Aspects of bacteriology and endocrinology of cows with pyometra and retained fetal membranes

In an effort to clarify the pathogenesis of pyometra, 20 cows with retained fetal membranes and 20 without, but with contemporary calving dates were studied. They were palpated and their uteri were subjected to sample collections for bacteriologic cultural examinations twice weekly for 4 weeks. Blood samples were obtained each day and evaluated for serum progesterone concentration. Three cows without and 3 with retained fetal membranes developed pyometra during the study, resulting in 3 groups designated control (CON), cows with retained fetal membranes (RFM), and cows with pyometra (PYO). Bacterial isolations occurred less frequently in the CON group than in the PYO and RFM groups. Growth patterns of bacteria also varied between groups. Coliform and incidental bacteria disappeared from the uterus of the PYO group by the end of the 3rd week. In contrast, heavy growth of Corynebacterium pyogenes and gram-negative anaerobic bacteria developed during this same period in the PYO group. In cows with pyometra, the significant persistent pathogenic bacteria recovered were C pyogenes and gram-negative anaerobic bacteria, especially Fusobacterium necrophorum and Bacteroides melaninogenicus. Anaerobic bacteria were isolated simultaneously with C pyogenes in most cows of the PYO group, but less often in CON and RFM groups, and highest growth levels were present near the time of ovulation. Clinically, pyometra usually developed about 10 days after observation of concurrent ovulation and high growth levels of C pyogenes and gram-negative anaerobic bacteria. A hypothesis is presented for development of pyometra in the cow.     

Progesterone receptors in feline mammary adenocarcinomas

Estradiol and progesterone receptors were measured in tumor cytosols from 3 intact and 4 neutered female cats with spontaneously occurring mammary adenocarcinomas. Serum from 2 of the intact cats which had been in estrus 4 and 4 to 6 weeks before tumor excision contained progesterone concentrations of 16.2 and 2.2 ng/ml, respectively; serum progesterone in the other cats was less than 2 ng/ml. Estradiol receptors were not detected in any cytosols. Progesterone receptors were detected in all of the cytosols, in concentrations ranging from 4.0 to 11.7 (mean = 7.2) fmol/mg of protein. Scatchard plot analysis of tumor cytosol from an 8th cat with mammary adenocarcinoma revealed presence of high affinity progesterone binding with a dissociation constant (Kd) of 3.47 nM. Tumor receptor content could not be correlated with stage of the estrous cycle nor with whether the cat was intact or neutered.     

Trials of an inactivated equid herpesvirus 1 vaccine: challenge with a subtype 1 virus

Vaccinated yearlings , two-year-old and in-foal pony mares with appropriate controls were exposed to aerosols of a subtype 1 virus one to two months after two or three vaccinations; all became infected. No obvious differences in the febrile responses, clinical signs and subsequent abortions were found between vaccinated and control mares. All vaccinated yearlings and two-year-old ponies developed a febrile respiratory disease but this was less severe than that suffered by the controls and the amounts and duration of virus shedding were reduced.     

The influence of the oestrous cycle on the intravenous glucose tolerance test in the bitch

The possibility that endogenous oestrogen and progesterone affect carbohydrate tolerance in the female dog was investigated by relating the results of repeated intravenous glucose tolerance tests to the phases of the oestrous cycle, namely anoestrus, pro-oestrus, oestrus and dioestrus. Neither the glucose tolerances nor the insulin responses were significantly different between these phases of the oestrous cycle in 12 Dalmatian bitches.     

Dexamethasone and prednisolone in the horse: pharmacokinetics and action on the adrenal gland

Pharmacokinetics of dexamethasone and prednisolone were studied in 6 horses given dexamethasone alcohol (IV or IM) or dexamethasone 21-isonicotinate as a solution IV or IM (50 micrograms/kg of body weight), prednisolone 21-sodium succinate IV or IM (0.6 mg/kg of body weight), or prednisolone acetate IM (0.6 mg/kg of body weight). Plasma concentrations were determined using a high-performance liquid chromatographic method. After dexamethasone alcohol (IV) or dexamethasone 21-isonicotinate (IV), the half-life of elimination was similar (53 minutes) for both formulations. After dexamethasone (alcohol and isonicotinate, IM), concentrations were low or nondetected. After prednisolone 21-sodium succinate (IV), the half-life of elimination (99.5 minutes) was significantly (P less than 0.01) longer than that for dexamethasone. After prednisolone 21-sodium succinate (IM), absorption was rapid and bioavailability was high. After prednisolone acetate (IM), absorption was slow and prednisolone was present in plasma for about 7 days. Due to the nonlinearity of prednisolone kinetics, a bioavailability higher than 100% was obtained. The basal plasma hydrocortisone concentration was approximately 70 ng/ml. After dexamethasone (IV or IM), plasma hydrocortisone values decreased after a 2-hour delay and returned to base line after a 3 to 4 day delay. After prednisolone 21-sodium succinate (IV or IM), plasma hydrocortisone decreased immediately (IV) or rapidly (IM) and returned to base line after a 24-hour delay. After prednisolone acetate (IM), plasma hydrocortisone decreased for up to 21 days.     

Ecology of Rhodococcus equi

A selective broth enrichment technique was used to study the distribution of Rhodococcus equi in soil and grazing animals. Rhodococcus equi was isolated from 54% of soils examined and from the gut contents, rectal faeces and dung of all grazing herbivorous species examined. Rhodococcus equi was not isolated from the faeces or dung of penned animals which did not have access to grazing. The isolation rate from dung was much higher than from other samples and this was found to be due to the ability of R. equi to multiply more readily in dung. Delayed hypersensitivity tests were carried out on horses, sheep and cattle, but only horses reacted significantly. The physiological characteristics of R. equi and the nature of its distribution in the environment suggested that R. equi is a soil organism.     

Ovine uterine morphogenesis: histochemical aspects of endometrial development in the fetus and neonate

Uterine tissues obtained from fetal (d 60 to term; n = 17; d 0 = day of mating) and neonatal (n = 9; d 0 = birth) lambs were subjected to alcian blue-8GX and fluorescein isothiocyanate (FITC)-lectin histochemistry to determine if alcianophilic properties of the epitheliomesenchymal interface (EMI) changed during endometrial morphogenesis and to characterize distribution of binding sites for seven FITC-lectins during uterine development. Neonatal lambs were subjected to bilateral ovariectomy and unilateral hysterectomy (BOHX; n = 3) or unilateral ovariohysterectomy (UOHX; n = 3) on d 0. Remaining tissues were recovered on d 14. Procedures allowed within-animal comparisons of endometrial responses and assessment of the role of the ovary in endometrial morphogenesis. Uteri also were obtained from three intact neonatal lambs by hysterectomy (d 14, d 15 and d 26). Alcianophilic properties of the EMI characteristic of polyanionic glycosaminoglycans (GAG) changed with onset of endometrial remodelling after fetal d 60 and were characterized by loss of EMI alcianophilia at or above .3 M MgCl2 and at low pH. Alcianophilic properties of the neonatal endometrium suggested restabilization of lumenal EMI and destabilization of the EMI in developing endometrial glands. Five of seven FITC-lectins bound to both fetal and neonatal uterine tissue. Tissues from UOHX, BOHX and intact ewes were indistinguishable histochemically. Data provide evidence of a role for GAG in ovine endometrial morphogenesis, ovary-independent initiation of endometrial glandular development, and illustrate potential uses of FITC-lectin conjugates in studies of ungulate uterine tissues.     

Cattle breed comparison and crossbreeding trials in Europe; A survey prepared by a working party of the European association for animal production

A Working Party of the European Association for Animal Production surveyed the breed comparison and crossbreeding trials which were being carried out in Europe. The survey summarizes the experimental work in the different countries and gives details on 86 separate projects concerned with breed and strain evaluation in pure and crossbreeding situations. The paper gives a general summary of the survey and recommendations on the methodology for future experiments. More detailed abstracts of the individual trials included in the survey are obtainable on request.