Prevalence of Swimming Puppy Syndrome in 2,443 Puppies during the Years 2006-2012 in Thailand

The most common congenital malformations in dogs: Literature review and practical guide

Congenital malformations can affect almost 7% of canine newborns. The increase of commercial dog breeding and inbreeding used to maintain the striking characteristics of each breed, the appearance of malformations has become increasingly common, especially in brachycephalic dogs. The causes are diverse, and include genetic, nutritional, iatrogenic, and infectious factors, often making it difficult to establish a cause-consequence relationship. The high mortality associated with malformations comes not only from the fact that some are incompatible with life, but also because even if many undergo surgical treatment or correction, they require specific management, monitoring, and clinical treatment for an indefinite period of time. The most common malformations such as cleft lip and palate, hydrocephalus and anasarca have been studied for a long time, and it is currently known that brachycephalic dogs have a greater predisposition, however, for other less common conditions as gastroschisis and hypospadias, there is only a few case reports. The appearance of congenital defects in a litter leads to financial losses for the breeder, emotional losses for the owner and the veterinarian and harms the well-being of that individual. For this reason, the aim of this review article is to gather relevant information on the characteristics, diagnosis, and management of the main malformations in puppies. It is essential that the veterinarian is prepared to diagnose and treat these conditions, reducing negative impacts on animals and owners.

A questionnaire-based investigation of the swimming puppy syndrome: 115 dogs

Swimming Puppy Syndrome (SPS) is a benign reversible condition of unknown etiology in multiple dog breeds. Affected dogs show laterally abducted limbs and are unable to stand and walk on their own. The current knowledge of this condition derives from few case reports or small case series. Therefore, the aim of this study was to collect data on the clinical course from a large cohort of dogs with SPS with an online questionnaire supported by video footage. Potential risk factors were compared between 110 litters with SPS and 103 unaffected litters. SPS was reported in 115 dogs from 48 different breeds comprising a wide range of small, middle, and large breeds. Litters with SPS were significantly smaller than unaffected litters. Cesarean sections were reported more frequently in affected litters, but the overall rate of reported birth complications did not differ significantly from unaffected litters. Most puppies were able to stand and walk at a median age of 4.5 weeks (up to 12 weeks) and clinical signs resolved at a median age of six weeks (up to 12 weeks). Puppies from large breeds showed faster recovery than puppies from medium and small breeds. Occasionally, residual deficits were reported and only three dogs failed to recover. A clustering of SPS occurred in closely related litters in four kennels of four different dog breeds (Greater Swiss Mountain Dog, Golden Retriever, Miniature Bull Terrier, Norwich Terrier). The study shows the benign clinical course of SPS in a large cohort of puppies from multiple dog breeds. Potential risk factors including reports on birth complications, size and muscle mass compared to littermates and diet of the dam during pregnany were evaluated and no influence on the occurrence of SPS was identified.

Two Types of Management for the Noninvasive Treatment of Pectus Excavatum in Neonatal Puppies-Case Reports

Pectus excavatum is a deformity of the thorax characterized by ventrodorsal narrowing of the sternum bone and costal cartilages, which can lead to compression and cardiopulmonary alterations in dogs, presenting a high prevalence in brachycephalic breeds. The aim of this report was to describe two types of management for the noninvasive treatment of pectus excavatum in newborn puppies of the breeds French Bulldog and American Bully. The puppies presented dyspnea, cyanosis and substernal retraction during inspiration. The diagnosis was performed by physical examination and confirmed by chest X-ray. Two types of splints were performed (a circular splint with plastic pipe and a paper box splint on the chest), aiming at thoracic lateral compression and frontal chest remodeling. The management was effective for the conservative treatment of mild-grade pectus excavatum, resulting in the repositioning of the thorax and improvement of the respiratory pattern.

Factors contributing to the swimmer puppy syndrome found in Labrador retrievers

Background

Swimmer puppy syndrome is a disease found in neonatal puppies mainly characterized by the inability to stand, but its direct cause is unknown. Since swimmer puppies were observed infrequently but continuously among the Labrador retriever colony at the Hokkaido Guide Dogs for the Blind Association in Japan, based on their birth record and pedigree, factors related to the onset of swimmer puppy syndrome in Labrador retrievers were examined.

Results

The total number of offspring over seven years was 436, of which 16 were swimmer puppies. Most of the affected puppies except one recovered steadily. As for the swimmer puppies, the litter size was significantly lower, and the body weights on the 10th and 28th day after delivery were significantly higher than the non-symptomatic puppies. These results suggested that the onset may be related to weight gain in the neonatal stages due to a small litter size. According to the genetic analysis, 26 ancestors common to the affected individuals were confirmed, but the causative individual could not be identified with the inbreeding coefficient. The heritability of the swimmer-puppy onset trait was 0.80, and the heritability for the the 10th-day body-weight trait was equally high at 0.78, both of which strongly suggest genetic involvement.

Conclusions

In this study, the onset of swimmer puppy syndrome in the Labrador retrievers was associated with litter size and early weight gain, and result of study suggests that genetic influence might be involved.

A genetic assessment of the English bulldog

Background

This study examines genetic diversity among 102 registered English Bulldogs used for breeding based on maternal and paternal haplotypes, allele frequencies in 33 highly polymorphic short tandem repeat (STR) loci on 25 chromosomes, STR-linked dog leukocyte antigen (DLA) class I and II haplotypes, and the number and size of genome-wide runs of homozygosity (ROH) determined from high density SNP arrays. The objective was to assess whether the breed retains enough genetic diversity to correct the genotypic and phenotypic abnormalities associated with poor health, to allow for the elimination of deleterious recessive mutations, or to make further phenotypic changes in body structure or coat. An additional 37 English bulldogs presented to the UC Davis Veterinary Clinical Services for health problems were also genetically compared with the 102 registered dogs based on the perception that sickly English bulldogs are products of commercial breeders or puppy-mills and genetically different and inferior.

Results

Four paternal haplotypes, with one occurring in 93 % of dogs, were identified using six Y-short tandem repeat (STR) markers. Three major and two minor matrilines were identified by mitochondrial D-loop sequencing. Heterozygosity was determined from allele frequencies at genomic loci; the average number of alleles per locus was 6.45, with only 2.7 accounting for a majority of the diversity. However, observed and expected heterozygosity values were nearly identical, indicating that the population as a whole was in Hardy-Weinberg equilibrium (HWE). However, internal relatedness (IR) and adjusted IR (IRVD) values demonstrated that a number of individuals were the offspring of parents that were either more inbred or outbred than the population as a whole. The diversity of DLA class I and II haplotypes was low, with only 11 identified DLA class I and nine class II haplotypes. Forty one percent of the breed shared a single DLA class I and 62 % a single class II haplotype. Nineteen percent of the dogs were homozygous for the dominant DLA class I haplotype and 42 % for the dominant DLA class II haplotype. The extensive loss of genetic diversity is most likely the result of a small founder population and artificial genetic bottlenecks occurring in the past. The prominent phenotypic changes characteristic of the breed have also resulted in numerous large runs of homozygosity (ROH) throughout the genome compared to Standard Poodles, which were phenotypically more similar to indigenous-type dogs.

Conclusions

English bulldogs have very low genetic diversity resulting from a small founder population and artificial genetic bottlenecks. Although some phenotypic and genotypic diversity still exists within the breed, whether it is sufficient to use reverse selection to improve health, select against simple recessive deleterious traits, and/or to accommodate further genotypic/phenotypic manipulations without further decreasing existing genetic diversity is questionable.