Is a repeat treatment of antibiotic therapy necessary?

Interrelations between host, bacterium and antibiotic compound in antibiotic therapy of bacterial infections are analysed. Some methods for the evaluation of antibacterial activity of antibiotics in vitro are described and their limits, in particular of the widely used MIC tests, are demonstrated. Data from trials comparing antibiotic applications once and twice a day as well as discussions in chemotherapy, concerning the applicability of in vitro results to therapy, are used to try to find practicable guidelines for the repetition of antibiotic therapy.     

Response time of broiler chickens to cimaterol: meat tenderness, muscle composition fiber size, and carcass characteristics.

The response time to cimaterol (CIM), a beta-adrenergic agonist, by broiler chickens for carcass characteristics, muscle composition, muscle fiber size, catheptic enzyme activity, and tenderness was determined. Two trials were conducted in which chickens were fed a control diet (CON) containing 0 ppm of CIM or a diet containing 1 ppm of CIM. Trial 1 consisted of 55, 31-d-old broiler chickens individually fed for up to 48 h. At 0, 6, 12, 18, 24, and 48 h, five CON and five CIM-fed chickens were killed. Trial 2 consisted of 160, 33-d-old broiler chickens group-fed for up to 14 d. At 2, 4, 6, 8, 10, 12, and 14 d, 10 CON and 10 CIM-fed chickens were killed. The breast muscle (BM) and leg muscle (LM) weight, cathepsin B and L activities, DNA, RNA, and protein concentration, and BM shear force value (SFV) were measured in both trials. Thigh muscle (TM) SFV were measured in Trial 2 only. Fiber size of BM was measured (five birds per treatment) at d 2, 6, 10, and 14. In Trial 1, BM weight and SFV were lower in CIM-fed birds at 6 h (P less than .05). In Trial 2 BM SFV were higher at d 8 (P = .06) and d 10 (P less than .05) in CIM-fed chickens. The SFV of CIM-fed chickens were higher at d 4, 8, 10, 12, and 14 (P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Microcirculation in the follicles and corpora lutea of the bovine ovary--a corrosion anatomical study

With the help of a new synthetic material follicles and corpora lutea from the ovaries of 80 cows in different stages of the sexual cycle were examined for modifications of their blood vessel architecture. In the theca externa the main artery which runs towards the follicle, separates into arterioles of which capillaries derive in the theca interna, building a basket-like network around the zona granulosa. After ovulation the follicle wall forms characteristic fields. Capillaries grow into the zona granulosa and thus the folds form the lobular structure of the corpus luteum. Capillaries which rise from the ruptured part of the follicle, spread centripetally and together with lutein cells they build up the not lobulated cupola of the corpus luteum. The regression of the corpus luteum starts around the 16th day of the cycle, beginning at the capillary network of the cupola. A contraction of the vessels and a quick decrease of the volume follow.     

Surgical repair of skull fractures in four horses using cuttable bone plates.

Three horses with severely comminuted, open facial bone fractures and one horse with a comminuted, open orbital rim fracture were referred for treatment. Severe facial bone asymmetry and epistaxis were apparent in all cases and subcutaneous emphysema was present in two, however physical and neurological examinations were otherwise normal. Radiography and endoscopy were of some use in assessing the degree of damage, although the true extent of the damage was more apparent at surgery. Surgical reduction of the fractures was recommended to maximise cosmetic and functional outcome. After surgical debridement and reduction of the fractures the bone fragments remained unstable and were not amenable to stabilisation with interfragmentary wires alone, so 2 mm cuttable bone plates were used to maintain fracture alignment. Screw migration occurred in three horses and in one of these horses the plate had to be removed. Other complications were minor and in all horses the fractures healed with good cosmetic and functional outcome. The use of cuttable bone plates should be considered as a reasonable alternative to inter-fragmentary wiring for unstable, comminuted fractures of the facial bones, even where fractures are open.     

Bilateral ureterocystostomy in a 450-kg horse with ectopic ureters.

A 450-kg yearling Clydesdale filly was determined to have bilateral ectopic ureters. The resulting incontinence caused severe malodorous perineal dermatitis. Bladder capacity was measured at 800 ml. The urethral sphincter lacked tone, and the horse was seen to urinate in a normal manner only 2 or 3 times a week. A midline celiotomy was performed, and the ureters were identified by cannulation from the ectopic openings. The ureters were ligated, and the cut ends were anastomosed to the dorsal bladder surface by an extravesicular end-to-side technique. A partial thickness seromuscular layer of the bladder was sutured over the ureters in a cranial direction from the anastomosis site for 15 mm. This fixed the ureters to the dorsal surface of the bladder and protected the anastomosis site from tension. After surgery, the horse urinated n a normal manner many times a day. Urinary incontinence continued, but gradually improved. Bladder capacity increased over 13 months to 4.3 L. Surgical (urethral extension) and medical (phenylpropanolamine and estrogen) treatments were instigated to increase urethral sphincter tone. Urinary incontinence continued to improve and, at 11 months after surgery, incontinence was negligible, and the perineal dermatitis had healed.     

Squamous cell carcinoma of the corneoscleral limbus in a dog.

Squamous cell carcinoma is an uncommon tumor of the cornea in dogs. A 12-year-old Shih Tzu with a history of chronic keratoconjunctivitis sicca was diagnosed as having squamous cell carcinoma of the corneoscleral limbus. The lesion was treated by surgical resection and cryotherapy. One year after surgery, multiple tumors, apparently unrelated to the first tumor, appeared on the same cornea. Keratoconjunctivitis sicca may have predisposed the dog to corneal squamous cell carcinoma development.     

Efficacy of AHR-13268, an antiallergenic compound, in the management of pruritus caused by atopic disease in dogs.

Twenty-nine pruritic, atopic dogs were entered into a double-blind, placebo-controlled, crossover study to evaluate the efficacy of an investigational antiallergenic compound, AHR-13268. Fourteen dogs were evaluated by a veterinary dermatologist (at intervals) and the owner (daily). Fifteen dogs were evaluated only by the owner. The mean (+/- SE) owner scores for pruritus, erythema, and lesions with placebo treatment (higher score = worse signs) were 3.24 (+/- 0.12), 2.73 (+/- 0.12), and 2.61 (+/- 0.09), respectively. With drug treatment, the corresponding scores were 2.89 (+/- 0.12), 2.50 (+/- 0.12), and 2.25 (+/- 0.09). Scores for pruritus and lesions (but not erythema) were significantly better with drug treatment than with placebo treatment. Investigator scores showed similar trends, but the differences were not great enough to be statistically significant. Overall, 11/29 (38%) owners reported their dogs had moderate or better improvement from drug capsules, and 4/29 dogs (14%) improved on placebo capsules. A variety of adverse effects were reported following both drug (9/29 dogs) and placebo (8/29 dogs) capsule administration, but were mild and well tolerated. Results of this study indicate that AHR-13268 has potential for empiric treatment of allergic inhalant dermatitis in some dogs.     

Hepatitis contagiosa canis (H.c.c.)--2 cases in Austria

Two cases of H.c.c. which occurred in winter 1987 in Vienna are described. Case one was a female Chow-Chow, 8 weeks of age, that died from the peracute form of the disease. The diagnosis was confirmed by histology and direct immunofluorescence. Case two, a 9-month old female Kuvacz, showed clinical signs of the subacute form of H.c.c. She was hospitalized and therapy was successful. The disease was diagnosed by the typical clinical signs and the raise of antibodies in paired serum samples. Etiology, clinical signs and immunology of H.c.c. are discussed.     

Residues of aminoglycoside antibiotics in eggs after medication of laying hens

1. The transfer of aminoglycoside antibiotics into eggs was determined separately from albumen, yolk or whole egg after oral administration of dihydrostreptomycin (DHS), neomycin and spectinomycin and after an intramuscular injection of DHS. Residues were assayed by an agar plate diffusion method in cylinders with a specific test organism for each antibiotic. 2. Only DHS, administered by the intramuscular route, led to detectable residues in eggs. The total amount of DHS excreted via the eggs represented 1% of the dose administered. 3. Residues in the whole egg were detected for 8 d.     

Isotypic antibody responses in cattle infected with Haemophilus somnus

Bovine antibody responses to Haemophilus somnus were compared on the basis of clinical and bacteriological findings. Serum IgG1 and IgM antibody titres were significantly increased in clinically normal cattle that were bacteriologically positive for H somnus from the nasal or vaginal mucosae compared with clinically normal, negative cows. IgG2 titres did not differ significantly between these two groups. However, IgG2 antibody was significantly higher in animals with H somnus disease (pneumonia or abortion) than in clinically normal cattle (whether bacteriologically positive or negative), while IgG1 and IgM titres did not differ between diseased and bacteriologically positive, clinically normal cattle. These antibody trends were duplicated in experimental H somnus abortion or pneumonia, with the greatest response occurring within the IgG2 subclass. Cattle vaccinated systemically with killed whole H somnus produced a predominant IgG2 response with minimal IgG1 and IgM responses. These results demonstrate that IgG2 antibody is consistently elevated in H somnus disease, and suggest that this response may be useful in discriminating diseased from asymptomatic cattle.