The growth of the heart, relative to body weight, was measured by M-mode echocardiography in dogs during the first year of life. Echocardiographic measurements were obtained from 16 English Pointers at 1, 2, 4, and 8 weeks of age and at 3, 6, 9, and 12 months of age. Left atrial (LA), aortic (AO), left and right ventricular internal dimensions, interventricular septal and left ventricular wall thickness measurements increased in curvilinear fashion relative to increasing body weight. Least-squares regression analysis, performed on logarithmically transformed data, was used to develop power-law equations describing the relationship of echocardiographic measurements to body weight. Linear dimensions of the LA, AO, left and right ventricular internal dimensions and interventricular septal and left ventricular wall thickness changed proportionally to slightly differing exponential powers of body weight (BW), varying from 0.31 to 0.45 (BW(0.31) to BW(0.45)). Fractional shortening and the LA to AO ratio decreased slightly, but significantly, as body weight increased. Indexing echocardiographic measurements to BW(1/3) was more appropriate than indexing such measures linearly to body weight, offering a practical method for developing accurate normative graphs or tables for M-mode echocardiographic dimensions in growing dogs.

Ultrasonic pachymetry was used to measure central, superior peripheral, and temporal peripheral corneal thicknesses of 75 dogs (150 eyes) with normal corneas, anterior chambers, and intraocular pressure. Mean corneal thickness averaged over the 2 eyes, 3 locations, and 75 dogs was 562 +/- 6.2 micromole. The peripheral cornea was thicker on average than the central cornea by 49.43 +/- 8.45 micromole and this difference increased with age at 6.97 +/- 1.3 micromole/month of age. Mean corneal thickness changed with age (14.23 +/- 2.26 micromole/month), and weight (1.83 +/- 0.38 micromole/kg). Females had significantly thinner corneas (22.43 +/- 11.03 micromole than males) after adjusting for age and weight.

The purpose of this study was to evaluate the effectiveness of an aromatic-dependent mutant of Salmonella typhimurium as a parenteral vaccine for prevention of fecal shedding of Salmonella spp. Pigs and chickens were vaccinated IM, with 1 X 10(9) and 1 X 10(8) organisms, respectively, followed by a second identical vaccination 2 weeks later. Salmonella organisms were not detected by analysis of fecal or cloacal swab specimens from any animal after vaccination. Deleterious side effects were not noticed after vaccination. Pigs were challenge-inoculated PO with 1 X 10(12) virulent S typhimurium 1 week after the second vaccination. Chickens were challenge-inoculated PO with 3 X 10(8) organisms of either S enteritidis or the virulent parent strain of S typhimurium 3 weeks after the second vaccination. Vaccinated pigs shed Salmonella spp significantly less frequently than did nonvaccinated pigs. Vaccinated chickens challenge-inoculated with either S enteritidis or S typhimurium also shed Salmonella less frequently than the corresponding nonvaccinated control birds; however, the difference was not significant.

It has been shown that zearalenone disrupts early pregnancy in swine without altering intrauterine content of estradiol 17 beta or progesterone, embryo migration, or estradiol-17 beta thesis by blastocysts. However, serum concentrations of progesterone were reduced 2 to 3 weeks after mating in gilts that ingested zearalenone. Therefore, progesterone was administered to gilts during early pregnancy to determine whether it could counteract the detrimental actions of zearalenone on embryonic development. Thirty-two crossbred gilts (Hampshire X Chester White X Yorkshire X Duroc) were assigned randomly to a 2 X 2 factorial arrangement of treatments: zearalenone (Z); zearalenone plus progesterone (ZP); progesterone (P); or control (C). From postmating days 4 to 15, Z- and ZP-treated gilts were fed 1 mg of Z/kg of body weight, and P-treated and C gilts were fed ethanol as vehicle in a corn-soybean diet. On postmating days 3 to 15, P- and ZP-treated gilts were injected IM with 100 mg of progesterone, and C and Z-treated gilts were injected with progesterone carrier (15% ethanol, 15% benzyl alcohol, 70% propylene glycol). Blood was collected from gilts by puncture of the jugular vein daily from days 3 to 15, on alternate days from days 17 to 31, and then twice weekly until the end of the experiment. Fetal development was assessed in Z and ZP-treated gilts on postmating day 47.6 +/- 2.9 by cesarean section and in P-treated and c gilts at slaughter on postmating days 51.2 +/- 3.2. Serum concentrations of progesterone in P-treated gilts were greater on days 7 to 8, 10 to 15, 17, and 19 than in C gilts. Serum concentrations of progesterone were greater on days 8, 10, and 12 in ZP-treated than in C gilts. However, serum concentrations of progesterone were lower in ZP-treated gilts than in C gilts on postmating days 19 to 31. Serum concentrations of progesterone were lower in Z-treated gilts than C gilts on postmating days 15, 17, and 19. At slaughter or cesarean section, viable fetuses were not found in Z-treated gilts, but 80% of the C and P-treated gilts had viable fetuses. All Z-treated gilts were classified as pseudopregnant because uteri were turgid and the ovaries had functional corpora lutea. Uteri of ZP-treated gilts appeared normal. Corpora lutea of pregnancy had regressed by postmating day 35 in 7 of 8 ZP-treated gilts. Crown-to-rump length was similar between P-treated and C gilts (94 vs 92 mm). Fetal weight was similar between P-treated and C gilts (70 vs 62 g). These data demonstrate that 100 mg of progesterone/d failed to counteract the adverse effects of 1 mg of Z/kg of body weight on early pregnancy in primiparous gilts.

Sixty-nine specific pathogen-free male Wistar rats approximately eight weeks of age were used to evaluate the efficacy of an attentuated strain of sialodacryoadenitis (SDA) virus in providing protection against infection on subsequent challenge with virulent SDA virus. Fifty-four animals were inoculated intranasally with approximately 10-1.5 median cell culture infectious doses of the 25th passage of SDA virus in L-2 cells. Randomly-selected vaccinated animals were killed in order to evaluate the safety and efficacy of attenuated virus by histopathological examination of the salivary glands, lacrimal glands, and lower respiratory tract, and titration of sera for antibody to SDA virus. At three months and six months post-vaccination (pv), animals were selected at random and challenged with virulent SDA virus. Seronegative, age-matched animals were also challenged, and served as controls. In animals examined at six to ten days pv, lesions were absent in submandibular and parotid salivary glands and lacrimal glands, but transient lesions were present in major airways of the lower respiratory tract. In a comparison of the incidence and extent of lesions, and antibody titers in challenged vaccinates and seronegative controls, lesions were minimal or absent in vaccinates compared to challenged naive rats, particularly in animals inoculated at three months pv. In addition, antibody titers in challenged vaccinates were much higher than were postinoculation titers in inoculated controls. In a comparison of lesions in salivary and lacrimal glands in vaccinated and control animals challenged at six months pv, there was a significant reduction in the number of animals without lesions in the vaccinated group (p = < 0.0001). Based on the incidence of lesions in target tissues and the marked antibody response in vaccinates on challenge with virulent SDA virus, it was concluded that prior inoculation with the attenuated strain of SDA virus provided a significant level of protection for up to six months postvaccination.

Pulmonary function tests were performed on seven adult dairy cows with an expanded tung field (ExLF) and the results were compared to the values from seven cows with normal lung fields. The cows with ExLF had an increased functional residual capacity (FRC) and end-tidal N2 concentration of the final breath of the multiple-breath N2 washout (FET(N2),fb), and an abnormal distribution of ventilation. The measurements of ventilation and gas exchange and pulmonary mechanics did not differ between the two groups. Postmortem examination of the lungs of five of the cows in each group indicated the cows with ExLF had a bronchiolitis with varying degrees of goblet cell hyperplasia, epithelial cell hyperplasia and metaplasia, smooth muscle hypertrophy, inflammatory cell infiltrate, vascular thickening, peribronchiolar fibrosis, and a mild overinflation of the lung. A histopathological score, based on the preceding indices and bronchus-associated lymphoid tissue, was correlated with FRC, FET(N2),fb, the lung clearance index and pulmonary resistance. There were no correlations between the histopathological score and any of the measures of ventilation and gas exchange.

To evaluate the use of technetium pertechnetate (99mTcO4) as a means of estimating gastric mucosal integrity, nuclear images of the empty stomach were obtained from 6 dogs at 20, 40, 60, 120, 180, and 240 minutes after IV administration of the radiopharmaceutical. Blood and gastric secretion samples were collected during the same time intervals. The left lateral-view image of the stomach was used to calculate the relative fraction of the dose in the stomach and the count density ratio. Between 20 and 40 minutes and 40 and 60 minutes, significant differences (P < 0.001) were apparent in the amount of 99mTcO4 in the stomach. Blood concentration of 99mTcO4 decreased significantly (P < 0.001), whereas gastric secretion concentration increased significantly (P < 0.001) over time. Qualitative assessment of the gastric nuclear scans and the statistical analytic results indicated that the optimal time for imaging the canine stomach was between 40 and 60 minutes after radiopharmaceutical administration. In a second study, the same dogs were pretreated with the H2-receptor antagonist cimetidine and the cholinergic antagonist glycopyrrolate to block gastric secretions. Over time, changes in the relative dose fraction in the stomach and the density ratio were the same as values obtained during the experiment performed without use of cimetidine and glycopyrrolate. Results of the study indicate that nuclear imaging with 99mTcO4 outlines normal canine gastric mucosa and that pretreatment with cimetidine and glycopyrrolate has no effect on the quality of the gastric image.

Praziquantel was used successfully for treatment of a small number of dogs and 1 cat infected with Paragonimus kellicotti. To further evaluate the usefulness of this drug in treating such infections, 7 cats and 7 dogs were inoculated orally with metacercariae (12 and 20 to 22, respectively) obtained from crayfish, then were treated after the infections became patent; 2 cats and 2 dogs served as noninfected controls. Beginning 1 week before infection, and continuing weekly thereafter, physical, hematologic, and fecal examinations were performed on each animal; thoracic radiography was performed every other week. By postinoculation week 6, all dogs given metacercariae had patent infection diagnosed on the basis of positive results of fecal examination. By postinoculation week 7, 5 cats had confirmed patent infection, but 2 cats given metacercariae never had patent infection or had signs of infection. Clinical signs of infection were minor and included increased respiratory tract noise, slight inducible cough, or mild dyspnea. Transient eosinophilia was detected in dogs around postinoculation week 3. Pretreatment radiography revealed cavitated lesions in cats only; pleural lines and patchy infiltrates in cats and dogs; or pneumothorax in dogs only. The treatment regimen consisted of 23 mg of praziquantel/kg of body weight given every 8 hours for 3 days; 1 infected cat and dog were not treated. By 11 days after treatment, eggs had disappeared from the feces of infected animals, and marked resolution of lung lesions was evident radiographically. The 2 untreated animals and 1 treated dog were euthanatized and necropsied to verify lesions and their resolution. All treated animals were considered cured of infection by use of this treatment regimen.

Viral RNA oligonucleotide fingerprinting was used to discriminate 3 cytopathic vaccine bovine viral diarrhea viruses (BVDV) grown in medium supplemented with serum contaminated with noncytopathic BVDV from the same 3 viruses grown in cell culture free of BVDV. Oligonucleotide tide fingerprinting also effectively discriminated between reference Singer BVDV, NADL BVDV, and New York-1 BVDV grown in BVDV-free noncontaminated or BVDV-contaminated cell cultures. Oligonucleotide fingerprint mapping of viral RNA maybe used to determine the purity of virus stocks, as well as that of BVDV vaccines.

The ability of 25 Pasteurella multocida isolates to adhere in vitro to porcine respiratory tract mucus was examined. Microplate wells were coated with crude mucus preparation, then bacteria were added. After incubation, unbound bacteria were removed by washing, and the number of mucus-bound bacteria was estimated by quantitation of the adherent colony-forming units and by use of an ELISA. Pasteurella multocida had affinity to respiratory tract mucus, although significant differences were not observed in affinity of capsular type-A and type-D isolates. Preliminary characterization, using ultrafiltration, gel filtration chromatography, electrophoresis, and enzymatic treatments, indicated that the receptors may be a class of protein molecules of low molecular weight (< 25,000). The origin of these receptors, however, is not known at this time.