Animal Breeding, Welfare and Ethics Flashcards
Selective breeding - history.
- Originally, specific breeds of dog were developed to enhance traits that made them suitable for particular tasks or jobs, e.g. to run fast, guard, point, retrieve.
- Towards the end of the 19th century the focus changed to breeding for particular aesthetic traits, i.e. appearance and what was considered to be attractive and appropriate from the human perspective.
- Selective breeding to produce desired traits can have positive and negative outcomes.
Benefits of selective breeding.
- Selective breeding maintains a variety of breeds.
- Using dogs as an example, the diversity of breeds show variation in appearance, temperament, function and utility.
- The ability, to some extent, to predict behaviour (although environment will be a significant contributing factor).
- Many different breeds have been bred that demonstrate abilities and characteristics favourable to humans, e.g. tracking dogs, assistance dogs.
- Selective breeding can be used to help eliminate specific disease, e.g. Canine Leukocyte Adhesion Deficiency (CLAD), a fatal immunodeficiency disease in Irish Setters.
Selective breeding can result in –
Ill health due to inappropriate selection during breeding can also impact on the owner’s quality of life in terms of owning an animal with medical problems, the consequent veterinary treatment and the potential for an animal dying younger than expected.
• Morphological Extremes.
• Physical conformation that can result in disability or pain and behavioural problems.
• Increased prevalence of certain inherited disorders as a result of reduced
genetic diversity.
• High rates of heritable disease (therefore, illness becomes more common).
• Behavioural concerns.
• Significantly lower life expectancy than crossbreeds.
Breed standards.
• In the UK and many other countries the breeding of pedigree dogs follows breed standards, defined and
often controlled by breed societies.
• Breed standards often focus on aesthetics rather than health and welfare.
Potential owners often use a puppies “pedigree” as a gauge of the “quality” of the dog.
inherited disorders as a result of reduced genetic diversity.
- Many breeds were established on the basis of a few individuals and problems intensify when breeding with a small number of “high quality” sires.
- Little attention is given to progeny evaluation within companion animal breeding in contrast to breeding of farm animals or horses.
- As a consequence, predispositions for certain diseases are seen in specific breeds (see examples).
Behavioural concerns in selective breeding
- If the focus for breeding animals is appearance, there is a risk that behavioural problems will be more prominent in pedigree animals.
- There is growing evidence that puppies can inherit less than desirable genetic behavioural traits from parents, for example -
- Noise sensitivity - linked to information processing by researchers in the USA.
- Nervousness.
- A higher propensity for anxiety and stress when presented with novel environmental stimuli.
- Idiopathic aggression (i.e. aggression there is no clear cause for) toward other dogs and/or people.
Boxer health problems
- Cancer - Boxers are very prone to several different kinds of cancer which reduces their life expectancy.
- Heart disease - Many boxers develop dilated cardiomyopathy often requiring lifelong medication.
- Brachycephalic Obstructive Airway Syndrome.
Dalmatian health problems
- Dilated cardiomyopathy (heart disease) - This can cause fainting, tiredness and other signs of heart disease
- Congenital deafness – Statistically significant proportion of puppies are born deaf.
- Bladder stones - Many Dalmatians have an abnormality that causes them to produce a certain kind of stone in their bladder causing pain, recurrent infections and often requires surgery for removal.
- Atopic dermatitis (atopy) - chronic itchiness and the consequent scratching can cause skin damage leading to skin infections.
Shar Pei health problems
- Chronic skin infections - A Shar Pei’s many skin folds provide a hot and humid environment for bacteria and yeast growth, consequently, Shar Peis often suffer from repeated skin infections throughout their life causing irritation and distress to the dogs.
- Elbow dysplasia.
- Hip dysplasia.
- Atopic dermatitis (atopy)
- Entropion (ingrowing eyelashes) - The shape of the eyelids causes the eyelashes to grow inwards and scrape the surface of the eye.
- Painful and can lead to eye ulcers, often requiring corrective surgery.
Munchkin health problems
.
• The Munchkin has abnormally short fore and hind limbs similar to those of the canine breeds of Dachshund and Bassett hound.
• The breed standard promotes short limbs as a key feature of the Munchkin breed although breed standards allow hind legs to be longer than forelegs.
• Whilst the welfare compromises have not been fully explored in the Munchkin breed, it is known that animals that experience abnormal stresses and loads on joints are predisposed to developing osteoarthritis and consequent long-term pain.
Scottish Fold health problems
- Originated in Scotland in the 1960s from matings of a cat with a naturally occurring mutation in which its ears folded forward, to local farm cats and British Shorthairs.
- The folding of the ear is due to osteochondrodysplasia which is a developmental abnormality of the cartilage that can affect the whole of the body.
- Cats that are homozygous for the abnormal gene develop a progressive, crippling arthritis early in life.
- Affected cats may be grossly deformed, with short wide limbs, a short, inflexible tail, lameness, swollen carpal and tarsal joints, abnormal gait and are reluctant to move and jump.
- Severely affected individuals become crippled and unable to walk.
- Excluded from the Cat Fancy of Great Britain’s list of recognised breeds in 1974 due to the crippling deformity of the limbs and tail that was evident in the breed.
Oriental Shorthairs/Siamese health problems
- Excessive prolongation of the face with the resulting deep eye socket may predispose to ocular infections and motility disorders of the eyelids.
- Mediastinal lymphoma – coughing and breathing difficulties.
- Asthma - coughing, laboured and/or fast breathing, noisy breathing, wheezing.
- Progressive retinal atrophy - genetic eye problem which causes progressive blindness.
- Hip dysplasia.
- Systemic amyloidosis – protein is deposited abnormally in various organs such as the liver, kidneys and intestines which can lead to liver or kidney failure.
Persian health problems
.
• Brachycephalic - Breathing difficulties, dental disease, difficulties in grooming, irritation and ulceration of the eyes and face.
• Chediak-Higashi syndrome - impairment in how the body manages waste substances within cells - leads to partial albinism, sensitivity to light, cataracts, impaired immune function and prolonged blood clotting times.
• Dermatophytosis (ringworm) – predisposed and suffer more severe and prolonged forms - thought to be due to abnormally long coat, which is caused by homozygosity of a mutant gene.
Urinary tract calcium oxalate stones – more common in the female, stones can irritate, inflame and damage the bladder or urethral walls leading to pain, uti and obstruction.
• Portosystemic Shunt - abnormality of the circulation in which venous blood from the intestines partially by-passes the liver leading to waste product accumulation and toxic effects on the body – low growth rates, depression, muscle tremors, drooling, head- pressing, chronic malaise, chronic pain, brain damage, coma and death.
• Polycystic Kidney Disease - genetic fault in kidney cell development leading to multiple cysts forming in the kidneys leading to kidney failure.
Assessing the problem of selective breeding Welfare perspective.
• When assessing a welfare problem, in order to determine how serious a compromise we are dealing with we usually assess the severity of the problem, duration of the problem and numbers of animals affected.
• Severity – health issues with pedigree breeds can be significant and life-limiting and quality of life is reduced.
• Duration – Effects can be long-lasting (often whole of life).
• Numbers of animals affected – Very large numbers of animals affected – approximately 6
million pure-bred dogs in the UK (75 % of the overall population).
• Dogs and cats of specific breeds have a very high likelihood of being denied one of the five freedoms.
Assessing the problem of selective breeding Moral perspective.
- Deliberately breeding animals with a high propensity to suffer is ethically unsound.
- Breeding animals with a propensity to suffer is unnecessary and could be avoided.
- Most dog-breeding and showing is a hobby and therefore, not strictly necessary.
- Historically, we have grown accustomed to the idea that certain breeds have “their problems” and as a society we generally have not considered this to be a major problem.
- Family pets becoming ill and dying earlier than necessary can have significant impact on the wellbeing of the owners.
