Pure Bred Pets
There’s been a bit of publicity and media attention lately on the TV concerning the potential problems associated with pure-bred animals. I thought I would take the opportunity to discuss what all the fuss is about.
In a nutshell, anytime you reduce the genetic diversity in a population of living creatures you increase the chance of unfavorable combinations of genes coming together and allowing inherited disease or faults to manifest themselves in the off-spring. Thus, diseases like diabetes, heart disease or chronic allergies may greatly increase in frequency in some groups or breeds of animals.
As well as actual disease, other consequences of a small genetic pool may include decreased fertility and a less effective immune system with increased suceptibility to infectious diseases such as Demodectic Mange or Parvo virus.
Related to such problems is the situation where a population, or breed, is selected for certain physical or behavioral characteristics which in some cases can: 1) directly interfere with the animal’s physical well being (for example in short muzzled animals their respiratory capacity can be affected) or 2) may predispose the animal to related problems (e.g.: Giant breeds of dog have a higher risk of certain types of fatal bone cancer).
Generally, extremes of body type (Giant, Miniature, Short faced, Short legged, unusual tail shape etc) will predispose to a raft of related problems.
It follows then, that if a species (e.g. dog) has a range of breeds that are produced by selective breeding from a small number of individuals, and /or the characteristics of that breed involve unusual or extreme variations of body-type compared to their ancestral origins, that those breeds will have an increased predisposition for various diseases, behavioural traits, dysfunctions and malformations.
It’s a ‘no brainer’ really. In human terms, consider some members of the British Royal family…
Conversely, in cross bred animals we generally see less congenital or inherited disease and healthier, longer-lived animals. ‘Hybrid vigour’, is a term that describes this phenomenon in a commercial situation like cattle breeding.
There’s no black and white to all this, and none of this means that all pure breeds are basket cases or that all cross breeds are healthy, but is does pay to be aware of some of the common inherited problems when choosing your future pet.
Currently the Australian Veterinarian Association along with many others are working to improve breed strength and identify and reduce potential problems. There’s a way to go but good progress has been made in many areas.
For more information you should visit www.ava.com.au and check out their media release on the topic. It’s an emotive issue of course, and a complex one, but recognizing the problem goes a long way to eventually sorting it out. Here’s hoping!
Bye now! Evan, Lennox Head Vet Clinic