Genetic Diseases


All breeds suf­fer from some genetic dis­eases and Bull Ter­ri­ers are no excep­tion. Dis­eases that affect the Bull Ter­rier breed are:

  • Deaf­ness (Uni­lat­eral & Bilateral)
  • Heart Dis­ease
  • Kid­ney Dis­ease (hered­i­tary and PKD)
  • Lux­at­ing Patella

All the respon­si­ble breed­ers must test their ani­mals before breed­ing and all the respon­si­ble own­ers to be must ask for these tests before tak­ing a puppy. This is the road to a health­ier bull ter­rier breed !!!


From the first days of the breed Bull Ter­ri­ers has been rec­og­nized to have deaf­ness issues. For many years it was believed that only the white ani­mals could be deaf but this is not true because nowa­days we know that there are also some coloured ani­mals that was found deaf! Breed­ers had stopped breed­ing from ani­mals that were deaf in order to face this prob­lem but there were still some pup­pies born deaf and the rea­son for that is that until recently it wasn’t pos­si­ble to accu­rately iden­tify ani­mals which are par­tially deaf, and that breed­ers may have inad­ver­tently been breed­ing from ani­mals with less than per­fect hear­ing. Nowa­days it is pos­si­ble to test Bull Ter­ri­ers elec­tron­i­cally, to iden­tify exactly how well the ani­mal can hear. This test, known as the B.A.E.R. (Brain Audi­tory Evoked Response) Test, can car­ried out from about 5 weeks old and it’s a quite sim­ple and easy process. There are three deaf­ness classifications:

  • Nor­mal bilat­eral hearing
  • Uni­lat­eral deaf (deaf in one ear)
  • Bilat­er­ally deaf­ness (deaf in both ears)

Only the ani­mals with nor­mal bilat­eral hear­ing should be bred, to try and erad­i­cate this gene from the breed­ing stock.


Bull Ter­ri­ers are affected mostly by Mitral Dys­pla­sia and Subaor­tic Steno­sis. The affected ani­mals can suf­fer from heart attacks whilst other sign may be lack of activ­ity or short­ness of breath. A vet­eri­nary car­di­ol­o­gist can detect heart mur­murs that come with those dis­eases with stetho­scope aus­cul­ta­tion. There are also some tests you can do in order to check heart’s health which include x-ray of the chest, elec­tro­car­dio­graph to mea­sure the heart’s elec­tri­cal activ­ity and a color Doppler test.


There seem to be two types of kid­ney dis­eases in Bull Ter­ri­ers. The first one is Poly­cys­tic Kid­ney Dis­ease (PKD) and the sec­ond one is hered­i­tary Nephritis.

Typ­i­cal signs of kid­ney fail­ure include the following:

  • poor appetite
  • dull­ness or lethargy
  • weight loss or stunted growth
  • poor hair coat
  • vomiting/diarrhea
  • foul breath and mouth ulcers
  • mus­cle twitch­ing and convulsions
  • drink­ing excess water and pass­ing too much urine
  • pale gums (anemia)
  • dehy­dra­tion (sticky dry gums)

In order to diag­nose these dis­eases you can do a kid­ney ultra­sound or a biopsy but the most com­mon and easy way is a blood test to deter­mine the Urine Pro­tein Cre­a­ti­nine ratio (UP/C). In most breeds a read­ing of up 1.0 is nor­mal how­ever the rec­om­men­da­tion for the Bull Ter­rier is that must not be /higher than 0.3.


The patella is a small bone slid­ing in a groove in the sti­fle joint — equiv­a­lent to the kneecap in the human knee. If the groove is too shal­low the patella may slip side­ways out of the groove, caus­ing the dog to limp, until it slips back — often seen as a limp, a skip and hop fol­lowed by nor­mal move­ment. The patella may slip out of its groove eas­ily or only occa­sion­ally. In a badly affected dog the joint is painful and becomes arthritic. The mode of inher­i­tance is poly­genic (con­trolled by sev­eral or many genes) and can only be com­bated by breed­ing from unaf­fected par­ents. A vet­eri­nary sur­geon can test the joint by feel­ing how firmly seated the patella is in its groove and by a sim­ple x-ray.
It is wise to limit your puppy/adolescent Bull Terrier’s activ­ity (i.e. don’t allow them to jump from heights, etc.) to help reduce undue strain on young joints, for the first six months. It is advis­able that all breed­ing stock should be tested for this inher­ited prob­lem and any dog found to have the dis­ease, should be removed from any breed­ing program.

With love and pas­sion for breed­ing try­ing to pro­tect the health,

Labrini Maniati — Kostas Lentoudis