The domestic dog species shows more size variation than any other land mammal on the planet. This fact is no better illustrated than my recent experience with "Porcha" a 7 year old Chihuahua from Coventry who was presented at Fairfield with a severe right hind lameness.

"Porcha" had been referred to me by the owner's insurance company who were keen to have her problem solved without paying an exorbitant fee. As the third veterinary practice to be consulted it was clear that her problem was not likely to be straightforward.

Whilst the diagnosis was relatively simple the surgery was a lot more demanding. "Porcha" was suffering from a severe dislocation of her kneecap (Grade 4 luxating patella). Weighing in at only 1.34kg (2.95lb) she is amongst the smallest patients on which I have ever had to operate. It is worth bearing in mind that most cats will weigh between 8 and 12lb.

In order to resolve her dislocated knee I had to break her shin bone (tibia) to which the knee-cap (patella) attaches and then reset the fracture in a better alignment using a partially threaded stainless steel pin. There was absolutely no room for error. The wrong size pin or only a couple of millimetres off centre could have spelled disaster.

Fortunately, everything went as planned and "Porcha" was using her new knee within a couple of days. They say "the best things come in small packages" and I don't believe "Porcha's" owners will disagree!