Canine Leukocyte Adhesion Deficiency (CLAD) in Setters

Canine leukocyte adhesion deficiency or CLAD for short is a hereditary health condition that affects two of the setter dog breeds, being the Irish setter and the Irish red and white setter.

It is caused by a gene mutation that stops the dog’s white blood cells (an important part of the immune system) from bonding with and eliminating viruses and bacteria from the body, which means that affected dogs will not be able to fight off infections, even minor ones, effectively.

The condition tends to be fatal at a young age in affected puppies, who are apt to develop infections shortly after birth, sometimes around the belly button where the umbilical cord terminates.

Based on worldwide health testing schemes and results, around 10% of all Irish setters carry a copy of the gene mutation that causes the condition, although some of these dogs will be unaffected carriers for the condition rather than affected themselves.

Canine leukocyte adhesion deficiency cannot be passed from dog to dog other than by means of heredity, and because the condition is serious and terminal, it is important when considering breeding from a dog that the combination of both parent dogs does not lead to a litter of affected puppies.

In order to allow breeders to make an informed decision about breeding based on their own dog’s status, The Kennel Club lists canine leukocyte adhesion deficiency as a risk to the health and wellness of the Irish setter breed as a whole, and oversees a testing and monitoring scheme for the breed to allow dog owners to find out the status of their own dogs.

This in turn allows breeders to make an informed decision about whether or not to breed.

In this article, we will look at canine leukocyte adhesion deficiency in more detail, including how the heredity of the condition works, and how dogs can be tested for their status. Read on to learn more.

More about canine leukocyte adhesion deficiency

Puppies that are born with the affected form of canine leukocyte adhesion deficiency rarely survive for more than a few days or weeks after birth, as the condition leads to immune suppression that makes them very susceptible to picking up infections and illnesses that in other dogs, would be minor and not cause any problems.

Such dogs cannot heal themselves when exposed to viruses or bacteria, and even prompt treatment with large doses of the appropriate antibiotics is not enough to save affected pups.

This means that affected puppies are highly unlikely to live for long enough to be bred from themselves; however, carriers of the condition can pass it on to their own offspring without actually being affected by the condition, which is why testing is so important.

What sort of dogs can be affected by the condition?

Canine leukocyte adhesion deficiency affects the Irish setter and Irish red and white setter dog breeds, and the affected form of the condition becomes evident shortly after birth. Around 10% of all dogs of the breed that make it to adulthood are potential carriers for the condition, and the only way to find out the status of any given dog is by means of DNA testing.

In a small number of cases, cross breed dogs with one setter parent may develop the condition too, but due to the hybrid vigour produced by out crossing dogs of the breed to another breed, this is very rare.

How does the heredity of the condition work?

Canine leukocyte adhesion deficiency is an autosomal recessive hereditary condition, which means that the status of any given dog depends on the combination of genes that they inherit from both sides of their breed line. Dogs are assigned to one of three statuses for the condition: clear, carrier or affected.

Affected dogs generally die shortly after birth, so unlike many autosomal recessive hereditary disorders, dogs born with the affected form of the condition are unlikely to make it to adulthood and so, will not stand a chance of breeding and passing the disorder on themselves.

However, carriers of the condition are asymptomatic and not affected by the illness themselves, which means that breeding from carriers comes with potential risks, depending on the status of the other dog in the pairing.

• Two clear dogs will produce clear puppies.
• A clear dog and a carrier will produce puppies that are 50% clear and 50% carrier.
• Two carrier dogs will produce affected puppies.

How to get your dog tested for their status

Because carriers of the condition will not show any signs of the condition and will not be affected themselves, DNA testing is the only effective method of finding out the status of any given dog prior to breeding.

In order to get your dog tested, you will need to send a DNA sample in the form of a blood sample (your vet can take this for you) off to one of The Kennel Club’s approved laboratories, who will then return the status of your dog to you.