Habituation by the immature fowl in response to repeated injections of corticotrophin.

1. Immature birds treated for 7 d with corticotrophin (30 IU/kg, one injection per day) had significantly poorer growth rates and decreased adrenal cholesterol concentrations. Plasma glucose, corticosterone and cholesterol concentrations and adrenal weight were within the normal range 24 h after the last injection.

2. The responses of birds pretreated as described above to a single injection of corticotrophin (30 IU/kg) were determined.

3. A similar degree of hyperglycaemia had developed in both groups after 2 h but thereafter the responses differed: the concentration of plasma glucose did not increase further in those pretreated with corticotrophin and had begun to decrease at 6 h, whereas that of the birds pretreated with saline increased progressively.

4. The concentrations of plasma corticosterone had increased similarly in the two groups to a peak at 2 h but there was a significantly more rapid decrease in the birds pretreated with corticotrophin.

5. Both groups showed a transient hypercholesteraemia but the increase was significant only in the group that had previously received saline.

6. There were decreases in the concentrations of adrenal cholesterol in both groups. The decrease, in absolute terms, was 2–4 times greater in the group receiving corticotrophin for the first time: percentage changes were similar, however.     

Rotaviral diarrhea in pigs: brief review.

Rotavirus is a name given to a group of viruses that have similar characteristics and are generally capable of causing diarrhea in the young. Infection of pigs with porcine rotavirus is common and widespread and can result in diarrhea, especially in 1- to 4-week-old pigs. This virus is frequently associated with a diarrheal syndrome popularity known as "white scours," "milk scours," or "3-week-old scours." Pigs less than 1 week old are infrequently infected, presumably because of adequate passive immunity. The infection resembles enzootic transmissible gastroenteritis. Diagnosis can be made by immunofluorescent staining of mucosal scrappings from the small intestines.     

Experimental infection of eastern cottontail rabbits Sylvilagus floridanus) with infectious bovine rhinotracheitis virus.

Experimental infection of eastern cottontail rabbits (Sylvilagus floridanus) with infectious bovine rhinotracheitis virus caused acute keratoconjunctivitis and a fatal systemic infection. The clinical syndrome was characterized initially by blepharospasm and ocular discharge. The rabbits were markedly depressed on post-exposure day (PED) 5 and were dead or moribund on PED 6. The virus was readily recovered from liver and adrenal gland tissue on PED 6 and from conjunctival swabs on PED 1 to 6. Histopathologic studies revealed a few necrotic foci in the liver and multiple focal to diffuse necrosis of the adrenal glands. Viral isolation and immunofluorescence tests were used to demonstrate a direct association between infectious bovine rhinotracheitis viral antigens and the lesions.     

Influence of a mycoplasma respiratory tract infection on sheep erythrocyte and complement receptor-bearing cell composition in the respiratory tract of swine.

Pulmonic and peripheral blood lymphocyte subpopulations in healthy and Mycoplasma suipneumoniae-infected pigs were compared. The T- and the B-lymphocyte populations were counted, the B cells by the complement receptor (zymosan-complement rosettes) technique and the T cells by the ED-rosette technique (sheep RBC-dextran rosettes). The T cells were found to predominate among pulmonic, as well as blood, lymphocytes. Pulmonic B-cell and blood T-cell percentages were increased after mycoplasma respiratory tract infection. However, blood B-cell and pulmonic T-cell percentages were not significantly affected. A significant (P less than 0.001) correlation between pulmonic and blood T-lymphocyte compositions was found; conversely, no correlation was observed between blood and pulmonic B-cell percentages. These data could imply that pulmonic B cells are predominantly involved in local immune reactions after a mycoplasma respiratory tract infection.     

Adrenal gland function in the horse: effects of cosyntropin (synthetic) and corticotropin (natural) stimulation.

The plasma concentration of hydrocortisone was determined in mares given either cosyntropin (100 IU, given IV) or corticotropin (200 IU, given IM). Plasma hydrocortisone concentrations of the mares treated with cosyntropin increased by 46%, 57% and 80% at 30, 60, and 120 minutes, respectively, when compared with base-line values; these values returned to base line at 240 minutes. In mares treated with corticotropin, mean plasma hydrocortisone concentrations increased by 42%, 143%, 101% and 155% at 30, 60, 120, and 240 minutes, respectively, when compared with base-line values. Differences in total leukocyte count, total eosinophil count, and plasma concentrations of electrolytes (calcium, sodium, magnesium, potassium) of cosyntropin- and corticotropin-treated mares, and these values in control animals were not significant. Results of the present study indicated that the horse responds to small dosages of cosyntropin (IV) in a prompt and reproducible manner as determined by plasma hydrocortisone values. Response to corticotropin was slow and less consistent. Thus, administration of cosyntropin to the horse, according to test results with paired samples collected (before administration and again at 2 hours after injection), was found to be a prompt and meaningful test of adrenal gland function.     

Influence of environment on adrenal cortical response to ACTH stimulation in clinically normal dogs.

Effect of testing environment on adrenal cortical responses to an injection of ACTH in clinically normal dogs was examined in three locations, presumably of increasing order of stress elicitation: in a home; veterinary hospital (VH), 4 hours in a cage; and VH, overnight in a cage. Basal cortisol (hydrocortisone) values for plasma were significantly lower (P less than 0.001) for the home group (1.8 microgram/dl) when compared with values for the VH, 4-hour cage (3.8 microgram/dl) or the VH, overnight cage (3.9 microgram/dl) groups. However, significant differences (P greater than 0.05) were not observed 2 hours after ACTH admininstration for the home group (13.7 microgram/dl); VH, 4-hour cage group (14.8 microgram/dl); or VH, overnight cage group (16.0 microgram/dl). Responses of individual dogs were consistent (P less than 0.005). The testing environment did not markedly affect results of adrenal cortical function tests for dogs when ACTH stimulation was utilized. The response of dogs to ACTH, as monitored by immunologic assay techniques (competitive protein-binding assay or radioimmunoassay), was consistent and was useful as a diagnostic aid for adrenal malfunction.