My Bull Terrier was diagnosed with PKD — here’s what I wish I’d known sooner

The word came up almost as an aside. We had taken our four-year-old EBT, Mojo, in for a routine wellness check. The vet was running through his results when she said, almost casually, that his SDMA levels were slightly elevated and she wanted to do an ultrasound. I went home and Googled SDMA. By the time I had been on the internet for twenty minutes I was spiralling. By the time the ultrasound results came back two weeks later confirming polycystic kidney disease, I had read enough to understand what it meant — but I wish I had known much earlier.

Because here is the thing about PKD in Bull Terriers: the disease is silent. Mojo showed no symptoms that I had noticed. He was eating well, exercising happily, drinking normally — or so I thought. When I went back through the notes I had been keeping in the app, I could see, going back three months, that his water intake had crept up slightly. Not dramatically. Not enough to alarm me. But it was there in the data.

What the diagnosis actually meant

The vet explained it clearly once I asked the right questions. PKD is hereditary — a dominant gene, meaning one copy from one parent is enough to cause the condition. Mojo had cysts in both kidneys, visible on ultrasound. His SDMA was elevated but his creatinine was still within normal range, which meant we had caught it relatively early. We were at Stage 2, she said. Not great, but a much better position than if we had caught it when he was symptomatic.

The first change was diet. We switched to a lower-phosphorus food and added marine omega-3 supplementation. The vet explained the reasoning: excess phosphorus accelerates kidney damage, and the kidneys of a PKD dog have less capacity to excrete it. We also started monitoring blood pressure at each visit. And we scheduled blood and urine tests every six months rather than annually.

What I track now

The biggest change in how I manage Mojo’s day-to-day health has been logging his water intake properly. I measure it. A 28 kg dog should drink roughly 1.4 to 1.7 litres a day under normal conditions. I log it in Bull Terrier Buddy. If it goes significantly above that baseline for more than a couple of days, I contact the vet rather than wait for the next scheduled appointment. That early warning system — which is just a daily measurement and a log — is how we caught the incremental change that led to the SDMA flag in the first place.

I also log appetite, energy on walks, and weight monthly. Not because I expect drama, but because having the baseline makes any deviation obvious rather than something you have to try to remember retrospectively at a vet appointment.

What I would tell someone whose EBT has just been diagnosed

First: this is not an immediate crisis. Many dogs with PKD live comfortably for years after diagnosis with the right management. The stage at diagnosis matters enormously. Second: start the management changes immediately and consistently — particularly diet. The phosphorus restriction is not optional. Third: get the monitoring schedule in your diary and treat it as non-negotiable. Blood and urine every six months is the minimum. Fourth: start logging properly. Not for the sake of it — but because the data you build over the coming months and years becomes your most useful tool at every vet appointment.

And if you have an EBT and you do not know whether they have been PKD screened, ask your vet to include SDMA in the next routine blood panel. It is the earliest functional marker available, and catching this condition early is the single most important determinant of long-term outcome.

See the full Bull Terrier kidney disease guide for everything you need to know about PKD — symptoms, staging, diagnosis, treatment, and what to ask your breeder before buying a puppy.