HD (hip dysplasia):
Hip dysplasia is a malformation of one or both hips. Fortunately the American Collie is not a breed that is largely affected by HD. To maintain this situation, only dogs that are not affected by HD and have been radiologically examined as being HD A or HD B are accepted for breeding. At least one mating partner must have achieved the result HD A.
ED (elbow dysplasia):
ED summarizes several malformations of the elbow. Here again, the American Collie is not a breed that is largely affected by ED. Only dogs that have radiologically been examined as being not affected by ED – with the results ED 0 or ED border liner – are accepted for breeding. At least one mating partner must have achieved the result ED 0, if the dogs have been radiologically examined. ED examination is not mandatory for accepted dogs originating from another association, if they already were X-rayed for HD and the ED examination has not been mandatory at that time in the other association. This is because they should not be exposed to the risk of anesthesia for X-raying, as low as this risk may be. New breeding candidates though should have the ED examination ideally together with the X-raying for HD.
This intolerance for multiple drugs is very common amongst herding dogs and thus this is also the case for collies. For the American Collie we fortunately have a large genetic pool of healthy genes in Europe. For that reason at least one mating partner must have a status of being genetically unaffected of MDR (MDR1+/+). By this, the birth of MDR1 affected puppies can completely be prevented within the association “American Collies Europe”!
DM (Canine degenerative myelopathy):
DM is an incurable disease of the nerve tracts with progressive signs of paralysis starting at the hind legs and the dogs being fully conscious. Unfortunately it is yet unknown which genes are responsible for this in particular. However, the risk factor Exon2-mutation in the SOD1-gene has been detected by all tested collies suffering from DM. Due to the large genetic pool of healthy genes we decided that at least one mating partner must be genetically unaffected of DM (DM (Exon2) +/+, respectively N/N). By this, the birth of DM (Exon2) affected puppies can completely be prevented within the association “American Collies Europe”!
CEA (collie eye anomaly):
This comprises several stagnating genetic changes of the retina in the eye. This is very common amongst herding dogs, especially collies. It is assumed that approximately 67% of the collies are affected by a mild form of CEA (chorioretinal hypoplasia or CEA-1) which does not mean a restriction to visual capacity for most collies because the changes of the retina are comparably slight. These changes can often be verified best at the age of 6 – 8 weeks by an ophthalmologist. After this age the changes are often superimposed by pigments. Such dogs are also called “go normal”. Evidence can be achieved by CEA-CH genetic examination because all affected dogs are also genetically affected (CEA-/- respectively CEA/CEA). Approximately 13% of the affected collies have a coloboma with a key-hole shaped bulge at the visual nerve. Usually these changes are minor and restrictions to visual capacity are rare. Nevertheless these dogs are excluded from breeding as well as the in the end only 3% of the collies that suffer from the most severe form of CEA that is accompanied by internal bleedings sometimes as far as retinal detachment which inevitably results in blindness.
Because nobody wants this to happen, there is need for action. As so many dogs are affected, not all of them can be excluded from breeding as it would mean that only the remaining 33% would be available. If we additionally would only breed with MDR1 non-affected dogs, the available gene pool would drop to merely 2%. If additional factors would be included, we would end up at nearly 0%. This way we would not get very far. This is the reason why collies with a mild form of CEA are accepted for breeding if they do not have any restrictions to their visual capacity. Nevertheless, the mating of two of such dogs is not allowed as it unnecessarily increases the probability that the puppies come down with the severe form. As we have a rather good gene pool of singular healthy genes amongst the American Collies in the meantime, we can go as far as demanding that at least one partner be genetically unaffected (CEA+/+, respectively N/N) or at least be carrier (CEA+/-, respectively N/CEA). With this measure we could achieve to lower the risk for visual inabilities – depending on the particular mating partners – to a probability that lies between 0% and 1.5%!!!
rcd2-PRA (progressive retinal atrophy):
This widespread incurable heritable eye disease that affects many breeds gets increasingly worse and finally leads to blindness. The gene pool in Europe is sufficiently large in regards to the American Collie. Consequently one mating partner must be genetically unaffected (rcd2-PRA+/+, respectively N/N). By this, the birth of rcd2-PRA affected puppies can completely be prevented within the association “American Collies Europe”!
MPP (Membrana Pupillaris Persistens):
During the embryonic phase the eye is covered with a fine membrane. This recedes until the eyes open up. But sometimes small tissue remnants remain. These are called MPP (or PPM = persistent pupillary membrane) and can be found among many breeds. Usually they are rather marginal among collies and do not lead to a restriction of visual capacity. These dogs can be accepted for breeding, but it is recommended to mate them only to MPP unaffected dogs. A consequent and reasonable implementation will only be possible in several years from now as the MPP cases only have been consequently recorded in the examination forms since few years.
GCS (Gray Collie Syndrome):
This leads to a cyclical decrease of neutrophil granulocytes which are of very high importance for the immune defense. Affected dogs usually die early because of infections. Due to the large genetic pool of healthy genes, at least one mating partner must be genetically unaffected (GCS+/+, respectively N/N). By this, the birth of GCS affected puppies can completely be prevented within the association “American Collies Europe”!
DMS is an autoimmune disease, similar to JDM (Juvenile Dermatomyositis) among humans. DMS primarily appears among Shelties and Collies every now and then. Crusty lesions evolve on protruding bones that are sparsely covered with muscles, especially in the face, on the tip of the tail and on the legs. The skin is sometimes flaky, reddens and the fur falls out. It is typical that the affected regions do not itch, especially in the early stages before a secondary infection appears. Wounds heal in mild cases, although most of the times spots remain changed for a long period of time, shaped by dark or stained pigmentation and ongoing loss of hair. In serious cases, muscles are affected to such an extent that e.g. drinking or eating (chewing and swallowing) becomes increasingly harder as well as walking (muscles of the feet and the legs). Humans experience a pain that reminds of sore muscles. Dogs are often susceptible to infections (fungal, bacterial, viral), especially during an immunosuppressive therapy. Treatment is very often difficult, despite the fact that they are caused by germs that would not even harm a healthy dog. Sensitivities of the gastrointestinal tract may occur too. In later stages, dogs may lose single claws that usually grow again later.
Genetic modifications and environmental factors play an essential role. The skin lesions seem to be triggered by stress factors like virus diseases, vaccinations or traumatic experiences. Hormone changes can have an intensifying effect (bitches: heat, pregnancy, false pregnancy / male dogs: hormonal boosts), vaccinations (overly extensive vaccinations, leptospirosis, rabies), increased stress, likelihood of infection and intolerances (food, medication, allergens). DMS can break out at any age, but the most common breakout is during the first year of age. Good treatment success (but not complete cure) can be achieved by using Trental (Pentoxiphyllin), Vitamin E and in serious cases also steroids. Castration often helps if the dog reacts strongly to hormone changes. Preventive measure in cases of increased risk, is to avoid possibly amplifying triggers. Healthy nutrition without much chemical ingredients but with optimal composition can surely be supportive. Extensive vaccination (too often or too much in one go) can be prevented by testing the titer for the respective antibodies and only vaccinate when really necessary. Same is true for worm treatment where fecal samples can be tested.
Genetic screening performed by Leigh Anne Clark and Jacquely Evans from the Clemson University in the USA showed that three risk factores are associated with the disease.
The first is the MHC gene class, the immune system variant. This could be related to JDM among humans, besides environmental triggers. Among dogs it is the MHC-II class leucocytes antigens, to be more specific the DLA genes (DLA-DRB1/-DQA1/-DQB1). They are coded in number combinations. Unfortunately, variations are very sparse among Collies. In the study, Collies almost without exception showed the combinations 002:01/009:01/001:01, rarely the combination 015:01/009:01/001:01. This probably indicates an inherent bread dependent affinity for DMS, at a level of 3% according to the current state of the study (01/2017). A further very rare DLA variant with the combination 006:01/050:11/007:01does exist, but it cannot be stated yet that the risk is lower, because of the small quantity. But even if this was the case, a choice for breeding would hardly be feasible because of the sparseness.
The research team discovered two further risk factors. These are two gene alterations that are directly correlated with the risk for the dog to develop DMS. This is why they are referred to as high-risk genes, called “A” (PAN2) and “B” (MAP3K7CL). The impacted genes are important concerning the regulation of inflammations. This is why DMS could as well be described as the inability to regulate inflammatory reactions.
As the genes are always present in pairs (alleles), they can be compensated by the non-affected genes “a” and “b” (“Aa” or “Bb”) which lowers the risk for developing the disease. If the second half is genetically free (“aa” or “bb”), the risk for "Aa bb" oder "aa Bb" is 4% according to the current status of the study (01/2017).
If both are genetically non-affected, the risk for "aa bb" is 3% on the basis of the above described DLA genes according to the current status of the study (01/2017).
But as soon as “A” or “B” are present homozygous (“AA” or "BB"), a moderate risk of 39% for "AA bb" or "aa BB" exists according to the current status of the study (01/2017).
The situation changes immediately when an additional “A” or “B” appears, no matter whether homozygous or not. In this case, also the risk for "Aa BB" and "AA Bb" increases to 90 - 92% according to the current state of the study (01/2017).
Are both affected, the risk increases to almost 100% for "AA BB", according to the current state of the study (01/2017).
“B” occurs among Collies less frequently than “A”. The reason for this is presumably the fact that DMS affected collies were discarded for breeding since the 1980s when the first more intensive research started. It is an interesting fact that the merle gene only exists in combination with an unaffected "a"! This means that a merle can only have an “aa” or at the worst “Aa”, but is never homozygous ("AA").
The research studies of Leigh Anne Clark and her team are not only interesting for further JDM research for humans, but are also very valuable for us as Collie breeders. In 2016, the working group succeeded to develop a test for showing the risk for each collie. The test is not a proof for the disease itself. This is only possible through biopsies on the affected spots. The test alone is merely a risk evaluation. It neither means that every genetically affected dog will automatically develop the disease, it merely bears a moderate or high risk to develop the disease. Vice versa, the possibility exists that a dog with the lowest possible risk will develop the disease, as according to the current scientific status the stage “no risk” does not exist at all.
As the consequences of an outbreak can be very unpleasant, it nevertheless makes sense to integrate the test into the breeding program to minimize the danger of DMS. We would like to start by promoting an appropriate recommendation to test all breeding dogs, for logical reasons before mating. The data is collected at the stud book office and will influence our breeding program. We already recommend at present to consider all three genes during breeding selection and to prefer mating partners that will not give birth to puppies with a high risk to develop DMS.
Even if - according to current knowledge - no puppy was born in our association “American Collies Europe” that developed DMS, it nevertheless is our particular concern that just Collie will be born with a risk for this disease as low as possible in the future. This is why ideally at least one mating partner should be unaffected by the particular risk genes “A“ and “B“, i.e. DMS “aa” and “bb”. This can as well be mutually alternating, i.e. one mating partner is unaffected by the risk gene “A” (“aa” - non-carrier) and the other one is unaffected by the risk gene “B” (“bb” - non-carrier). Thus, the risk for newborn puppies can be reduced to the lowest possible level of 3%, respectively 4%.
Unfortunatly, the problem cannot be eliminated overnight as there are too few collies worldwide that are genetically free of the risk genes “A” and “B”. If only birth of genetically unaffected puppies would be allowed, the collie breed would disappear soon. Besides, the DMS risk was even caused by very selective breeding and the whole breed is based on very few collies worldwide. The fact that comparatively few collies were brought from Europe to America and only few of these were used for breeding did not improve this situation. This is why heterozygosity remains the primary goal to compensate each affected gene with an unaffected and lower the overall risk among the breed. We cannot completely exclude the mating of two carriers in the years to come for the sake of the gene pool. But in the worst case 25% of collies with moderate risk will be born and none with a high risk. The number of genetically unaffected collies is 22% according to the study and to only rely on them for further breeding is impossible given the fact that not even all of these are even used for breeding.
From 01.01.2019, after two years transitional period, the next stage comes into force. At each mating, at least one mating partner must have a proven genetically risk for DMS, like DMS aa bb, aa Bb, Aa bb or Aa Bb (according to the Clemson University DMS-study of 01/2017).
IPD (Inflammatory pulmonary disease)
IPD is a recurrent inflammatory lung disease with an inherited background. It usually breaks out at the breeder's home a few days after birth. The dogs suffer from repeated foamy vomiting, nasal discharge, fever, only breathe shallowly, have increased breathing noises and cough. Medications, such as antibiotics and secretolytics, only help for a short time, after which there are rapid relapses. Two long-haired collies described in one study were still alive after three years with frequent yellowish nasal discharge. The rare disease appears to occur predominantly in British Rough Collie lines. Usually only homozygous affected animals show symptoms. So, it seems to be inherited recessively and both parents must carry an affected gene. There was also found that an inheritance must be involved, since an accumulation of this disease occurred after mating with a certain male (the name is not published publicly). This shows how important it is to deal with problems openly and pass them on, so that such clusters are noticed at all. Ultimately, it's about the health of our breed. On the initiative of some breeders, in collaboration with Laboklin and Prof. Leeb from the University of Bern, a corresponding mutation for IPD in the so-called AKNA gene (which regulates inflammation) was identified and a genetic test developed for this purpose, which has recently (2019) on the Market is (Laboklin). The study is available here: https://www.mdpi.com/2073-4425/10/8/567/htm. Ideally, at least one breeding partner should be genetically free (noncarrier), i.e. IPD + / + or N / N, so that the birth of affected puppies can be completely ruled out. If the risk situation worsens, at least one mating partner must be genetically unaffected (IPD +/+, respectively N/N). By this, the birth of homozygous IPD affected puppies can completely be prevented within the association “American Collies Europe”! In general, efforts are made to ensure that Collies are tested with a possibly increased risk.
MH (Maligne Hyperthermie):
This genetical defect can occur among all breeds, but fortunately is rather scarce among collies. It is a drug intolerance that affects specifically the striated muscles. Massive cramp attacks, cardiac arrhythmia as well as rise of body temperature (hyperthermia) culminating in disintegration of the muscle cells (rhabdomyolysis) can be caused by administration of particular medicine for inhalation anesthesia or muscle relaxation. The metabolic products can cause massive kidney problems right up to organ failure and death, if not treated immediately in a competent manner. The test is voluntary as the disease rarely occurs among collies. Here again one mating partner should ideally be genetically unaffected (non-carrier), i.e. MH+/+ resp. N/N to avoid the possibility of affected puppies.
HUU (Hyperurikosurie / Hyperurikämie):
This is a genetical defect of the urea metabolism (purine). In contrast to humans and if the dog is healthy, the end product uric acid is further degraded to allantoin that is better water soluble. This process is impaired if the dog is HUU affected by a mutation of the SLC2A9 gene. This can lead to gout and formation of urinary calculi by subsequent crystalline residues. The test is voluntary as the disease rarely occurs among collies. Here again one mating partner should ideally be genetically unaffected (non-carrier), i.e. HUU +/+ resp. N/N to avoid the possibility of affected puppies. In the past, HUU was listed under the name SLC.
AVK (Ahnenverlustkoeffizient = ancestor-loss coefficient for preservation of the genetic diversity of the individual):
To preserve the genetic diversity of each individual dog to a high degree, the AVK of the puppies must not fall below 86% over 4 generations. This implies the prohibition of inbreeding or tight line breeding. Only with as many diverse genes as possible (heterozygosity) the individuals of a breed can remain as healthy as possible in the long run. It is possible to obtain an exemption for an AVK of at least 80% for the mating with imported dogs from America - that are often bread very tightly - or their descendants in the first or where appropriate second generation. In these cases it must be ensured that there will be no further deprivation of the ancestors. Finally, the breeding commission decides by the majority.
IK (Inzuchtkoeffizient = inbreeding coefficient):
The IK – in contrast to the AVK – also incorporates the closeness of relatives. Thus, double ancestors that are more distant (like great-great grandparents) have less severe influence than if e.g. the father would appear several times. It is recommended that the IK of puppies should not exceed approximately 6%. Furthermore, the circumstance of double ancestors should generally be avoided during the first three generations to preserve and promote the diversity and variety of genes.
No Popular Sire Syndrome (preservation of a large gene pool for the whole breed):
The excessive use of an individual stud dog should be avoided to preserve the genetic diversity of the breed. The more dogs are related the smaller the gene pool of the breed will get. Some diseases and other defects only develop at a higher age. Should affected dogs have produced abundant offspring, there is the danger that these defects have spread unintentionally.
The aspired goal is to have at least 50% (good if more) of American bloodlines (collies bred in the U.S. or Canada over several generations). More important for preserving the breed however is in the long run the conservation of the genetic diversity (of the individual) as well as the large gene pool (of the breed). Especially important is appearance (according to the original American breed standard), besides character etc. of mating partners particularly with regard to the expected puppies.
It is very important that character and temper are taken into consideration when choosing mating partners. It should especially be looked at how already existing offspring developed. It should be considered whether I want to breed rather calm dogs or very active ones. Do I have enough interested parties being able to meet the particular challenges? Or should I rather aim at breeding dogs of medium temper.
The goal of breeding always is to breed for a dog that resembles the ideal picture of the American Collie most closely. To achieve this, one has to deal with the potential of available mating partners. Good judges and breed wardens can surely support with this. While choosing mating partners it must never be forgotten that it is not a question of breeding the dog with the optimal health values, but rather the overall package has to be right.
Color variants like double merles (genetically homozygous carriers of merle, originating from a mating of two dogs carrying the merle factor) are excluded from breeding according to animal protection laws. Even an envisaged mating that might result in such puppies is not allowed! Only one mating partner may carry the merle factor at maximum. Should the merle status of a dog not be ensured, especially if there is risk for cryptic merle (genetically heterozygous carriers for merle that is not visible), the dog must be genetically tested before the breeding application to be able to exclude later mating of two merles.
Bitches must be at least 22 months of age for breeding, stud dogs must be at least 18 months of age.
Quality before quantity:
Besides complying with above mentioned values that ensure and enhance the quality, it must also be considered that a dog should not be used for breeding excessively. For the stud dogs this was described under the point “Popular Sire Syndrome”. Bitches should be used for breeding in a way that there is at least a period of one year between successful mating. One should also aim at a recovery period of at least on year between litters; our bitches are no birthing machines! An overuse will inevitably result in a decrease in quality of the puppies and this must never happen! This is the reason why only four litters are allowed for a bitch throughout her lifetime.
The breeding permission for a bitch expires when the 7th birthday is reached. A one year extension can be acquired if a health certificate together with a clearance certification for further breeding issued by a veterinarian is presented. Concluding, the breeding commission decides by the majority.
The breeding permission for stud dogs expires when the 8th birthday is reached. An extension can be acquired, especially if the sperm of the dog is very valuable for the breed. Concluding, the breeding commission decides by the majority.
To be able to keep high-quality standards long-term and to optimize them further, it is essential that irregularities (anomalies, diseases, etc.) are reported to the stud book office. The data is collected and interpreted. According to the cause, frequency, etc. further appropriate measures can be applied to optimize future breeding further.