Results of Wellness Examinations of 28 African Hunting Dog (lycaon Pictus) Puppies at the Denver Zoological Foundation

a INTRODUCTION Between 2002 and 2004 the Denver Zoological Foundation (Denver Zoo) had 28 African hunting dog (Lycaon pictus) puppies born in 3 litters to the same dam and sire. The pack size ranged from 3 to 10 adults when the 3 litters were born. In nature, wild dog puppies stay in the den with the dam for approximately the first 3 months, so this aspect of wild dog ecology has been little studied 15. There was an opportunity to perform 3 wellness examinations on each litter with pups ranging in age from 6 to 14 weeks. In addition to complete physical examinations and administering vaccinations, blood samples were obtained for complete blood counts and serum biochemistry. Weights, morphometric measurements, rectal cultures for potential enteric pathogens were taken and dental eruption patterns were noted. Blood counts and serum biochemistry were also compared with results from the adult dogs. All 28 puppies


INTRODUCTION
Between 2002 and 2004 the Denver Zoological Foundation (Denver Zoo) had 28 African hunting dog (Lycaon pictus) puppies born in 3 litters to the same dam and sire.The pack size ranged from 3 to 10 adults when the 3 litters were born.In nature, wild dog puppies stay in the den with the dam for approximately the first 3 months, so this aspect of wild dog ecology has been little studied 15 .There was an opportunity to perform 3 wellness examinations on each litter with pups ranging in age from 6 to 14 weeks.In addition to complete physical examinations and administering vaccinations, blood samples were obtained for complete blood counts and serum biochemistry.Weights, morphometric measurements, rectal cultures for potential enteric pathogens were taken and dental eruption patterns were noted.Blood counts and serum biochemistry were also compared with results from the adult dogs.All 28 puppies survived at least to 24 months of age.This report details the results of the wellness examinations.

MATERIALS AND METHODS
Twenty-eight African hunting dog puppies were born in 3 litters at the Denver Zoo.There were 7 pups in the 1st litter, 14 pups in the 2nd, and 7 pups in the 3rd.The dam and sire were the same for each of the 3 litters.The dam was 22, 31 and 53.5 months old, respectively, when she had the 3 litters.Puppy sex distribution for the 3 litters was as follows: litter one, 5 females and 2 males; litter two, 7 males and 7 females, and litter three, 5 males and 2 females, resulting in a 50/50 distribution for the 28 puppies.Three wellness examinations were performed on each litter.Pups were transported to the zoo hospital for examination at ~09:00.The timing of examinations (pup age at examination) was the same for all pups within a litter but the timing varied between litters.The examination range was 6-14 weeks of age and was performed under manual restraint.
The pups were whelped in wooden crates 95 cm high, 81 cm long and 127 cm wide divided into 2 compartments with a communicating doorway.The doorway to the outside had a lip 10 cm high to keep the pups in the crate until they were walking.Pups were not offered any solid food until they were 5 weeks old.For example, at 5 weeks of age the 14-pup litter was offered ~450 g of a commercial horse meat diet (Nebraska Brand Canine Diet, Central Nebraska Packing Inc., North Platte, Nebraska, USA) in the morning.The diet was increased to 1 kg at 6 weeks and 1.6 kg at 8 weeks.
A mean and standard error was calculated for complete blood counts, biochem-istry values, weights and morphometric measurements for each age group.In addition, means were compared with ANOVA and Bonferroni's post hoc test used for pairwise comparisons.Data were checked for normality and homogeneity of variances using a Bartlett's test.Nonnormally distributed data were transformed using either sine or log.Outliers were removed from the analysis.All pups were weighed (kg) at each examination.Morphometric measurements (cm) were not taken on all pups at each examination.Morphometric measurements performed were; total body length (TBL, the tip of the nose to the base of the tail), girth (thorax just caudal to front legs), height (top of scapula to bottom of foot placed flat), tail length and neck circumference (midpoint).
Rectal cultures were performed on 17 occasions from 14 puppies (3 pups were cultured twice) looking for potential enteric pathogens (non-lactose fermenters).Rectal cultures were collected using a BBL™ CultureSwab™ (Beckton, Dickinson and Co.) and then (1) streaked to trypticase™ soy agar with 5 % sheep blood (Beckton, Dickinson and Co.); (2) streaked to Hektoen enteric agar (Beckton, Dickinson and Co.) and (3) transferred to a GN broth which selects for Gram-negative organisms.Cultures were evaluated after 24 and 48 hours for growth.The GN broth was streaked to Hektoen enteric agar after 24 hours to evaluate for non-lactose fermenting organisms (Beckton, Dickinson and Co.).Isolated organisms were identified using the BBL™ crystal identification system (Beckton, Dickinson and Co.).
The oral cavity was periodically inspected for erupted deciduous teeth during each examination.

RESULTS
Results from complete blood counts and sera biochemistry are given in Tables 1 and 2. It was noted that the packed cell volume (PCV) of the pups was low compared to adults and gradually increased over the course of the neonatal evaluations.White cell counts (specifically neutrophils and lymphocytes) for domestic puppies are reported to be high at birth (compared with adults), declining during the 1st month, increasing in the 2nd month, and then slowly declining as they mature 2,3,4 .White cell counts in the wild dog puppies at the Denver Zoo were approximately at adult levels at 6 week of age, rose at 10-14 weeks, and then decreased to adult values.Statistically a consistent trend for values in both Tables 1 and 2, with few exceptions, was noted.There were no significant differences at ages 10, 12 and 14 weeks.Packed cell volume, TP (primarily composed of Alb and Glob), Alt, BUN, Creat and Na had a general tendency to increase over time to adulthood.This was in contrast to Alk Phos, Phos, K and amylase, which had a general tendency to decline over time to adulthood.Calcium values remained steady within the study groups.There did not appear to be any discernible pattern for glucose and TB in this study.
Weights and morphometric measurements are reported in Table 3. Six-weekold pups from the 14-pup litter were 63.6 % of the mean weight of pups from the two 7-pup litters.There was less of a difference for TBL and girth body measurements from 7-pup litters compared to the single 14-pup litter at 6 weeks (smaller by 95.8 % and 96.2 % for TBL and girth, respectively).Results at 10 weeks of age followed a similar trend.Pups from the 14-pup litter were 66.3 % of the weight and 92.7 % and 91.2 % smaller for TBL and girth compared to pups from 7-pup litters at 10 weeks of age.The pups had a 4-fold increase in weight, 1.5-fold increases in TBL and height, 1.35-fold increases in tail length and 1.2-fold increases in girth and neck dimensions from 6 to 14 weeks of age.
At 6 weeks of age, all deciduous upper and lower incisors and canines (I1-3, i1-3, C1, c1) were present.At the same age there were also 2 upper and lower premolars (P1-2, p1-2) present in 7 pups and the 3rd lower premolar (p3) was present in 21 pups.At 9-10 weeks of age, a 3rd upper premolar (P3) was present in all pups.Finally, at 12-14 weeks of age a 4th lower premolar (p4) was present in all pups.
Non-lactose fermenting bacteria were successfully cultured from 5 of 14 cultures (3 of the pups were cultured twice).Organisms recovered were Yersinia enterocolitica on 2 occasions and Plesiomonas shigelloides on 3 occasions.

DISCUSSION
African wild dogs are medium-sized, extremely social carnivores of the family Canidae, subfamily Simocyoninae, and are the only representative of the genus and species, Lycaon pictus 11,15 .Wild dogs are readily identifiable by their variegated pelage.The alpha male and female typically dominate reproduction 5 .Females are reported to be sexually mature at ~23 months 13 .Gestation length as determined by steroid analysis is 73-79 days 13 .Litter sizes can range from 2 to 19, but 7-10 are more typical 11 .For 36 litters in the Selous Game Reserve the mean litter size reported was 7.9 ± 0.5 SD 6 .The mean litter size at the Denver Zoo for 3 litters was 9.3 ± 4.0 SD pups.In 3 studies it has been Pairwise comparisons with the same letter superscript were not significantly different using a Bonferroni's post hoc test.
reported that there was a bias in sex distribution, being skewed towards males (53.7 % to 60 % male puppies) 13 .This may be due to a female bias in leaving the natal pack and subsequent high dispersal mortality 5 .For the 3 litters born at the Denver Zoo the sex distribution was even.For free-ranging wild dogs reproduction is seasonal with births typically timed to coincide with the region's dry season 6 .The hypothesis is that dens are located close to permanent water which serves to concentrate thirsty ungulates during the dry season 6 .Denver Zoo pups were born in November, January and February.It is believed there is not a reproductive seasonality preference for captive hunting dogs.
Many newborn animals experience a neonatal or physiological anaemia 10 .At birth, domestic puppies (Canis familiaris) from research colonies have adult values for packed cell volume [2][3][4] .The PCV begins to decrease when the puppy begins nursing and continues to decline for the 1st month 2 .Suggested factors for this physiological anaemia include increased plasma volume from colostrum diluting red cell mass, decreased red cell production, shortened red cell life-span, decreased erythropoietin production, rapid growth expanding vascular space without a concomitant increase in red cell mass and the replacement of foetal red blood cells with the adult line [2][3][4]10 . Thi same pattern was also present in the Denver Zoo wild dog puppies.The range for red cell mass for pups 6-14 weeks of age

Table 1 : Complete blood count values obtained from African hunting dog puppies during wellness examinations expressed as mean ± standard error. All puppies received 3 wellness examinations but they were not conducted on exactly the same schedule for each litter. ANOVA was used to compare means.
0038-2809 Jl S.Afr.vet.Ass.(2007) 78(1): 36-39