, FA
Murphy, R Roitt, MJ Studded and DO White, Russia.     

Effects of ranitidine, famotidine, pantoprazole, and omeprazole on intragastric pH in dogs

OBJECTIVE: To identify the normal gastric acid secretion profile in dogs and determine the degree of gastric acid suppression associated with 4 gastric acid suppressants. ANIMALS: 12 healthy Beagles. PROCEDURE: Intragastric pH was measured continuously for 24-hour periods with a digital recording system placed via a gastrostomy tube. Baseline measurements were obtained when food was withheld and when dogs were fed a standard diet. Dogs were then treated with ranitidine (2 mg/kg, IV, q 12 h), famotidine (0.5 mg/kg, IV, q 12 h), pantoprazole (1 mg/kg, IV, q 24 h), omeprazole (1 mg/kg, PO, q 24 h), or saline solution for 7 days; intragastric pH was recorded on days 0, 2, and 6. Subsequently, the effects of administering famotidine (0.5 mg/kg, IV, q 8 h; 6 dogs) and omeprazole as a suspension (1 mg/kg, PO, q 12 h; 6 dogs) were evaluated. Median 24-hour intragastric pH, percentage of time pH was > or = 3, and percentage of time pH was > or = 4 were determined. RESULTS: Median pH, percentage of time pH was > or = 3, and percentage of time pH was > or = 4 were all significantly higher when food was withheld than when dogs were fed. Famotidine, pantoprazole, and omeprazole significantly suppressed gastric acid secretion, compared with saline solution, as determined on the basis of median 24-hour pH and percentages of time pH was > or = 3 or > or = 4. However, ranitidine did not. Omeprazole suspension suppressed gastric acid secretion. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that in healthy dogs, famotidine, pantoprazole, and omeprazole significantly suppress gastric acid secretion. Twice daily administration of a suspension of omeprazole, was the only regimen tested that approached the potential therapeutic efficacy for acid-related disease when assessed by criteria used for human patients.     

Multifocal cutaneous histiocytic sarcoma in a young dog and review of histiocytic cell immunophenotyping

A 9‐month‐old male Great Dane had progressive generalized nodular dermatopathy for several months. There were > 100 raised, alopecic, firm, painful nodules throughout the skin. Aspirates from several lesions yielded moderate numbers of irregularly round or polygonal to spindle‐shaped cells with mild to moderate anisocytosis and few inflammatory cells, and the cytologic interpretation was proliferation of mesenchymal or histiocytic cells. On histopathologic examination, nodules were composed of densely packed sheets of round to spindle‐shaped cells with mild anisokaryosis and low mitotic activity. Multifocal histiocytic sarcoma with a spindle‐cell pattern was diagnosed based on morphologic features and intense expression of CD18. Additional immunophenotypic analysis on frozen sections of tissue confirmed the diagnosis of histiocytic sarcoma; expression of CD18, CD45, CD1a, CD11b, and CD11c, limited expression of Thy‐1 (CD90) and CD80, and lack of expression of CD4, CD11d, and CD86 indicated that the cells were likely interstitial dendritic cells; a review of reactive and neoplastic dendritic cells is provided. Based on staging, internal organs were not affected. Sequential treatment with lomustine and doxorubicin failed to prevent progression of the cutaneous lesions, and the dog died 3 months after initial diagnosis. At necropsy, a focus of neoplastic cells was present in one lymph node, but except for skin other organs were not involved. The clinical presentation of histiocytic sarcoma may be unusual, and neoplastic cells may lack overt features of malignancy on cytologic and histopathologic examination. In some instances, immunophenotyping is required to differentiate histiocytic sarcoma from other histiocytic disorders.     

Molecular evidence for the infection of zoo chimpanzees by pig Ascaris

We here describe the transmission of the pig roundworm, Ascaris suum to chimpanzees maintained in the Copenhagen Zoo, Denmark. Using a technique for whole genome fingerprinting, amplified fragment length polymorphism (AFLP) and the technique PCR restricted fragment length polymorphism (PCR-RFLP) of the internal transcribed spacer region (ITS) of the nuclear ribosomal DNA, the worms from the chimpanzees were compared with Ascaris spp obtained from humans and pigs in order to identify the source of the infection. By the use of different distance and clustering based methods on the AFLP data set the worms from the chimpanzees were assigned to the same cluster as that of the worms from pigs. The PCR-RFLP analysis supported the AFLP results. Therefore, the zoo chimpanzees have required Ascaris infections by cross-infection from pigs. Pigs as a potential source of Ascaris infections for both captive and wild chimpanzees and other animals, therefore needs to be considered and appropriate steps taken to prevent such infection.