The immune system plays a crucial role in fighting off unwanted visitors into the body, including bacteria, viruses, fungi and parasites. While all dogs can be afflicted by immune conditions, some research suggests German Shepherd Dogs (GSDs) to be even more prone. Does this mean that they have weaker immune systems than other breeds? And if so, how can it affect their health?
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How does the immune system work?
The immune system is a defence system, composed of many parts. At its most basic mechanical level, this includes the skin and mucosa (lining of a body cavity or organ), providing a physical barrier to unwanted guests. On a more cellular level, we have innate and acquired immunity which are far more specific and involves the production of antibodies, killer cells, and chemical defences to target and remove bacteria, viruses and toxins directly.
The two arms of the immune system can be described as:
- Innate -a person or animal is born with a level of immunity that doesn’t have to be learned, and will respond straight away
- Acquired – this is learned when the body encounters a new invader, responds to it, and then remembers this for if the invader visits again
What are German Shepherds predisposed to?
There is evidence to suggest that GSDs have a higher predisposition to a condition called Selective Immunoglobulin A Deficiency. This means low levels of a type of antibody called immunoglobulin A (IgA); one of the most common antibodies found which works mainly in the gut, nose, and lungs to fight infection from bacteria and viruses.
This is more likely due to decreased production by tissue associated with immunity. Ultimately this means that they cannot form an appropriate immune response, leaving them more open to infection and possibly allergies. Affected individuals may struggle earlier on in life, appearing to be the ‘runt’ of the litter. And they will continue to have recurring infections throughout their life.
IgA is particularly linked to the mucosa. In most simple terms, the cells lining body areas like the intestine, respiratory system and urogenital tract produce the antibodies (also called immunoglobulins, hence the name) required to fight off infection. Therefore, it would make sense that a lack of protection may mean a higher chance of infection in these areas.
The condition can be diagnosed via a lab test called serum protein electrophoresis, that will give an indication of levels of immunoglobulin in the blood. The condition itself cannot be treated, but secondary conditions should be managed. It is likely that this is a heritable condition, and affected animals should not be bred from.
What can this mean for their health?
There have been a few studies that show a link between IgA deficiency and chronic gastrointestinal issues, due to overgrowth of bacteria in the gut causing long term inflammation. Signs of this can include diarrhoea or loose stools, weight loss, lethargy and loss of appetite.
Not only may this mean that GSDs are more prone to gut-related diseases, but there is also evidence to suggest links between IgA deficiency and other diseases; including respiratory disease, skin conditions like pyoderma and dermatitis, and ear infections. These conditions may be long-term or recurrent.
And what about autoimmune disease?
An autoimmune disease means that the body’s immune system doesn’t recognise its own cells and attacks them like they are invaders. German Shepherd Dogs are over-represented in a few conditions:
Exocrine Pancreatic Insufficiency
While there are a number of causes of this disease, one of those is when the immune system attacks the cells of the pancreas responsible for producing digestive juices. Affected animals have signs including weight loss despite a ravenous appetite, soft greasy stools, and poor coat condition. It can be accurately diagnosed via a blood test. Affected dogs can be supplemented with digestive enzymes that they’re otherwise unable to produce.
GSDs are often listed as one of the most commonly affected breeds for skin-related autoimmune conditions; including Pemphigus Foliaceous and Lupus Erythematosus. Most conditions tend to be managed with immunosuppressants, but can be difficult to control.
Do GSDs have weaker immune systems? It’s probably not that simple. While IgA deficiency is reported, cases are few and far in between, and there is still a lot of research needed to further appreciate both how common the condition is, as well as its link to other health conditions. As mentioned previously, there’s no cure for the condition; only secondary infections can be managed on a case-by-case basis. But it’s something your veterinarian may consider further investigating, especially if you are looking to breed from an affected individual.