Food intake and growth of German shepherd puppies

The nutritional programme followed during the growth and development of the German shepherd puppy may have a significant influence on the dog's value as a potential working or breeding animal. Limited research has been undertaken on the nutrition of the dog from birth until four to five weeks of age. The objective of this study was to establish a baseline in terms of food intake and growth, which can be used in a nutritional and managerial programme in a commercial breeding unit. The food intake and growth of 10 German shepherd dog litters, with an average of six puppies per litter, were monitored from birth to 12 weeks of age. Both food intake and growth was described by regression equations. A commercially available diet was fed throughout the study. Performance criteria, namely food intake and bodyweight, were established which could be used in a commercial German shepherd dog breeding unit.     

Serum concentrations of leptin in pregnant and non-pregnant bitches

Leptin regulates body weight and several physiological processes including reproduction. We evaluated the circulating levels of leptin in pregnant and non-pregnant bitches as well as their correlation with body weight, food intake and number of foetuses. Nineteen healthy German shepherd bitches were used and divided in two groups (pregnant n = 12 and non-pregnant n = 7). Blood samples were collected every 15 days starting from ovulation (Day 0) throughout pregnancy (pregnant group, P) or throughout luteal phase (non-pregnant group, NP) In pregnant bitches, leptin concentrations increased from the day of ovulation (1.32 ± 0.06 ng/ml) up to day 45 (1.51 ± 0.06 ng/ml; p < .01) and returned to baseline values from day 60 post-ovulation. In non-pregnant bitches, leptin concentrations remained constant throughout the whole observation period (estimated marginal mean ± SE=1.33 ± 0.38 ng/ml). Pairwise comparisons showed significant differences between P and NP at day 45 post-ovulation (p < .05). Multivariable models indicated that, controlling for time and litter size, there was a positive relationship between leptin concentration and BW (p < .05) although Pearson coefficients showed that the correlation between BW and leptin was only significant in NP animals at day 45 (r = 0.76, p < .05). The multivariable approach also suggested that, holding BW and time constant, leptin concentrations tend to increase as the number of puppies increased (p = .06). Our study supports indirectly the contribution of the feto-placental unit to the circulating maternal leptin concentration.     

Seasonal and breed effects on reproductive parameters in bitches in the tropics: a retrospective study

OBJECTIVES: To investigate the influence of season and breed on reproductive parameters in bitches raised under tropical climatic conditions. METHODS: Over a seven year period, from 1998 to 2004, 310 oestrous periods of 53 bitches were observed. The dogs were of various breeds; dobermann (number of bitches/number of oestrous cycles) (n=2/19), German shepherd dog (n=35/211), Labrador retriever (n=14/68) and Rottweiler (n=2/12). In 250 of the 310 oestrous periods, natural matings took place on days 9 and 11 after the onset of pro-oestrus. The whelping rate was analysed for bitches of each breed. Variables, including breed and the whelping rate, by month of the year, were used for analysis of the inter-oestrus interval, gestation length, total number of pups born, number of live pups born and the weight of the pups at birth. RESULTS: A low frequency of oestrous activity was found during the summer. Breeding dogs in the summer resulted in a low whelping rate. No difference (P>0.05) was seen in the whelping rate of each breed: dobermann (70.5 per cent), German shepherd dog (61.5 per cent), Labrador retriever (67.9 per cent) and Rottweiler (100 per cent). The Labrador retriever had a longer inter-oestrus interval (252 [114] and 190 [61] days) (P<0.01) and a larger litter size (8.2 [1.8] and 6.6 [2.8]) (P<0.05) than the German shepherd dog. CLINICAL SIGNIFICANCE: The environmental factors in summer tend to reduce oestrus incidence and fertility in the bitches. According to litter size, the Labrador retriever seems to have a more efficient reproductive performance than the German shepherd dog. The Labrador retriever had a longer inter-oestrus interval than the German shepherd dog.     

Effects of whelping and season of the year on the interoestrous intervals in dogs

An analysis of 319 interoestrous intervals of 36 beagles, 36 German shepherd dogs and 20 labrador retrievers was made to study the influence of whelping on the length of this interval and the within-year variation in length of interoestrous intervals and timing of the oestrous periods. The mean interoestrous interval was significantly longer for beagles (247±5 days) than for German shepherd dogs and labrador retrievers (both 198±5 days)(P<0–001). For bitches that had not whelped there were no significant differences between breeds (beagles 172+10; German shepherd dogs 166±6; and labrador retrievers 172±7 days). The mean interoestrous interval after whelping was significantly lengthened in all breeds (P<0–001). This increase was more pronounced for beagles (84 days)(P<0–001) than for German shepherd dogs (58 days) and labrador retrievers (52 days). Heat periods were evenly distributed over the year for the labrador retrievers and German shepherd dogs that were kept as family pets. For the beagles kept as a colony and housed outdoors without heating or supplementary light, there were significant differences between months (P<0001), with a peak in May. The longest interoestrous intervals were found in beagle bitches that had been in oestrous and whelped during autumn.     

Long-term study of aerobic bacteria of the genital tract in stud dogs.

The aerobic bacterial flora of the genital tract was characterized in 15 stud dogs in an 18-month study. The dogs represented 4 breeds and were from 3 kennels. Bacterial samples from the prepuce and semen were collected every month, except in connection with matings, when they were collected weekly (464 samples). The dogs that were included all mated at least once during the study. The mean pregnancy rate, litter size, and pup mortality for the bitches with which they had mated were all within normal limits. The most frequent bacteria isolated from the prepuce and semen were Pasteurella multocida, beta-hemolytic streptococci, and Escherichia coli. There was a tendency for breeds to differ in frequency of the most common bacterial species. Bacterial culture yielded no aerobic growth in 14.2% of the preputial samples and 69.8% of the semen samples. Bacteria were transferred between dog and bitch at mating. In this study of healthy breeding dogs, neither the fertility of the dog nor that of the bitch was affected by the bacteria transferred.     

A retrospective study on some reproductive parameters of German shepherd bitches in Kenya

Data relating to reproductive parameters of German shepherd bitches were collected from registered German shepherd dog (GSD) breeders with information kept over a 15-year period (1982-1997). The information obtained was verified using the East African Kennel Club records. A total of 594 bitches from 280 breeders were recorded. From these, 798 heats were observed, 594 of which were used for breeding, resulting in 3592 puppies. The mean age at puberty was 519.0 +/- 41 days. Heats occurred throughout the year, although significantly (P < 0.05) higher and lower incidences were observed in October and April respectively Pregnancy significantly (P < 0.01) increased interoestrous interval, which was 247.8 +/- 99.6 and 183 +/- 52 days among bred/pregnant and non-bred bitches respectively. Most bitches in oestrus (73.7%) were bred, and breeding was carried out throughout the year, with a distribution closely related to that of heat incidence. Subsequently, whelping occurred throughout the year, and 95.5% of the bitches that were mated whelped. A mean gestation period of 60.6 +/- 5.1 days was observed. The mean litter size was 6.4 +/- 0.4 puppies, and did not differ significantly between months. The preweaning losses were low, with 2.3% stillbirths, 0.9% culls and 11.4% mortalities.     

Fenbendazole treatment of pregnant bitches to reduce prenatal and lactogenic infections of Toxocara canis and Ancylostoma caninum in pups

A granulated formulation of fenbendazole was tested in a total of 23 treated and control, pregnant, parasite-free Beagle bitches experimentally infected with Toxocara canis and Ancylostoma caninum. The drug was administered to each treated bitch once daily in canned dog food at a dosage of 50 mg/kg body weight. Each of 2 treatment regimens tested was initiated on the 40th day of pregnancy. One regimen involved daily treatment continuing through the 14th postpartum day, and it resulted in 89% fewer ascarids and 99% fewer hookworms in pups born to medicated bitches, as compared with pups born to unmedicated controls. The other regimen of treatment, which was stopped on the day of parturition, was less effective in reducing ascarid and hookworm burdens (64% and 88% reductions, respectively). Three to 5 bitches from each of the treatment and control groups were allowed to whelp a 2nd litter without further treatment or further exposure to parasite infections. Hookworm burdens in 2nd-litter pups born of bitches that had initially received fenbendazole through the 14th postpartum day were significantly lower (P < 0.01; 85% reduction), when compared with the 2nd-litter control pups. All other parasite burdens were not significantly different. It was concluded that granulated fenbendazole is effective in reducing burdens of Ancylostoma caninum and Toxocara canis in newborn pups when the bitch is treated during the last third of pregnancy, especially when treatment (50 mg/kg/day) extends from the 40th day of pregnancy through the 14th postpartum day.     

The Hereditary Nature of Canine Pancreatic Degenerative Atrophy in the German Shepherd Dog

The incidence of pancreatic degenerative atrophy (PDA) was investigated in 59 German shepherd dogs from two kindred. The male progenitors were the same in both kindred. In the four litters of the first kindred the incidence of PDA was 24 % (10 dogs out of 41), and there was at least one affected dog in each litter. When one of the litter bitches, later affected with PDA, was mated with one of the obligate carriers of PDA, one of the resultant seven offspring has so far been found to suffer from PDA. In the second kindred when a PDA-affected bitch and a clinically healthy male (heterozygote) were mated, two of the resultant six offspring were found to suffer from PDA.These results indicate that PDA is a disease inherited as an autosomal recessive trait, although the possibility of dominant inheritance with incomplete penetrance cannot be excluded.     

Efficacy and toxicity of tamoxifen citrate for prevention and termination of pregnancy in bitches

Five groups of bitches were given tamoxifen citrate (1 mg/kg of body weight) orally twice daily for 10 days. Drug administration commenced during late proestrus, day 4 of estrus, day 2 of diestrus, day 15 of diestrus, or day 30 of diestrus (n = 4/group). Nineteen of the bitches accepted natural mating by 1 or more of 3 stud dogs of known fertility (1 bitch did not). Twenty days after cessation of drug administration, ovarian, uterine, and hepatic specimens were obtained from each bitch in 4 of the groups. Pregnancy proceeded to natural termination in bitches of the remaining group (diestrous day 30). Pregnancy was not detected in any bitch of the proestrus, estrous, or early diestrous groups. Of 4 bitches of each of the remaining groups (diestrous day 15 and diestrous day 30), 2 aborted fetuses and/or resorbed placental remnants; the other 2 bitches in each of these groups had normal-appearing fetuses (diestrous day-15 group) or clinically normal pups (diestrous day-30 group). Of the 20 bitches given tamoxifen citrate, 5 developed endometritis with or without pyometra, and 4 of these had ovarian cysts. Although tamoxifen citrate is effective for preventing or terminating pregnancy in the bitch, the regimen used in the study reported here was associated with high frequency of pathologic changes in the reproductive tract.     

Estimated pregnancy length from ovulation to parturition in the bitch and its influencing factors: a retrospective study in 162 pregnancies

An accurate timing of parturition is very useful for managing canine parturition. It is generally accepted that parturition in bitches occurs between 64 and 66 days after the luteinizing hormone peak. In this retrospective study, we determined pregnancy length in different breeds and its influencing factors dating it from the estimated day of ovulation (EDO), defined as the day when peripheral plasma level of progesterone (P4) reaches 6 ng/ml. From January 2001 to December 2006, 162 pregnancies in 151 bitches of 53 different breeds were followed. Different parameters concerning the bitch, the litter, the type of semen and the type of reproduction were studied. The mean estimated pregnancy length in the bitch from EDO to parturition was 63.1±2.1 days. The main influencing factors for the pregnancies studied were the breed, the size of the bitch and the number of puppies within the litter.     

The relationship of food intake during growth and food intake at maturity with lactation food intake in a mouse model

Selection for increased leanness and improved food efficiency in pigs has resulted in a decreased voluntary food intake. It has been argued that voluntary food intake during lactation should be considered in sow breeding programmes. The aim of the present study was to investigate the phenotypic correlation of food intake during growth and food intake at maturity with maximum lactation food intake in a mouse model. A total of 179 records were available on female mice selected for litter size at birth (S-line) and non-selected control females (C-line) from 3 weeks of age to 21 days in lactation. Half of the litters were standardized to eight pups per litter (s) and half were not standardized (ns). Growth intake was measured as the average intake between 21 and 42 days of age, mature intake was measured from a linear regression of food intake against age between 42 and 69 days of age, and lactation intake was measured as a linear regression of food intake against days in lactation between 5 and 14 days in lactation. In both lines, females with a higher growth intake also had a higher mature intake (r = 0.63 to 0.75, P < 0.0001). Lactation intake was related with growth intake and mature intake in Sns females (r = 0.50 and 0.46, P < 0.01) and with growth intake in Ss females (r = 0.32, P < 0.05). In both lines, lactation intake was highly correlated with litter weight (r = 0.48 to 0.94, P < 0.001). Sns and Ss females with higher growth intake supported larger litter weights during lactation (r = 0.32 and 0.30, respectively, P < 0.05) and Sns females with higher mature intakes tended to support larger litter weights (r = 0.28, P = 0.060). It is suggested that lactating C-line females eat to support a given litter size, while S-line females support the maximum litter weight that is allowed for by their intake capacity, and still produce at high levels when litters are standardized. Since lactating sows mobilise body reserves, the relationship of food intake during growth with that during lactation may be reflected in the relationship between growth intake and body condition.     

Vaginal cytology and cervicovaginal mucus arborisation in the breeding management of bitches

Fifty bitches were mated on the basis of results of vaginal cytological and cervicovaginal mucus arborisation examination. When these were compared with a control group of 50 bitches mated on days 10 and 12 after the onset of proestrus there was a significant increase in pregnancy rate from 78 to 92 per cent. The litter size and bitch productivity was also increased, although this was not statistically significant. Forty-two per cent of bitches had two peaks of anuclear epithelial cells in the vaginal smear, separated by a mean of 3–6 ± 1–5 (SD) days. For these bitches, the maximum percentage of anuclear cells at the second peak was between 57 and 98 per cent, and the mean interval between the calculated day of the surge in plasma luteinising hormone (LH) and the second peak of anuclear cells was 4-4 ± 2-0 days. In bitches with one peak of anuclear epithelial cells, the maximum percentage of anuclear cells was between 43 and 94 per cent and the mean interval between the calculated day of the LH surge and the peak of anuclear cells was 1–9 ± 2-1 days. Arborisation of mucus collected from the anterior vagina was noted in all bitches; the mean interval between the calculated day of the LH surge and the peak of ferning was 2–3 ± 2-1 days. The collection of exfoliative cells by aspiration from the cranial vagina and the assessment of the anuclear cell index, may allow the identification of the fertile period after the surge of plasma LH. The anuclear cell index offers advantages over other methods of classification of exfoliative vaginal cells. When used in combination with examination of arborisation of cervicovaginal mucus this method can improve the breeding management of bitches.     

Hormonal calcium regulation and calcium setpoint in offspring of bitches with different calcium intakes during pregnancy

High maternal calcium (Ca) intake may lead to alterations in development and differentiation of fetal tissues and may result in altered 'programming' of Ca homeostasis, with eventual effects on Ca handling and skeletal development in the offspring during later life. In bitches fed a diet with a Ca intake three times above recommendations (3.27 g/100 g vs 1.14 g/100 g dry matter) during the second half of pregnancy, the plasma concentration of 1,25 dihydroxy cholecalciferol (1,25 (OH)₂ vit D) appeared to decrease, while plasma Ca, phosphorus (P), parathyroid hormone (PTH) and calcitonin (CT) concentrations remained unchanged. High maternal Ca intake did not result in altered basal or stimulated plasma concentrations of Ca, P, PTH, CT and 1,25 (OH)₂ vit D in the offspring (n = 7) when compared with pups from bitches fed a normal Ca diet during the entire pregnancy (controls, n = 7). The Ca setpoint for PTH secretion (^Ca S_for PTH) was therefore not different from controls. From this pilot study it may be concluded that excessive Ca intake during late pregnancy in the bitch has no deleterious effects on hormonal Ca homeostasis in the offspring.     

Termination of mid-term pregnancy in the dog with oral RU 486

A total of four pregnancies were terminated in three bitches (two beagles and one flatcoated retriever) with a single dose of 20 mg/kg (one case), two doses of 8-3 mg/kg (one case) or 20 mg/kg plus 40 mg/kg (two cases) RU 486 by mouth (Mifepristone; Roussel-Uclaf, France) from day 26 to day 36 after the first day of mating of the bitch. Abortions occurred within two, four, 11 and 11 days after the initial treatment, respectively. The clinical status of the bitches was similar to that observed during a normal parturition, ie, lowering of the body temperature, shivering, panting and nesting behaviour. No side effects were seen. The beagle bitch that aborted twice, was mated at the first oestrus after the first abortion, conceived and aborted the same number of puppies the second time. The peripheral plasma progesterone concentration at the time of treatment in all bitches was < 75 nmol/litre. It had decreased to between 24-2 and 13-1 nmol/litre at the time of abortion and to between 4-0 to 0–5 nmol/litre at four to 15 days after the initial treatment. Peripheral plasma levels of prolactin increased three- to fourfold within 24 to 48 hours after treatment, concomitant with the drop in progesterone and had returned to basal levels within two to three days. Prolactin concentrations also increased around the time of intrauterine fetal death. Prostaglandin F_2aα-metabolite concentrations increased slowly after treatment, and around the time of abortion the levels increased five- to 10-fold. RU 486 seems to be a safe and effective abortifacient for use during mid-term pregnancy in the dog.     

An epidemiological survey demonstrating decline in reproductive efficiency with age and non-seasonality of reproductive parameters in German shepherd bitches in Kenya

An epidemiological survey undertaken in Kenya indicated that 2 previously well-established factors, namely decline in reproductive efficiency with age, and non-seasonality of canine reproductive parameters, hold true for German shepherd (GSD) bitches in Kenya. Data collection forms were distributed to randomly selected GSD breeders and information so obtained was verified using East African Kennel Club records. Whelping was recorded throughout the year. The litter size varied from 1 to 14 pups per litter with a mean of 6.3 +/- 0.4 SD puppies. Records of 567 whelpings and 3592 puppies were studied. The mean monthly whelping rate was 47.3 +/- 7.2. There was no significant difference in the mean litter size by month (P < 0.05).     

Plasma levels of specific coagulation factors and oestrogens in the bitch during pregnancy

During pregnancy in twelve bitches a significant increase was observed in the circulating activity of the specific coagulation factors VII, VIII, IX and XI. Such changes did not occur in two bitches which were bred but did not conceive. Comparison of the plasma procoagulant activity and oestradiol-17 β levels indicated that alterations in the coagulation factor activity may, at least in part, be mediated by the changes in oestrogen levels which occur in the pregnant bitch.     

The association between the signalment, common causes of canine otitis externa and pathogens

Objective : To determine whether associations exist between pathogens, allergies, conformational abnormalities, endocrinopathies and signalment in canine otitis externa (OE). Methods : Medical records of 149 dogs which met predetermined inclusion criteria were evaluated retrospectively. Correlations between pathogens and the presence of allergy, endocrinopathy, conformational abnormalities and signalment were evaluated statistically. Results : The shar‐pei, German shepherd and cocker spaniel breeds were over‐represented compared with the hospital's breed distribution (P<0·001). German shepherd dogs and cocker spaniels were statistically more prone to infection with rod‐shaped organisms and Labrador retrievers less than other breeds (P=0·034). Almost all dogs that were older than five years when diagnosed with OE had cocci (P=0·01) and also had higher levels of rods (P=0·028). The incidence of rods was higher in endocrinopathies (P=0·004), while that of Malassezia spp. tended to be higher in allergies (P=0·098). There were no statistically significant differences among the groups for all the other parameters examined. Clinical Significance : OE infection is usually not influenced by primary causes or predisposing factors. Endocrinopathies may be followed by a more severe otitis, however. OE may be more severe when it affects older dogs.     

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.     

Estimation of maintenance energy requirements in German shepherd and Labrador retriever dogs in Bangalore,India

Maintenance energy requirements (MERs) were calculated for 17 German shepherd and 20 Labrador retriever adult dogs using an in‐home prospective dietary trial. The dogs were fed the same dry pet food and body weight, food intake, body condition score and physical activity were monitored for 10 weeks. Labrador retrievers were significantly heavier and had higher body condition scores than German shepherd dogs, but there was no difference between males and females within each group. Body weights remained stable over the study period, with an average daily gain of 9.1 g. Mean (SD) MER was 103.4 (16.3) kcal/kg BW^0.75, which was some 20% lower than that currently suggested for moderately active young adult dogs. Individual MER ranged from 66.8 to 141 kcal/kg BW^0.75. There were no significant differences in MER between the two breeds, or between males and females within and between the two breeds. There was a significant inverse relationship between MER and body condition score, reflecting the lower energy expenditure of adipose tissue. The lower MER of dogs in this study, relative to previous observations, may reflect climatic and environmental differences and highlight the necessity for accurate estimates of MER in relation to the production and feeding of pet foods.     

Evaluation of a new non-hormonal substance for terminating pregnancy in bitches in clinical trials

A new non-hormonal contragestational agent (DL 717-IT), the 2-(4 chlorophenyl)-s-triazole |5,1-a|-isoquinoline, was tested in clinical trials to determine its efficacy for interrupting the pregnancy in the bitch. Five hundred and sixty-five bitches were given a single intramuscular injection of the drug between the first and 15th day after the mating. Of the 475 bitches that received 2–5 mg/kg, 430 (90-5 per cent) did not whelp at all, 15 (3-2 per cent) delivered a few stillborn or weak puppies that died some hours after birth, and 30 (6-3 per cent) delivered at least one normal live pup. Of 90 bitches treated with 3–5 mg/kg, 87 (96-7 per cent) did not whelp at all, two (2-2 per cent) delivered a few stillborn or weak puppies that died some hours after birth, and one (1 1 per cent) delivered normal live puppies. DL 717-IT, owing to the high effectiveness and minimal side effects, must be considered a very reliable drug for the interruption of pregnancies in the bitch.