Polycystic kidney disease (PKD) is a hereditary kidney disease that is common in Bull Terriers. Affected Bull Terriers begin to develop multiple small cysts within both kidneys early in life.
As the Bull Terrier ages, these cysts gradually begin to increase in both size and number and replace normal, functioning kidney tissue. This leads to a decreased amount of kidney tissue that is available to remove waste from the bloodstream. Over time, affected Bull Terriers begin to develop signs of chronic kidney disease. This progressive and irreversible kidney disease often results in renal failure.
Kidneys usually slowly lose function over a period of years. The obvious symptoms appear when the disease is at an advanced stage. PKD may also lead to a bacterial kidney infection that can spread into the bloodstream.
What causes polycystic kidney disease?
PKD is an autosomal dominant inherited condition. This means that the cause of PKD is that the Bull Terrier inherited the abnormal disease gene from one of their parents. Bull Terriers who receive a defective copy of the gene from either one of their parents may show signs of polycystic kidney disease. In other words, a Bull Terrier only needs one of their parents to be affected with PKD in order to inherit the abnormal gene and be affected.
All Bull Terriers with polycystic kidney disease have cysts in their kidneys, but the number of cysts and the rate at which the cysts enlarge varies between Bull Terriers.
If your Bull Terrier is diagnosed with PKD, it is important not to breed your Bull Terrier, as they would be passing the abnormal gene to the litter.
What do your Bull Terrier’s kidneys do?
When blood flows through your Bull Terrier's kidneys, they filter out waste products generated from the breakdown of food, old cells, toxins, metabolic byproducts, and many drugs. They also trap good substances, like proteins, back in the body. Your Bull Terrier’s kidneys have many essential functions:
- Remove waste material from the bloodstream
- Help regulate blood pressure
- Regulate levels of certain essential minerals such as potassium and sodium
- Produce a variety of hormones
- Regulate the amount of water in the blood and produce urine
- Stimulate red blood cells formation
- Help regulate calcium and vitamin D levels
Early diagnosis is imperative for all potential breeding Bull Terriers.
Symptoms of polycystic kidney disease in Bull Terriers
In young Bull Terriers, polycystic kidney disease is generally asymptomatic. As Bull Terriers age, their functional kidney is gradually displaced by cysts and kidney function decreases. The clinical signs of PKD are often first observed in mature, middle-aged Bull Terriers. The obvious symptoms appear when the disease is at an advanced stage.
Signs of polycystic kidney disease are variable. The most common symptoms of polycystic kidney disease in Bull Terriers are:
- Diarrhea or constipation
- Lack of appetite
- Gradual but consistent weight loss
- Enlarged kidneys
- Increased thirst and urination
- Acute blindness
- Seizures or coma
Less common symptoms include:
- Weakened bones
- Bruising of skin
- Itchy skin due to calcium and phosphorus deposition in the skin
- Bleeding in the gut or stomach
Bull Terriers vary significantly in how rapidly cyst development and other signs of renal failure will progress. Many Bull Terriers with polycystic kidney disease can survive to 8-10 years of age, as long as appropriate treatment and monitoring are provided.
Polycystic kidney disease often occurs so gradually in dogs that by the time the symptoms become obvious in Bull Terriers, it is already late to manage the disease effectively.
Diagnosing polycystic kidney disease in Bull Terriers
The primary indicator of polycystic kidney disease in Bull Terriers is dilute urine. The vet needs to take some blood and urine tests including a chemical blood profile and a complete blood picture. Bull Terriers with polycystic kidney disease may have abnormal electrolyte levels, anemia, elevated blood pressure, and abnormally high levels of blood creatinine and blood urea nitrogen (BUN).
Other tests may include X-rays and ultrasounds to check cysts and the size and shape of the kidneys. The severity of polycystic kidney disease can be estimated based on blood waste product elevations. It is also measured by abnormalities in urine like the presence of protein in the urine.
Treatment of polycystic kidney disease in Bull Terriers
Polycystic kidney disease in Bull Terriers is not a disorder that can be cured and there is no specific treatment for polycystic kidney disease. However, it can be managed through supportive treatments.
Treatments of PKD may include a prescription diet, fluid supplementation, and medications to manage the effects of kidney disease. The vet may suggest a low-protein diet for your Bull Terrier and vitamin D supplements.
Fluid therapy is the cornerstone of treatment primarily to prevent dehydration. Your Bull Terrier should have access to fresh and clean water at all times. Potassium is often added to the diet or fluid to safeguard against muscle weakness.
You should observe how much food and water is consumed by your Bull Terrier. Also, try to weigh your Bull Terrier weekly to make sure they are getting enough calories to maintain their body weight. Provide an organic food diet to the Bull Terriers suffering from polycystic kidney disease. Feed your Bull Terrier a high-moisture diet that is low in protein and phosphorus.
How is polycystic kidney disease prevented?
The only way to prevent polycystic kidney disease is to avoid breeding affected Bull Terriers. This can be challenging because most Bull Terriers do not show any symptoms of the disease until they're past prime breeding age.
There is no cure for polycystic kidney disease but Bull Terriers can go on to live full lives. If your Bull Terrier is showing any symptoms of kidney disease, seek treatment to ensure the issue does not become severe. A vet annual examination is a key part of preventive care.
Given the increased risk of this PKD in Bull Terriers, genetic testing is recommended to screen Bull Terriers prior to breeding. Making the right choices will help you to avoid guilt and regret.
If you suspect your Bull Terrier is sick, call your vet immediately. For health-related issues, always consult your vet, as they have examined your Bull Terrier, know the Bull Terrier's health history, and can make the best recommendations for your Bull Terrier.