Ovine pulmonary transit of tetracycline and minocycline.

Following cannulation of the right external jugular vein and the efferent duct of the right caudal mediastinal lymph node (the caudal end of this node was ligated to cut off the inflow of systemic lymph, i.e., 90%-95% of the efferent lymph was of pulmonary origin), sheep were given either tetracycline or minocycline as single doses of 5 mg/kg body weight infused intravenously over 30 min. Venous blood plasma and pulmonary lymph collected contemporaneously before infusion and from 5 min to 24 hr postinfusion were assayed by a well-agar diffusion method using Bacillus cereus. Peak concentrations of both drugs were observed in both plasma and lymph at 5 min postinfusion. Tetracycline penetrated into the lymph better than minocycline (percent penetration 67.3% of cf. 38.2%). The concentration of tetracycline was significantly higher in lymph during and 5 min postinfusion (p less than 0.01), a factor that may be of importance when selecting a tetracycline for the treatment of a pulmonary infection.

The effect of age on the nucleic acid content of slow- and fast-twitch muscle in normal and dystrophic mice and their litter mates.

RNA, DNA, and NCP content were measured in fast- and slow-twitch skeletal muscle of normal and dystrophic mice (HDM) and their littermates at ages 4 through 29 weeks. In normal and litter mate mice RNA and DNA content were far greater in the soleus than in the gastrocnemius while the RNA/DNA ratio and NCP content were greater in the gastrocnemius. In dystrophic mice, however, the differences between nuleic acid content of the 2 muscles were far less, apparently due to a proportionately higher content in the dystrophic gastrocnemius. Due to a proportionately lower ratio in the gastrocnemius, dystrophic RNA/DNA ratios for the 2 muscles were essentially the same. Age had a marked effect on the nucleic acid content of both muscles in all 3 mice types but to varying degrees. In the soleus, RNA and DNA content rapidly decreased until 9 to 10 weeks of age followed by a gradual decline. Soleus RNA/DNA ratios showed little change with age except in the HDM mice in which there was a significant overall decline. In the gastrocnemius, RNA content followed the same pattern but with a smaller decline in the younger ages. Age had no affect on DNA content in the normal gastrocnemius, but there was significant decline in the HDM gastrocnemius. RNA/DNA gastrocnemius ratios showed marked fluctuations in both normal and dystrophic mice but did not appear to be affected by age.

Mechanical properties of the tibia from chickens with idiopathic scoliosis.

The tibia from six-week old chickens that develop idiopathic scoliosis were studied with stress relaxation experiments and torsional strength testing. Most parameters observed did not show any significant differences between tibias obtained from chickens with scoliosis and tibias from the control birds; however, the rate of stress relaxation of the tibia from the birds with scoliosis was minimally increased over the controls. There were no significant differences noted in ultimate torsional strength, maximum angular deformity or modulae of torsional rigidity of the tibias from scoliotic chickens when compared to tibias from control chickens.

Flow cytometric analysis of lectin-binding to canine blood lymphocytes.

The cell surface glycoconjugates of blood lymphocytes from 19 dogs with and without neoplastic disease were quantitated using flow cytofluorometric analysis of the binding characteristics of 3 lectins, namely, wheat germ agglutinin, concanavalin-A, and Lens culinaris agglutinin. The specificity of lectin binding was determined using competitive monosaccharide inhibitors. The results show enhanced binding of concanavalin-A to blood lymphocytes from dogs with lymphosarcoma relative to healthy dogs, or those with a variety of neoplastic and nonneoplastic diseases.

Chronic oral infections of cats and their relationship to persistent oral carriage of feline calici-, immunodeficiency, or leukemia viruses.

Two hundred and twenty-six cats from the Veterinary Medical Teaching Hospital (VMTH), a cat shelter, and a purebred cattery were tested for chronic feline calicivirus (FCV), feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) infections. Chronic oral carriage of FCV was present in about one-fifth of the cats in each of the groups. FIV infection was not present in the purebred cattery, was moderately prevalent (8%) in the pet population of cats examined at the VMTH for various complaints and was rampant in the cat shelter (21%). Unexpectedly high FeLV infection rates were found in the hospital cat population (28%) and in the purebred cattery (36%), but not in the cat shelter (1.4%). FCV and FeLV infections tended to occur early in life, whereas FIV infections tended to occur in older animals. From 43 to 100% of the cats in these environments had oral cavity disease ranging from mild gingivitis (23-46%), proliferative gingivitis (18-20%), periodontitis (3-32%) and periodontitis with involvement of extra-gingival tissues (7-27%). Cats infected solely with FCV did not have a greater likelihood of oral lesions, or more severe oral disease, than cats that were totally virus free. This was also true for cats infected solely with FeLV, or for cats dually infected with FeLV and FCV. Cats infected solely with FIV appeared to have a greater prevalence of oral cavity infections and their oral cavity disease tended to be more severe than cats without FIV infection. FIV-infected cats that were coinfected with either FCV, or with FCV and FeLV, had the highest prevalence of oral cavity infections and the most severe oral lesions.

The utility of regional cancer mortality data for identifying occupations at high risk.

Mortality rates by geographic areas have been used successfully in the past to identify occupations with a high risk of cancer. The 1975 Atlas of Cancer Mortality for U.S. Counties: 1950-1969 for white males showed that mortality rates in three California counties (Alameda, Sacramento, and San Francisco) were significantly elevated compared to other US counties, and in Sacramento County the lung cancer death rate was significantly high also. This current study was to determine if the excess in the cancer mortality rate found in Sacramento County was possibly related to specific occupational categories. Death certificates for all white males dying of cancer were retrieved, Last occupation, industry, and length of service were coded according to the Index of Industries and Occupations prepared by the US Bureau of the Census. Observed frequencies of cancer deaths were compared to an expected number which was based on US census data by occupation for Sacramento County. Elevated standardized mortality ratios (SMRs) for cancer deaths were found for technicians, metal craftsmen, nonfarm laborers, construction workers, and drivers. SMRs were high for cancer of the esophagus, pancreas, respiratory tract, skin, and central nervous system.

A quantitative study of the effect of endotoxin on embryonating chicken eggs.

A quantitative study of the effect of endotoxin on embryonating chicken eggs revealed the importance of several variables. In the study, the chorioallanotic membrane was detached (i.e.,dropped) from the eggshell membrane on the 9th and 11th incubation days. Various doses of endotoxin in various amounts of diluent were applied on the dropped membrane on the 11th day. Embryo deaths were greater when the membrane was dropped on the 11th day. Within the limits of our trial, the variables were, in decreasing order of significance: 1) the day the membrane was dropped; 2) the amount of endotoxin applied; and 3) an interaction between 1 and 2. The volume of diluent had no significant effect on mortality. The importance of these variables is discussed with reference to the design of additional experiments with endotoxin.

The effect of Mycoplasma meleagridis infection and egg dipping on the weight-gain performance of turkey poults.

Turkey poults were observed throughout their first 7 weeks of life to evaluate the effects of embryonic infection with Mycoplasma meleagridis (MM) and the effects of a control measure, egg dipping with tylosin and gentamycin. Fifty-thousand poults from four sister flocks were divided among eight groups according to MM-infection status [MM (+) or MM (-)] , sex, and egg-dipping status (dipped or nondipped). These birds were raised under natural field conditions in the Central Valley of California. The MM (+) poults had significantly (P less than 0.05) greater weights during the first part of the trial and, although usually not significantly (P greater than 0.05), consistently during the later part.

Enzyme immunoassay of Chlamydia in birds.

Serum samples from 192 free-living birds (27 species) were tested for antibodies against Chlamydia using the enzyme-linked immunosorbent assay (ELISA); 97 (51%) were seropositive. The highest antibody prevalence was among pheasants (96%), ducks (88%), and blackbirds (86%). None of 41 starlings tested were seropositive. The serotesting of 42 confined pheasants indicated 100% exposure to the organism. The ELISA is a sensitive, rapid serologic method that can be of epidemiologic and diagnostic value for detecting exposure to Chlamydia. The ELISA could also be used for mass-screening of pet birds where chlamydiosis may be considered a potential public health hazard.

The use of loglinear model to evaluate factors associated with sero-prevalence of Campylobacter fetus in dairy cattle.

Campylobacter fetus is one of the leading infections causing bovine infertility and abortion. In a cross-sectional study, the associations of parity, herd, serological status against Leptospira hardjo and Haemophilus somnus with the sero-prevalence of Campylobacter fetus in dairy cattle were evaluated. Four hundred dairy cows from three herds were included in the study. Blood samples from the cows were collected in December 1986. An enzyme-linked immunosorbant assay (ELISA) was used to determine positive or negative status of cows against Campylobacter fetus , Haemophilus somnus and Leptospira hardjo antigens. Loglinear analysis was used to describe the relationship of four categorical variables with the sero-prevalence of Campylobacter fetus . The final loglinear model was interpreted as a logit model. The final loglinear model included a three-way interaction among Campylobacter fetus , Leptospira hardjo and herd and a two-way interaction between Campylobacter fetus and parity. The adjusted odds of being a positive Campylobacter fetus reading were highest for cows with parity >6 (e.g. 27.8, 95% confidence interval (CI) = 12.9, 60.1); it was next highest for cows in parity <4 (e.g. 18.0, 95% CI = 13.5, 24.2); and it was lowest for cows in parity 4 to 6 (e.g. 13.3, 95% CI 7.3, 24.4). The herd management practice that was associated with the carrier state in early and late parities is identified in the study, and the biological implication of a three-way interaction among Campylobacter fetus , Leptospira hardjo and herd are discussed.

Application of enzyme-linked immunosorbent assay for epidemiological studies of diseases of livestock in the tropics of Mexico.

This study was conducted at the Centre for Research, Teaching and Extension in Tropical Livestock (Centro de Investigación, Enseñanza y Extensión en Ganadería Tropical) of the Faculty of Veterinary Medicine of the National Autonomous University of Mexico. During the latter part of 1986 and throughout 1988 and 1989, the herd of Holstein x zebu cattle at the University was tested for IgG antibodies to twenty-one viral, bacterial, rickettsial and parasitic agents. Antigens prepared from twenty infectious disease agents were used as the solid phase in an enzyme-linked immunosorbent assay, and the agar gel immunodiffusion procedure was used to test for antibodies against bovine leukaemia virus. The prevalence of IgG antibodies was high (> 50%) for bluetongue virus, Anaplasma marginale and Mycoplasma bovis. Antibodies to Brucella abortus were absent and antibodies against bovine virus diarrhoea virus and infectious bovine rhinotracheitis virus showed a very low prevalence (< 5%). Antibodies to fifteen other antigens showed intermediate prevalence (15-46%). Antibodies to Campylobacter fetus, A. marginale, bluetongue virus, bovine leukaemia virus and Haemophilus somnus displayed seasonal variations. Levels of antibody to bovine leukaemia virus, M. bovis and Listeria monocytogenes exhibited increasing secular trends while antibodies to bovine virus diarrhoea virus and C. fetus showed declining trends. Prevalence of antibodies increased with the age of animals tested. No consistent difference in antibody prevalence was found between three genotypic groups examined.

Silica-containing urinary calculi in dogs (1981-1993).

Silica-containing urinary calculi obtained from 773 dogs and submitted by veterinarians throughout the United States were analyzed by quantitative crystallographic analysis to determine mineral composition. Specimens were composed of either multiple mineral layers (535 specimens) or 1 mineral layer (238 specimens). Most multiple-layer calculi were composed of 80% or greater silica (300 of 535, 56%) or 20% to 79% silica (184 of 535, 34%) in any mineral layer. Most 1-layer calculi were composed of 100% silica (212 of 238, 89%). Most dogs forming silica-containing calculi were of male gender (679 of 773, 88%). Bacterial cultures of calculus or urine or both were performed on 49% (376 of 773) of the specimens, and bacterial growth was obtained from 37% (139 of 376) of samples cultured. The prevalence of calculus-associated urinary tract infection was 35% (113 of 321) in males and 47% (26 of 55) in females. The gender prevalence for infection with Staphylococcus species was 16% (51 of 321) in males and 33% (18 of 55) in females. The breed and gender of dogs that formed calculi (silica population) were compared with the hospital population (Veterinary Medical Teaching Hospital [VMTH] population) and with a population of calculus-forming dogs (Stonelab population) to determine risk factors for silica calculus formation. For all breeds compared, the ratio of males to females was higher in the silica population. The German Shepherd Dog and Old English Sheepdog were significantly overrepresented when the silica population was compared with either the VMTH population or the Stonelab population. We conclude that male German Shepherd Dogs and Old English Sheepdogs are at increased risk for formation of silica-containing urinary calculi.

Renal calculi in dogs and cats: prevalence, mineral type, breed, age, and gender interrelationships (1981-1993).

Three hundred seventeen specimens of urinary calculi of renal origin from 214 female dogs and 103 male dogs, and 71 specimens of urinary calculi of renal origin from 38 female cats and 33 male cats were submitted for mineral analysis between July 1, 1981, and December 31, 1993. Among dogs, 45 breeds were affected with renal calculi. Thirty-three breeds and a crossbred group were represented among females, but 8 breeds and the crossbred group accounted for 81% of the total. Among male dogs, 30 breeds and a crossbred group were represented, but 7 breeds and the crossbred group accounted for 69% of the total. Among cats, 10 breeds and a crossbred group were represented. Dogs and cats with renal calculi were older than those of 2 comparison population groups. More than one-half of the renal calculi in both dogs and cats were from the 1st known episode of urolithiasis. The risk of formation of renal calculi was found to be higher for cats than for dogs, when compared to other stone-forming cats and dogs (approximately 4.95 per 100 stone-forming cats and 2.88 per 100 stone-forming dogs). Among dogs, breeds at highest risk of developing renal calculi were Miniature Schnauzers, Shih Tzus, Lhasa Aposos, Yorkshire Terriers, and female Pugs. Also at high risk were male Dalmatians and male Basset Hounds. Among small dogs, females generally were at higher risk of developing renal calculi than were males. Regardless of size, terrier breed males generally were at higher risk of developing renal calculi. Breeds of dogs at low risk for development of renal calculi included crossbreds. German Shepherd Dogs, Labrador Retrievers, Golden Retrievers, and female Dachshunds. When only 1 kidney was involved, the risk of left renal calculus was greatest for both dogs and cats, but bilateral renal involvement was relatively common in both species (19% and 9%, respectively). Among dogs, specimens composed of 1 mineral substance (e.g., struvite) occurred more often in males (58.3%) than in females (37.9%). Female dogs formed renal calculi containing struvite or oxalate more often than did males; males formed calculi containing urate more often than did females. Calculi containing oxalate, apatite, or some combination of these minerals predominated among cats; only 1 specimen from 38 female cats and only 4 specimens from 33 male cats contained neither oxalate nor apatite. Crossbred cats were significantly less likely to have renal calculi than were other breeds. A single renal calculus specimen was identified in several uncommon breeds including Tonkinese and Birman cats, and Affenpinscher, Clumber Spaniel, English Shepherd, and Field Spaniel dogs. No significant differences were observed between male and female dogs or between male and female cats with regard to mineral type of the specimen and the presence of urinary tract infection.

Interrelations of organism prevalence, specimen collection method, and host age, sex, and breed among 8,354 canine urinary tract infections (1969-1995).

Selected information was compiled from canine urinalyses and urine cultures conducted between January 1969 and December 1995. Eight thousand three hundred fifty-four microbial isolates (bacteria and fungi) included 4,873 isolates from females and 3,481 from males. Ten bacterial genera accounted for 96.3% of the urinary isolates, including Escherichia coli (44.1%), Staphylococcus spp. (11.6%), Proteus spp. (9.3%), Klebsiella spp. (9.1%), Enterococcus spp. (8.0%), and Streptococcus spp. (5.4%) as the 6 most common isolates in both genders of dogs. Among these 6 genera, female dogs were generally predisposed over males, although males had more urinary tract infections (UTIs) caused by Klebsiella spp. Distributions of ages at UTI diagnosis tended to be similar between genders. Infection with a single microbial species was responsible for >72% of UTIs in both genders. Among females, 40 breeds and a mixed-breed group represented 90.2% of all positive urine cultures, 88.4% of the individual dogs with UTIs. and 88.2% of the microbial isolations. Among males, these same 41 breed groups represented 87.9% of all positive urine cultures, 87.6% of the individual dogs, and 88.2% of the microbial isolations.

20 year follow-up on microinvasive squamous carcinoma of the cervix.

MISC of the cervix is a potentially fatal disease if not properly classified and treated. Strict criteria for diagnosis are required to provide appropriate therapy. It is recommended that a radical approach be considered for those patients in whom the depth of invasion of the carcinoma is greater than 3 mm on cone biopsy and in all cases where vascular invasion is demonstrated. Confluency may not of itself be a reason for more radical therapy but is an indicator of the aggressiveness of the tumor. Vascular invasion is seen more frequently with increased depth of invasion but may be found with minimal infiltration and has a serious connotation. Further refinement of the definition of MISC of the cervix appears to be needed.

Dairy calf mortality rate: characteristics of calf mortality rates in Tulare County, California.

Sixteen dairy farm owners in Tulare County, California, provided data on heifer calf births and deaths. Eleven of these dairymen had maintained records on the calves before this study was done, and 5 agreed to maintain them for 6 months. Basic statistical techniques, including time series analyses and life-table methods, were used to examine the data for temporal and demographic characteristics. Overall, the calf mortality rate on the 16 farms averaged 17.3 to 20.2%. The interfarm variation in mortality rate was large, ranging from 3.7 to 32.1%. Time series studies indicated that the extent of death losses increased during midsummer (June, July, August) and midwinter (November, December, January), with mortality rates in winter months being 20% greater than those in summer. Death losses in October and March were highly variable; however, losses in October usually exceeded the yearly average; those in March did not. Also, 80% of the dairymen recorded the same relative change in mortality rate during each of 2 consecutive winters and 2 consecutive summers. The risk of death for calves was greatest in their 1st week of life on most of the farms; of all deaths in calves less than 5 weeks old, 55% occurred during the 1st week of life, and 27% occurred during the 2nd. In general, the death loss in calves between 5 weeks and 3 months old was less than 2%.

Dairy calf mortality rate: influence of management and housing factors on calf mortality rate in Tulare County, California.

Data on calf mortality, calving site, calf-rearing facilities, and calf-management procedures were collected from 16 dairy farms in Tulare County, California. Discriminant analyses were used to test if any significant differences in these factors existed between farms with higher than average and farms with lower than average death losses. The average mortality rate over a period of at least 2 years on individual farms varied from a low of 3.5 +/- 1.1% to a high of 30.6 +/- 3.1%. Calf management personnel was the only factor significantly related to the mortality rate, with considerably fewer death losses on farms where the owner managed the calves than on farms where employees performed these duties. In general, other factor categories relating to size of the cow herd, calving site, and calf housing were not related significantly to calf deaths. The average number of heifer calves born each year on individual farms was increasing year by year, and on some farms, there seemed to be a concomitant increase in death losses. This, together with the tendency toward greater number of deaths on the larger owner-managed farms, indicated that calf care was diluted under these conditions.

Serum concentrations of immunoglobulins G, A, and M in dogs with neoplastic disease.

The concentrations of the three major classes of immunoglobulins (Ig) were determined in canine serum by single radial immunodiffusion against calibrated standards. Serum samples were collected from 121 dogs categorized into 3 groups: normal dogs (n = 34), those with lymphosarcoma (n =41), and those with malignant, solid neoplasms other than lymphosarcoma (n = 46). The mean value for serum IgM concentration in the group of dogs with lymphosarcoma was significantly (P less than or equal to 0.02) higher than was the mean IgM concentration of the normal dogs. Dogs with neoplasms other than lymphosarcoma had significantly increased serum concentrations of IgG and IgM antibodies. There was no significant difference in serum IgA concentration among the three groups. A wide range of Ig concentrations was in the serum of clinically normal dogs, as well as in dogs with neoplastic diseases. Although individual dogs with neoplasms had low serum Ig concentrations, the 81 dogs with neoplastic disease were generally able to synthesize Ig.

Neonatal survival in swine: effects of low birth weight and clinical disease.

Data were collected for 3,636 full-term pigs born in a commercial swine herd to determine the effects of birth weight and clinical disease on survival during the first 3 weeks of life. Logistic regression models were constructed for 7-day survival for all live-born pigs, and for 21-day survival for pigs surviving the first week of life. Estimates of birth weight and disease effects were adjusted simultaneously for other risk factors including litter size, parity, and within-litter variation in birth weight. The 7-day survival model indicated that survival odds improved significantly with increasing birth weight. Maximal survival, relative to pigs weighing less than 601 g at birth, was evident in pigs weighing greater than 2 kg at birth (odds ratio [OR] = 349). Diarrhea (OR = 2.7) and splayed limbs (splay leg; OR = 37.3) significantly (P less than 0.05) reduced 7-day survival. Models of 21-day survival indicated a smaller, but still significant, effect of birth weight on survival. Adjusted survival odds for pigs in the heaviest weight group (greater than 2 kg) were 20.1 times higher than pigs weighing less than 801 g. Diarrhea (OR = 2.7) and lameness (OR = 2.6, 2 limbs) significantly (P less than 0.05) decreased 21-day survival.

Antibiotic and sulfonamide agents in bob veal calf muscle, liver, and kidney.

During the fiscal year 1988, USDA-FSIS detected 3,095 antimicrobial violations in bob veal calves, using the calf antibiotic and sulfonamide test. Of the 3,095 carcass submissions involved, 945 were tested further to identify the causative agents. The results of tests on the available kidney, liver, and muscle specimens are reported. Kidney specimens yielded a specific agent most often (71.2%), with neomycin (42.6%) being cited most among agents found in kidneys. Neomycin was found less frequently in liver (4.5%) and muscle (0.2%). Among all tissues, unidentified microbial inhibitors were either the largest or second largest category found (kidney, 10.5%; liver, 27.1%; muscle, 7.8%), and no other agent exceeded 7.0% (streptomycin in kidney). The proportion of liver and muscle specimens that had unidentified microbial inhibitors is particularly important because the next most common classes were streptomycin in liver at 5.5% and sulfamethazine in muscle at 2%. The frequency of unidentified microbial inhibitors may justify the addition of tests to the FSIS battery for identification of agents. Not all tissues were tested for sulfonamides, hence these agents are likely to have been underreported. Less than 10% of the muscle specimens evaluated yielded an agent, suggesting most calf antibiotic and sulfonamide test-positive carcasses may have been safe with regard to residues in meat, although organs might have been adulterated. Specimens for verification were not selected completely randomly from the population of all calf antibiotic and sulfonamide test-positive animals and calves selected for testing were not chosen strictly by random sampling; therefore, extrapolation of the contents of this report to the bob veal calf industry must be done with caution.