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Hereditary Defects of the Australian Shepherd

The Australian Shepherd is a healthy breed compared to many but is not without hereditary problems. Hip Dysplasia and several different eye defects are the most common problems in the breed.

Hip Dysplasia (HD) is found in all dog breeds and is basically bad development of the hip joints. This disease is not caused by a single pair of genes, but instead is "polygenic". This means many gene pairs determine the condition and development of the hip joints. This has made the disease extremely difficult to understand and to determine the genetic inheritance involved. It has been found that the incidence of HD can be lessened by careful selection of breeding stock. Australian Shepherd breeders have been leaders in the control of the disease in this breed.

Why is HD such a concern? Lameness varying from slight to very severe crippling can occur, usually between six months to a year or in the dogs older years. Some dogs never show lameness at all but have the disease. These dogs can run and jump but carry the disease and can pass it on to their offspring.

HD can only be diagnosed with x-rays taken by a competent veterinarian after the dog is past it's second birthday. The Orthopedic Foundation for Animals (OFA) has for many years served as the diagnostic expert for this disease. X-rays submitted to the OFA are sent to three independent radiologists for a consensus opinion. OFA will not certify a dog free from HD until it is two years old. Dogs may be x-rayed for a preliminary evaluation earlier than two years, but because of the progressive nature of the disease, OFA will not certify them until two years of age.

Most recent statistics from OFA report an incidence of 6.5% of Aussies with HD from 9,712 evaluated. This sounds like a small percentage, but it is about 1 out of 15 which would be one in every two litters. This statistic comes from dogs owned by conscientious breeders and owners who use the OFA, and not the general population so this may be deceiving. To be a conscientious breeder, breed only OFA certified individuals and guarantee pups to be free from HD. Littermates and siblings are also important. An animal diagnosed as having HD should never be bred.

The Aussie also can be affected by eye defects with varying degrees of hereditability. Progressive Retinal Atrophy (PRA) is a very serious disease which is caused by a recessive gene. The end result is complete blindness. We do know that affected dogs inherit the gene from both parents, so both parents are carriers. All the puppies from an affected dog will have the disease or be carriers. This disease may not show up until later in the dog's life which is a reason for yearly eye exams by a veterinary ophthalmologist.

A regular veterinarian can not diagnose most eye diseases. When a dog is examined by a veterinary ophthalmologist and diagnosed free of disease the owner will receive a form. The owner can submit this form to CERF to receive a number declaring the dog free from eye defects. If CERF is not used, the owner should be able to provide a copy of the ophthalmologist forms to potential buyers.

Another eye defect diagnosed in the Australian Shepherd is Collie Eye Anomaly (CEA) which is also hereditary. Again a veterinary ophthalmologist needs to check the eyes of all dogs used for breeding.

A defect that can be seen without special equipment is the Iris Coloboma, and it is especially noticeable in blue eyes. The inheritance of this defect has not been identified although studies have shown it occurring in families. In these eyes the pupil appears to extend into the iris (colored part of the eye) often with a jagged edge. The ASCA breed standard calls for the pupil to be well defined and perfectly positioned. If the pupil is not perfectly round and in the center of the eye, the eye is not normal. Most dogs with an Iris Coloboma appear to function normally, but there is evidence that this is inherited and affected dogs should not be bred.

Spay and Neuter

The topic of neutering is emotionally charged for many pet owners.

It’s become the “responsible” thing to do. So we commonly hear of the benefits of this surgery … but rarely the risks. When savvy pet owners avoid early neutering (or forgo neutering altogether) to mitigate that risk … they’re often vilified for contributing to the pet over-population problem. But decisions made on emotion aren’t usually the best decisions we can make.

So here’s an objective and scientific look at what’s causing all the fuss. Let’s start with one well-known study that showed reasons to reconsider early neutering in dogs …

In February 2014, a study was completed on over 2500 Vizsla dogs and the results were a blow to those who vehemently defend spay/neuter (1). But this study is just the one of a long line of work showing that removing a quarter of the dog’s endocrine system might not be in the dog’s best interests – and maybe not even in the best interests of rescues and shelters.

Effects Of Neutering A Dog Too Early

1. Early NeuterIng And Joint Disease

We’ll get to the Vizsla study later. They didn’t investigate the link between neuter and joint disease … but they didn’t really need to. There was already plenty of research showing the link. Hip Dysplasia, A 2013 study on Golden Retrievers found that male dogs who were neutered before 12 months of age had double the risk of hip dysplasia than their intact counterparts (2). Other research shows that dogs sterilized before the age of six months have a 70% increased risk of developing hip dysplasia. The authors of this study propose that … “…it is possible that the increase in bone length that results from early-age gonadectomy results in changes in joint conformation, which could lead to a diagnosis of hip dysplasia.“ There’s even more evidence that neutering can increase the risk of hip dysplasia. In a 2005 study, Van Hagen et al found that of the sample dogs diagnosed with hip dysplasia, those who were neutered six months prior to the diagnosis were nearly twice as likely to develop hip dysplasia (3).

Cruciate Ligament Tears Cranial cruciate ligament (CCL) tears have also been linked to neutering in numerous studies. The Golden Retriever study found that although there were no cases of cruciate tear in the intact dogs, 5% of males neutered before 12 months (and 8% of females) did suffer tears. Whitehair et al (JAVMA Oct 1993), found that spayed and neutered dogs of any age were twice as likely to suffer cranial cruciate ligament rupture (4). In 2004, Slauterbeck et al also found an increased risk of cruciate tears (5). Chris Zinc DVM PhD DACVP explains (6) …

“…if the femur has achieved its genetically determined normal length at eight months when a dog gets spayed or neutered, but the tibia, which normally stops growing at 12 to 14 months of age continues to grow, then an abnormal angle may develop at the stifle. In addition, with the extra growth, the lower leg below the stifle likely becomes heavier (because it is longer), and may cause increased stresses on the cranial cruciate ligament.“

Additionally, sterilization can cause obesity and a loss of bone mass (7). Both of these factors could lead to an increased risk of cranial cruciate ligament tear and hip dysplasia. And a 2005 Austrian study showed that spayed/neutered dogs are over three times more likely to suffer from patellar luxation (8). There are many things you can do to help your dog’s joints. Unfortunately … there are even more sinister issues with early neutering in dogs.

2. Neutering And Cancer

Contrary to popular belief, we can’t neuter cancer. In fact, this surgery mostly increases the risk of many common canine cancers. The Golden Retriever study found that the incidence of lymphosarcoma was three times higher in males neutered before 12 months of age. These results are similar to other studies. They also found that spayed/neutered dogs were 3.5% more likely to suffer mast cell cancer and 4.3 times more likely to suffer lymphoma. 2002 research on Rottweilers at Purdue University found that male and female dogs neutered or spayed before 1 year of age had an approximate one in four lifetime risk for bone sarcoma … and they were significantly more likely to develop bone sarcoma than dogs that were sexually intact (9).

A 2002 study at Utrecht University found that prostate cancer occurs in neutered males about four times as frequently as in intact males (10) … despite the popular belief that neutering prevents prostate cancer.

3. Neutering And Behavior

Neutering had been previously linked to cognitive impairment and even a three-fold risk of hypothyroidism (which often creates behavior changes). But the Viszla study yielded some particularly interesting insight into this link. They found that neutered dogs were also more likely to develop behavior disorders than intact dogs. The problems included:

  • Fear of storms

  • Separation anxiety

  • Fear of noises

  • Timidity

  • Excitability

  • Aggression

  • Hyperactivity

  • Fear biting

Another study in 2010 (10) found neutered dogs were more:

  • Aggressive

  • Fearful

  • Excitable

  • Less trainable than intact dogs

This is contrary to the popular belief that neutering reduces aggression and other behavior problems.

These findings also present a conundrum for shelters and rescues who advocate early neutering in dogs.

What Happens If You Neuter A Dog Too Early?

Reducing the number of dogs in shelters is an important goal … but it would be much better to prevent them from ending up at the shelter in the first place. Most people believe that shelters are full because of over-population. But in fact, behavior problems are the most common reason owners give up their dogs. And is it fair for shelters to burden adopters with the increased risk of cancer and joint disease? There are alternatives to the complete removal of the reproductive organs and this might play a role in reducing the risk of cancer, joint disease and behavior issues. Conventional neutering immediately shuts off the supply of protective hormones in the body. Hormones produced by the reproductive organs are essential for reproduction … but they’re also vital in developing …

  • Homeostasis

  • Body condition

  • Cholesterol levels

  • Energy levels

  • Urinary continence

  • Muscle tone

  • Cognition

  • Behavior

Reproductive hormones also play a role in the immune system. The rise in the risk of many cancers after removal of the reproductive organs is evidence of this. Hopefully the emerging research will encourage more shelters to look into safer and less intrusive options.

MDR1 Drug Sensitivity


Multidrug Resistance 1 (MDR1) drug sensitivity is the result of a genetic variant that can place dogs at risk of severe or life-threatening complications after taking particular medications at specific doses.  

Treatment focuses on prevention by avoiding or lowering the dosages of drugs that may cause side effects in dogs who have this genetic variant.  Genetic testing is the most helpful tool for diagnosing MDR1 drug sensitivity.  


MDR1 drug sensitivity occurs when dogs inherit a genetic variant in their ABCB1 gene (formerly known as the MDR1 gene). This variant causes a change in a protein called P-glycoprotein (P-gp). Under normal conditions, the protein helps eliminate drugs after administration and helps keep specific substances — including some drugs and toxins — out of the brain and other organs.  However, when P-gp is not functioning correctly, these drugs and toxins can build up or even cross into the brain, causing severe and sometimes fatal reactions. 

Breed predisposition​ 

The MDR1 variant is most commonly found in herding breeds, including, but not limited to the following:  

  • Collies 

  • Australian Shepherds 

  • American Shepherds 

  • German Shepherds 

  • Shetland Sheepdogs  

  • Old English Sheepdogs 

Clinical signs 

The most common signs of drug toxicity in dogs with MDR1 drug sensitivity include: 

  • Vomiting  

  • Weakness 

  • Uncoordinated movement 

  • Tremors  

  • Seizures   

  • Blindness 

  • Death 

Drugs of concern 

P-gp affects the absorption, elimination and distribution of many drugs, but only a few of these drugs can cause severe toxicity in animals with the MDR1 variant.  For example, medications commonly used in heartworm preventatives, such as ivermectin, can cause toxicity if given in high dosages. However, heartworm preventatives are still safe for MDR1 drug-sensitive dogs to take at low, FDA-approved dosages. Other medications that should be used with caution and at reduced doses include sedatives like acepromazine and butorphanol, anti-cancer medications and more. One drug that should be avoided entirely is an anti-diarrheal medication called loperamide (sold under the brand name Imodium). Certain medications, when used in combination with each other, can increase the total concentration of individual drugs and introduce more risk of an adverse reaction — even in dogs without the genetic variant. Examples include ketoconazole, cyclosporine and spinosad (Comfortis). Speak with your veterinarian before changing any drug dosages or discontinuing their use. 


A variant that causes MDR1 drug sensitivity is identified by genetic testing. However, an initial diagnosis often occurs in young dogs after they have an adverse reaction to a particular drug.  


There is no cure or antidote for MDR1 drug sensitivity. Treatment involves decreasing drug doses to avoid adverse reactions or choosing alternate drugs altogether. Dogs with adverse drug reactions are treated based on their symptoms and supportive care.  

It is important to know that not all drug sensitivities are due to the MDR1 variant, and you should talk to your veterinarian about other concerns regarding drug sensitivity. 


With proper consideration of drug interactions and dosages, MDR1 drug-sensitive dogs can live normal lives without incident.  

Severe and potentially life-threatening consequences can occur if drugs are taken at incorrect dosages, if they are used in certain combinations with other drugs or if at-risk dogs are unintentionally exposed to problem drugs (e.g. ivermectin used to deworm horses).  


The ABCB1 gene encodes P-glycoprotein, determining its base-level functionality. A dog may be severely affected by drug sensitivity if they inherit two copies of the ABCB1 variant, giving them only an abnormal P-gp. Dogs can still experience drug toxicity even with just one copy of the variant, but the effects are generally less severe. 

Because MDR1 drug sensitivity can be easily managed after it is identified, the elimination of all dogs with this variant from a breeding program is not recommended. 

List of MDR1 Drugs to avoid

MDR1leaflet.pdf (

Vaccine Protocol

Did you know your dog’s (and cat’s) vaccines last a lot longer than 3 years? In fact, most pet vaccines protect for a minimum of 7 to 15 years.

Immunology research proved this fact decades ago. Yet many veterinarians continue to insist on you vaccinating your dog at least every 3 years. Some even push for annual shots. But there’s no scientific basis for these practices.

Vaccine Research

Veterinary immunologist Ronald Schultz PhD chaired the University of Wisconsin’s Department of Pathobiological Sciences. He spent his career as a veterinary immunologist at the forefront of vaccine research.

The vaccines Schultz studied include …

  • Canine distemper vaccine

  • Canine parvovirus vaccine

  • Feline panleukopenia vaccine

  • Rabies vaccine

  • Feline rhinotracheitis

  • Feline calicivirus

In a 1999 paper, Dr Schultz outlined the duration of immunity for several vaccines. In other words … how long they will protect your pet.

Minimum Duration Of Immunity For Canine Vaccines

Here’s the minimum duration of immunity for common vaccines. (Challenge means the researchers exposed the animal to the disease and serology means they measured blood antibody levels.)

Distemper – 7 years by challenge/15 years by serology
Parvovirus – 7 years by challenge/7 years by serology
Adenovirus – 7 years by challenge/9 years by serology
Canine rabies – 3 years by challenge/7 years by serology

Dr Schultz concluded …

“Vaccines for diseases like distemper and canine parvovirus, once administered to adult animals, provide lifetime immunity.” 

And yet many vets continue to vaccinate annually. Dog owners even feel they’re lucky if their vets vaccinate every 3 years instead of every year. But why do we allow it? This information has been available for about 30 years. And researchers have replicated the studies time and again.

Other Immunologists Agree

Another prominent immunologist, Ian Tizard BVMS ACVM ScD PhD authored the standard textbook on Veterinary Immunology. 1998 research by Tizard states:

“With modified live virus vaccines like canine parvovirus, canine distemper and feline panleukopenia, calicivirus and rhinotracheitis the virus in the vaccine must replicate to stimulate the immune system. In a patient that has been previously immunized, antibodies from the previous vaccine will block the replication of the new vaccinal virus. Antibody titers are not significantly boosted. Memory cell populations are not expanded. The immune status of the patient isn’t enhanced. After the second rabies vaccination, re-administration of rabies vaccine does not enhance the immune status of the patient at one or two year intervals. We do not know the interval at which re-administration of vaccines will enhance the immunity of a significant percentage of the pet population, but it’s certainly not at one or two year intervals.” In plain English … this means that vaccinating more often doesn’t make your pet more immune! So why do veterinarians stick to this pointless schedule?

A Harmful Practice Since 1978

Dr Schultz commented …“The recommendation for annual re-vaccination is a practice that was officially started in 1978. This recommendation was made without any scientific validation of the need to booster immunity so frequently. In fact the presence of good humoral antibody levels blocks the anamnestic response to vaccine boosters just as maternal antibody blocks the response in some young animals.” And he warned … “The patient receives no benefit and may be placed at serious risk when an unnecessary vaccine is given. Few or no scientific studies have demonstrated a need for cats or dogs to be revaccinated. Annual vaccination for diseases caused by CDV, CPV2, FPLP and FeLV has not been shown to provide a level of immunity any different from the immunity in an animal vaccinated and immunized at an early age and challenged years later. We have found that annual revaccination with the vaccines that provide long-term immunity provides no demonstrable benefit.” So the expert veterinary immunologists are very clear. Why then, have vets not embraced the concept of lifelong immunity in dogs?

Is It About Money?

It’s easy to suspect profits are at the root of vets’ resistance to update their protocols. Without vaccines, clients might be less inclined to make yearly veterinary visits. The American Animal Hospital Association (AAHA) reports that vaccine revenues are about 15% of the average practice’s income. So veterinarians stand to lose big.

Proven Risks Of Vaccines

Every holistic vet recognizes the vaccine damage they see in dogs they treat. But this list isn’t just anecdotal … it’s from Dr Schultz’s research. Here is Dr Schultz’s 2007 list of adverse events from vaccines.

Common Reactions

  • Lethargy

  • Hair Loss, hair color change at injection site

  • Fever

  • Soreness

  • Stiffness

  • Refusal to eat

  • Conjunctivitis

  • Sneezing

  • Oral ulcers

Moderate Reactions

  • Immunosupression

  • Behavioral changes

  • Vitiligo

  • Weight loss (Cachexia)

  • Reduced milk production

  • Lameness

  • Granulomas/Abscesses

  • Hives

  • FacialeEdema

  • Atopy

  • Respiratory disease

  • Allergic uveitis (blue eye)

Severe Reactions

  • Vaccine injection site sarcomas

  • Anaphylaxis

  • Arthritis, polyarthritis

  • HOD hypertrophy osteodystrophy

  • Autoimmune hemolytic anemia

  • Immune Mediated Thrombocytopenia (IMTP)

  • Hemolytic disease of the newborn (neonatal Isoerythrolysis)

  • Thyroiditis

  • Glomerulonephritis

  • Disease or enhanced disease that the vaccine was designed to prevent

  • Myocarditis

  • Post vaccinal encephalitis or polyneuritis

  • Seizures

  • Abortion, congenital anomalies, embryonic/fetal death, failure to conceive

What You Can Do

Holistic veterinarian Dr Patrician Jordan says:

“The truth is the majority of vets are not going to change until they are forced to – which isn’t likely to happen due to politics and due to the lack of concern by the one entity that could protect the public and ensure animal welfare: the individual state veterinary medical boards. This change will have to come from the public, they have to stop allowing the over-servicing; they need to start filing lawsuits when their pets are manipulated and their purses are raided.” So it’s up to us dog owners. Educate yourself on vaccination and start being a more active partner in your dog’s vaccine decisions. At the very least, question every vaccine that goes into your animal. Be your dog’s advocate – protect him with knowledge and by taking a stand against unnecessary vaccination. His life may depend on it! And share this article with other dog owners. Together we must push for change.

Core and Non-Core Vaccines

It’s important to understand the difference between so-called “Core” and “Non-Core” vaccines for your dog, and what those terms mean.

Core vaccines

Aee the ones most vets recommend your dog should have as a puppy. These vaccines all protect against dangerous viral diseases. They are:

  • Rabies

  • Distemper

  • Parvovirus

  • Adenovirus (Canine Hepatitis)

Non-Core vaccines include:

  • Bordetella

  • Lyme Disease

  • Leptospirosis 4-way (this is sometimes included in combination vaccines with core vaccines, but it is a non-core vaccine and should be considered separately)

  • Canine Influenza

  • Parainfluenza

  • Adenovirus Intranasal

Several of the non-core vaccines (Bordetella, Lyme and Leptospirosis) are bacterial vaccines. Bacterial vaccines have low efficacy rates coupled with high incidence of adverse reactions. This means they should rarely be used, and then, only after careful consideration of all the risks of vaccinating vs not vaccinating against these diseases.

But if you do plan to give your dog any of these vaccines (or you already have), you’ll need to know how long they last and how to protect him after. But that still doesn’t answer the question of which ones your dog needs. We’llget to that shortly.

Why You Shouldn’t Over-Vaccinate Your Dog

Vaccinating your dog more often than necessary can be very dangerous for him. All vaccines have potential adverse reactions. These can range from fairly mild reactions like lethargy or soreness, to really severe ones like anaphylactic shock, autoimmune diseases and even death. The vaccine can also cause the disease it’s intended to prevent!

When your dog is protected by the vaccines he’s already had, vaccinating him again does not make him “more immune.” Vaccines also contain other ingredients that are potentially harmful for your dog.

Ingredients in Vaccines

Most vaccines include toxic ingredients that add to the risks of vaccinating your dog.

Two of these are:


This is a mercury based additive used as a preservative. Mercury toxicity is well known and repeatedly proven in studies. Yet it’s still contained in most veterinary vaccines today. Even some vaccines that claim to be thimerosal-free may still contain small amounts of thimerosal. That’s because it can be used in processing but not added as an ingredient, so the manufacturers don’t have to disclose it.


This is an antibiotic. According to the FDA, antibiotics are in vaccines to prevent bacterial infection during manufacturing, So when your dog gets a vaccine, he’s getting antibiotics whether you like it or not.

So it’s always a good idea to give your dog probiotics (soil based probiotics or S. boulardii are best) to help reduce gut damage caused by antibiotics and other drugs.

RELATED: Find out about other dangerous ingredients in dog vaccines …

For Core Vaccines

If your veterinarian presses you to over-vaccinate your dog with core vaccines, you can draw her attention to Dr Schultz’s research. Dr Schultz’s studies show the minimum duration of immunity that likely protects your dog for life once he’s had his core vaccines as a puppy or adult.

If your vet needs more convincing, you can ask for titers to confirm your dog’s protected. Some vets charge an exorbitant amount for titers (perhaps because they really don’t want to do them) and some may even refuse.

If that’s the case, you can ask your vet to draw the blood for you (usually about a $20 charge) and then send it yourself to Hemopet for testing. You can submit your titer request on Hemopet’s website. A distemper and parvo titer costs a little over $50 and you can ship the vial of blood cheaply via a US Postal Service Priority Mail Small Flat Rate Box.

For Non-Core Vaccines

Your vet is likely to recommend Bordetella and Leptospirosis vaccines, as well as Lyme if you live in a high tick area. All of these vaccines carry a high risk for your dog and don’t work very well. Check the vaccine issues listed on the chart, and also consider these points before vaccinating your dog.

  • Bordetella: If you board your dog, try to find a kennel that doesn’t require Bordetella. If your kennel does, ask to sign a waiver accepting the risk of your dog getting kennel cough on their premises … that’s what they’re afraid of. Or better yet, have a pet-sitter come to your home and then you don’t need to worry about vaccination requirements.

  • Leptospirosis: If you think your dog is at risk for lepto, make sure you find out from your local health authority what strains of lepto are in your area. The vaccine covers the L. canicola, L. icterohaemorrhagiae, L. grippotyphosa and L. pomona serovars. If these strains aren’t prevalent where you live, there is no point in taking the risk of vaccinating your dog.

Also note that some vets give the Leptospirosis vaccine in conjunction with core vaccines. You may see a vaccine called something like DHLPP. That “L” is leptospirosis … make sure you know what vaccines your vet is using. Your dog could still get the lepto shot.

  • Lyme: if your dog’s not out in the woods picking up ticks, he’s probably not at risk for Lyme disease. If you do take your dog into tick-infested areas, use natural protection methods to keep the ticks away. Check him thoroughly for ticks when you get home. Removing the ticks promptly will help prevent the tick from infecting him.

So which dog vaccines are absolutely necessary? That’s a question only you can answer! But now you have the information you need to decide for your individual dog.


Which Dog Vaccines Are Necessary? - Dogs Naturally (


What Should I Fed My Dog

At Terwin, we believe in feeding our dogs and puppies the diet nature intended. Like the human diet, fresh and natural as opposed to processed, is the healthiest way to build strong bones and muscle as well as maintain optimum health and immunity. There are a whole host of pet food providers that carry easy to provide/scoop and feed raw food. I am happy to discuss the advantages both nutritionally for your dogs and financially for you pocketbook. Check out the freezer section of your local pet food store or direct raw food suppliers in your area. I use Woodland Raw, you can try big Country Raw, Ren's Pet stores etc. there are no shortage for raw pet food distributors. 

Raw diet info and inoculations

Here are some other sites...

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