Bull Terrier nutrition and inherited kidney disease

Protein in the urine is an early, measurable sign of the Bull Terrier's inherited kidney disease, and it can be found with a simple urine test long before the dog looks unwell. That makes a urine protein check the most useful routine test for the breed, and it is also what decides whether a Bull Terrier's diet should change. The rest of feeding this breed is mostly about keeping a heavily muscled dog at a lean weight.

Hereditary nephritis

Hereditary nephritis damages the glomeruli, the tiny filters in the kidney. As the filter membrane breaks down, protein leaks into the urine, and over time the kidneys lose their ability to clear waste. The disease came to attention after reports of a high rate of kidney failure in Australian Bull Terriers. Studying a family of 33 dogs, researchers found that every affected dog had at least one affected parent, with males and females affected about equally. That pattern points to autosomal dominant inheritance, in which one copy of the faulty gene is enough to cause disease. In that family the disease showed up as protein in the urine, changes in the filter membrane under the microscope, and kidney failure.

Dominant inheritance matters for buyers, because an affected dog can pass the disease to about half of its puppies. Ask for the parents' urine protein results before buying a puppy.

Bull Terriers also carry a second inherited kidney disease, polycystic kidney disease, in which fluid-filled cysts gradually replace kidney tissue. It was found in 19 of 99 dogs in an Australian study of Bull Terrier hearts and kidneys. The study found it with kidney ultrasound.

What the urine test shows

The urine protein to creatinine ratio (UPC) compares protein with creatinine in the same sample, so it does not matter how dilute the urine is. According to Veterinary Partner, the International Renal Interest Society (IRIS) treats a UPC above 0.5 in dogs as abnormal. A high result is normally repeated two to four weeks later, after a urine infection or other bladder problem has been ruled out, to confirm that the loss is persistent. The ratio can also vary by up to 30% from one sample to the next, so a smaller change means little.

Feeding a dog with protein in the urine

For a healthy Bull Terrier with normal urine results, there is no reason to restrict protein. A complete and balanced adult food meets the breed's needs, and the muscle the breed is known for is maintained by adequate protein and exercise, not by extra protein.

Once protein loss is confirmed, the approach changes. Veterinary Partner describes the usual treatment for kidney protein loss as a combination of an ACE inhibitor, which reduces the amount of protein leaking through the filters, a renal diet and omega-3 fatty acids. The aim is a UPC below 0.5 or at least a 50% fall.

• Renal diets are lower in protein and sodium than standard foods. It seems odd to cut protein in a dog that is losing it, but the same source explains that feeding extra protein makes blood albumin fall faster in these dogs. Toppers and home-cooked extras undo the formulation, so feed the diet on its own.
• Omega-3 fatty acids are already added to most renal diets. Veterinary Partner notes that they have been shown to improve survival in dogs with kidney disease, and extra supplementation is sometimes advised.
• Water matters more as the kidneys lose concentrating ability. Wet food, water added to meals and several bowls around the house all help.

A renal diet is not meant for a healthy dog with normal urine results, and the protein level of a renal diet is chosen alongside blood results and blood pressure. Changes should be made with the vet, and the UPC rechecked after each one.

Heart valve disease

Bull Terriers are prone to both mitral valve disease, in which the valve between the left chambers leaks, and narrowing of the outflow from the left ventricle, which includes aortic stenosis. In the Australian study, ultrasound of the heart found mitral valve disease in 39% of the Bull Terriers examined, becoming more common with age, and signs of outflow obstruction in 53%. Murmurs were more common in dogs with polycystic kidney disease or with an affected ancestor.

A puppy's heart should be checked at its first vet visits, and a murmur at any age followed up with an echocardiogram. A normal stethoscope check does not rule heart disease out: in the same study, 46% of the dogs with no murmur or irregular rhythm had heart disease on echocardiography. Signs of heart trouble include tiring quickly, fainting during exercise, coughing and fast breathing at rest. Diet changes such as sodium restriction are part of treatment once heart disease is diagnosed, and the vet should set them, particularly in a dog that also has kidney disease.

Calories and body condition

The American Kennel Club gives the breed's weight as 50 to 70 pounds (23 to 32 kg) and its life expectancy as 12 to 13 years. Daily calories can be estimated from the resting energy requirement (RER) in the Merck Veterinary Manual: 70 times body weight in kilograms raised to the power 0.75. A neutered adult needs about 1.6 times RER, an intact adult 1.8 times and a dog that gains weight easily 1.4 times. Rounded to the nearest 5 kcal:

Merck stresses that individual dogs can need 30% more or less than these figures. A Bull Terrier's broad chest and heavy muscle make it look solid even when it is carrying fat, so judge condition by touch. The ribs should be easy to feel under a thin layer, with a waist visible from above. The Royal Kennel Club suggests up to an hour of exercise a day, and most dogs become less active as they age, so portions usually need trimming as activity drops.

Skin, coat and hearing

The short coat needs brushing about once a week. Itching, red skin, repeated ear infections or licking the paws need a vet visit to find the cause, which may be parasites, infection, environmental allergy or a food reaction. If food allergy is suspected, a strict elimination trial with a hydrolyzed or new protein diet, fed for several weeks with no other food or treats, is the standard way to test for it.

Lethal acrodermatitis is a separate, inherited disease of Bull Terriers and Miniature Bull Terriers. Affected puppies grow poorly, have weak immune defenses and develop skin lesions, especially on the feet. It is recessive, so both parents must carry the variant. A 2018 study identified the responsible gene change, which allows breeding dogs to be DNA tested.

White coat color is linked to congenital deafness. When 1,060 Bull Terrier puppies in England were hearing tested, about 10% were deaf in one or both ears, and 96% of the deaf puppies were white or white with patches. About one in five white puppies was affected. The Royal Kennel Club lists BAER hearing tests, including litter screening, among its minimum good-practice tests for breeding dogs. A dog deaf in one ear often goes unnoticed at home. A fully deaf dog can be trained with hand signals and is safer approached from the front, including at mealtimes.

Sources

1. Hereditary nephritis in the bull terrier: evidence for inheritance by an autosomal dominant gene. The Veterinary Record, 1990.
2. Auscultation and echocardiographic findings in Bull Terriers with and without polycystic kidney disease. Australian Veterinary Journal, 2005.
3. Glomerulonephritis in Dogs and Cats. Veterinary Partner, VIN.
4. Bull Terrier dog breed information. American Kennel Club.
5. Nutritional Requirements of Small Animals. Merck Veterinary Manual, 2024.
6. Bull Terrier breed information. The Royal Kennel Club.
7. MKLN1 splicing defect in dogs with lethal acrodermatitis. PLoS Genetics, 2018.
8. Prevalence, heritability and genetic correlations of congenital sensorineural deafness and coat pigmentation phenotype in the English bull terrier. BMC Veterinary Research, 2016.