Breed Information
Broken T Australian Shepherds is a family-run business with a passion for these intelligent and loyal dogs. We have dedicated ourselves to providing the best care, advice and resources to help you and your furry friend get the most out of life. At Broken T, we offer a wide selection of Aussie-related products from books and toys, to food and accessories. We also provide helpful information and tips to ensure that you and your Aussie Shepherd have the best bond possible. Whether you’re looking for the perfect gift for a special pup, advice on training or just want to learn more about these amazing animals, Broken T has you covered.
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Coat Genetics
Coat Genetics
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Australian Shepherd coats come in four main varieties: blue merle, red merle, black tri and red tri. Whether a litter produces reds or blacks, solids or merles depends on the parents' genes.
There are two main coat colours: red and black. A blue merle Aussie has a black base colour, as does a black tri. Red merles and red tris have a red base colour. There are also two main coat patterns: solid and merle. It is the presence or absence of the merle gene which dictates whether the coat pattern will be merle or solid. To be red, an Australian Shepherd must carry two red genes since they are recessive. If one gene is black, black will cover the red since it is the dominant gene. However, a black Aussie may still produce red pups if it has one black and one red gene. This is what is called being 'red-factored'.
Merle to Merle should not be bred
Merle is a dominant genetic factor, that is, only one mutated copy of the merle gene is required to produce an effect on coat color. The possible matings are as follows:
(A) – Normal X Merle. A typical mating is done between a merle dog and a dog that is non-merle, to give birth, in theory, to 50% merle pups (M/N) and 50% puppies that are non-merle (N/N).
(B) – Merle X Merle. A mating between two merle dogs should be strictly avoided, since the litter will have 25% normal pups (N/N), 50% merle puppies (M/N) and 25% double merle puppies (M/M). It is necessary to prevent the birth of double merle dogs because the mutation of the two copies of the merle gene predisposes them to health problems
(C) – Cryptic Merle X Merle. A cross between a cryptic merle dog (Mc/N) and a typical merle dog presents an additional complication which is the possibility of giving birth to a cryptic double-merle puppy (Mc/M).
Health Genetics
MDR1 Drug Sensitivity
All of our dams and sires will be health tested through Pawprint Genetics before breeding. Our goal is to produce Health Tested Clear puppies but know some could have a potential of being carriers depending on their dam/sires health testing. Carriers are ok as long as they are not bred to another carrier. We strongly suggest all aussies be treated as if they are MDR1 Carriers.
Multidrug Resistance 1, also called MDR1, is an inherited condition affecting several breeds of dogs, especially herding dogs such as the Australian shepherd. The Mutation in the ABCB1 gene associated with MDR1 causes dysfunction of P-glycoprotein, which is responsible for removing certain drugs and toxins from the body. Clinical signs are most commonly associated with distribution of the drug in the central nervous system. MDR1 is inherited in an autosomal incomplete dominant manner in dogs meaning that dogs only need to inherit one copy of the mutated gene to be at an increased risk of developing adverse reactions to certain medications. Though adverse reactions to certain drugs are most commonly seen in dogs having two copies of the mutated gene, Carrier dogs can also experience drug sensitivities and dosages need to be adjusted accordingly. Thus, dogs that have one or two copies of the mutation are considered at-risk for adverse drug reactions. If an at-risk dog is treated with one of several common drugs (see below*), they are at risk of developing neurologic symptoms that could range from tremors, excess salivation, anorexia, and blindness to coma and even death. Because of the defective ability to metabolize specific drugs, these drugs can be lethal even at low doses. The MDR1 mutation does not cause adverse effects in dogs unless the dog is exposed to these drugs. Therefore, veterinarians should be notified when a dog is at risk for multidrug resistance 1 prior to administration of any medications.