Scottish Terrier Genetic Issues
Scottish Terriers, like all living creatures, are subject to congenital, hereditary, and acquired health disorders. Thanks to antibiotics and vaccines, most of the problems that result from these causes can be treated effectively. The most serious health problems your dog will face are genetic. Scotties are fortunate to have few serious genetic problems compared to other breeds. Responsible breeders are working hard to manage these problems in the Scottie Gene pool. Here is some information about the most common genetic health problems seen in the Scottish Terrier. These are not in any particular order in either frequency or seriousness.
Scottie Cramp is the most wide-spread hereditary disorder in the breed and it is also the least serious, from the dog's point of view. Affected dogs are normal at rest and exhibit normal ability to walk until they are stressed. Common stimuli are exercise, hunting, fighting, or courtship. As the dog's level of stress increases, his gait begins to change. The forelegs move out to the side and forward rather than straight forward, called winging. The spine in the lumbar area may arch and the rear legs begin to over flex. If the excitement or exercise continues, the dog begins to exhibit a "goose-stepping" gait. If the dog is running, he may somersault and fall. Severely affected dogs may find their ability to walk or run completely inhibited. This is not a seizure. There is no loss of consciousness. As soon as the stimulus abates, the symptoms disappear almost immediately.
The severity of symptoms in affected dogs varies widely as does the amount and type of stimulation necessary to elicit clinical signs. The symptoms appear to be caused by a buildup or depletion of some chemical compound in the dog's central nervous system, most probably serotonin. In layman's language, the signal from the brain telling the dog how to run gets garbled in transmission on its way to the various muscles. The Scottie's muscles are not cramping and he is not experiencing pain. He has just temporarily lost the ability to coordinate his movements.
Scottie Cramp is present from birth, but it often takes the eye of an experienced breeder to spot it. Affected dogs soon learn to anticipate the onset of cramping and abruptly stop running or playing. By the time such a puppy is grown, he may never exhibit any signs at all. Similarly, an affected dog with a very laid-back personality is less likely to exhibit symptoms than a more hyperactive Scot.
Scottie Cramp is a permanent condition, but it does not worsen with age. Nearly all dogs affected with Scottie Cramp make perfectly wonderful companions, able to share virtually all activities with their families. Treatment is seldom necessary but, in severe cases, Vitamin E, Diazepam and Prozac have all proven to be effective.
Von Willebrand's Disease (VWD) is the name given to a group of similar inherited bleeding disorders that occur in humans, pigs, dogs and rabbits. VWD is usually less clinically severe than hemophilia and is inherited as an autosomal trait. This means that it can be transmitted equally by and to both sexes.
Carriers are asymptomatic but affected dogs may exhibit any of the following symptoms:
- Excessive bleeding when the nails are cut too short
- Severe bleeding during surgery
- Bleeding from the nose or gums, particularly during teething
- Bleeding from the vagina or penis
- Hematomas on the surface of the body, limbs or head
- Internal bleeding
- Lameness from bleeding into the joints
- Stillbirths or neonatal deaths with evidence of hemorrhage at autopsy
- Chronically infected and bloody ears
- Prolonged bleeding during the heat cycle or after whelping
- Bleeding in stools or urine
Cushing's Syndrome is a collection of symptoms caused by an excess of a hormone called cortisol. There are three main causes of Cushing's Syndrome: a tumor on the pituitary gland; a tumor on the adrenal gland; or veterinarians who over-prescribe corticosteroids to treat itching skin. It is, as yet, unknown whether there is an inherited predisposition to Cushing's Syndrome in Scottish Terriers.
- He is drinking huge amounts of water and urinating frequently
- He is losing coat
- His skin is darkening
- His muscles are atrophying and he develops a pot belly
- If your vet finds the following four symptoms, your Scottie probably has Cushing's Syndrome:
- The dog is drinking copious amounts of water and urinating frequently.
- The dog has an elevated SGPT.
- The dog has an elevated alkaline phophatase level
- The dog's ratio of urinary cortisol to urinary creatine is greater than 24
Cushing's Syndrome is usually treated successfully with a drug called Lysodren. Surgery is rarely recommended and radiation therapy, used in humans, is very expensive and rarely available for dogs.
Hypothyroidism is an underproduction of hormones by the thyroid gland. Symptoms of hypothyroidism include:
- Abnormal loss of coat (often bilateral and symmetrical), poor coat condition, fading of coat color
- Chronic skin disorders and infections, skin allergies, dry or scaling skin
- Weight gain
- Fatigue, lethargy
- Intolerance of cold
It is important to determine the exact cause of your dog's hypothyroidism before embarking on a course of treatment. Your veterinarian must run a full thyroid panel and have the blood tested at a laboratory which uses canine thyroid values. Do not be tempted to start thyroid treatment without proper veterinary supervision. The balance of the endocrine system is critical to your dog's health and you can cause an otherwise healthy thyroid gland to atrophy by giving medication improperly.
Seizures may be caused by a number of conditions, including low blood sugar, brain tumor, heat stroke, poison, nutritional deficiency and distemper. Classic or idiopathic (meaning "of unknown cause") epilepsy is characterized by recurrent seizures with no active underlying disease process occurring in the brain. This form of epilepsy is not usually seen until a dog is mature, usually between three and five years of age.
In a typical seizure, the dog will salivate excessively. There is usually dilation of the pupils and stiffening of the limbs. The dog may arch its back and paddle its legs. Frequently, the dog's temperature will spike up three to five degrees. Urination or defecation may accompany or follow the episode. Seizures usually last only a minute or two, but severely affected dogs may have longer and more frequent episodes. Dogs who have infrequent seizures do not require treatment. When treatmen is required, phenobarbital, dilantin and primidone are frequently used.
In recent years, there seems to be an increase of reported seizures in Scottish Terriers. While some of the increase may be due to environmental hazards, inherited epilepsy has definitely made inroads into the Scottie gene pool.
Craniomandibular Osteopathy (CMO) is an inherited disorder characterized by an abnormal growth of the bone of the lower jaw. CMO usually appears between four and seven months. A puppy with CMO usually pulls away, flinches or screams with pain when his mouth is examined, depending on the severity of the disease. Other early symptoms are lethargy, fever and unwillingness to eat. An acutely affected puppy may be unable to open his mouth but mild cases may be misdiagnosed as teething problems or virus symptoms. An accurate diagnosis of CMO requires X-ray confirmation.
CMO is nearly always treatable. Mild cases respond to aspirin or other non-steroidal anti-inflammatory drugs such as ibuprofen or while acute cases may require the use of steroids such as prednisone or prednisolone. Fortunately, as the dog matures, the abnormal bony growth abates and is often undetectable in the adult dog, even by radiography.
Cerebellar abiotrophy (CA) is an inherited disorder causing death of Purkinje cell in the cerebellum. The disorder is seen in several canine breeds and other species including humans. In the Scottish Terrier, the disorder has an median onset of 7 months. The disease often has progressive deterioration in gait, but not in all cases.
Generally, the affected dogs appear normal when walking. However, they show hind limb ataxia when going up or down stairs. As the disease progressed, owners report dogs show noticeable gait abnormalities in all 4 limbs. It becomes progressively more difficult for dogs to negotiate stairs and they lose contol of their pelvic limbs when running.
The assumed mode of transmission is an autosomal recessive trait. However no gene or genes have been isolated to cause the disorder.
Transitional Cell Carcinoma (TCC)
The most common cancer of the dog urinary bladder is invasive transitional cell carcinoma (TCC) of intermediate to high grade. TCC is also called urothelial carcinoma. TCC is a malignant tumor that develops from the transitional epithelial cells that line the bladder. In dogs, this tumor invades into the deeper layers of the bladder wall including the muscle layers. As the cancer enlarges in the bladder, it can cause obstruction to the flow of urine from the kidneys to the bladder or from the bladder to the outside of the body. Canine TCC also has the ability to spread to lymph nodes and to other organs in the body (lung, liver, others). TCC most frequently is found in the bladder, but can also develop in the kidneys, ureters, prostate, and urethra. In regards to human bladder cancer, most cases fall into two general categories: (1) lower grade, superficial tumors, and (2) higher grade, invasive tumors. It is fortunate that the majority of people with bladder cancer have the lower grade, superficial form of the disease, which typically does not spread beyond the bladder. Dogs, on the other hand, most often develop the higher grade, invasive form of bladder cancer that can grow more quickly and can spread throughout the body.
What causes TCC in dogs?
The exact cause of TCC in an individual dog is usually not known. In general, canine TCC results from a combination of several factors including genetic predisposition and environmental factors. A genetic predisposition is strongly suspected because TCC is more common in specific breeds of dogs. Scottish Terriers have an 18-20 fold higher risk of TCC than other dogs. Shetland Sheepdogs, Beagles, West Highland White Terriers, and Wire Hair Fox Terriers are 3 to 5 times more likely to develop TCC than other dogs. Dogs in related breeds may also have a higher risk of TCC, but this has not been studied yet. Environmental factors identified as risk factors in early studies have included pesticides and insecticides such as "old generation" flea dips. The greatest cause of TCC in humans is smoking. Further study is needed to determine the extent to which second hand smoke could contribute to TCC in dogs.
An association has been found between exposure to lawn herbicides and pesticides and the risk of TCC in Scottish Terriers. Investigators at the Purdue University School of Veterinary Medicine have published a case control study in Scottish Terriers to determine risk factors for the development of TCC. As discussed above, Scottish Terriers have an 18-20 times higher risk for developing TCC than dogs of other breeds. The study was performed to determine if exposure to certain types of environmental chemicals would further increase the risk of TCC in this breed of dog. Environmental exposure histories were compared between 83 Scottish Terriers with TCC (cases) and 83 Scottish Terriers of approximately the same age with other health-related conditions (controls). A significantly increased risk of TCC was found for dogs exposed to lawns or gardens treated with herbicides and insecticides or herbicides alone. In fact dogs exposed to treated lawns were seven times more likely to develop TCC. These findings indicate that Scottish Terriers, as well as other dogs of high-risk breeds for TCC, should be restricted from lawns treated with herbicides and pesticides. The risk of lawn chemicals to dogs in other breeds has not yet been determined.
What are the signs & symptoms of TCC ?
- Blood in the urine
- Straining to urinate
- Making repeated frequent attempts to urinate are the most frequent signs of TCC in dogs
- Lameness (less common)
How is TCC diagnosed?
- A tissue biopsy can be obtained by surgery, cystoscopy (insertion of a fiberoptic scope into the bladder and biopsy through the scope), or in some cases with a urinary catheter.
What evaluation is needed for a dog with TCC?Once a diagnosis of TCC is made, it is important to determine tumor staging. Tumor staging is performed to determine the best way to treat the cancer, to provide some information regarding prognosis, and to establish a baseline set of tumor measurements in order to determine if subsequent treatment is being successful.
Tumor staging for TCC includes:
- xrays of the thorax to look for lung metastasis
- xrays and ultrasound (or CT scan) of the abdomen to look for metastasis in the abdomen and to assess any changes in the kidneys that result from obstructed urine flow
- imaging of the bladder to determine the exact location and size of the tumor within the bladder
How is TCC treated?
Surgery:For dogs with TCC that has not spread beyond the bladder, surgical excision could be considered. In order to surgically excise the tumor, however, it needs to be located away from the neck (also called the trigone) of the bladder and the urethra. Unfortunately, structures in the area ureters, urethra, urethral sphincter) usually prevent surgical resection of tumors in the neck area of the bladder. This is especially true because malignant tumors, like TCC, need to be removed with a "margin" of normal tissue around the tumor in order to help prevent regrowth of the tumor. Most canine TCCs invade down into the bladder wall and therefore, surgical excision requires removal of a complete full thickness section of bladder wall.
- Radiation therapy has been used to successfully control TCC growth in the bladder in dogs.
- Chemo agents such as mitoxantrone, Vinblastine, chlorambucil, Cisplatin or Carboplatin
What is the prognosis for dogs with TCC?
It is not known how long dogs with TCC that are not treated will live. Survival is affected by the growth rate of the tumor, the exact location of the tumor within the bladder, and whether the tumor has spread to other organs or not.
What symptomatic care can be given to dogs with TCC?
Dogs with TCC are very prone to developing bacterial infection (cystitis) in the bladder. Therefore, frequent urinalysis, culture, and treatment with antibiotics may be necessary. A secondary bacterial infection can result in a sudden worsening in symptoms (blood in urine, straining to urinate) in dogs with TCC, and these dogs will improve with treatment with antibiotics.
TCC can block the flow of urine into and out of the bladder. Complete obstruction can rapidly lead to a buildup of urea and life-threatening complications. If urine flow is obstructed, stents (small tubes) can be placed in the ureters or urethra, as needed, to open up the "channels" and restore urine flow.
Can TCC be prevented?
Steps that can be taken to reduce the risk of TCC in dogs:
(1) avoiding older generation flea control products, i.e. flea dips
(2) avoiding lawns treated with herbicides and pesticides
(3) feeding vegetables at least three times per week.
TCC screening for early detection
The Wellness Clinic in the Purdue University Veterinary Teaching Hospital is providing a TCC screening program for older dogs in high-risk breeds (Scottish terriers, West Highland white terriers, Wire hair fox terriers, Shetland sheepdogs, beagles). The screening includes an ultrasound exam of the bladder and tests performed on the urine at six-month intervals. This program is considered optional in the care of dogs. Although the screening is expected to lead to earlier diagnosis and the chance to treat the cancer before it becomes advanced, it is not yet known if it this screening program will improve the outlook for dogs or not. Pet owners who wish to schedule an appointment or check the availability and costs of the program can call the Purdue Small Animal Clinic at 765 494-1107. Stay tuned, as an expanded option for TCC screening is under development in 2013.
BREAKING NEWS MARCH 2016:
Please click on the Powerpoint presentation below by Dr. Matthew Breen from North Carolina State University about an early diagnostic test which detects a single gene mutation called BRAF that has been found to be present in 85% of TCC cases.
This early diagnostic tool allows for the detection of cancer cells before they become imbedded in the muscle tissue of the bladder making it easier for resection of the cancer tumor before it metastasizes.
Dr. Breen has been working with the parent clubs of each of the top 10 breeds most susceptible to TCC to do early testing of the diagnostic procedure with dogs over the ages of 6-7, and so far his results have been impressive! The process includes collection of urine which is then sent to a lab every 4 months for screening.
While the roll out will start in April 2016 Dr. Breen is asking us to start letting our own veterinarians know about this new diagnostic tool that will become available later this year!
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The purpose of this information is educational and informational only. Always seek the advice of your veterinarian with any questions you may have regarding a condition or treatment and before undertaking a new health care regimen, and never disregard professional veterinarian advice or delay in seeking it because of something you have read on this website.
The Scottish Terrier Club of Michigan, Inc. does not recommend or endorse any specific tests, veterinarians, products, procedures, opinions or other information that may be mentioned on this page.
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