Pre-laying behaviour in battery cages

The pre-laying behaviour of hens from two strains of domestic fowls housed in battery cages was studied. Hens from one strain exhibited stereotyped pacing before laying, whereas hens from the other tended to sit during the pre-laying period. Hens from both strains performed vacuum nest-building behaviour before laying. Implications of these findings in relation to the improvement of animal welfare are discussed.     

In vitro properties of diffuse cytoplasmic esterase-positive canine mononuclear leukocytes

Depletion of cytoplasmic esterase-positive canine peripheral blood monocytes from mononuclear cell suspensions was attempted using plastic adherence, carbonyl iron ingestion and/or Sephadex G-10 filtration. An esterase-positive, nonadherent, nonphagocytic subpopulation was identified and further characterized by the presence or absence of cell membrane receptors for the Fc portions of immunoglobulin and the activated third component of complement. The majority of these nonadherent cells lacked these receptors. The data suggests that canine peripheral blood monocytes are a heterogenous cell population.     

Influence of selenium on aflatoxin B1 or crotalaria toxicity in turkey poults

This research compared the toxic effects of aflatoxin B1 and monocrotaline, the active principle of Crotalaria spectabilis, and the additive effect between aflatoxin B1 and monocrotaline in turkey poults. It was of interest whether selenium fed at dosage levels of 0.1, 5, or 10 micrograms/g of feed would protect against the toxic effect of aflatoxin and/or monocrotaline, and whether the toxicants would result in detectable residues in poult tissues. A total of 180 healthy 1-day-old male turkey poults was assigned at random to 12 treatment groups (15 birds/group). Body and liver weight losses, and low serum concentrations in total protein (TP), albumin (A), alpha-globulin (alpha G), and beta-globulin (beta G), as well as high values in gamma-globulin (gamma G), were produced in the groups fed crotalaria. Pathologic changes were induced by monocrotaline with no protection afforded by the added selenium. Low values in TP, A, alpha G, and beta G and in body and liver weights were observed in groups given the combination of aflatoxin plus crotalaria. Gross lesions were associated with an additive toxic effect and a lack of protective effect of selenium against this combination. However, higher values in TP, A, alpha G, and beta G, and liver weights in groups fed aflatoxin B1 plus selenium indicated that selenium had a protective effect against aflatoxin toxicity. Residues of aflatoxin B1 and aflatoxin M1 were found in the kidneys of poults fed aflatoxin B1; also, dehydroretronecine (the metabolite of monocrotaline) was detected in livers of poults fed Crotalaria spectabilis seeds.     

Serum protein changes in grass sickness

Polyacrylamide gel electrophoresis was used to compare serum taken from ponies before and during clinical illness confirmed as grass sickness. A consistent rise in the level of haptoglobin was seen in serum from animals which had shown symptoms for more than two days. Serum albumin was also shown to have altered mobility at the onset of clinical disease. Estimation of the haemoglobin-binding capacity confirmed the haptoglobin increase. This haptoglobin has been purified and some of its properties determined. In contrast to the situation in acute inflammatory conditions no other acute-phase proteins increased to a significant extent in grass sickness. It is concluded that the neurotoxin known to be present in sera of animals experiencing acute grass sickness cannot itself be detected by polyacrylamide gel electrophoresis but may be bound to serum albumin.     

Hematologic and biochemical abnormalities associated with induced extrahepatic bile duct obstruction in the cat

Bile duct obstruction was induced in 6 cats by surgical ligation and transection of the common bile duct. Clinical and laboratory changes were monitored weekly for 25 to 54 days. Clinical signs of obstruction were similar in all cats and included anorexia, pyrexia, lethargy, intermittent vomiting, weight loss, palpable gallbladder, hepatomegaly, and bleeding tendencies. Tissue jaundice and acholic feces were evident grossly as early as postsurgical day (PSD) 4 with a mean onset of jaundice at PSD 5.3 +/- 0.4. Hematologic changes were initially characterized by a mild neutrophilic leukocytosis that increased with the chronicity of bile duct obstruction. Regenerative anemia developed in 4 cats associated with gastrointestinal blood loss. Acute serum biochemical changes were characterized by a marked increase in the mean values of aspartate aminotransferase, alanine aminotransferase, total cholesterol, and copper. Comparatively, only moderate increases in mean serum alkaline phosphatase activity were observed. Mean total bilirubin values increased remarkably at postsurgical week (PSW) 1, reaching a maximal value of 23.1 +/- 4.4 mg/dl at PSW 3 with 71.6 +/- 2.7% direct bilirubin. With chronicity of bile duct obstruction ranging from PSW 3 to PSW 7, the mean serum values of aspartate aminotransferase, alanine aminotransferase, total cholesterol, serum alkaline phosphatase, and total and direct bilirubin stabilized and then declined, whereas the increased mean serum copper values persisted. At PSD 25 to 54, hepatic copper values and serum bile acids were markedly increased. Seemingly, clinicopathologic changes of induced cholestatic hepatic injury depended largely on the duration of biliary obstruction.(ABSTRACT TRUNCATED AT 250 WORDS)     

Simple technique for the direct isolation of toxoplasma tissue cysts from fetal ovine brain

A simple technique is described for the isolation of Toxoplasma gondii tissue cysts from fetal ovine brain by centrifugation on a discontinuous density gradient of 30 per cent and 90 per cent Percoll (colloidal silica solution). Brain samples from 51 aborted ovine fetuses were examined by both the Percoll and mouse inoculation techniques; eight infections were detected by the Percoll technique compared to 12 by mouse inoculation. Possible reasons for this discrepancy and the scope for improving the Percoll technique are discussed.     

Pathogenicity of Eperythrozoon suis alone and when mixed with Babesia trautmanni in experimentally-infected pigs

The pathogenicity of a single infection with Eperythrozoon suis and of a mixed infection of E. suis and Babesia trautmanni in experimentally-infected pigs, was described. In the pigs with a single infection, parasitaemia of E. suis was observed 4 days after blood inoculation. Although parasitaemia with this parasite was also observed on the 4th day in a mixed infection, the parasitaemia of B. trautmanni was not noted until 14 days after inoculation at a period when that of E. suis had started to fall. No parasitaemia was observed in any of the pigs in the splenectomized and unsplenectomized uninoculated control animals. The pigs carrying either single or mixed infections had pyrexia and their temperatures were consistently higher than those of the control animals. Infected pigs also showed anaemia with significant decline in Pcv, Hb and RBC values. The total WBC count rose in the infected pigs and the rise was more pronounced in pigs carrying E. suis alone. In addition, it was only in pigs infected by E. suis alone that a decline in the percentage of neutrophils and a rise in percentage lymphocytes was observed.     

Naturally occurring lethal parvovirus infection of juvenile and young-adult rats

A lethal disease characterized by hemorrhage and necrosis of the brain, testes, and epididymides developed in young adult rats housed in specific pathogen free quarters. Morphological, virological, and serological investigations of the outbreak indicated that the probable causative agent was rat virus (Kilham), a common parvovirus of rats that usually induces persistent, asymptomatic infection in adult rats.     

Experimental Pseudomonas aeruginosa ulcerative keratitis model in the dog

Primary Pseudomonas aeruginosa ulcerative keratitis and accompanying secondary ocular disease were induced bilaterally in 12 of 12 dogs subjected to corneal trephination and intrastromal inoculation. Successful experimental infection was based on recovery of viable Pseudomonas organisms from the lesions, as well as gross and biomicroscopic appearance of the corneas.