The
CAIRN TERRIERS
of
New Zealand
Cairn Health
The Cairn Terrier is a generally healthy little dog, often living into his late teens.
Like all breeds, purebred or mixed, there are some potential problems the Cairn is predisposed to.
Responsible breeders will screen for these and will not breed from any affected Cairns.

This website created and maintained by Kelbryn Dezign. © 2012


PORTOSYSTEMIC SHUNT (PSS)


A Portosystemic Shunt (PSS), also known as a liver shunt, is a bypass of the liver by the body's ciculatory system. It can be either a congenital (present at birth) or acquired condition.
PSS is a congenital abnormality that can occur with Cairn Terriers (and other breeds).
Congenital PSS is caused by the failure of the foetal circulatory system of the liver to change. Normally, the blood from the placenta bypasses the liver and goes into circulation via the ductus venosus, a blood vessel found in the foetus. A failure of the ductus venosus to close causes an intrahepatic shunt, while extrahepatic shunts are usually a developmental abnormality of the viteline veins, which connect the portal vein to the caudal vena cava. Thus in the juvenile and adult animal with PSS, blood from the intestines only partly goes through the liver, and the rest mixes into general circulation. Toxins such as ammonia are not cleared by the liver. Most commonly, extrahepatic shunts are found connecting the portal vein or left gastric vein to the caudal vena cava.
Congenital shunts are usually solitary.

Symptoms:

Usually appear by six months of age and include failure to gain weight, vomiting, and signs of hepatic encephalopathy (a condition where toxins normally removed by the liver accumulate in the blood and impair the function of brain cells) such as seizures, depression, tremors, drooling, and head pressing. Urate bladder stones may form because of increased amounts of uric acid in circulation and excreted by the kidneys. Initial diagnosis of PSS is through laboratory blood-work showing either elevated serum bile acids after eating or elevation of fasting blood ammonia levels.
All these symptoms can occur variably. It is very well possible that a Cairn with a liver shunt has periods of looking seemingly healthy, alternating with periods of being very sick.

Treatment:

Shunts can be closed surgically.

Prevention:

There is currently no DNA test to test to prove what dogs are carriers for PSS. At 6 - 7 weeks of age a blood test (bile acid test) can be conducted on puppies to prove healthy liver function.
LUXATING PATELLA

Luxating patella (or trick knee, subluxation of patella or floating knee) is a condition in which the patella or kneecap, dislocates or moves out of its normal location. The condition is inheritable or can be caused by blunt force trauma. Patella luxation is a common condition in dogs, particularly small and miniature breeds. The condition usually becomes evident between the ages of 4 to 6 months.

There are different grades of severity with luxating patellas:
Grade 1 - the patella can be manually luxated but is reduced (returns to the normal position) when released;
Grade 2 -  the patella can be manually luxated or it can spontaneously luxate with flexion of the stifle joint. The patella remains luxated until it is manually reduced or when the animal extends the joint and de-rotates the tibia in the opposite direction of luxation;
Grade 3 - the patella remains luxated most of the time but can be manually reduced with the stifle joint in extension. Flexion and extension of the stifle results in re-luxation of the patella;
Grade 4 -  the patella is permanently luxated and cannot be manually repositioned. There may be up to 90% of rotation of the proximal tibial plateau. The femoral trochlear groove is shallow or absent, and there is displacement of the quadriceps muscle group in the direction of luxation.

Treatment:

Grades II, III and IV require surgery to correct, if the animal has difficulty walking. The surgery required is governed by the type of abnormality present.

Prevention:

Dogs with luxating patellas should be not be bred from. A health check of the parents by a vet will determine that the parents are sound.


by Kathryn Smith - Duncairn Cairn Terriers (Aust)
Reproduced with permission