I love all dogs… I love purebreds and knowing in general what to expect makes me feel more prepared. I like the traditional Heinz 57 (true mutt and a classic). I am also learning about this new trend of “designer dogs”. A designer dog is NOT a hybrid. Hybrids are a species cross like a dog to a wolf.
Before getting a purebred educate yourself on what it takes to train and care for a dog. Next, look into the breed specifics. Some breeds have more health issues than others. Each breed has certain characteristics that make it unique.
Before getting a Heinz 57 again look into training and what it takes to care for a dog. Understand this dog may have many breed traits and characteristics. Although there is a chance this dog may be healthier—it is not a guarantee.
Before getting a “designer dog” look up training and general care of owning a dog. However, educate yourself and understand that this dog may have characteristics of each breed and some traits may conflict with each other. Understand that this dog may have all or some health issues from every breed that was used to create this “designer dog”. Just because someone breeds two or more breeds together does not mean they have cancelled out certain breed traits or health issues. Putting two breeds together may result in health issues from both breeds and traits from both breeds.
One of the things designer breeders have started doing is crossing a merle patterned dog with another breed. Caution: The MERLE patternis a neat “look” however most people with any background and research on this color will know that it comes with its own set of health issues because of the gene that causes this pattern is flawed. According to the American Dog Breeders Association and other sources, Health issues associated with the merle allele. The (M) allele is an excellent example of pleiotropy, the phenomenon where a single allele can cause distinct and seeming unrelated physical effects. Even in the heterozygous (Mm) dog the (M) allele is associated with deafness, eye defects, and problems with the dogs immune system. This can be explained by understanding a little bit about the early fetal development of the dog. FYI:Merle is NOT a color that Miniature Schnauzers come in unless a breeder has introduced an Aussie or Pom. In addition, MS are to NEVER have any eye color but brown and in some cases hazel with Liver.
The process of coloration and color pattern in dogs begins with embryonic development. The specific cells that become the pigment producing cells come entirely from the same area of the embryo (neuronal crest) that the cells of the nervous system come from. It stands to reason, that if you have defects in genes associated with color genetics you can have nervous system defects because both cells are derived from the same neuronal crest. This can explain why it is likely that certain dilute or patterned dogs, such as extreme piebalds, albinos, etc. as well as those that have the merle allele are prone to sensory, neurological and /or immunological problems. These defects have been observed and researched in other dog breeds (i.e. Australian Shepherds, Great Danes, Shetland Sheepdogs) that also carry these dilution alleles including the merle allele.
From this research it has been determined that the merle allele when expressed in the homozygous state (MM) is highly correlated to sensory, neurological and immune system defects in dogs. Some include distortion of the eye’s appearance, lack of the reflective substance (tapetum lucidum) that lines the back of the dog’s eye. Dogs that lack this substance have night blindness and other visual problems. Other eye problems have been identified with the merle allele includes small eyeballs, with prominent third eyelids, and a physical cleft in the iris of the eye. Abnormalities of the eyes are a key indicator of other neurological defects. Deafness or a reduction in hearing has also been identified, as the merle color locus exerts effects on ear development. Excessive white or dilution in a dog of any color can be a warning sign of hearing problems. From talking to breeders who’s lines contain merle dogs, they relate that they are very aware of the potential health problems (sometimes being lethal to the affected pups). So not only will the dog possibly suffer as a result of this gene that creates merle coloring but also suffer from its breeds health issues as well. Source: http://www.adbadog.com/p_pdetails.asp?fspid=47
Conclusion: No matter what kind of dog you bring home… it will need trained, it will need vet care, and it will need love and attention. Any dog can have health issues but some may be more prone to them than others because it is breed related or something else. You can be prepared by educating yourself on the options between a Purebred, a Mutt, or the new 'Designer' fads.