Cairn Terriers are a generally Healthy Breed

*AmCanCh Quarrydene's Black Diamond (Jewel) on her 16th birthday, still going strong.*

Cairn Terriers are a generally healthy breed, well known for their hardiness. Many live well into their mid-late teens. However, as with any breed, health issues do occur. Some of these are amenable to intervention through genetic testing. For these, appropriate selective breeding practices have significantly reduced the risk of affected puppies. For other conditions, risk cannot (yet) be ameliorated through use of genetic tests, but affected puppies may be identified by various testing procedures prior to placement. A good breeder will do appropriate genetic and health testing to ensure that all puppies placed are as healthy as possible. Not all health conditions can be identified through screening or prevented by genetic testing or other examination of parents. Health testing is a topic you will want to discuss in detail with your breeder. The Cairn Terrier Club provides recommendations for health testing specific to Cairn Terriers and, along with other Cairn Terrier clubs around the world is working to address common health issues in the breed. Research is actively underway to identify genetic markers for renal dysplasia and liver shunt as well as other conditions.

The following is not an exhaustive list of all health problems that may be encountered by Cairn owners, but rather focuses on conditions for which one or more of the following apply.

Cairns may be at higher than average risk compared to other breeds.
The condition is serious and has been reported in Cairns (but may be uncommon).
Specific testing of breeding stock or puppies is recommended for Cairn Terriers.

It is important to note that all breeds (and mixed breeds) are susceptible to a variety of conditions and the length of any such list is not a reflection on the overall health of the breed. Many websites will claim that Cairn terriers are at high or increased risk for various conditions not listed here. Not all such information is based on scientific data; often these comments are based on personal experience with one or a small number of Cairn Terriers or single case reports and are not substantiated in the scientific literature.

Allergies

Cairn terriers are not generally highly allergy prone, however any breed and any dog can develop allergies. Allergens can be airborne (such as pollens) or ingested (such as chicken). Signs and symptoms of allergy may include itchiness, hives, chewing at the feet, rubbing the eyes or ears. (And on the flip side, while some websites claim Cairns are 'hypoallergenic', that is not necessarily the case. If you are concerned about human allergies to Cairns, the only way to know if that will be a problem is to spend sufficient time, ideally indoors, with a Cairn to see what happens.)

Craniomandibular Osteopathy

CMO is a bone disorder in which there is noninflammatory, nonmalignant overgrowth of bone affecting the mandible, petrous bone and temporal-mandibular joint of some terrier breeds – especially West Highland White, Scottish and Cairn Terriers. CMO presents with jaw pain, difficulty opening the jaw and chewing, weight loss, fever and tender enlargement of the mandible (lower jaw bone). Onset occurs in juvenile dogs – between 3 and 8 months of age. While CMO is typically self-limiting and progression ceases with maturity, it can be disabling while active and, if severe, can lead to permanent difficulty with eating. It also occurs during an important developmental phase of the dog's life so can have lasting impact on things like behaviour and social interactions. The gene responsible for CMO in West Highland White, Scottish and Cairn Terriers is labelled 'SLC37A2' and differs from the genes found to be responsible for CMO in other breeds. Inheritance of CMO in WHW, Scottish and Cairn Terriers is believed to be autosomal dominant with incomplete penetrance. While most affected dogs will carry two copies of the affected gene (homozygous for the mutant gene), only about 57% homozygous dogs will develop clinical signs of disease. Dogs carrying only one copy of the mutant gene (heterozygous) can also be affected, but much less often. Dogs carrying two copies of the mutant gene are considered high risk for CMO and those carrying one copy of the gene are are considered lower risk. Dogs that carry the gene whether affected or not, should not be bred. Because not all dogs carrying mutant genes will be clinically affected, but can all pass the gene to offspring, genetic testing is critical to determine if there is risk of disease in potential offspring.

Globoid Cell Leukodystrophy

GCL is caused by an enzyme deficiency leading to accumulation of myelin breakdown products in the myelin producing cells of the nervous system. (Myelin acts as an insulator for nerve cells and improves conduction of electrical impluses along the nerves.) Affected dogs begin to show symptoms between 6 and 22 weeks of age. Typical symptoms include muscle weakness and poor coordination leading to abnormal gait, tremors and jerky movements. The disease is progressive and fatal. GCL is an autosomal recessive genetic disease (both parents must pass the abnormal gene to the offspring). Selective breeding to avoid breeding two carriers together greatly reduces the risk of an affected puppy.

Heart Defects and Murmurs

Innocent murmurs (murmurs not associated with underlying heart defects) are very common in puppies – up to 28% in some studies. Cairns are not noted for having an increased risk of structural heart abnormalities but all puppies should be examined for murmurs prior to placement and those with murmurs should receive follow up and if needed, echocardiogram. Most innocent murmurs resolve by 3 months, although some will persist for longer periods. A murmur persisting beyond 3 months should be further investigated by a veterinary cardiologist.

Renal Dysplasia / Aplasia

Renal dysplasia is a developmental condition in which the kidneys fail to develop properly and maintain immature characteristics. The degree of immaturity of the kidney can be quite variable. Significantly affected dogs will have impaired renal function which deteriorates over time leading to renal failure and premature death. Dogs with more minor involvement may reach a relatively normal life span. Symptoms include excessive water intake and frequent urination of large amounts of dilute urine (the kidneys are unable to properly concentrate urine). Affected dogs are highly prone to dehydration from water restriction or gastric upset. Dehydration must be avoided as it will cause further kidney damage. Although renal dysplasia is thought to be a genetic disorder we do not yet have a reliable test to identify carriers. All breeding stock should be screened with ultrasound prior to breeding. Some breeders may choose to screen puppies prior to placement. Minor abnormalities are often seen in very young puppies and the significance of these changes is uncertain. Many of these changes may be due to the immaturity of the kidneys at this age and resolve as the puppy matures so it is important that ultrasounds are done by experienced and qualified veterinary ultrasonographers. Renal Aplasia is a condition where one kidney is normal and the other is missing. This may be genetic but can also occur on the basis of non genetic but congenital factors. Puppies with a single normal kidney can live an entirely normal life but care should be taken to avoid use of medications with potential to cause renal damage and to avoid dehydration. Puppies with renal aplasia should not be bred.

Liver Disorders

Portosystemic Vascular Anomaly (Liver Shunt): Liver Shunt is a condition where abnormal blood vessels redirect blood from the portal system (which normally passes blood from the gut into the liver) directly into the systemic circulation, bypassing the liver. The liver plays a critical role in metabolizing and detoxifying substances. When this does not happen, toxins (ammonia, mercaptans, gamma amino butyric acid and others) build up and cause symptoms. Puppies may appear normal for the first few weeks or months of life but typically present by 6 months of age with poor growth and muscle development as well as neurological symptoms (disorientation, staring, seizures, abnormal gait and behaviours). Some dogs will also experience vomiting and diarrhea. High protein meals may exacerbate symptoms. Some shunts may be correctable surgically but more complex and intrahepatic shunts may not be amenable to correction. Bile acid or ammonia levels are used to screen puppies for liver shunt prior to placement. Affected dogs should never be bred. There is currently no genetic test available for liver shunt but this is an area of active research supported by Cairn Terrier Clubs around the world.

Microvascular dysplasia of the liver is related to liver shunt but rather than one, or a few, large abnormal vessels, in MVD, the abnormal vessels are very small and widespread through the liver. MVD is thought to have a genetic basis, likely autosomal dominant with incomplete penetrance (meaning an abnormal gene needs to be inherited from one partner only, but inheriting the gene does not always result in disease). Severity is quite variable and many dogs may be asymptomatic and live normal life spans. Others may have minor to severe symptoms. No treatment is required for asymptomatic dogs. Symptomatic dogs are treated with hepatoprotective agents such as Milk Thistle, Vitamin E and others, along with a low protein diet. Affected dogs should not be bred.

Hematologic (Blood) Disorders

Pyruvate Kinase Deficiency (PKD): PKD is an inherited condition in which red blood cells lack the pyruvate kinase enzyme, leading to premature break down of red blood cells (hemolytic anemia). Affected dogs present with lethargy, poor exercise tolerance and pallor. When severe, heart, liver and bone marrow failure ensue, usually by age 5. Inheritance is autosomal recessive (both parents must pass the abnormal gene to a puppy). A genetic test is available and allows breeders to avoid breeding two carriers to each other, thus largely eliminating risk of an affected puppy.

Congenital Macrothrombocytopenia (CM): CM is a benign condition in which dogs have mild to moderate decreases in the platelet count but larger than normal platelets. Generally the low platelet count is not associated with increased bleeding risk. Inheritance is autosomal recessive (a copy of the mutated gene must be inherited from each parent). This condition is highly prevalent in Cavalier King Charles Spaniels (up to 30-50% of dogs affected) and is also fairly common in Norfolk and Cairn Terriers. A puppy affected with CM can have a normal active life and a normal life span. No treatment is required (or helpful). Awareness of the condition is important mainly to avoid investigations and inappropriate treatment for other causes of low platelet count. Genetic testing does allow selective breeding to reduce the frequency of this condition but given its benign nature, there is no prohibition on breeding carriers. In fact, eliminating carriers of CM from breeding programs would have a negative impact on genetic diversity of the breed and overall health so is NOT recommended.

Hemophilia B / Factor IX Deficiency: In Hemophilia B a point mutation in the gene that produces Factor IX, a critical protein in the coagulation cascade results in complete lack of Factor IX in the circulation. Affected dogs are prone to prolonged / excessive bleeding with trauma or surgery, development of hematomas after minor bumps and bleeding into joints (which can give rise to premature arthritis). The disorder is sex-linked, recessive. The gene is carried on the X chromosome. Affected females must carry to copies of the affected gene (one from each parent) but males need only one affected gene. Carriers, who are asymptomatic may be identified through genetic testing. Carriers should not be bred.

Eye Disorders

Ocular Melanosis / Pigmentary Glaucoma: In OM, pigment cells accumulate in the eye. With proliferation of pigment cells, pigmented material is released into the aqueous fluid of the eye and eventually blocks the small channels that drain fluid from the eye. This leads to increased intraocular pressure (secondary glaucoma), which in turn damages the retina and optic nerve leading to blindness. Dark pigment may also be deposited on the white of the eye (sclera). The age of onset is widely variable (from 1-16 years) and rate of progression is variably but usually slow. OM is a genetic disorder, and pedigree analysis of affected dogs suggests an autosomal dominant inheritance pattern. Studies are underway to identify a genetic test but at present the only means of diagnosis is eye examination. Eye exams to look for features of OM should be done prior to breeding and on an ongoing basis as the age of onset is quite variable. Even though Cairns are known to be one of the most common breeds affected with OM, the incidence is still quite low – less than 0.1% of Cairns.

Cataracts: A cataract is opacification of the lens / lens capsule of the eye leading to visual impairment. Cataracts can be age related, post traumatic, post inflammatory or developmental / hereditary. Dogs with hereditary or possibly hereditary cataracts should not be bred. Cataracts in a young dog of breeding age should be assumed to be hereditary unless there is a documented reason (such as trauma) for the cataract.

Progressive Retinal Atrophy: PRA is caused by degeneration of the light sensitive cells of the retina, beginning with the rod cells (responsible for vision in dim light). Dogs initially have difficulty seeing in low light situations (‘night blindness’) but over time will have progressive vision loss resulting in complete blindness. PRA is a genetic disorder, likely due to several different mutations in different breeds. With further scientific study we will see more accurate genetic testing become available. At this point genetic testing for PRA is not reliable in Cairn Terriers. Eye exams will help identify early evidence of PRA in breeding animals. Affected animals should not be bred.

Musculoskeletal Disorders:

Legg-Calve’ Perthes’ disease: LCP is aseptic (non infectious) necrosis of the head of the femur. This typically affects toy and small breed puppies under 1 year of age, and presents with lameness (abnormal gait, favouring the affected limb). Cairns may be at somewhat higher risk for LCP than average. Diagnosis is made through X-rays of the affected hip. A genetic basis is suspected and research is underway to identify a genetic marker,

Luxating Patella: LP is a condition where the kneecap slips out of the grove where it normally sits. This is a common problem in small breed dogs can usually be diagnosed through physical exam between 4 and 6 months of age. While it is believed to have a genetic basis, there is currently no useful genetic test. Severity is quite variable (veterinarians grade the severity from Grade I-IV) and dogs with minor degrees of luxation may be able to compensate quite well. One or both knees may be affected. Affected dogs are at increased risk of cruciate ligament injuries so care should be taken to avoid early spay / neuter (which increases risk of ligament injuries) and to consult with a veterinarian before engaging in physically demanding activities. Because of altered weight bearing on affected limbs, the dog may also be more prone to developing arthritis. Corrective surgery is indicated for all but Grade 1 cases and should be done as early as possible to decrease the risk of arthritis.

Hip Dysplasia: The incidence of hip dysplasia in Cairns is considered to be low, much lower than that in larger dogs. It is important to be cautious in the diagnosis of hip dysplasia in Cairns as radiologic criteria used in diagnosis of HD in larger dogs has not been shown to be predictive of hip dysplasia related complications in smaller breeds such as Cairn Terriers.

Final thoughts:

Good breeders do everything they can to produce healthy puppies from health testing of parents and puppies to understanding everything they can about the pedigrees of the parents. Even so, at times unexpected problems can occur.

Be sure to inform your breeder if your Cairn does develop any serious health condition. A good breeder will want to be informed of any serious health issues as this knowledge is important for future breeding decisions.

There is much you can do to help maintain your Cairn in good health.

Ensure you get your Cairn from a breeder who does recommended health screening of parents and has pups tested appropriately before they are placed.
Use a good quality, WSAVA approved diet and a scheduled feeding routine (vs. free feeding), to avoid obesity. https://wsava.org/wp-content/uploads/2020/01/The-Savvy-Dog-Owner-s-Guide-to-Nutrition-on-the-Internet.pdf
Make sure your Cairn gets adequate exercise to avoid obesity and maintain good physical conditioning.
Establish a regular tooth brushing / oral hygiene program – dental disease is common in older dogs and can contribute to bad breath, poor appetite and overall poor health (increased risk for heart, liver and kidney disease).
Have regular health maintenance veterinary checks and use parasite prevention appropriate to your area as recommended by veterinarian .
If your pet engages in vigorous physical activity such as prolonged hiking or very physically demanding performance sports be sure to mention this to your vet so he / she can pay close attention to the musculoskeletal exam. Learn how to keep your dog in top physical conditioning and use proper warm up and cool down techniques.

Consider investing in health insurance. Many breeders will be part of a breeder program that provides a ‘free trial period’ when the puppies go home. Be sure to sign up for this even if you do not intend to carry on. During your free period it is a good idea to look around and compare different insurance options to find the one that suites you best. If you choose not to purchase health insurance, do consider setting up your own ‘health insurance’ account and setting aside the money you might otherwise spend on premiums for future health needs of your pet. Doing this on a regular basis and letting the amount build up can help provide for expensive care if it ever proves necessary – and if it never does, you will have a ‘next puppy’ fund ready to go!

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