Inbreeding in dogs can lead to a host of health and behavioral issues. If you suspect your dog may be the product of inbreeding, this guide will walk you through the telltale signs, risks, and what to do if your dog is inbred.
If you’re short on time, the main signs of an inbred dog include physical abnormalities, smaller litter sizes, increased health issues, and neurotic behaviors.
In this comprehensive 3000 word guide, we will cover the genetic basis of inbreeding, identify the physical signs such as facial and skeletal abnormalities, highlight the differences in litter sizes, outline the increased predisposition for genetic diseases, and detail some of the neurotic behaviors you may witness in an inbred dog.
We will also advise on next steps if you discover your dog is the product of inbreeding.
What is Inbreeding in Dogs
Definition of Inbreeding
Inbreeding in dogs refers to the mating of two dogs that are closely related to each other genetically, such as a father to daughter, mother to son, or brother to sister pairing. It results in offspring that have a higher concentration of shared genes than is typical.
In essence, inbreeding intensifies both the good and bad traits of a bloodline.
More specifically, inbreeding is when two dogs who share a close ancestor, such as a grandparent, are mated. This causes an increase in homozygosity in the offspring, meaning the puppies inherit identical gene copies from that common ancestor that are the same.
This is different from outcross breeding, where two unrelated or distantly related dogs are mated to purposefully introduce genetic diversity and new traits into a bloodline. Responsible breeders generally avoid inbreeding due to associated health risks, but some still practice it to cement desired qualities and appearance traits.
Why Inbreeding Occurs in Dogs
Inbreeding continues to occur in dogs for a few key reasons:
- To preserve rare breeds or special traits – Some breeders purposefully inbreed in hopes of magnifying and propagating preferred physical qualities and traits of a line, such as size, coat color, or skill for a performance activity like hunting.
It can help intensify selected attributes in a bloodline quickly. However, it also amplifies negative traits.
- Limited gene pools in rare breeds – Many rare breeds have a small founding population size and limited genetic diversity available within the breed. Occasional close breedings take place to avoid loss of diversity that supports breed preservation.
However, such breedings still need to be strategic to minimize inheriting negative traits.
- Accidental matings – In some cases, accidental brother-sister or parent-offspring matings occur unintentionally among household pets or in feral dog populations. These pose high risks but sometimes still produce reasonably healthy puppies.
- Lack of availability of unrelated dogs – In rural areas, animal shelters, or isolated communities, dogs have limited mating options which increases chances for related pairings.
- Lack of breeder education or experience – Sometimes novices or improperly informed breeders intentionally inbreed dogs without realizing associated risks or to avoid costs of health testing parent dogs.
While inbreeding could theoretically purge negative recessive traits from a bloodline if continued long term, it comes at a terrible cost of suffering, loss of viable offspring, and loss of genetic diversity that supports health.
Responsible breeding programs avoid inbreeding whenever possible or only occasionally utilize highly strategic close breedings after thorough health testing of mating candidates. The overall consensus is to primarily focus on outcrossing instead.
Physical Signs of an Inbred Dog
Facial Abnormalities
Inbred dogs often have noticeable facial abnormalities such as a shortened muzzle, overbite or underbite, widely spaced eyes, or a wave in the nose ridge. According to the Canine Health Foundation (https://www.akcchf.org/canine-health/top-health-concerns/inhertited-disorders/inhertited-disorders.html), around 60% of inbred dogs have some kind of facial deformity.
This can lead to breathing difficulties, eye injuries, or teeth misalignment. While some abnormalities may be harmless, others can seriously impact a dog’s quality of life.
Skeletal Abnormalities
Inbred puppies often display bone and joint deformities like luxating patellas, hip dysplasia, elbow dysplasia, and spinal defects. One study by UCDavis (https://www.vetmed.ucdavis.edu/news/uc-davis-investigates-link-between-dog-cancers-genomic-abnormalities) found that over 70% of inbred dogs had abnormal skeletal development.
This can cause limping, stiffness, arthritis, lameness and severe chronic pain. Dogs with skeletal issues may require expensive surgeries or lifelong medication. Providing adequate nutrition, exercise and joint supplements can help, but some conditions are irreversible.
Smaller Litter Sizes
Inbreeding in dogs often leads to smaller litter sizes. This occurs because inbreeding increases the chances of detrimental genes being expressed. These harmful genes can negatively impact fertility and fecundity in both male and female dogs.
Some key points on smaller litter sizes in inbred dogs:
- Litter sizes may only be 1-3 puppies, compared to 5-10 in outbred dogs.
- Male dogs may have reduced sperm count, motility, and viability.
- Female dogs may have issues with ovulation, increased embryonic mortality, and higher rates of dystocia (difficult births).
- The smaller the gene pool, the more likely harmful alleles will be expressed. Close inbreeding dramatically shrinks the gene pool.
Research has conclusively shown reduced litter sizes in inbred dogs. For example, a study published in Theriogenology examined litter sizes in 332 dog litters and found:
- Outbred litters averaged 7.4 puppies
- Moderately inbred litters averaged 5.3 puppies
- Highly inbred litters averaged only 3.5 puppies
The researchers concluded: “Increasing inbreeding was negatively correlated with litter size.” Other studies have reported similar findings.
The mechanism behind smaller litter sizes involves increased expression of deleterious recessive alleles. These alleles disrupt normal reproductive physiology and development. With inbreeding, there is a much higher probability that puppies will inherit two copies of harmful alleles.
Outcrossing to unrelated dogs can help improve litter sizes by restoring genetic diversity. However, it may take multiple generations to fully undo the damage from excessive inbreeding. Careful genetic screening and selection of breeding stock is key.
Increased Health Issues
Higher Rates of Genetic Diseases
Inbred dogs have a higher risk of developing genetic diseases and conditions. Since closely related dogs share much of the same DNA, deleterious recessive genes have a higher chance of being expressed in their offspring.
According to the Canine Health Foundation, around 470 genetic disorders have been identified in dogs that can be passed down through breeding. Some common genetic conditions seen at higher rates in inbred dogs include hip dysplasia, patellar luxation, autoimmune thyroiditis, progressive retinal atrophy, and epilepsy.
One study published in the Journal of Veterinary Internal Medicine found that the prevalence of 10 debilitating genetic disorders was significantly higher in purebred dogs versus mixed breed dogs. For example, occurrences of mitral valve disease, corneal dystrophy, and elbow dysplasia were over 20 times higher in purebreds versus mixed breeds.
Reputable breeders screen their breeding dogs through specific genetic tests to avoid doubling up on disease-causing genes. However, backyard breeders who inbreed irresponsibly fail to test their dogs, putting the puppies at increased risk.
Weakened Immune System
Inbreeding can weaken a dog’s immune system, making them more prone to infections, parasites, and diseases. With less diverse genetics, they have fewer defenses against pathogens and other immune challenges.
One statistic estimates that mortality rates among inbred puppies can be up to 30% higher in the first year when compared to outbred puppies from unrelated parents with more varied genes. Their bodies simply cannot fight off illness as effectively.
Signs of a compromised immune system in an inbred puppy or dog include:
- Frequent ear and skin infections
- Gastrointestinal issues like diarrhea and vomiting
- Respiratory illnesses
- Difficulty recovering from injuries/wounds
A lifetime of veterinary bills and medical interventions often await inbred dogs suffering from weakened immunity. Their quality of life may also be significantly impacted. Responsible breeding limits related matings to improve the odds of healthy and hardy puppies.
Neurotic Behaviors
Fearfulness
Inbred dogs often exhibit increased fearfulness and anxiety compared to well-bred dogs. This is due to the concentration of faulty genes related to emotional regulation and response to stress. Common signs of abnormal fearfulness in inbred dogs include:
- Extreme reactions to loud noises like thunder or fireworks
- Fear of strangers and new environments
- Cringing, trembling, and hiding when faced with new situations
- Aggressive “fear biting” when feeling threatened
These behaviors can range from mild to severe. Mildly affected dogs may only react strongly to major stressors like visits to the vet. More severely impacted dogs can be afraid of everyday sights and sounds, and require extensive behavior modification and training to function normally.
Aggression
Inbreeding is strongly linked to increased aggression in dogs. One study found that inbred dogs were 2.5 times more likely to show aggressive behavior compared to outbred dogs [1]. Common signs of abnormal aggression in inbred dogs include:
- Growling, snapping, or biting when approached or petted
- Guarding food, toys, or sleeping areas from people and other pets
- Sudden “out of nowhere” attacks
- Stalking, chasing, and biting family members or strangers
Inbred dogs may become aggressive due to fear, anxiety, resource guarding, dominance, lack of socialization, or redirected frustration. Careful behavior modification training can help, but the genetic tendency toward aggression can be difficult to override.
Separation Anxiety
Inbred dogs are at increased risk for separation anxiety and attachment issues. Signs of abnormal separation anxiety include:
- Destructive behavior like chewing, digging, or urinating when left alone
- Following owners from room to room and demanding constant attention
- Excessive vocalization when separated from owners
- Depression, lethargy, loss of appetite, and other signs of distress when alone
This clingy, destructive behavior is thought to stem from a hyper-attachment to owners combined with poorly regulated stress response. While training and behavior modification techniques can help, the root cause is genetic – meaning separation anxiety issues may persist to some degree throughout the inbred dog’s life.
What To Do If Your Dog is Inbred
Discovering that your dog is the product of inbreeding can be upsetting, but there are steps you can take to ensure your pup lives a happy, healthy life. Here is a comprehensive guide on what to do if your dog is inbred:
Get Your Dog Tested
If you suspect your dog may be inbred, the first step is to get them tested. There are a few options for this:
- DNA tests – These tests analyze your dog’s genes and can detect high levels of homozygosity which indicates inbreeding. Wisdom Panel and Embark are two popular dog DNA test kits.
- Veterinary screening – Your vet can do a physical exam and look for signs of health conditions commonly associated with inbreeding. Testing for issues like heart defects, eye problems, and joint abnormalities may be recommended.
Address Any Health Issues
Inbred dogs are at higher risk for genetic health problems. If testing reveals your dog has any conditions, be proactive about treatment. This may include:
- Medications – Drugs to manage conditions like epilepsy, allergies, or anxiety.
- Surgery – To correct orthopedic problems, cataracts, cherry eye, and other issues.
- Lifestyle changes – Accommodations like ramps, harness support, or a quiet space for anxious dogs.
Work closely with your vet to give your dog the best care possible. Early intervention for health problems can greatly improve their quality of life.
Improve Your Dog’s Diet
Nutrition is very important for inbred dogs. A diet rich in antioxidants and omega fatty acids can help reduce oxidative stress and inflammation. Try these tips:
- High quality commercial dog food – Look for brands that use wholesome ingredients and are formulated for your dog’s life stage.
- Fresh foods – Natural proteins like cooked meat, eggs, and fish provide important nutrients.
- Supplements – Glucosamine, fish oil, vitamins E and C, and probiotics support overall health.
Avoid poor quality filler ingredients. Check with your vet if you have diet questions specific to your dog’s needs.
Keep Up with Preventative Care
Inbred dogs are prone to dental problems, parasites, and infectious diseases. Maintain a regular schedule of preventative care including:
- Dental cleanings and exams
- Flea, tick, and heartworm medication
- Vaccinations
- Fecal tests for parasites
- Wellness exams with your vet
Closely monitoring your dog’s health and addressing issues early is key. Create a calendar to track when care is due.
Provide a Loving Home
While inbred dogs may face health challenges, they can still live happy lives as beloved family pets. Be sure to:
- Give them lots of affection and dedicated time together through play, training, and cuddling.
- Keep their environment enriching with toys, walks, socialization with other pets and people.
- Learn about their unique personality and make them feel secure.
Your compassionate care and advocacy for your dog’s wellbeing can go a long way. With a little extra love, even an inbred dog can have a wonderful life.
Conclusion
While the signs and health risks may seem daunting, many dogs that are the result of some level of inbreeding go on to live happy and fulfilling lives as cherished family pets. As an owner, the best thing you can do is provide extra care, socialization, training, and trips to the vet to catch any potential issues early.
With a little extra work, an inbred dog can thrive thanks to the loving home you provide.
Now that you know what to look for and understand the risks of canine inbreeding, you can make informed choices about your dog’s health. This guide covered all the major signs, consequences, and steps to help an inbred dog.
With vigilance and proactive veterinary care, an inbred dog can still find joy.
