Persistent Hyperplastic Tunica Vasculosa Lentis (PHTVL) in Dogs

Persistent Hyperplastic Tunica Vasculosa Lentis is a congenital eye anomaly that appears to affect certain breeds more than others with Dobermann Pinschers being among those most affected by the condition. The condition starts developing in puppies when they are still forming in their mother's womb which is typically four to five weeks after she has conceived. The condition occurs because blood vessels responsible for the lens in a dog’s eye fails to be reabsorbed which as a result can affect a puppy's vision to varying degrees. In short, their sight can be mildly affected by the condition or it can be so severely impaired they are born blind.

Signs and Symptoms

Sadly, it is really hard to see any signs of there being a problem with a puppy's eyes when they are first born. However, a vet would be able to examine their eyes when they are around 4 weeks old, but it is more typical for a correct diagnosis to be made when puppies are that much older which is usually between the ages of 8 and 12 weeks.

What About Treatments?

Unfortunately, PHTVL is not easily treatable, but if a puppy's sight is only mildly affected they can go on to lead good quality lives especially as dogs are so adept at compensating for their impaired vision by using their acute sense of smell and hearing to get around.

If a vet deems the condition to be severe, it is possible for a dog to undergo surgery with an end goal being to correct their vision. However, the surgery involved is not only extremely specialised and delicate, but it is also very expensive and there are never any guarantees of the surgery being successful. In short, more often than not it is that much kinder for a puppy that's born blind to be put to sleep.

Breeds Most Affected by PHTVL

The breeds that appear to be the most affected by Persistent Hyperplastic Tunica Vasculos Lentis are as follows:

• Dobermann Pinscher
• Staffordshire Bull Terrier
• Basenji

How Common is PHTVL?

Fortunately, the condition is not very common in Dobermanns with around 1% of dogs tested on an annual basis being affected. If the condition is mild and a dog's vision is only mildly impaired, it is not a life threatening health issue that owner's need to worry about. However, it is a congenital condition and therefore all stud dogs should be deemed clear of PHTVL before being used in a breeding programme. With this said, even if a parent dog is screened and the tests come back clear, there is no guarantee that a puppy would not be born with the condition, it just means there is less chance of it happening.

The Importance of Responsible Breeding

Breeders should always have their stud dogs screened for any eye abnormalities which includes for PHTVL because this is the only way of reducing the risks of puppies being born with this congenital eye disorder. As such, when buying a breed that is known to be prone to suffering from Persistent Hyperplastic Tunica Vasculosa Lentis, it is really important to contact responsible breeders who routinely have their dogs eye tested.

Living with a Dog with PHTVL

As previously mentioned, if a dog's vision is only mildly affected by the condition, they can go on to lead full and happy lives. However, if their sight is more seriously impacted by the condition, then owners have to take extra care when looking after their pets. Dogs need to be routinely seen by the vet so their vision can be assessed on a regular basis. This will help determine whether a dog's sight is getting any worse which is especially important as they mature and reach their senior years when many eye issues tend to present themselves anyway.