LaVonne D. Meunier, Bonnie V. Beaver, in Laboratory Animal Welfare, 2014
Dogs
Purpose-bred dogs have the advantage of being able to be raised with scripted experiences, and it is this variety of social and physical stimuli that builds confidence for coping strategies. Handling puppies between birth and weaning has been reported to have effects on many characteristics, including rate of growth and weight gain, learning, exploratory behavior, emotionality, physiology, response to food and water deprivation, and the occurrence of some diseases or pathogens (Committee on Pain and Distress in laboratory Animals, 1992). It is particularly critical for puppies to be socialized to people and other dogs and to be acclimated to a variety of environments from 3 to 12 weeks of age (Scott and Fuller, 1965). Reinforcement of socialization and acclimation should be an ongoing process because dogs have been known to show behavioral regression when older (Boxall et al., 2004).
Young puppies have a strong developmental need for close, sustained social contact with conspecifics (Scott and Fuller, 1965), and this should be easily met at a breeding facility as long as there are no health problems with the puppy, mother, or littermates. If a puppy does need to be separated from its mother or littermates, procedures should be in place to provide human socialization and limit as much as possible the time it is separated. Puppies should have separation experiences early in their development, preferably in a familiar area with no physical restraint too. Dogs tend to become excessively reactive when they are finally exposed to separation from littermates (Elliot and Scott, 1961), so incremental separations can be less stressful.
Another important part of training for puppies is to learn to have confidence in the leadership of people as part of their social structure. Just as puppies learn to be controlled by their mothers, animal care staff must also teach them to accept human control in a nonthreatening way. It can be helpful to assess how well puppies accept human interaction and control (Meunier, 2006; Wolfle, 1990).
For older dogs acquired from random-source dealers, the long-term background information is unknown. Temperament evaluations will be the major determination regarding the dog’s suitability for use in a laboratory setting. Unfortunately, temperament tests are not well standardized or reliable, but general traits can be assessed (Beaver, 2009). Relaxed, nonaggressive, and adaptable dogs are preferred.View chapterPurchase book
Cloning of Canines
Byeong Chun Lee, in Principles of Cloning (Second Edition), 2014
History of Dog Cloning
Dog cloning began with large breed dogs. “Snuppy,” the first cloned dog, was born in 2005 using a donor cell from a male Afghan hound, and the results, entitled “Dogs cloned from adult somatic cells,” were published in the journal Nature (Lee et al., 2005). The first cloned dog was achieved using an in vivo matured oocyte, which was enucleated and then fused with an adult skin cell of the donor dog. The following year, three female cloned Afghan hounds were born (Jang et al., 2007), and we monitored their growth and assessed their reproductive ability by artificial breeding with “Snuppy.” From these studies, we proved that both male and female dogs can be cloned by SCNT, and also that they possess normal reproductive abilities (Park et al., 2010). In 2006, a cloned toy poodle was produced from a 14-year-old donor (Jang et al., 2008). A donor fibroblast cell was injected into the enucleated oocyte of a large breed dog. After fusing the somatic cell of the small breed dog and the oocyte of the large breed dog, the reconstructed SCNT embryos were transferred to an oviduct of a large breed dog. In this way, we showed that large breed dogs can be used as oocyte donors and as surrogate mothers to clone a small breed dog (Jang et al., 2008). In the same year, two female cloned beagles were produced from fetal fibroblasts using a large breed recipient (Hong et al., 2009a). From these studies, it was demonstrated that dog fibroblasts taken from the fetal stage up to old age can be reprogrammed by SCNT. In 2006 and 2007, cloned female (Kim et al., 2007) and male wolves (Oh et al., 2008) were successfully produced via interspecies SCNT; this result implied that the dog cloning technique has potential for conservation of canine species in extreme situations, including sudden death. Seven cloned drug-sniffing dogs were produced in 2007 from a dog having this distinct talent (Oh et al., 2009). Subsequently, a cancer-sniffing dog was propagated by SCNT in 2008 (Park et al., 2009a), and a quarantine dog to detect an agricultural item in 2012 (Oh et al., 2013). Cloned drug-sniffing dogs, cloned cancer-sniffing dogs, and cloned quarantine dogs have now been validated, having performed these duties in the field. These results indicate that canine SCNT techniques have possibilities for producing dogs with outstanding abilities. Lastly, a cloned dog was produced that continuously expressed the red fluorescent protein (RFP) gene (Hong et al., 2009b), and another that conditionally expressed the green fluorescent protein (GFP) gene (Kim et al., 2011). It was proved by germline transmission using natural breeding that these cloned dogs were transgenic.
Dogs have now been cloned for the past 8 years; a lot of history has been made, and no doubt canine SCNT techniques will continue to find applications in a wide variety of fields in the future.View chapterPurchase book
Canine Genomics and Genetics☆
Elaine A. Ostrander, Falina Williams, in Reference Module in Life Sciences, 2019
Breeds and Population Structure
The largest registering body of dog breeds in the world is known as the Fédération Cynologique Internationale, which recognized 339 breeds as of 2013. The 339 breeds are divided into 10 groups based upon appearance and/or behavior and function. Other niche populations exist or are “in process” and technically, if not formally, meet the definition of a breed, yielding estimates of over 500 domestic dog breeds worldwide.
The American Kennel Club (AKC) currently recognizes 189 breeds with many, but not all, selected on the basis of appearance. To become a registered breed, the breeding population must not only conform to the established standards regarding body conformation and behavior, but those changes must “breed true.” That is, a cross between members of the breed should produces puppies that meet the same standards as the parents. For a single individual to be registered with the breed, the dog must have had parents who were registered members of the same breed. Recent molecular studies using a large array of SNPs have provided considerable insight as to how dog breeds relate one to another, hinting at how many breeds likely developed (Fig. 1).
