A Hamilton man tied his dog's legs together, hung it from a tree, used a Stanley knife to cut the dog's scrotal skin and then squeezed out the poor pooch's testicles.

Those details were among the gruesome facts heard in the Hamilton District Court today, after a 33-year-old was sentenced for performing on his dog a home castration that went horribly wrong.

The court heard the man, who hasn't been identified, took his seven-month-old crossbreed dog into Hamilton Veterinary Services on August 26, 2015.

The dog had scrotal wounds.

Source: Seven Sharp

At the time, the man claimed the wounds were caused by the dog jumping over a low fence two days earlier.

Two vets examined the dog and immediately suspected that the dog had been deliberately castrated.

Further examination under anaesthetic confirmed their suspicions, and staff notified the SPCA.

In a media statement, SPCA today stated a vet at the time had to perform surgery on the dog to remove its entire scrotum.

When interviewed, the defendant admitted that on August 24, 2015, he tied the dog's four legs together with a rope.

He then tied its mouth shut with a cloth and hung the dog from a tree, to stop it from moving.

Then, using a Stanley knife, he cut the scrotal skin, squeezed out the testicle and cut the cord to remove it.

He did this same procedure on the other side.

The man finished by washing the wounds with salt water and cutting the dog loose.

The vet who performed surgery said the dog would have suffered significant pain and distress during and after the procedure.

The defendant admitted he wasn't a qualified veterinarian, did not seek any advice before carrying out the procedure and claimed he was unaware that home castration was illegal in New Zealand.

The defendant surrendered the dog to the SPCA.

It has since made a full recovery and has been adopted by new owners.

The man was sentenced to 150 hours community work, fined $350, ordered to pay $500 towards legal costs and pay reparations of $442.40.