Seven mature dairy cows from 6 herds were obtained with history, clinical signs of disease, and laboratory findings suggestive of advanced paratuberculosis. A surgically implanted collection chamber was used to obtain peripheral tissue fluid. Blood, mammary gland flush fluid, and collection chamber flush fluid (CCFF) samples were obtained 6 times over a 2-week period from each cow. Mononuclear cell-rich portions of these fluids obtained by gradient centrifugation were submitted for bacteriologic culture of Mycobacterium paratuberculosis and for total and differential cell counts. Bacteriologic culture of feces for M paratuberculosis and complete necropsy performed on each cow at the conclusion of the study confirmed the diagnosis of paratuberculosis. Numbers of tissue macrophages obtained from CCFF samples were lower than expected. Mean (+/- SD) differential count of tissue macrophages collected from CCFF was 65.57 (+/- 23.39). Mean calculated tissue macrophages (total cell count X differential count) collected from CCFF samples was 623.1 (+/- 784.55) cells/microliter. Mycobacterium paratuberculosis was isolated from 1 of 42 (2.4%) collections of mononuclear cell-rich portions of plasma and from 2 of 42 (4.8%) CCFF samples. Mycobacterium paratuberculosis was not isolated from any collections of mammary gland flush fluid. The collection and processing techniques used in this study did not enhance detection of M paratuberculosis infection in cows with advanced paratuberculosis, beyond that of ileocecal lymph node biopsy or fecal culture.

Fourteen cats were inoculated orally with 1 of 2 infective doses of Toxocara canis to induce eosinophilia. Cats were subsequently challenge exposed twice via intraperitoneal injection with 1 of 2 T canis antigen preparations. Peritoneal lavage was performed 2 days after antigenic challenge exposure, and eosinophils in the peritoneal lavage fluid were quantified. None of the cats developed clinical signs of disease after infection. All cats developed peripheral eosinophilia after infection. Significant (P < 0.05) difference in mean eosinophil count from the lavage fluid was observed between lavage 1 (prechallenge exposure) and lavages 2 and 3 (postchallenge exposure) in both groups of cats. Significant difference in eosinophil count was not found between cats given different doses of eggs. After initial challenge exposure, significantly (P < 0.05) more eosinophils were obtained from cats given antigen preparation 2 (prep-2) than from those given antigen prep-1. This difference was no longer observed after the second challenge exposure with higher doses of either antigen prep-1 or prep-2. In cats given antigen prep-2, significant difference was not found between lavages 2 and 3. However, in cats given antigen prep-1, eosinophil count was significantly (P = 0.005) greater in fluid obtained from lavage 3, compared with eosinophil count from lavage 2. Mean +/- SEM percentage of eosinophils in the fluid from lavage 3 in all cats was 70.8 +/- 2.2%. Other cell types included macrophages, neutrophils, lymphocytes, and mast cells. Gross postmortem findings were mild. One- to 3-mm nodular white foci of inflammation were observed on the serosal surfaces of the liver, spleen, kidneys, and omentum. Microscopic examination of tissues revealed pulmonary artery hypertrophy (n = 4), eosinophilic peribronchitis and perivasculitis (n = 10), mild granulomatous interstitial nephritis (n = 6), interstitial pancreatitis (n = 1), focal lymphocytic myocarditis (n = 1), focal eosinophilic granulomatous hepatitis (n = 1), and eosinophilic hyperplasia of bone marrow (n = 14). Large numbers of eosinophils could be harvested from the peritoneal cavity of cats inoculated orally with 500 embryonated T canis eggs and subsequently challenge-exposed intraperitoneally with preparations of parasite antigens. After the second challenge exposure, at least 108 eosinophils could be harvested from each cat, yielding eosinophils in the quantity required to begin isolation of granule constituents.