Biomedical subjects

C E Franti

Publications and source records attributed to C E Franti.

At least 19 recordsLinked to original sources

PubMed1999

Urolithiasis in dogs V: regional comparisons of breed, age, sex, anatomic location, and mineral type of calculus.

OBJECTIVE: To determine extent and nature of regional differences in distribution of canine urinary calculi. SAMPLE POPULATION: 13,552 calculus specimens: 7,056 (52.1%) from females, 6,492 (47.9%) from males, and 4 from dogs of unrecorded sex. Procedure Records were used to compile information from all specimens submitted between July 1981 and December 1995. Results from mixed-breed and various breeds of stone-forming dogs were analyzed. Interrelations of breed, sex, and age of dogs, and anatomic location and mineral composition of specimens were analyzed and compared for 6 US geographic regions. RESULTS: Struvite-, apatite-, and urate-containing calculi were reported significantly most often from female dogs of the Mountain/Pacific region. Oxalate-, silica-, and brushite-containing calculi were reported significantly most often from male dogs in the New England/mid-Atlantic (NEMA) region. Cystine-containing calculi were reported most frequently from the NEMA and South Central (SC) regions. Dogs from the NEMA region were oldest in average age at diagnosis. Significant regional differences in distribution were found for several breeds. Sex distribution of renal calculi in 11 breeds of dogs (Lhasa Apso, Yorkshire Terrier, Shih Tzu, Basset Hound, Pug, Mastiff, Bichon Frise, Doberman Pinscher, Dalmatian, English Bulldog, and Pekingese) reported to be at high risk of renal lithiasis differed among the 6 geographic regions. Renal and ureteral calculi were reported significantly most often from dogs in the South Atlantic region, and bladder and urethral calculi were reported most often from dogs in the SC region. CONCLUSIONS: Wide regional differences exist in distribution of stone-forming dogs by sex, average age at diagnosis, breed, and minerals contained within and anatomic location of calculi.

Age Factors↗

PubMed1998

Urolithiasis in dogs. I: Mineral prevalence and interrelations of mineral composition, age, and sex.

OBJECTIVE: To compile and statistically analyze selected data from a large number of canine urinary calculi. SAMPLE POPULATION: 11,000 specimens: 5,781 from female dogs, 5,215 from male dogs, and 4 from dogs of unrecorded sex. PROCEDURE: Records were used to compile information from all canine calculi analyzed between July 1981 and January 1994. Interrelations of mineral composition, location of specimens within the urinary tract, age and sex of affected dogs, and number of previous episodes of urolithiasis were determined. RESULTS: Approximately 70% of the specimens were from a first episode of urolithiasis. Calculi were located in the urinary bladder of 93.1% of females and 79.0% of males, and in the upper urinary tract of 4% of females and 2% of males. Calculi were found in multiple sites in 23.1% of males and 5.2% of females. Significantly higher proportions of struvite, apatite, and urate were found in uroliths from females; oxalate, cystine, silica, and brushite were significantly more prevalent in males. Sixty-one percent of specimens from males and 29% from females were composed of a single mineral substance. The most common mineral combination of 2 or more minerals included struvite and apatite. An additional 67 specimens from male dogs and 49 from female dogs contained other mineral combinations. In 48% of specimens from males and nearly 62% of specimens from females, the minerals formed several distinct layers of differing composition. CONCLUSIONS: Male and female dogs from urinary calculi composed of 1 or more of several distinct minerals. Prevalence of canine uroliths differs between ages and between the sexes. Many specimens contain complex layering of minerals; most specimens were found in the urinary bladder. CLINICAL RELEVANCE: Sex and age of dogs, mineral types of likely calculi in males versus females, and their anatomic location are important considerations for clinicians when evaluating risk in dogs with urolithiasis.

Age Distribution↗

PubMed1998

Urolithiasis in dogs. II: Breed prevalence, and interrelations of breed, sex, age, and mineral composition.

OBJECTIVE: To analyze selected breed-related data for canine urinary calculi. SAMPLE POPULATION: 11,000 specimens: 5,781 from female dogs, 5,215 from males, and 4 from dogs of unrecorded sex. PROCEDURE: Information was compiled for all canine urinary calculi submitted between July 1981 and January 1994. Results for a mixed-breed group and 26 of the most common breeds of stone-forming dogs were analyzed. Interrelations of breed, sex, and age of affected dogs and mineral composition of the specimens were determined. RESULTS: Prevalence of 5 specific mineral types was significantly correlated between the sexes of 27 common breed groups: struvite, calcium phosphate (apatite), calcium oxalate, brushite, and urate. Struvite-containing calculi were seen in high proportions in both sexes of 7 breeds, and in low proportions in both sexes of 7 other breeds. Male and female Lhasa Apsos, Cairn Terriers, and 5 other breeds had high proportions of oxalate-containing calculi; values in males were substantially higher. Low numbers of oxalate-containing calculi were seen in both sexes of 7 breeds; Dalmatians had the lowest numbers. Males and females of 6 breeds had high numbers of urate-containing calculi, Dalmatians and English Bulldogs had the highest numbers. Low amounts of urate were found in calculi from males and females of 6 breeds, Samoyeds had the lowest numbers. Highest proportions of cystine-containing calculi were seen in male Dachshunds, English Bulldogs, and Chihuahuas. Males of 8 breeds had no specimens that contained cystine; only 2 such specimens were obtained from females. CONCLUSIONS: Prevalence of uroliths differs among breed, age, and sex of affected dogs. CLINICAL RELEVANCE: Breed, sex, and age of dogs; mineral types of calculi in males versus females; and their anatomic location within the tract are important considerations for clinicians when evaluating risk in dogs with urolithiasis and in identifying areas that need further in-depth applied or clinical investigation, or both.

Age Distribution↗

PubMed1998

Urolithiasis in dogs. III: Prevalence of urinary tract infection and interrelations of infection, age, sex, and mineral composition.

OBJECTIVE: To compile and statistically analyze selected data from a large number of canine urinary calculus specimens that were subjected to quantitative, layer-by-layer mineral analysis. SAMPLE POPULATION: 11,000 canine urinary calculus specimens. 5,781 from female dogs, 5,215 from male dogs, and 4 from dogs of unrecorded sex. PROCEDURE: Records of the Urinary Stone Analysis Laboratory, School of Veterinary Medicine, University of California were used to compile information regarding all canine urinary calculus specimens submitted for analysis between July 1981 and January 1994. Interrelations of sex and age of the affected dogs, mineral composition of the specimens, and associated urinary tract infections were analyzed statistically. RESULTS: Urolithiasis was associated with growth of bacteria isolated from urine or calculi, or both, in 65% of females and nearly 44% of males. Staphylococcus intermedius was isolated most often from either sex (54% for females, 30% for males). In addition to staphylococci, 22 other bacterial species were isolated from specimens from females, and 17 other bacterial species and 1 species of yeast were isolated from males. A single bacterial species was isolated from 87.6% of cultures from females and from nearly 90% of cultures from males. Among females, nearly 98% of pure cultures of staphylococci were associated with calculi that contained struvite; this was true for 80% of pure cultures of staphylococci from males. CONCLUSIONS AND CLINICAL RELEVANCE: There are wide sex differences in prevalence of urolithiasis- and specific mineral-associated bacterial infections. In several instances, bacterial infections were significantly related to urinary calculus location. These variables should be considered in any evaluation of canine patients that have uroliths.

Age Distribution↗

PubMed1998

Urolithiasis in dogs. IV: Survey of interrelations among breed, mineral composition, and anatomic location of calculi, and presence of urinary tract infection.

OBJECTIVE: To compile and analyze selected data from a large number of canine urinary calculus specimens that were subjected to quantitative, layer-by-layer mineral analysis. SAMPLE POPULATION: 11,000 canine urinary calculus specimens: 5,781 from female dogs, 5,215 from male dogs, and 4 from dogs of unrecorded sex. PROCEDURE: Records of the Urinary Stone Analysis Laboratory, School of Veterinary Medicine, University of California were used to compile information regarding urinary calculus specimens from dogs. Records surveyed were of all canine calculi submitted for analysis between July 1981 and January 1994. Results analyzed included those of a mixed-breed group and 26 common breeds of stone-forming dogs. Interrelations of breed, sex, and age of the affected dogs, mineral composition of the specimens, and associated urinary tract infections were analyzed statistically. RESULTS: Proportions of culture-positive specimens were significantly correlated between the sexes (r = 0.494, P = 0.008). Staphylococcus intermedius was isolated most often from either sex, ranging from 36.1% (Basset Hounds) to 67.9% (Pekingese) of cultured specimens from females and 8.7% (Chihuahuas) to 71.4% (Scottish Terriers) of specimens from males. The second most frequently isolated bacterial species, Escherichia coli, ranged from 0% in males of 2 breeds and females of 4 breeds to 25% in Cairn Terrier males and 19.4% in Basset Hound females. Streptococcus spp were the third most frequently isolated bacterial species. Significant correlations between the sexes were found for percentages of calculi located in the urinary bladder (r = 0.490, P = 0.008), and for calculi voided in the urine (r = 0.503, P = 0.006). CONCLUSIONS: Breed and sex differences in prevalence of urolithiasis- and mineral-associated bacterial infections are numerous. Staphylococcus intermedius was the most common isolate from specimens from all but 3 of 54 breed/sex groupings. For either sex, streptococcal infections were significantly related to proportions of calculi passed in the urine.

Age Distribution↗

PubMed1995

Evaluation of factors associated with development of calcium oxalate urolithiasis in cats.

OBJECTIVE: To evaluate dietary and environmental factors as potential risk factors for calcium oxalate urolithiasis in cats. DESIGN: Case-control study. ANIMALS: 84 cats with uroliths composed of at least 90% calcium oxalate and 258 age- and gender-matched control cats. PROCEDURE: Owners of cats with calcium oxalate urolithiasis and control cats were surveyed between November 1990 and August 1992. Owners completed a standard questionnaire administered during a single telephone interview. Data collected included information regarding signalment, environment, urination and defecation, diet, and medical history. RESULTS: Calcium oxalate uroliths tended to develop in middle- to older-aged, domestic shorthair cats of typical weight. A gender predilection was not detected. Factors associated with an increase in the risk of calcium oxalate urolithiasis in cats were feeding urine-acidifying diets, feeding a single brand of cat food without providing additional foods or table scraps, maintaining cats in an indoor-only environment, and being of the Persian breed. CLINICAL IMPLICATIONS: Control of diet and environment may help prevent calcium oxalate urolithiasis.

Age Distribution↗

PubMed1995

Twin pregnancy diagnosis in Holstein cows: discriminatory powers and accuracy of diagnosis by transrectal palpation and outcome of twin pregnancies.

The objective of this prospective cohort study was to determine the sensitivity, specificity, accuracy, and predictive value of twin pregnancy diagnosis by rectal palpation and to examine fetal survival, culling rates, and gestational lengths of cows diagnosed with twins. In this prospective study, 5309 cows on 14 farms in California were followed from pregnancy diagnosis to subsequent abortion or calving. The average sensitivity, specificity, accuracy, and predictive value of twin pregnancy diagnosis were 49.3%, 99.4%, 96.0%, and 86.1%, respectively. The abortion rate for single pregnancies of 12.0% differed significantly from those for bicornual twin pregnancies and unicornual twin pregnancies of 26.2% and 32.4%, respectively (P < 0.05). The early calf mortality between cows calving with singles (3.2%) and twins (15.7%) were significantly different (P < 0.005). The difference in fetal survival between single pregnancies and all twin pregnancies resulted in 0.42 and 0.29 viable heifers per pregnancy, respectively. The average gestation for single, bicornual, and unicornual pregnancies that did not abort before drying-off was 278, 272, and 270 days, respectively. Results of this study show that there is an increased fetal wastage associated with twin pregnancies and suggest a need for further research exploring management strategies for cows carrying twins.

Abortion, Veterinary↗

PubMed1994

Pregnancy incidence in high producing dairy cows treated with recombinant bovine somatotropin.

Reproductive performance in cows exposed for two lactations to recombinant bST was measured using unconditional logistic regression. Intramuscular administration of 17.2, 51.6, and 86 mg of recombinant bST/d per cow started at d 70 postpartum and ended at dry-off or 305 d postpartum. Performance was measured as the cumulative incidence of cows becoming pregnant by 305 d post-partum. Within each parity group, cows treated with bST had higher total milk yield. During the first study lactation, the log odds of a cow becoming pregnant decreased linearly as dose increased, following adjustment for serum cholesterol, blood urea N, average daily milk yield, peak milk yield, net energy balance, and body condition score. However, differences in pregnancy incidence between treated and untreated cows were statistically significant only at the higher dose categories, the 51.6 and 86.0 mg of recombinant bST per cow. During the second study lactation, pregnancy rates were similar to those in the first lactation; rates reduced as recombinant bST dose increased. The singular exception was for cows exposed to recombinant bST during the previous lactation but not during the second. In the latter group, previously treated cows had higher pregnancy incidence than did the controls.

Animals↗

PubMed1994

Interval from calving to conception in high producing dairy cows treated with recombinant bovine somatotropin.

Intervals from calving to conception in cows treated for two lactations with recombinant bST were ascertained using survival analysis methods. Daily intramuscular administration of placebo, 17.2, 51.6, or 86 mg of bST per cow started at d 70 postpartum and ended at culling or drying off. Breeding began at d 70 postpartum. Multiparous cows treated during the first lactation had significantly longer intervals from calving to conception. Cows treated during the previous lactation, but not during the second lactation, had significantly shorter intervals from calving to conception. Cox proportional hazards regression analysis was used with adjustment for the confounding effect of serum metabolites, milk production, energy balance, and body condition.

Animals↗

PubMed1994

Reproductive performance in high producing dairy cows treated with recombinant bovine somatotropin.

The reproductive performance of 156 cows treated with recombinant bST for two consecutive lactations was assessed as part of a target animal safety study conducted in the San Joaquín Valley of central California. Daily intramuscular administration of 17.2, 51.6, and 86 mg of bST per cow started at d 70 postpartum and ended at dry-off or 305 d postpartum. The AI did not begin until d 70 postpartum. During the first lactation study, multiparous cows treated with bST had significantly decreased pregnancy rates, increased behavioral anestrus, and increased anestrus confirmed by palpation. Treated primiparous cows in first lactation had shorter mean days to first standing estrus. In the second lactation study, cows treated with bST had an increased rate of delayed uterine involution, cystic ovarian condition, behavioral anestrus, and anestrus confirmed by palpation. Progeny from the first lactation cows were evaluated for rates of growth, morbidity, mortality, and for reproductive performance; no difference was detected between the progeny from different groups.

Analysis of Variance↗

PubMed1993

Urolithiasis in Dalmations: 275 cases (1981-1990).

From July 1, 1981 to December 31, 1990 the Urinary Stone Analysis Laboratory, School of Veterinary Medicine, University of California received 292 urinary calculi from 275 Dalmations (14 females, 14 episodes; 261 males, 278 episodes). The mean age of dogs at the time of the first episode of calculus formation was 4.5 years for males and 5.5 years for females. Bacteria were isolated from 22 of 49 calculi (45%). The bacteria were gram-positive with 2 exceptions; coagulase-positive staphylococci accounted for 62.5% of the isolates. Polarized light microscopy was used to determine the mineral content of the calculi. One hundred ninety three calculi were 100% urate; 78 calculi contained > or = 50% urate in 1 or more layers and were classified as mixed urate calculi; 7 calculi contained < 50% urate in all layers; and 14 calculi contained no urate. The secondary minerals most commonly encountered in mixed urate calculi were struvite (77%, 60 of 78 calculi), and oxalate (17%, 13 of 78 calculi). There were 65 struvite-containing calculi, 16 oxalate-containing calculi, 7 apatite-containing calculi, 5 silica-containing calculi, and 1 calculus specimen was composed of 100% cystine. The risk of forming urate-containing calculi was high in Dalmations, whereas the risk of forming calculi containing other minerals was consistently lower in Dalmations than in other breeds. X-ray diffraction and high pressure liquid chromatography were performed on all calculi from dogs known to have been given allopurinol (n = 19).(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗

PubMed1993

Lumbosacral transitional vertebrae as a predisposing cause of cauda equina syndrome in German shepherd dogs: 161 cases (1987-1990).

The records of 161 German Shepherd Dogs were divided into groups depending on whether there was a radiographic diagnosis of degenerative disk disease (DDD) involving the lumbosacral disk and lumbosacral transitional vertebral segments (TVS) and whether the dogs had cauda equina syndrome (CES). Statistical analysis of the data suggested an association between TVS and CES and an association between DDD and CES. Establishment of confidence intervals revealed the group without either DDD or TVS indicators differed markedly from the other 3 groups of CES relative to the presence of DDD and TVS. There was some overlap in the confidence intervals, but the proportions of CES were higher when DDD and TVS were both evident. This suggests that the important clinical syndrome of CES is at least partially dependent on TVS, which is probably an inherited condition. Because German Shepherd Dogs have a higher frequency of TVS than dogs of other breeds, this partially explains the higher frequency of CES in this breed. Because TVS are probably familial, we suggest the presence of this lesion should be considered in selection of breeding stock. Although it is believed that DDD is partially dependent on the existence of TVS, it is known that DDD can develop in the absence of TVS.

Animals↗

PubMed1993

The association between antibody titres against Campylobacter fetus and milk production efficiency in dairy cattle.

The association between serological evidence of exposure to Campylobacter fetus and milk production performance was studied in 178 lactating cows from three California Dairy Herd Improvement Association herds using a cross-sectional study design in December 1986. ELISAs were used to determine the antibody titres against Campylobacter fetus, Haemophilus somnus and Leptospira hardjo, which were classified as either negative or positive. The status of a cow as negative or positive against C. fetus and H. somnus represents the serological evidence of natural exposure to the corresponding bacteria. However, the status against L. hardjo was assumed to be the level of vaccinal titre against this organism since all the cows studied had been vaccinated against this agent. The data on demographic and productivity variables relating to the current lactation of the cows were obtained from Dairy Herd Improvement Association individual cow records for December 1986. Four measures of milk production efficiency for the current lactation were used. The status against L. hardjo and other covariates suggested by previous studies were included in modelling the relationships of interest. Stepwise multiple linear regression was used to study the adjusted relationship of C. fetus with each measure of milk production efficiency. Multivariate analyses revealed that the adjusted relationships of C. fetus with the test-day's milk production, the extended 305-day milk production and the relative value of milk production were not significant (p > 0.1). However, after adjusting for possible covariates, C. fetus-positive cows had an average of 7.43% lower mature equivalent milk production than C. fetus-negative cows (p = 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

The association between antibody titres against Campylobacter fetus and reproductive efficiency in dairy cattle.

The relationship between the antibody titres against Campylobacter fetus and various indices of reproductive efficiency was studied in a cross-sectional study of 178 dairy cows from three California Dairy Herd Improvement Association herds. Blood samples were collected from the lactating cows during December 1986. Enzyme-linked immunosorbent assays were used to determine the antibody titres of the cow against Campylobacter fetus, Haemophilus somnus and Leptospira hardjo and were classified as either negative or positive. The status of a cow as either negative or positive against Campylobacter fetus and Haemophilus somnus represents serological evidence of natural exposure to the corresponding bacterial agents. However, the status against Leptospira hardjo was assumed to reflect a vaccinal titre since all the cows studied had been routinely vaccinated against this organism in September 1986. The data on demographic and reproductive parameters pertained only to the current lactation of the cows and were obtained from Dairy Herd Improvement Association individual cow records of December 1986. Five indices of reproductive efficiency were used, namely the recent calving interval, the calving-to-conception interval, the calving-to-last-service interval, the number of services per conception, and the number of services since last calving. The serological status against Haemophilus somnus, Leptospira hardjo and other covariates suggested by the results of previous studies were included in modelling the relationships of interest. Stepwise multiple linear regression analyses were carried out to study the adjusted relationship of Campylobacter fetus with each measure of reproductive efficiency. Multivariate analyses revealed that the adjusted relationship for Campylobacter fetus with all five measures of reproductive efficiency was non-significant (p > 0.05). Among the covariates, Leptospira hardjo had a strong and independent relationship with recent calving interval, the unstandardized partial regression coefficient being -0.77. The possible biological mechanisms of these associations are discussed.

Animals↗

PubMed1993

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.

Age Factors↗

PubMed1992

Cystine-containing urinary calculi in dogs: 102 cases (1981-1989).

One hundred and seven cystine-containing urinary calculi from 1 female and 101 male dogs were analyzed. Cystine-containing calculi accounted for 2% (107 of 5,375) of all canine urinary calculi submitted to the urinary stone analysis laboratory from July 1981 through December 1989. Male dogs that formed cystine calculi were compared with 3 other canine populations to determine whether certain breeds were apparently at increased or decreased risk for cystine calculus formation. In one or more of 3 population comparisons, significantly increased risk of cystine calculus formation was found in Mastiffs, Australian Cattle Dogs, English Bulldogs, Chihuahuas, Bullmastiffs, Newfoundlands, Dachshunds, Basenjis, Australian Shepherd Dogs, Scottish Deerhounds, Staffordshire Terriers, Miniature Pinschers, pitbull terriers, Welsh Corgis, Silky Terriers, and Bichon Frises. Significantly low risk of cystine calculus formation was found in German Shepherd Dogs, Poodles, Schnauzers, and mixed-breed dogs.

Animals↗

PubMed1992

Serologic survey for brucellosis in feral swine, wild ruminants, and black bear of California, 1977 to 1989.

A retrospective analysis of brucellosis serologic testing results in eight wildlife species in California from 1977 to 1989 was done. Samples were collected from 5,398 live-captured or hunter-killed animals and tested by combinations of up to six serologic tests for antibodies to Brucella spp. Twenty-three of 611 (3.8%) feral swine (Sus scrofa), one of 180 (0.6%) black bear (Ursus americanus), one of 355 (0.3%) California mule deer (Odocoileus hemionus californicus), and one of 1,613 (0.06%) blacktail deer (Odocoileus hemionus columbianus) samples were considered reactors. Suspect serologic reactions occurred in three of 619 (0.5%) desert bighorn sheep (Ovis canadensis nelsoni) and one of 355 (0.3%) California mule deer samples. Brucellosis is not considered an important wildlife health problem in California except in feral swine.

Animals↗

PubMed1992

Cohort study of natural transmission and two methods for control of caprine arthritis-encephalitis virus infection in goats on a California dairy.

A prospective observational cohort study of 361 dairy goat kids was conducted to compare 2 methods of controlling caprine arthritis-encephalitis virus infection under commercial dairy conditions. To compare effectiveness of feeding kids pasteurized milk vs serologic testing and segregation in addition to pasteurized milk feeding, goats were monitored up to the age of 30 months by use of monthly agar gel immunodiffusion testing. Survival analysis methods were used to determine whether age at seroconversion differed between the 2 groups. Significantly lower rates of seroconversion were observed in the segregated group (P < 0.001), compared with the nonsegregated group. Of 193 goats in the pasteurized milk-only group, 146 (75.6%) seroconverted within the 30-month study period, whereas infection was detected in 39 (23.2%) of 168 goats in the test/segregated group. Nonsegregated goats were 3.37 times more likely to seroconvert by 24 months of age, and 70.3% of seroconversions by 24 months of age could be attributed to nonsegregation. For age-specific intervals beyond 180 days of age, 70 to 100% of seroconversions could be attributed to lack of segregation. Cohort life tables for age at seroconversion were reported for each group. Type of colostrum fed, sex, and weaning group (season) were not significantly associated with age at seroconversion. Saanen goats had lower age-specific risk of seroconversion in the nonsegregated group alone and overall. Non-Saanen goats wee 1.5 times more likely to seroconvert than were Saanen goats, when adjusted for a possible confounding effect of weaning group. Results indicate that pasteurized milk feeding and routine test and segregation would be a substantially more effective means of control of the disease in dairy goat herds than would pasteurized milk feeding alone.

Age Factors↗