Some observations on the aerobic bacterial flora of the genital tract of the dog and bitch

The aerobic bacterial flora from the genital tracts of 143 bitches and 51 dogs was investigated. Beta haemolytic streptococci (group G), Staphylococcus aureus and Escherichia coli were among the organisms isolated from normal bitches in heat, abnormal bitches and normal dogs. Repeated sampling of two bitches during oestrus, and the dog to which they were mated, showed that bacteria were transmitted from bitch to dog, but did not become established. Guarded swab samples taken from the vagina collected less bacteria than samples from the vestibule. Numerous bacteria were seen in vaginal smears taken from bitches during oestrus, but numbers fell rapidly with the appearance of leucocytes in the smear at the onset of metoestrus.     

Establishment of a Pregnancy Following Intravaginal Insemination with Epididymal Semen from a Dog Castrated due to Benign Prostatic Hyperplasia

Benign prostatic hyperplasia was diagnosed in an American Staffordshire Terrier of high breeding value presenting concurrent haematuria. Castration as a treatment was synchronized with the oestrus cycle of a bitch selected for insemination. After castration the cauda epididymis was flushed with Gent semen extender and collected spermatozoa were filtered and analysed by Hamilton Thorn computer assisted sperm analysis. A total of 7 ml semen containing 742 x 10(6) spermatozoa with 76.5% mean motility was used for insemination. Intravaginal insemination of the bitch was performed with an insemination catheter for dogs (Kruuse, Marslev, Denmark) on the day when plasma progesterone levels reached 9.9 ng/ml. Normal pregnancy without complications resulted in eight live-born puppies 63 days after insemination. This is the first report of a normal pregnancy and birth of puppies from a bitch inseminated with epididymal semen obtained from a dog affected by benign prostate hyperplasia.     

Antibiotics for the preservation of koala (Phascolarctos cinereus) semen

Aim To determine the normal microbial flora of the koala ejaculate and prepuce in order to select appropriate antibiotics for addition into diluents designed for the preservation of semen.
Procedure Bacteriological samples of the koala prepuce (n = 12) and ejaculate (n = 20) were submitted for microbial culture and sensitivity testing. Microbial flora of ejaculates collected by electroejaculation and artificial vagina were compared. The effects of varying concentrations of penicillin G and gentamicin on sperm motility and on the growth of bacteria in diluted semen stored at room temperature and 16°C over a 24 h period were investigated.
Results A range of bacteria was isolated from the koala prepuce and ejaculate. The predominant organisms in semen collected by electroejaculation and artificial vagina were Corynebacterium spp, none of which could be assigned to any recognised species. The addition of penicillin G and gentamicin to a PBS-based diluent at dose rates of 1000 to 2000 IU/mL and 100 to 200 m g/mL respectively, resulted in no adverse effect on sperm motility over a 24 h incubation period. Penicillin G (1000 IU/mL) and gentamicin (100 m g/mL) prevented growth of bacterial contaminants in diluted koala semen.
Conclusion By controlling the growth of bacteria in extended koala semen, penicillin G and gentamicin are likely to lengthen the period by which spermatozoa can be stored at 16°C and reduce the possibility of disease transmission during artificial insemination procedures.     

Genital lesions associated with visceral leishmaniasis and shedding of Leishmania sp. in the semen of naturally infected dogs

Although visceral leishmaniasis is primarily transmitted by a biological invertebrate vector, transmission in the absence of the vector has been reported, including venereal transmission in humans. Considering the possibility of venereal transmission, we studied genital lesions in dogs naturally infected with visceral leishmaniasis and shedding of Leishmania sp. in the semen. Approximately 200 dogs were serologically tested for anti-Leishmania antibodies and divided into three groups: 1) serologically negative dogs (n = 20), 2) asymptomatic serologically positive dogs (n = 20), and 3) symptomatic serologically positive dogs (n = 20). Samples from both testes, all segments of both epididymes, prostate gland, glans penis, and prepuce were histologically evaluated and processed for immunodetection of Leishmania sp. Semen samples were obtained from 22 symptomatic serologically positive dogs and processed for detecting Leishmania DNA by polymerase chain reaction. A significantly higher frequency of inflammation was observed in the epididymes, glans penis, and prepuce of dogs with visceral leishmaniasis, which was associated with a high frequency of immunohistochemically positive tissues (up to 95% of tissues from symptomatic dogs were positive by immunohistochemistry). Leishmania DNA was detected in eight of 22 semen samples from symptomatic dogs. Together these findings indicate that genital lesions and shedding of Leishmania sp. (donovani complex) in the semen are associated with visceral leishmaniasis. Additional studies should address the possibility of venereal transmission of the disease in the dog.     

Evaluation of bacterial and protozoal contamination of commercially available raw meat diets for dogs

OBJECTIVE: To evaluate bacterial and protozoal contamination of commercially available raw meat diets for dogs. DESIGN: Prospective longitudinal study. SAMPLE POPULATION: 240 samples from 20 raw meat diets for dogs (containing beef, lamb, chicken, or turkey), 24 samples from 2 dry dog foods, and 24 samples from 2 canned dog foods. PROCEDURE: Each product was purchased commercially on 4 dates approximately 2 months apart. Three samples from each product at each sampling period were evaluated via bacterial culture for non-type-specific Escherichia coli (NTSEC), Salmonella enterica, and Campylobacter spp. Antimicrobial susceptibility testing was performed on selected isolates. Polymerase chain reaction assays were used to detect DNA from Cryptosporidium spp, Neospora spp, and Toxoplasma spp in samples obtained in the third and fourth sampling periods. RESULTS: One hundred fifty-three of 288 (53%) samples were contaminated with NTSEC. Both raw and prepared foods contained NTSEC during at least 1 culture period. Salmonella enterica was recovered from 17 (5.9%) samples, all of which were raw meat products. Campylobacter spp was not isolated from any samples. In 91 of 288 (31.6%) samples, there was no gram-negative bacterial growth before enrichment and in 48 of 288 (16.7%) samples, there was no aerobic bacterial growth before enrichment. Susceptibility phenotypes were variable. Cryptosporidium spp DNA was detected in 3 samples. CONCLUSIONS AND CLINICAL RELEVANCE: Bacterial contamination is common in commercially available raw meat diets, suggesting that there is a risk of foodborne illness in dogs fed these diets as well possible risk for humans associated with the dogs or their environments.     

Bacteriological findings in different fractions of canine ejaculates showing normospermia,teratozoospermia or azoospermia

Objective There is little available information on the distinction between physiological and pathological bacterial flora in dog semen, or in fractions of the canine ejaculate. In order to improve the diagnostic basis, the present study describes the bacteriological findings in canine semen samples. Design and procedure The ejaculates were assigned to three groups: Group A, normospermia (n = 30); Group B, teratozoospermia (n = 33); Group C, azoospermia (n = 29). Results Our data show that irrespective of semen quality, bacterial contamination and stronger bacterial growth is more common in the pre‐sperm fraction than in the other two fractions. The number of bacteria and bacterial species did not vary between the three fractions or the three groups of dogs. Bacteria regarded as potentially pathogenic (β‐haemolytic Streptococci, Escherichia coli variation haemolytica) could be isolated in every group, with β‐haemolytic Streptococci tending to occur more frequently in all ejaculate fractions from dogs with teratozoospermia. Conclusion These data emphasise that the first fraction is more contaminated with bacteria than the second and third fractions which may be due to bacteria ascending from the urethra. The use of a fractionated collection of canine ejaculates seems to be beneficial to reduce or prevent bacterial contaminations.     

Dog sperm swimming parameters analysed by computer‐assisted semen analysis of motility reveal major breed differences

Dogs have undergone an intensive artificial selection process ever since the beginning of their relationship with humans. As a consequence, a wide variety of well‐defined breeds exist today. Due to the enormous variation in dog phenotypes and the unlikely chance of gene exchange between them, the question arises as to whether they should still be regarded as a single species or, perhaps, they be considered as different taxa that possess different reproductive traits. The aim of this study was therefore to characterize some male reproductive traits, focusing on kinematic characteristics of dog spermatozoa from several breeds. Thirty‐seven dogs from the following breeds were used: Staffordshire Bull Terrier, Labrador Retriever, Spanish Mastiff, Valencian Rat Hunting Dog, British Bulldog and Chihuahua. Semen samples were obtained via manual stimulation and diluted to a final sperm concentration of 50 million/ml, and they were subsequently analysed by the computer assisted semen analysis (CASA‐Mot) ISAS^®v1 system. Eight kinematic parameters were evaluated automatically. All parameters showed significant different values among breeds and among individuals within each breed. The fastest sperm cells were those of Staffordshire Bull Terriers and the slowest were recorded in Chihuahuas. The intra‐male coefficient of variation (CV) was higher than the inter‐male CV for all breeds with the Staffordshire Bull Terrier showing the lowest values. When taking into consideration the cells by animal and breed, discriminant analyses showed a high capability to predict the breed. Cluster analyses showed a hierarchical classification very close to that obtained after phylogenetic studies with genome markers. In conclusion, future workers on dog spermatozoa should bear in mind major differences between breeds and realize that results cannot be extrapolated from one to another. Because sperm characteristics are associated with breed diversity, dogs may represent a good model to examine changes in reproductive parameters associated with selection processes.     

Dog parentage testing using canine microsatellites

Canine microsatellites, comprising one to four base pair repeated sequences, were identified as part of a project to generate a genetic linkage map of the dog. They have been used to assign parentage in a range of doubtful paternity cases, for example, all the pups in a litter from a bitch mated on different days to two different stud dogs were identified by DNA analysis to come from one dog only. DNA typing in another case was able to exclude a male dog as the father of a litter. DNA analysis can be of relevance by allowing pedigree dogs, which would have previously been excluded on the basis of unknown paternity, to be registered with the appropriate kennel club.     

Breed distribution of the ABCB1-1Delta (multidrug sensitivity) polymorphism among dogs undergoing ABCB1 genotyping

OBJECTIVE: To evaluate the breed distribution of the ABCB1-1Delta polymorphism in a large number of dogs in North America, including dogs of several herding breeds in which this polymorphism has been detected and other breeds in which this polymorphism has not yet been identified. DESIGN: Cross-sectional study. ANIMALS: 5,368 dogs from which buccal swab samples were collected for purposes of ABCB1 genotyping. PROCEDURES: From May 1, 2004, to September 30, 2007, DNA specimens derived from buccal swab samples collected from 5,368 dogs underwent ABCB1 genotyping. These data were reviewed, and results for each dog were recorded in a spreadsheet, along with the dog's breed. The genotypes for each breed were tallied by use of a sorting function. RESULTS: The ABCB1-1Delta allele was identified in 9 breeds of dogs and in many mixed-breed dogs. Breeds that had the ABCB1-1Delta allele included Collie, Longhaired Whippet, Australian Shepherd (standard and miniature), Shetland Sheepdog, Old English Sheepdog, Border Collie, Silken Windhound, and German Shepherd Dog (a breed in which this mutation had not been detected previously). CONCLUSIONS AND CLINICAL RELEVANCE: The ABCB1-1Delta polymorphism is associated with increased susceptibility to many adverse drug reactions and with suppression of the hypothalamic-pituitary-adrenal axis and is present in many herding breeds of dog. Veterinarians should be familiar with the breeds that have the ABCB1-1Delta polymorphism to make appropriate pharmacologic choices for these patients.     

昆明犬群体遗传结构及受选择基因分析

旨在以昆明犬为主要研究对象探究昆明犬-国内唯一培育并广泛使用的工作犬品种的遗传多样性和群体遗传结构。本试验共采集16头昆明犬(3个品系)、4头马里努阿犬、4头德国牧羊犬血样并提取基因组DNA，用Illumina CanineHD Beadchip芯片对24头3个品种犬进行主成分分析(PCA)、STRUCTURE和邻接(NJ)树分析，检测3个品种警犬的遗传群体结构，并分析昆明犬选育中可能受到选择的候选基因。结果显示，芯片数据根据质控标准最终有86 270个SNPs被筛选出来用于分析。STRUCTURE群体结构分析表明，K=2时德国牧羊犬(DM)和其他品种犬完全区分开来，K=3时马里努阿犬(ML)可以和其他两个品种区分出来，昆明犬中存在部分德国牧羊犬的杂合。PCA和NJ树分析均能将3个品种犬清楚地分开。通过在常染色体上设置500 kb的滑动窗口和将这些区域注释后得到22个在昆明犬品种形成过程中可能受到正选择的基因，主要是参与腺苷酸环化酶活化g蛋白偶联受体信号通路的基因及蛋白和在神经元轴突的生长锥中影响轴突和前导突起生长的基因。本研究探讨了中国昆明犬与其他品种犬的遗传关系,为昆明犬受到强烈的人工选择而产生调节学习、记忆、应激刺激等适应的遗传机制提供了重要的参考。     

Effects of Oxygen Exposure and Gentamicin on Stallion Semen Stored at 5 and 15°C

This study was undertaken to investigate the effects of storage of stallion semen in a defined milk protein extender at 5 and 15°C under either anaerobic or aerobic conditions, with or without addition of the antibiotic gentamicin. Semen samples were collected from eight fertile stallions and stored for 96 h (day 0–4) and assessed daily for motility, velocity and membrane integrity (viability) using a CASA system. Samples for bacteriology assessment were taken on day 2 of storage. No significant (p > 0.05) differences in motility, velocity or viability were observed between treatments on days 0–2. On days 3 and 4, semen stored without gentamicin at 5°C had a significantly (p < 0.05) better semen quality compared with storage at 15°C without gentamicin, irrespective of oxygen exposure. On days 3 and 4, motility and velocity were greater in samples stored at 15°C with gentamicin, compared with the corresponding treatments without antibiotic (p < 0.05). This effect was also evident for viability on day 4. The decline in semen quality observed at 15°C most likely resulted from the effect of bacterial growth. Bacterial growth was the greatest in samples stored at 15°C without gentamicin, under both anaerobic and aerobic conditions (p < 0.05). Bacterial growth was inhibited by adding of gentamicin at 15°C, which accordingly reduced the decline in semen quality. Addition of antibiotic to samples stored at 5°C had no significant effect on any parameter analysed. In conclusion, storage at 15°C can be achieved by using an extender containing the antibiotic gentamicin. Storage at 5°C tended to maintain better semen quality irrespective of oxygen exposure, and did not necessitate an antibiotic treatment.     

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.     

Evaluation of techniques for diagnosis of canine prostatic diseases

Bacterial culture and cytology of semen, bacterial culture and cytology of prostatic fluid washings, urinalysis, bacterial culture of urine, and blood leukocyte counts were performed on specimens from dogs with prostatic hyperplasia, chronic prostatitis, or prostatic neoplasia. Hemorrhage was the most frequent abnormal finding in semen from dogs with prostatic hyperplasia. Inflammation was the most frequent abnormal finding in dogs with chronic prostatitis. Bacterial culture of semen was sensitive but not specific for chronic bacterial prostatitis, due to false-positive results from urethral contamination. Hemorrhage was the most frequent abnormal finding in prostatic fluid washings from dogs with prostatic hyperplasia. Inflammation was the most frequent abnormal finding in dogs with chronic prostatitis. Abnormal epithelial cells were found after prostatic massage in 4 dogs with neoplasia, although these cells were difficult to identify as neoplastic. Prostatic fluid washings were not useful for detecting chronic bacterial prostatitis, due to an inability to detect increases in bacterial counts in the fluid when urine bacterial counts were high. Hematuria was the predominant abnormal finding in urinalysis from dogs with hyperplasia and neoplasia. Pyuria was the most frequent abnormal finding in dogs with chronic prostatitis. Urine was usually culture-positive when there was prostatic infection. Blood leukocyte counts were normal in dogs with prostatic hyperplasia and usually normal in dogs with neoplasia. Leukocytosis, a left shift, and toxic white blood cells were predictive of abscessation, although the blood leukocyte count was not a very sensitive indicator for infection without abscessation.     

A review of official data obtained from dog control records generated by the dog control service of county cork, Ireland during 2007

ABSTRACT: BACKGROUND: There are no peer reviewed data on dog control records from an official agency in Ireland. In order to address this, a total of 2,669 official dog control service records generated during 2007 by Cork County Council dog control service were reviewed. RESULTS: Over 70 percent of records related to unwanted dogs and dogs not under their owners control. Stray dogs were collected by the service regularly throughout the year but with notable increase in voluntary surrenders by owners from January through to April. The majority of dogs collected or surrendered were male (2:1 ratio), of medium size, described as having a friendly temperament and were not wearing a neck collar. The Crossbreed and Greyhound breeds were more frequently collected as strays, while Greyhounds and German Shepherds were more frequently voluntarily surrendered by their owner. Restricted breeds such as Pit Bull terriers, German Shepherds and Rottweilers were more frequently reported by members of the public for aggressive behaviour while the only restricted breed reported for biting or snapping was the German Shepherd. CONCLUSIONS: Routine recording of dog control services in County Cork provide data on responsible dog ownership including the licensing of breeds, and surrender of owned dogs and the collection of stray dogs. Data capture and utilisation of dog control services by local authorities has potential to inform policy on responsible dog ownership and education programmes.     

Assessment of infectious organisms associated with chronic rhinosinusitis in cats

OBJECTIVE: To determine detection rates for feline herpesvirus type 1 (FHV-1), Mycoplasma spp, fungi, and bacteria in flush samples and biopsy specimens from the nasal cavities of cats with and without chronic rhinosinusitis (CRS). DESIGN: Prospective study. ANIMALS: 10 CRS-affected cats and 7 cats without signs of respiratory tract disease. PROCEDURES: Nasal flush samples and biopsy specimens were collected from all cats for bacterial (aerobic and anaerobic), fungal, and mycoplasmal cultures; additional biopsy specimens were collected for virus isolation and polymerase chain reaction (PCR) assay (to detect FHV-1 DNA). RESULTS: Aerobic bacteria were detected in flush samples from 5 of 7 control cats; culture of flush samples from CRS-affected cats yielded aerobic bacteria (9/10 cats), anaerobic bacteria (3/10), and Mycoplasma spp (2/10). No fungal organisms were isolated from any cat. Potential pathogens were isolated significantly more often from CRS-affected cats than from control cats. Bacterial culture of biopsy specimens yielded aerobic bacteria (2/7 control cats and 4/10 CRS-affected cats) and anaerobic bacteria (2/10 CRS-affected cats). Although FHV-1 was not detected in nasal biopsy specimens from control or CRS-affected cats, FHV-1 DNA was detected via PCR assay in specimens from 4 of 7 control cats and 3 of 10 CRS-affected cats. CONCLUSIONS AND CLINICAL RELEVANCE: Compared with findings in control cats, anaerobic bacteria, Mycoplasma spp, and a variety of potentially pathogenic organisms were detected more commonly in samples from cats with CRS. In both groups, FHV-1 was detected via PCR assay as a nonviable organism or in noncultivable amounts.     

Evaluation of the bacterial microflora of the conjunctival sac of healthy dogs and dogs with atopic dermatitis

The aim of this case–control study was to evaluate and compare the bacterial microflora from the conjunctival sac of dogs with atopic dermatitis and healthy dogs. Twenty‐one atopic dogs without clinical and/or cytopathological signs of bacterial blepharoconjunctivitis and 21 breed‐matched healthy dogs were enrolled. Under topical anaesthesia, the inferior conjunctival sac of one eye was scraped twice. Material was collected with a Kimura spatula, spread over a slide and stained with a Diff Quick^®‐type stain (Medion Diagnostics GmbH, Düdingen, Switzerland) for cytological examination. An area of 0.5 cm² was examined at ×1000 magnification, and the types and numbers of cells and bacteria were recorded. A bacterial swab was collected and inoculated into culture media for the growth of aerobic bacteria. Before sampling, each atopic dog was evaluated for severity of cutaneous lesions, pruritus and conjunctival inflammation. Significant differences were observed between atopic and healthy dogs for the presence of bacteria on cytology (P = 0.015), keratinized (P = 0.001) and nonkeratinized epithelial cells (P = 0.013), eosinophils (P = 0.019) and lymphocytes (P = 0.008). Bacteria were recovered from 12 atopic dogs and three healthy dogs (P = 0.004). Staphylococcus pseudintermedius was the most commonly isolated species in atopic dogs (seven of 12). In atopic dogs, no significant relation was found between conjunctival bacterial colonization (on cytology and culture) and the severity of any of the clinical parameters. This study suggests differences in conjunctival bacterial colonization and cytological features between atopic and healthy dogs.     

Evaluation of the presence of selected viral and bacterial nucleic acids in pericardial samples from dogs with or without idiopathic pericardial effusion

Many viruses have been identified in pericardial fluid and in tissue samples from humans with pericarditis by means of molecular diagnostics. In canine idiopathic pericardial effusion there is as yet no conclusive evidence to support the involvement of an infectious agent. This study was designed to investigate a possible relationship between idiopathic pericardial effusion in dogs and viruses most commonly encountered in humans affected with viral pericarditis. Coxsackievirus B3 RNA, influenza virus type A RNA, human adenovirus type 2 DNA, human cytomegalovirus DNA, and parvovirus B19 DNA were investigated using PCR on pericardial effusion samples and pericardial tissue specimens collected from 14 dogs with idiopathic pericardial effusion. PCR was also used to test for two bacteria, Borrelia burgdorferi and Chlamydia pneumoniae. The same microorganisms were also looked for in pericardial effusions or pericardial washes from 10 dogs with neoplastic pericardial effusion, and in samples collected from 10 dogs which died of a non-cardiac disease. One pericardial effusion sample from a dog with the idiopathic form of the disease tested positive for influenza virus type A and sequencing of the amplicon confirmed the PCR result. In another dog from the same group a cytomegalovirus was detected by PCR in the effusion, but sequencing showed this to be a false-positive result. The genomes of the microorganisms investigated were not detected in neoplastic effusions or pericardial washes. The results indicate that viral and bacterial DNA/RNA of relevance for human pericarditis is rare in pericardial samples from dogs with idiopathic pericardial effusion. The finding of influenza type A viral RNA in pericardial fluid from one dog with the idiopathic form of the disease warrants further investigation.     

Assessment of the qualitative variation in bacterial microflora among compartments of the intestinal tract of dogs by use of a molecular fingerprinting technique

OBJECTIVE: To evaluate the qualitative variation in bacterial microflora among compartments of the intestinal tract of dogs by use of a molecular fingerprinting technique. ANIMALS: 14 dogs (similarly housed and fed identical diets). PROCEDURE: Samples of intestinal contents were collected from the duodenum, jejunum, ileum, colon, and rectum of each dog. Bacterial DNA was extracted from the samples, and the variable V6 to V8 region of 16S ribosomal DNA (gene coding for 16S ribosomal RNA) was amplified by use of universal bacterial primers; polymerase chain reaction amplicons were separated via denaturing gradient gel electrophoresis (DGGE). Similarity indices of DGGE banding patterns were used to assess variation in the bacterial microflora among different compartments of the intestine within and among dogs. Bacterial diversity was assessed by calculating the Simpson diversity index, the Shannon-Weaver diversity index, and evenness. RESULTS: DGGE profiles indicated marked differences in bacterial composition of intestinal compartments among dogs (range of similarity, 25.6% to 36.6%) and considerable variation among compartments within individual dogs (range of similarity, 36.7% to 579%). Similarities between neighboring intestinal compartments were significantly greater than those between non-neighboring compartments. Diversity indices for the colon and rectum were significantly higher than those of the duodenum, jejunum, and ileum. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that the different intestinal compartments of individual dogs appear to host different bacterial populations, and these compartmental populations vary among dogs. In dogs, fecal sample analysis may not yield accurate information regarding the composition of bacterial populations in compartments of the gastrointestinal tract.     

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.     

Bacterial overgrowth in the duodenum of dogs with exocrine pancreatic insufficiency

Bacterial overgrowth (greater than 10(5) colony-forming units/ml duodenal juice) in the duodenum was demonstrated in 8 of 11 dogs with exocrine pancreatic insufficiency (EPI). In 4 of these 8 dogs, the overgrowth included large numbers (greater than 10(4) colony-forming units/ml) of obligate anaerobic bacteria and was associated with decreased activities of several brush border marker enzymes and, in 2 dogs, with partial villous atrophy in the jejunum. Changes in the jejunal mucosa of the remaining dogs (with either no overgrowth or overgrowth of aerobic bacteria alone) were characterized by increased activities of some brush border disaccharides and of lysosomal hydrolases. One dog was euthanatized without treatment, at the owner's request. The response of 4 of the remaining 10 dogs treated with enzyme replacement alone was poor or suboptimal, and all of these 4 dogs had bacterial overgrowth. One of these dogs had an excellent clinical response when also given oxytetracycline orally for 14 days, but the other 3 dogs did not improve further in response to the same treatment. It was concluded that bacterial overgrowth in the duodenum is common in dogs with EPI and that, when such overgrowth includes large numbers of obligate anaerobes, there may be associated biochemical and morphologic abnormalities in jejunal mucosa. Functional disturbances related to abnormal intestinal microflora may be responsible for the failure of some dogs with EPI to respond fully to oral pancreatic enzyme supplementation without antibiotic therapy.