Population genetic analysis of the new dog breed Elo

The breeding of the dog breed Elo was started in 1987. This dog breed was established by using 16 dogs of nine different breeds. All pedigree information of the dogs from 1987 to 2002 was included for the analysis of the proportion of genes of the different founder breeds, of the inbreeding coefficient, and relationship coefficients. Additionally, the number of died puppies per litter were investigated. The Eurasian dog breed contributed about 48% of the genes in the whole Elo dog population. Old English sheepdog and Chow Chow contributed about 23% and 10% of the genes. The other dog breeds were of minor importance. The mean inbreeding and relationship coefficients of the whole Elo dog population were 12.04% and 19.22%, respectively. With the exception of 3.5% of animals, all Elo dogs were related to each other. The mean litter size was 6.39 puppies. The percentage of stillborn puppies per litter averaged at 9.47%. The inbreeding coefficients of the puppies and of their dams, the age of the sire and the dam at the time of birth of the puppies, the litter size, the puppies' year of birth and the proportion of genes of the Chow Chow showed a significant effect on the number of stillborn puppies per litter. The heritability for the frequency of stillborn puppies was estimated using a linear animal model. After transformation of the linear estimates to the underlying liability scale, the heritability amounted to h2 = 0.15.     

Reproductive patterns of pedigree cats

A survey of Brisbane catteries was carried out to investigate reproductive patterns of pedigree cats. Eighteen breeders supplied data on 751 litters with a total of 3171 kittens covering the Persian, Chinchilla, Siamese, Burmese and Abyssinian breeds. The overall sex ratio at birth was 100 males to 92 females. There was a significant seasonal effect on sex ratio with litters conceived during the wet season (September to February) producing more males than expected and litters conceived during the dry season producing more females than expected. Litter size and breed had no significant effect on the sex ratio. The average litter size varied with the breed with the most prolific being the Burmese (5.0) then the Siamese (4.5), Persian (3.9), Abyssinian (3.5) and Chinchilla (2.8). The average litter size was smaller for the first litter than for the subsequent 3 litters. The maximum average litter size was reached at 6 years with only a moderate decline thereafter. There was a seasonal fluctuation in births with the greatest numbers being born in spring and the least in late autumn. Longhair cats showed a more marked seasonal distribution of births than the shorthairs which reproduced for most of the year, particularly the Burmese breed.     

Stillbirth in the pig in relation to genetic merit for farrowing survival

The objectives of this study were to analyze the incidence of different categories of stillborn piglets in relation to genetic merit for farrowing survival of sows and litters and to analyze relationships of total number of piglets born per litter, average BW of the litter, and within-litter variation in BW with genetic merit for farrowing survival of sows and litters. Records of 336 purebred litters, produced by 307 first-to eighth-parity sows, were collected on a nucleus farm in Brouennes, France. Breeding values for farrowing survival were estimated for sows (EBVfs_maternal) and litters (EBVfs_direct) using a large data set from which information obtained in the current study was excluded. For each litter, BW, number of stillborn piglets (classified as nonfresh stillborn, prepartum stillborn, intrapartum stillborn, and postpartum stillborn), and number of live-born piglets were recorded. Birth weights of stillborn piglets were lower than BW of live-born piglets (P < 0.0001), except for prepartum stillbirths. The total number of stillborn piglets per litter and the number of stillborn piglets in each category decreased with increasing EBVfs_maternal (P < 0.01). An increase in EBVfs_direct was also associated with a decrease in the total number of stillborn piglets per litter (P < 0.01). This decrease was due to a decrease in the number of nonfresh, prepartum, and postpartum stillborn piglets but not to a decrease in the number of intrapartum stillborn piglets. Probabilities of stillbirth in relation to EBVfs_maternal were higher than probabilities of stillbirth in relation to EBVfs_direct. Total number of piglets born decreased with increasing EBVfs_direct (P = 0.0003), but was not related to EBVfs_maternal. Average BW of the litter (P < 0.0001) and within-litter variation in BW (P = 0.05) decreased with increasing EBVfs_maternal but were not related to EBVfs_direct. Selection for the maternal genetic component of farrowing survival seems a better strategy than selection for the direct genetic component. Selection for the maternal genetic component of farrowing survival reduces stillbirth in all categories and does not affect litter size.     

Comparison of sow farrowing characteristics between a Chinese breed and three French breeds

Sow farrowing characteristics, including litter size, stillbirth, kinetics of births and piglet weight traits, were compared in 4 populations: Meishan (MS), Large White (LW), Duroc × Large White (DU × LW) and Laconie (LA). The kinetics of births was characterised by farrowing duration (FD), birth interval (BI), and farrowing irregularity, estimated by the standard deviation of BI (SDBI). The within-litter distribution of piglet birth weights was described by different traits including the mean (MBW) and standard deviation (SDBW) of birth weight. Additional characteristics of the sow were also analysed: weight at farrowing (SWF), gestation length (GEST), and birth assistance (BA). The data set included 47 MS, 605 LW, 55 DU × LW and 160 LA litters. For analyses, multivariate methods were used, including principal component analyses (PCA) and multiple factorial analyses (MFA). These methods allowed the relative importance of between-breed and within-breed variability of the correlation structure to be estimated and the homogeneity between populations (by comparison of the 4 breed correlation structures) to be investigated. Though most of the variability was observed within-breed (97%), between-breed variation appeared to be highly significant (P < 0.0001). This variation was essentially due to the Meishan breed departing from others, because of the lower weight at farrowing and, to a lesser extent, to the lower number of stillbirths and lower piglet mean and standard deviation in birth weight. Litter size did not contribute much to the variability between breeds. The rather strong correlations related to between-breed structures (r > 0.70) indicated that the correlation pattern was similar among breeds. Stillbirth was independent from litter size and appeared as closely associated with farrowing duration in the French breeds.     

Characteristics of pedigree cat breeding in the Netherlands: breeds, population increase and litter size

A survey of the Dutch Cat Fancy was carried out to determine reproductive, patterns of pedigree cats. The data of the present study were obtained by questioning the pedigree registers of the cat clubs participating in the foundation 'Overleg Platform van de Nederlandse Cat Fancy'. The Dutch Cat Fancy registers 34 different cat breeds. From 1992 up to 1996 a total of 25.985 litters were registered. Over this period the number of litters increased from 4989 to 5313. Litters from Longhair and Exotic Shorthair cats comprised the biggest group and accounted for 55% of the total number of litters. However, over this period, the number of Longhair and Exotic Shorthair litters decreased by 9%. Litters from British Shorthair, Birman, Maine Coon and Norwegian Forrest Cat increased in number as did litters from small breeds such as Ragdoll, Bengal and Sphynx. Litters from Abyssinian, Siamese, Oriental Shorthair cats remained relatively the same. The average litter size of the total cat population, based on pedigree certificates, was calculated at 3.3 kittens per litter. For different breeds litter size varied from 2.7 (Longhair and Exotic Shorthair) to 4.3 (Burmese and Maine Coon). Taking into account an average age of 14 years, the total Dutch pedigree cat population was estimated at 240,000 viz. about 10% of the total cat population.     

Influence of litter size and breed on variation in length of gestation in the dog

Summary

The variation in the length of gestation, the period from mating until parturition, was studied in 77 dogs of different breeds; the time for mating was determined by measuring peripheral blood progesterone levels. The mean length of gestation was 62.1 ± 0.2 (S.E.M.) days, with a variation of 11 days. The number of pups appeared to influence the length of gestation. Length of gestation was negatively correlated (r = ‐0.96, P < 0.001, n = 44) with litter size in litters with 7 or fewer pups. The intra‐breed variation in length of gestation in the five breeds represented by five or more bitches was 3 ‐ 6 days. The mean gestation of Alsatians (60.1 ± 0.5, n = 9) was shorter (P < 0.005) than that of the other breeds combined (62.3 ± 0.3, n = 68). The primiparous/multiparous status of the bitch did not influence the length of gestation.     

Effects of breed, parity, day of lactation and number of kits on milk production of rabbits

Lactation records (n = 86) from 60 does of four breeds (Californian, New Zealand White, Palomino and White Satin) were analyzed to assess the effects of breed, parity, day of lactation and number of kits on milk production. Breed of doe tended (P less than .07) to be important for mean milk yield according to ANOVA results. Californian does had numerically higher production than did does of the other breeds. Doe body weight, litter size born alive and weaned and litter weaning weight, likewise, were not influenced (P greater than .05) by breed of doe. Significant linear and quadratic relationships were found between milk production vs day of lactation, and milk production vs number of kits. However, breed x days and breed x number of kits interactions (P less than .05) indicated that the individual breeds responded differently to two of these effects. Peak lactation occurred at approximately 20 d after kindling. As kit number increased, milk yield also increased to a predicted maximum when 12 kits were suckling. Parity tended (P less than .10) to influence lactation yield in a curvilinear manner, increasing steadily through the seventh parity and declining thereafter. A nonsignificant residual correlation (.34) between milk production and doe body weight was observed. Corresponding correlations between milk production were high for litter size born alive and weaned (r = .62 and .87, respectively) and litter weaning weight (r = .86). Although lactation curves are unique to each particular breed, milk yield is influenced by several factors.     

A longitudinal study on growth and growth variables in dogs of four large breeds raised in domestic environments

The main objective of this study was to describe the growth patterns of 4 large dog breeds [Newfoundland (NF), Labrador retriever (LR), Leonberger (LEO), and Irish wolfhound (IW)] raised in domestic environments and concomitant changes in 2 growth-related clinical variables: total serum alkaline phosphatase (ALP) and the circumference of the distal radius and ulna (CDRU). The second objective was to investigate whether these measurements were affected by a range of independent variables like age, sex, litter number, and birth weight. Seven hundred dogs were included in the study, and BW data, separated by breed and sex, were fitted to the Gompertz function. Birth weight, adjusted for litter number, differed significantly between sexes for 3 breeds (LEO, P = 0.004; NF, P = 0.02; LR, P = 0.009) and approached significance for IW (P = 0.07). Estimated mean BW increased rapidly during the first 100 d after birth in all 4 breeds, then plateaued, with maturity being reached between 351 (female LR) and 413 d (male NF). Estimated mature BW ranged from 30.8 kg for the female LR up to 65.7 kg for the male IW. Weight gain, as expressed by the derivative of the Gompertz function, reached its peak in the smallest breed (LR) at the youngest age, 89 d for the females and 95 d for males. Log-transformed BW was significantly related to age, breed, and sex, and the age x sex and age x breed interactions. Within breeds, age, birth weight, and litter number had a significant effect on log-transformed BW. The estimated average CDRU increased from 90 d of age toward a peak at 180 d. Thereafter, CDRU declined and stabilized at about 1 yr of age. The estimated total ALP concentrations decreased from 90 to 360 d of age, after which they stabilized, at mean concentrations varying among breeds from 98 to 131 IU/L. Maximum least squares mean total ALP concentrations were found at 3 mo of age in all breeds, with the greatest least squares mean concentration in the IW breed (713 IU/L). In a mixed model analysis of the complete data set, total ALP was affected (P < 0.001) by age, breed, and the interaction of age x breed. This study described the main factors influencing growth and provided reference data for other studies, including those related to nutrition and disorders of growth.     

Proportion of litters of purebred dogs born by caesarean section

Objectives : To describe the frequency of caesarean sections in a large sample of pedigree dogs in the UK. Methods : Data on the numbers of litters born in the previous 10 years were available from a cross-sectional study of dogs belonging to breed club members (2004 Kennel Club/BSAVA Scientific Committee Purebred Dog Health Survey). In this survey 151 breeds were represented with data for households that had reported on at least 10 litters (range 10–14,15): this represented 13,141 bitches which had whelped 22,005 litters. The frequency of caesarean sections was estimated as the percentage of litters that were reported to be born by caesarean section (caesarean rates) and are reported by breed. The dogs were categorised into brachycephalic, mesocephalic and dolicocephalic breeds. Results : The 10 breeds with the highest caesarean rates were the Boston terrier, bulldog, French bulldog, mastiff, Scottish terrier, miniature bull terrier, German wirehaired pointer, Clumber spaniel, Pekingese and Dandie Dinmont terrier. In the Boston terrier, bulldog and French bulldog, the rate was > 80%. Clinical Significance : These data provide evidence for the need to monitor caesarean rates in certain breeds of dog.     

Inbreeding trends and pedigree analysis of Irish dairy and beef cattle populations

The objective of this study was to determine the inbreeding levels and to analyze the pedigree of Irish purebred populations of Charolais, Limousin, Hereford, Angus, and Simmental beef cattle, as well as the Holstein-Friesian dairy breed. Pedigree analyses included quantifying the depth of known pedigree, average generation intervals, effective population size, the effective number of founders, ancestors, and founder genomes, as well as identifying the most influential animals within the current population of each breed. The annual rate of increase in inbreeding over the past decade was 0.13% (P < 0.001) in the Hereford, 0.06% (P < 0.001) in the Simmental, and 0.10% (P < 0.001) in the Holstein-Friesian breeds. Inbreeding in the other breeds remained relatively constant over the past decade. Herefords had the greatest mean inbreeding in 2004, at 2.19%, whereas Charolais had the lowest, at 0.54%. Over half of each purebred population in 2004 was inbred to some degree; the population with the greatest proportion of animals inbred was the Hereford breed (85%). All 6 breeds displayed a generation interval of approximately 6 yr in recent years. In the pure-bred females born in 2004, the 3 most influential animals contributed between 11% (Limousin) and 24% (Hereford) of the genes. Effective population size was estimated for the Hereford, Simmental, and Holstein-Friesian only, and was 64, 127, and 75, respectively. The effective number of founders varied from 55 (Simmental) to 357 (Charolais), whereas the effective number of ancestors varied from 35 (Simmental and Hereford) to 82 (Limousin). Thus, despite the majority of animals being inbred, the inbreeding level across breeds is low but rising at a slow rate in the Hereford, Simmental, and Holstein-Friesian.     

Evaluation of Dorset, Finnsheep, Romanov, Texel, and Montadale breeds of sheep: I. Effects of ram breed on productivity of ewes of two crossbred populations

Effects of Dorset, Finnsheep, Romanov, Texel, and Montadale breeds for performance as sires were estimated in the initial phase of a comprehensive evaluation of these breeds as contributors to sheep crossbreeding systems. Objectives were to evaluate the effects of ram breed, ewe breed, season of mating, and two-way interactions. Rams from the five breeds were single-sire-mated with ewes from two breed types to produce lambs over a 3-yr period. Ewes were assigned to one of three distinct 35-d mating seasons initiated each year in August, October, and December. A different sample of six rams per breed was used each year across all three seasons, and each ram was penned with ewes of both breeds. Traits evaluated and number of ewe records were conception rate and litter weaning weight per ewe exposed (n = 3,261) and number born, litter birth weight, average birth weight, number weaned, and litter weaning weight per ewe lambing (n = 2,751). Ram breed and ewe breed interacted (P < .01) for conception rate and litter weaning weight per ewe exposed, implicating mating preferences, particularly of Romanov rams. In mixed groups of ewes exposed to Romanov rams, conception rate was 12.7% lower and litter weight weaned was 8.4 kg lower in the ewe breed presumably less preferred for mating by the rams. On a per ewe exposed basis, Romanov-sired litters produced either the largest or the smallest values for litter weaning weight, depending on the breed of ewe. Effects of ram breed on number born and litter birth weight interacted (P < .05) with season of mating. The largest litters within each ram breed were associated with the October mating season. Montadale and Romanov rams sired larger and heavier litters from August matings than from December matings, whereas the opposite was true for Dorset-sired litters. Texel- and Finnsheep-sired litters were similar in size and weight from August and December matings. Breed of ram differences affected per ewe lambing productivity measurements (P < .01). Differences between ram breeds for ewe productivity were noted, with increased number born and improved survival of crossbred progeny to weaning for Romanov-sired litters. These results may have implications for using these ram breeds as sires in different crossbreeding systems. Structured mating systems or the creation of new composite populations involving these breeds could be used to match the resources, environment, and market of specific production situations.     

Responses in ovulation rate, embryonal survival, and litter traits in swine to 14 generations of selection to increase litter size

Eleven generations of selection for increased index of ovulation rate and embryonal survival rate, followed by three generations of selection for litter size, were practiced. Laparotomy was used to count corpora lutea and fetuses at 50 d of gestation. High-indexing gilts, approximately 30%, were farrowed. Sons of dams in the upper 10% of the distribution were selected. Selection from Generations 12 to 14 was for increased number of fully formed pigs; replacements were from the largest 25% of the litters. A randomly selected control line was maintained. Responses at Generation 11 were approximately 7.4 ova and 3.8 fetuses at 50 d of gestation (P < .01) and 2.3 fully formed pigs (P < .01) and 1.1 live pigs at birth (P < .05). Responses at Generation 14 were three fully formed pigs (P < .01) and 1.4 live pigs (P < .05) per litter. Number of pigs weaned declined (P < .05) in the index line. Total litter weight weaned did not change significantly. Ovulation rate and number of fetuses had positive genetic correlations with number of stillborn pigs per litter. Significantly greater rate of inbreeding and increased litter size at 50 d of gestation in the select line may have contributed to greater fetal losses in late gestation, greater number of stillborn pigs, and lighter pigs at birth, leading to lower preweaning viability. Heritabilities of traits were between 8 and 25%. Genetic improvement programs should emphasize live-born pigs and perhaps weight of live-born pigs because of undesirable genetic relationships of ovulation rate and number of fetuses with numbers of stillborn and mummified pigs and because birth weight decreased as litter size increased.     

Effects of prepartum supplementary fat and muscle hypertrophy genotype on cold tolerance in newborn calves.

Effects of feeding pregnant dams supplemental dietary fat during the last 55 d of gestation on cold tolerance of newborn crossbred calves with (Piedmontese cross, P, n = 15) or without (Hereford cross, H, n = 16) the muscle hypertrophy allele was determined. Primiparous F1 dams gestating F2 calves of the respective breeds were assigned randomly within breed to receive gestation diets containing either 2.2 (Low Fat; LF) or 5.1% fat (High Fat; HF). Safflower (Carthamus tinctorius L.) seeds containing 37% oil with 79% linoleic acid were the supplemental fat source in diets formulated to be isocaloric-isonitrogenous. At parturition, calves were separated from their dams, fed 38 degrees C pooled dairy cow colostrum (30 mL/kg BW), muzzled to prevent suckling, and returned to their dams in a heated (22 degrees C) room for 3.5 h. At 4 h of age (birth = 0 h), a catheter was inserted into the jugular vein. At 5 h of age, calves were placed in a 0 degrees C room for 140 min, and rectal temperatures and blood samples were obtained at 10- and 20-min intervals. Blood was assayed for cortisol and glucose. Rectal temperature was affected by diet (P<.05), time, diet x time, and breed x time (P<.01 for time and the interactions). Cortisol and glucose concentrations were not affected by diet, breed, or the diet x breed interaction, but they were affected by time, breed x time (both P<.01), and diet x time (P = .06). Calves from HF dams had higher rectal temperatures than calves from LF dams, and the HF calves maintained higher rectal temperatures throughout cold exposure. Cortisol concentrations were lower (P = .06) in calves from HF dams, and these calves had more (P = .06) glucose available for metabolic heat production than calves from LF dams. Piedmontese-cross calves maintained higher (P<.01) rectal temperatures and had higher cortisol and glucose (both P<.01) concentrations than did H-cross calves. We conclude that feeding dams supplemental fat during late gestation increased heat production in newborn calves and potentially could increase calf survival; calves with muscle hypertrophy may have a different ratio of shivering vs nonshivering thermogenesis due to differences in body composition or relationships among uncoupling proteins.     

Hereditary cerebellar degeneration in three full sibling kittens

Two domestic shorthair littermate kittens had signs of cerebellar dysfunction, first observed between seven and eight weeks of age; a third littermate was unaffected. The signs were progressive and the more severely affected kitten was euthanased after six days. A postmortem examination revealed no gross lesions but the kitten had cerebellar cortical degeneration with extensive loss of Purkinje cells. The second kitten was euthanased at 10 months of age with similar, though more pronounced, changes. One of the two kittens in the next litter of the same parents had similar clinical signs and histopathological findings. The lesions in the cerebellum are interpreted as probably due to genetically determined abiotrophy. In addition, the two older kittens had medullary neuronal changes interpreted as probable neuraxonal dystrophy, and focal vacuolation of the neuropil in the medulla and cervical spinal cord.     

Half of 23 Belgian dog breeds has a compromised genetic diversity,as revealed by genealogical and molecular data analysis

The genetic diversity in 23 dog breeds raised in Belgium was investigated using both genealogical analysis and microsatellite markers. Some of these breeds are native breeds, with only small populations maintained. Pedigree and molecular data, obtained from the Belgian kennel club, were used to calculate the inbreeding coefficients, realised effective population size as well as probabilities of gene origin and average observed heterozygosity. Inbreeding coefficients ranged from 0.8 to 44.7% and realised effective population size varied between 3.2 and 829.1, according to the used method and breed. Mean observed heterozygosity ranged from 0.47 to 0.73. Both pedigree and molecular methods reveal low genetic diversity and presence of bottlenecks, especially in native Belgian breeds with small population sizes. Furthermore, principal component analysis on the set of investigated diversity parameters revealed no groups of breeds that could be identified in which similar breeding strategies could be applied to maintain genetic diversity.     

A retrospective study of female reproductive parameters in the Kunming dog

The Kunming dog is the first and only working dog breed from China to be recognized worldwide. As a domestic working dog, its excellent working performance has been well established; however, its normal reproductive parameters are not well understood. Therefore, this study was conducted to document the main reproductive parameters of this purebred working dog in field breeding conditions. Data on 1004 heats (753 with mating) from 203 bitches between 2008 to 2014, were collected and analyzed. The pregnancy rate and whelping rate was 79.42% and 75.30%, respectively. Finally, for 567 litters (4298 puppies), the mean litter size was 7.19 ± 0.12 puppies (range 1–15). The mean gestation period and birth weight were approximately 61.64 ± 0.10 days and 407.25 ± 1.21 g. The mean sex ratio was 1.03 males to 1.00 female. Estrus occurred throughout the year with no significant differences between seasons and months (P > 0.05), which confirms that Kunming dogs are non‐seasonal breeders; births occurred in every month of the year. Pregnant bitches exhibited significantly longer inter‐estrus intervals than non‐pregnant bitches (220.85 ± 2.05 vs. 180.19 ± 2.94 days, P < 0.05). Bitch parity influenced litter size, and the gestation length and birth weight of the puppies were negatively affected by litter size. This study helps elucidate the reproductive potential of this breed and provides reference values for reproductive performance in the Kunming dog.     

Reproductive capacity of free-roaming domestic cats and kitten survival rate

OBJECTIVE: To determine reproductive capacity of naturally breeding free-roaming domestic cats and kitten survival rate. DESIGN: Prospective cohort and retrospective cross-sectional study. ANIMALS: 2,332 female cats brought to a trap-neuter-return clinic for neutering and 71 female cats and 171 kittens comprising 50 litters from a cohort study of feral cats in managed colonies. PROCEDURE: Data collected for all cats included pregnancy, lactation, and estrus status and number of fetuses for pregnant cats. Additional data collected for feral cats in managed colonies included numbers of litters per year and kittens per litter, date of birth, kitten survival rate, and causes of death. RESULTS: Pregnant cats were observed in all months of the year, but the percentage of cats found to be pregnant was highest in March, April, and May. Cats produced a mean of 1.4 litters/y, with a median of 3 kittens/litter (range, 1 to 6). Overall, 127 of 169 (75%) kittens died or disappeared before 6 months of age. Trauma was the most common cause of death. CONCLUSIONS AND CLINICAL RELEVANCE: Results illustrate the high reproductive capacity of free-roaming domestic cats. Realistic estimates of the reproductive capacity of female cats may be useful in assessing the effectiveness of population control strategies.     

A genealogical survey of Australian registered dog breeds

Breeding practices were analysed for 32 registered dog breeds representing very small registries (120 Central Asian shepherd dogs) through to very large registries (252,521 German shepherd dogs) in Australia. The vast majority (91%) of registered kennels in Australia that were sampled did not regularly employ either close breeding or popular sire usage in their kennels and the weighted mean inbreeding coefficient of Australian pedigree dogs was <5%. Australian breed mean inbreeding coefficients ranged from 0% (Central Asian shepherd dog) to 10.1% (Bichon Frise). Breed effective population sizes ranged from 26 (Ibizan hound) to 1090 (Golden retriever), comparable with other species of domesticated animals. The relatively low levels of inbreeding suggest that pedigree dog disorders are unlikely to arise frequently from the use of popular sires or close breeding in Australian registered dog breeds. It is possible that deleterious allele fixation might be driven by founder effects, genetic drift or adverse selection practices, which were not assessed in this analysis. European popular sire definitions should be revisited for rare breeds.     

Methods and mortality results of a health survey of purebred dogs in the UK

Objectives : To collect information on the cause of death and longevity of dogs owned by members of the numerically largest breed clubs of 169 UK Kennel Club-recognised breeds. Methods : A cross-sectional study was carried out. Approximately 58,363 questionnaires were sent out to breed club members in 2004 (nine clubs failed to report the exact number of questionnaires sent out). Owners reported age at death and cause(s) of death for all dogs that had died within the previous 10 years. Results : A total of 13,741 questionnaires (24% response rate) containing information on 15,881 deaths were included in the analysis. Breed-specific response rates ranged from 64·7 to 4·5%. The median age at death was 11 years and 3 months (minimum=2 months, maximum=23 years and 5 months) and it varied by breed. The most common causes of death were cancer (n=4282, 27%), “old age” (n=2830, 18%) and cardiac conditions (n=1770, 11%). Clinical Significance : This survey shows breed differences in lifespan and causes of death, and the results support previous evidence that smaller breeds tend to have longer lifespan compared with larger breeds. Although many of the breeds in the study may not be representative of the general pedigree dog population in the UK, the results do contribute to the limited information currently available.     

Some observations on the population and natal patterns among purebred dogs in Malaysia

The results of a study of 28, 220 birth registration and 773 import records between 1980 and 1982 of the Malaysian Kennel Association are reported. The German Shepherd Dog was by far the most common breed followed by the Dobermann, Dachshund and Boxer. Most breeds made up only a small percentage of birth registrations. No distinct seasonal distribution of whelping was evident among the purebred litters studied. Mean litter size was 4–7 puppies per litter with larger breeds tending to produce larger litters. A sex ratio of 51 males per 100 births was computed. There was a steady decline in the number of imported dogs.