Ununited Anconeal Process in Dogs

Ununited anconeal process is a condition that affects a dog's elbow and it's where a bony growth known as a anconeal process does not fuse with the ulna. These are the smaller bones that make up a dog's front leg. Without the correct anconeal process, a dog's elbow joint cannot develop as it should and therefore it does not provide any stability in the joint particularly when a dog extends a front leg.

The Cause

When a dog's elbow joint has developed as it should and therefore it is healthy, the anconeal process fuses properly with the ulna which it does when dogs are around 6 months old. With this said, some dogs don't show any signs of there being a problem with their elbow joints until they are twelve months old. If the anconeal process fails to occur, it is around this time that a dog would start to show signs of being in pain and they would constantly be lame on an affected front leg.

Apart from the anconeal process not fusing with the ulna, a dog might also have other abnormalities in their elbow joints which could involve a bone fragment or bit of cartilage floating around in the joint which is a condition known as osteochondritis dissecans. This fragment of bone causes a lot more pain and discomfort to dogs. It contributes to them being lame and as the fragment moves around inside the joint, it causes a lot of damage.

Breeds Most Affected by the Condition

There are certain breeds that seem to be more predisposed to suffering from UAP than others with German Shepherds, Saint Bernards and Bassett Hounds being high on the list. It's thought the condition develops because of a badly formed elbow whether it's the ulna notch that’s not quite right or because a dog has short legs and therefore develops short ulna syndrome. The first sign of there being something wrong is when a dog is constantly lame on one or both legs and the prognosis depends on how early the condition is diagnosed and subsequently treated.

Signs to Watch Out For

The condition can affect one or both of a dog's elbows and the most obvious signs of there being a problem with a joint, as previously mentioned is when a dog is constantly lame on one or both front legs. However, other symptoms of UAP include the following:

• Swollen elbows
• Pain in the elbow, more especially when a dog extends an affected front leg

Diagnosing the Condition

A vet would need to thoroughly examine a dog that's suspected of suffering from UAP and they would take X-rays of an affected elbow joint to confirm their suspicions. However, in some cases the abnormality is so mild that it can be hard to detect on an X-ray, in which case a vet would recommend taking a CT scan to determine whether a dog is suffering from Ununited Anconeal Process or some other condition.

Treating the Condition

Early diagnosis makes for a much better prognosis for dogs suffering from UAP. The end goal of any treatment is for a vet to be able to reattach a ununited anconeal process which offers the best outcome. But this only applies if the condition has been caught early enough so that any loose fragment that’s floating around in a joint has not had time to damage or change the shape of the elbow joint. If the fragment has caused a lot of damage and there’s been a change in shape of an affected joint, a vet would typically recommend removing the anconeal process altogether and replace it with a false one which would allow a dog free movement of their elbow.

Should the condition be left untreated, it will get progressively worse causing a dog a great deal of pain until the joint becomes totally useless leaving them walking on three legs if only one of their elbow joints is affected by the condition. Should both elbows be affected, a dog would not be able to move at all. The other thing is that as a dog ages, their condition gradually gets more severe especially as arthritis sets in causing even more pain and discomfort.

Breeds More Predisposed to the Condition

The condition appears to affect certain breeds more than others which as previously mentioned includes the following:

• Saint Bernards
• German Shepherds
• Basset Hounds

Good Breeding Practices are Essential

Reputable breeders would never use a dog that's suffering from ununited anconeal process in a breeding programme because it is a genetically transmitted health issue that dogs can pass on to their offspring. As such anyone wishing to share a home with a breed that's known to be predisposed to suffering from the condition should ask breeders about a puppy's bloodlines to make sure they are free of UAP.