Immunization against cholecystokinin decreases appetite in lambs.

The effects of immunization against cholecystokinin (CCK) on feed intake, weight gain, and carcass characteristics were studied in sheep. Nine wether lambs at 10 wk of age were immunized with a conjugate of sulphated CCK octapeptide and human serum globulin or against human globulin alone. All CCK-immunized lambs produced antibodies, and the average titer 5 wk after the primary immunization was calculated to be sufficient to bind normal circulating levels of CCK. Mean daily feed intakes and BW were similar in the CCK-immunized and the control-immunized groups at the start of treatment, but after immunization, feed intake, appetite, and BW gain were decreased in the CCK-immunized animals. There was no effect on carcass composition or organ growth relative to body growth. It is concluded that the immunization procedure used in this study may have potentiated the actions of CCK rather than neutralizing its action as an appetite regulator.     

Efficacy of a drug combination of praziquantel, pyrantel embonate, and febantel against helminth infections in dogs.

Tablets containing praziquantel, pyrantel embonate, and febantel were tested for efficacy against helminths in dogs. A single treatment with this drug combination gave 100% reductions in Toxocara canis and Taenia hydatigena in experimentally induced infections in dogs. In dogs with naturally acquired infections, treatment gave > 97 to 98% reductions in fecal egg counts attributable to Toxascaris leonina, T canis, and Uncinaria stenocephala. Efficacy against Trichuris vulpis was > 92%.     

Isolation of Mycobacterium paratuberculosis after oral inoculation in uninfected cattle.

Feces from cows naturally infected with Mycobacterium paratuberculosis was given to 6 uninfected heifers by orogastric intubation, to determine whether ingested organisms could be passively excreted and detected by bacteriologic culture of feces (ie, false-positive result). Heifers were paired, and each pair received a different dose of feces on days 1 and 2. Fecal samples were collected from the heifers 3 times daily. Mycobacterium paratuberculosis was detected in fecal samples of all heifers within 18 hours of being given the first dose of feces. The number of colony-forming units peaked on days 3 or 4, and organisms were no longer detected by day 7. The number of colony-forming units in fecal samples from the heifers was approximately proportional to the dose given. On days 15 and 16, the experiment was repeated with feces from a second infected cow. Results were similar to those in the first experiment. All heifers remained seronegative (agar-gel immunodiffusion test and ELISA) and had negative results to the intradermal johnin test throughout the experiment. Lymph node and intestinal tissues were obtained from all 6 heifers at slaughter on day 28. Mycobacterium paratuberculosis was not isolated from mesenteric lymph nodes from the ileocecal valve region, but was isolated from ileal mucosal samples from each heifer.     

Enteral feeding of dogs and cats: 51 cases (1989-1991).

Feeding commercial enteral diets to critically ill dogs and cats via nasogastric tubes was an appropriate means for providing nutritional support and was associated with few complications. Twenty-six cats and 25 dogs in the intensive care unit of our teaching hospital were evaluated for malnutrition and identified as candidates for nutritional support via nasogastric tube. Four commercial liquid formula diets and one protein supplement designed for use in human beings were fed to the dogs and cats. Outcome variables used to assess efficacy and safety of nutritional support were return to voluntary food intake, maintenance of body weight to within 10% of admission weight, and complications associated with feeding liquid diets. Sixty-three percent of animals experienced no complications with enteral feedings; resumption of food intake began for most animals (52%) while they were still in the hospital. Weight was maintained in 61% of the animals (16 of 26 cats and 15 of 25 dogs). Complications that did occur included vomiting, diarrhea, and inadvertent tube removal. Most problems were resolved by changing the diet or adhering to the recommended feeding protocol. Nutritional support as a component of therapy in small animals often is initiated late in the course of the disease when animals have not recovered as quickly as expected. If begun before the animal becomes nutrient depleted, enteral feeding may better support the animal and avoid serious complications.     

Sudden acquired retinal degeneration ('silent retina syndrome') in two dogs.

Two unrelated adult dogs developed idiopathic, acute-onset, bilateral total blindness. The ophthalmoscopic changes were minimal and no electroretinographic response could be detected in either dog. The retinas were examined ultrastructurally 10 days (dog 1) and two-and-a-half months (dog 2) after they became blind. There was widespread loss of the outer segments of rod and cone photoreceptors. Where the outer segments persisted, there was marked tubulovesicular change with loss of normal orientation in their lamellae. Second order neurons (bipolar cells) and ganglion cells were unaffected. The cause of this selective and massive disruption of rod and cone endings was not established, but acute toxicity is proposed as a possible mechanism.     

Studies on the stability of a human adenovirus-rabies recombinant vaccine.

Human adenovirus type 5 containing the rabies virus glycoprotein gene (rHAd-RG1) has potential for the oral vaccination of animals. The stability of this recombinant was tested indoors and outdoors by measuring the loss in virus infectivity. Under indoor conditions the stability of the recombinant virus was studied in an egg yolk-containing commercial stabilizer and a simple buffered salt solution (EBSS; Earle's balanced salt solution) at 4 degrees C and room temperature (24-25 degrees C). Over 16 days, there was a more rapid loss in virus titer at room temperature than at 4 degrees C in both suspending media; however, these differences were slight and may be significant when the overall stability of the vaccine is considered. When the virus was mixed with either 10% (w/v) fox or skunk feces or EBSS, placed on stainless steel disks and the disks kept under ambient conditions (air temperature 24-25 degrees C; relative humidity 45-50%), there was a more rapid decline in virus titer in the fecal suspensions (3% remained after 72 h) than in EBSS (26% remained after 72 h). When bait-coated blister packs of the vaccine were placed in an outdoor location in the fall (October) season, there was a larger drop in the virus titer for vaccines placed in the sun (54% over 32 days) than for those in the shade (40% over 32 days). Incorporating proteinaceous stabilizers in the vaccine samples for outdoor study showed virus stability was not enhanced in their presence.(ABSTRACT TRUNCATED AT 250 WORDS)     

Incidence of non-laying in domestic hens.

1. Egg production records of 31,455 individually caged hens, 27 to 34 weeks of age and of 4 genotypes, were examined. 2. Sixty-nine non-layers were identified in the 30 to 40 week age group, and examined post mortem; an incidence of 2.1 per 1000. 3. Some of the 69 individuals had more than one abnormality. Forty-two percent were internal layers, 34% had some form of neoplasia, 24% had an abnormal or diseased oviduct, 18% were sex reversals, 16% had a diseased ovary, 8% were of poor condition and considered culls, and 7% were in good condition, but with small, immature ovaries. 4. Of 54 birds not in lay at 27 weeks, 43 (80%) had come into lay by 34 weeks of age. 5. Genotype influenced the incidence of neoplasia and, in turn, the number of non-layers.     

Changes in cell-mediated immune responses after experimentally-induced anaphylaxis in dogs.

Experimentally-induced type 1 hypersensitivities were induced in normal dogs to either ovalbumin or Ascaris antigen. In vitro and in vivo cell-mediated immune responses were measured before sensitization and again at 1 and 6 days after induction of anaphylaxis by intravenous challenge with antigen. Histamine-modulated lymphocyte functions, such as histamine-induced suppression, histamine co-mitogen induced blastogenesis and the in vivo cutaneous responses to intradermally injected mitogens decreased post anaphylaxis. Spontaneous suppression of the autologous mixed-lymphocyte reaction increased post anaphylaxis. Lymphocyte blastogenic response to Concanavalin A (Con A) decreased at 6 (but not at 1) days post anaphylaxis probably due to a mediator other than histamine. Blastogenesis of 24 h preincubated cells by suboptimal concentration of Con A, declined post anaphylaxis, but Con A-induced suppression was not significantly altered. Dogs with atopic dermatitis have some altered cell-mediated immune responses. Altered histamine-induced and spontaneous suppression, histamine suppression of mitogenesis and decreased contact sensitivity observed in this experimental type 1 hypersensitivity mimicked that of atopic dogs. Increased cutaneous response to mitogens observed in atopic dogs was not reproduced in the type 1 hypersensitive dogs. These findings suggest some of the altered cell-mediated immune functions observed in dogs with atopic dermatitis result from type 1 hypersensitivity. The other abnormalities may be intrinsic to the atopic state.     

Purification and characterisation of chicken liver monomeric glutathione peroxidase

1. A novel glutathione peroxidase, which is distinct from tetrameric glutathione peroxidase, was purified to homogeneity from a broiler chick liver cytosolic fraction using 5 different column chromatographic methods.

2. The enzyme in cytosol was separated from ‘classic’ tetrameric glutathione peroxidase and glutathione S‐transferases by DEAE‐Sephacel and Sephadex G‐100 chromatographies and further purified by Mono Q, hydroxylapatite and sulphobro‐mophthalein‐S‐glutathione‐agarose chromatographies.

3. The molecular weight of the purified enzyme determined by sodium dodecyl sulphate‐polyacrylamide gel electrophoresis was 19,500 and that found by gel filtration chromatography was comparable. This indicates that the enzyme protein is a single polypeptide. The isoelectric point of the enzyme was determined as 7.0 by polyacrylamide gel isoelectric focusing.

4. The purified enzyme catalysed the reduction of hydrogen peroxide, cumene hydroperoxide, tert‐butyl hydroperoxide and linoleic acid hydroperoxide. Furthermore, it reduced phosphatidylcholine hydroperoxide in the absence of phospholi‐pase A2. The optimum pH for the enzyme reaction was 7.0. The antiserum against the purified enzyme reacted with the 19.5 kDa polypeptide in the liver cytosol of duck and quail.