Morphine, pethidine and buprenorphine disposition in the cat

Pharmacokinetics of morphine, buprenorphine and pethidine were determined in 10 cats. Six cats received morphine (0.2 mg/kg) intravenously and four intramuscularly. Five received buprenorphine (0.01 mg/kg) intravenously and six intramuscularly. Six received pethidine (5 mg/kg) intramuscularly. Jugular venous blood samples were collected at time points to 24 h, and plasma morphine concentrations were measured by high performance liquid chromatograpy (HPLC), buprenorphine by radioimmunoassay (RIA) and pethidine by gas chromatography. Our data for morphine show elimination half-life (t1/2el) 76.3 min intravenous (i.v.) and 93.6 min intramuscular (i.m.); mean residence time (MRT) 105.0 and 120.5 min; clearance (Clp) 24.1 and 13.9 mL/kg/min; and volume of distribution (V(dss)) 2.6 and 1.7 L/kg, respectively. Comparable data for buprenorphine are t1/2el 416.8 and 380.2 min; MRT 417.6 and 409.8 min; Clp 16.7 and 23.7 mL/kg/min; and V(dss) 7.1 and 8.9 L/kg. For i.m. pethidine, t1/2el 216.4 min; MRT 307.5 min; Clp 20.8 mL/kg/min and V(dss) 5.2 L/kg. For i.m. dosing, the tmax for morphine, buprenorphine and pethidine were 15, 3 and 10 min, respectively. The pharmacokinetics of the three opioids in cats are broadly comparable with those of the dog, although there is a suggestion that the cat may clear morphine more slowly.     

Cytogenetic alterations in four feline soft-tissue tumours

Four mesenchymal neoplasms (two malignant fibroblastic histiocytomas, one fibrosarcoma, one fibroma) were investigated cytogenetically. Although no specific alterations were present, the frequent nonrandom involvement of chromosome E1 became clearly evident. Karyotypic alterations involving unrelated clonal changes were also present in the fibroma.     

Disseminated histoplasmosis in an Atlantic bottlenose dolphin (Tursiops truncatus).

An approximately 37-yr-old female Atlantic bottlenose dolphin (Tursiops truncatus) died after a 4-mo illness characterized by intermittent anorexia, lethargy, mild neutrophilic leukocytosis, and mild nonregenerative anemia. At necropsy, the lungs were diffusely consolidated, and histopathology of the lungs revealed severe pneumonia with macrophages containing clusters of numerous yeast cells. Inflammatory lesions and yeast also were found in pulmonary, mediastinal, prescapular, and duodenal lymph nodes, spleen, liver, kidneys, urinary bladder, pancreas, right adrenal gland, and the pyloric stomach. Histomorphology, fungal culture, and polymerase chain reaction analysis indicated that the fungus was Histoplasma capsulatum var. capsulatum. This is the first report of histoplasmosis in a cetacean.     

Characterization of changes related to mineral balance and bone metabolism in the young racing Quarter Horse

This study was conducted to determine physiologic responses reflective of bone metabolism during the onset of training and to relate those responses to the mineral requirements of young racehorses. Ten previously untrained Quarter Horse geldings were put into race training. They were fed a diet balanced to meet NRC recommendations for young horses in training. Feed, feces and urine were collected, weighed and analyzed over the experiment to determine mineral balance. Radiographs were taken of the left front leg to determine mineral content of a cross-sectional area of the third metacarpal. Blood samples were taken to determine osteocalcin, parathyroid hormone, 25-hydroxyvitamin D, Ca and inorganic P concentrations. Horses were gentled to ride, trained to gallop on the track and maintained in training for four 28-day periods. Blood serum was collected every 14 day, while radiographs and 72-hr total collections of urine and feces were taken every 28 d. Radiographs demonstrated that mineral content was lowest at day 56 in the dorsal, palmar and medial cortices of the third metacarpal. Urinary Ca declined dramatically from day 0 to day 28, then remained constant to day 56, before decreasing at day 84. Fecal Ca peaked at day 28 and remained elevated above day 0 amounts until day 112. calcium retention was negative at day 0, became slightly positive by day 28 and increased through day 112. Phosphorus and Mg balance remained relatively unchanged throughout the duration of the study. This study demon-strated changes in the mineral content of the third metacarpal and Ca balance during early training and suggests that further studies be performed.     

Effect of the gonadotrophins treatment on morphological alterations in ovary and peripheral plasma concentrations of steroid hormones in gilts

The present study was designed to examine the influence of gonadotrophins treatment on the ovarian morphology changes and plasma concentrations of steroid hormones in peripheral blood. The experiment was performed on sexually pubertal gilts (Large White x Landrace) of similar age (7-8 months) and body mass (100-110 kg) with two controlled subsequent estrous cycles. The animals were randomly divided into four groups: two control consisting of pigs with the luteal phase (n = 9, the 10th day of the estrous cycle) and the follicular phase (n = 6, the 20th day of the estrous cycle) and two experimental ones consisting of animals with both mentioned periods (n = 7 and n = 9) treated with gonadotrophins (PMSG and hCG). The gilts in the luteal phase were injected (s.c.) with gonadotrophins at a daily dose of PMSG 400 and hCG 200 IU from the 16th to the 27th day (the 6th day of the next estrous cycle). The gilts in the follicular phase, were injected with the same dose of gonadotrophins but from the 8th to the 19th day of the estrous cycle. Plasma concentrations of P4, A4, T, E1, E2 and metabolite of PGF2 alpha-PGFM were determined by radioimmunoassay (RIA) method. Injections of PMSG and hCG in both experimental groups produced several times enlarged: weight, size and volume of ovaries and alterations in a number of structural elements as compared with those found in the control animals. The morphological elements presented in ovaries: corpora haemorrhagica, corpora lutea, regular and atretic follicles and first of all cysts by distinctly differentiation thickness of the walls are characteristic for cystic ovarian degeneration. Plasma concentrations all determined hormones after gonadotrophins treatment in experimental groups were increased except E1 (insignificant decrease) in luteal phase as compared with those found in the control groups. Statistically significant increase (p < 0.001) in plasma concentrations of P4, A4, and T in both experimental groups and E2 (p < 0.001) in luteal phase were noted. In peripheral plasma concentrations increase of E1 and E2 in follicular phase of the estrous cycle were insignificant.     

Cattle Infected with Bovine Leukaemia Virus may not only Develop Persistent B‐cell Lymphocytosis but also Persistent B‐cell Lymphopenia

We investigated the distribution of B and T cells in the peripheral blood of haematologically inconspicuous (non‐persistent lymphocytotic, PL^?) cattle infected with the bovine leukaemia virus (BLV). Flow cytometric data were obtained from six PL^? cattle and compared with six age‐matched animals with persistent lymphocytosis (PL⁺) and five non‐infected healthy controls (BLV^?). In the PL^? group, the percentage and number of surface immunoglobulin‐positive (sIg⁺) B cells were significantly reduced. Whereas in BLV^? cattle, about 40% of the peripheral blood lymphocytes (PBL) were sIg⁺ and 24% were sIgM⁺ B cells. In the PL^? group, less than 20% of the PBL were sIg⁺ and sIgM⁺ B cells. Only 5% of the PBL co‐expressed sIgM⁺ and CD5⁺ versus 16% in BLV^?. This decrease was persistent over 3 years and predominantly affected: (i) B cells that did not express sIgM; (ii) sIgM⁺ B cells co‐expressing CD5 and CD11b; and (iii) equally both λ‐ and κ‐type light chain B‐cell subpopulations. In contrast, the number of all circulating lymphocytes, CD5^? and CD11b^? sIgM⁺ B cells and CD2⁺ T cells did not differ. In PL⁺ animals, about 75% of the PBL were sIgM⁺CD5⁺ B cells. These cells were of polyclonal origin, as light chains of the λ‐ and κ‐type were expressed in a ratio of 4:1 (57.7% of PBL λ⁺, 14% κ⁺) as in BLV^? animals (33.6% of PBL λ⁺, 8.7% κ⁺). In PL⁺ cattle the absolute number of B‐cells and, therefore, their relative percentage is significantly increased. For this reason, even in case of absolutely increased T‐cell numbers, the relative percentage of T‐cells could be lower than in normal controls. The cause for the observed B cell decrease in PL^? cattle is unknown, but it can be assumed that cytotoxic T cells are involved in this B‐cell lymphopenia.     

Canine lymphosarcoma and hypercalcaemia: clinical, laboratory and pathologic evaluation of twenty-four cases

Twenty-four dogs with lymphosarcoma and hypercalcaemia were studied clinically, haematologically and biochemically. There was no age or breed predilection, although the St Bernard dog appeared to be over-represented. Male dogs were more frequently affected (62 per cent) than female dogs. Anorexia, weight loss, muscular weakness, depression, polydipsia, polyuria, and bilateral peripheral lymphadenopathy were the most frequently observed clinical signs and physical findings. Hypercalcaemia, creatinaemia, azotaemia, hypercalciuria, hyposthenuria, and decreased endogenous creatinine clearance were the most frequent laboratory abnormalities. Detailed gross and histopathologic examinations of 10 dogs revealed the multicentric anatomic form of lymphosarcoma, absence of skeletal metastases, and normal parathyroid glands. The dogs were clinically staged, and ten were histologically classified. Histologic staging revealed five diffuse histiocytic lymphomas, and five diffuse lymphocytic poorly differentiated lymphomas.     

Duration of protection of calves against rhinovirus challenge exposure by infectious bovine rhinotracheitis virus-induced interferon in nasal secretions

Six calves inoculated intranasally with a vaccinal strain of infectious bovine rhinotracheitis (IBR) virus and 6 control calves were given a placebo. All calves were subsequently challenge exposed (by aerosol) with rhinovirus--3 of the calves from each group at 2 days after they were inoculated with IBR virus or with placebo and the remaining calves at 6 days. Nasal excretion of viruses, interferon (IFN) concentrations in nasal secretions (NS), and neutralizing antibody in sera and NS were determined. All calves given the vaccinal IBR virus subsequently had IFN in their NS. Interferon was detected as early as 1 day, reached maximal titers at 2 to 4 days, and persisted in individual calves for 5 to 10 days after inoculation. Rhinovirus shedding was not detected from IBR virus-inoculated calves whose NS contained both rhinovirus antibody and IFN at the time of challenge exposure; such calves were protected at either 2 or 6 days after IBR virus inoculation. The outcome of rhinovirus challenge exposure of calves whose NS contained IFN, but not rhinovirus antibody, varied with the day of challenge exposure. Rhinovirus excretion was detected from 2 of these calves challenge exposed 2 days after IBR virus inoculation, but was not detected from a calf challenge exposed 6 days after inoculation. However, while IFN was present in NS from the former 2 calves, rhinovirus shedding was markedly reduced as compared with that from control calves without IFN or NS antibody at the time of challenge exposure. Consistent relationship was not observed between the rhinovirus neutralizing antibody titer of calves' sera and NS. The antibody titer of NS more closely correlated with protective immunity to rhinovirus infection than did the serum antibody titer.