Lundehund Syndrome

Lundehund's intestinal syndrome is a stomach and intestinal pathology that causes malabsorption and protein deficiency.

Symptoms

This syndrome typical of Lundehund dogs includes symptoms such as low serum protein levels, vomiting, loss of weight and muscle mass, lack of appetite, lethargy, fluid accumulation in the abdomen and swollen paws. Symptoms can appear at any age between 6 months and 10 years. It can eventually lead to lymphoma, cancer of the intestine or stomach.

Disease Management

There is no cure for this condition, and management usually involves dietary changes, vitamin supplementation, administration of anti-inflammatory drugs and drugs to reduce the accumulation of cells in the intestines, improve lymph flow and eliminate harmful intestinal bacteria. The most common treatments are prednisone, metronidazole, cimetidine, FOS, Forti-flora and B12 injections. Treatment varies from dog to dog and the prognosis is highly variable, ranging from mild chronic diarrhea, often recurrent, to severe symptoms resistant to treatment.

Genetic basis

This disease follows an autosomal recessive mode of inheritance. Autosomal recessive inheritance means that the dog, regardless of sex, must receive two copies of the mutation or pathogenic variant to be at risk of developing the disease. Both parents of an affected dog must carry at least one copy of the mutation. Animals with only one copy of the mutation are not at increased risk of developing the disease, but may pass the mutation on to future generations. Breeding between dogs carrying genetic variants that can cause disease, even if they do not show symptoms, is not recommended.

Technical report

The exact cause of Lundehund syndrome is not fully understood, it is thought to be related to a combination of genetic and environmental factors. In 2016, the study by Metzger et al. was published which concluded that the c.1849G>C mutation in the P3H2 gene, which is the one we discuss here, may be the cause of the syndrome. The P3H2 gene (previously known as LEPREL1) was expressed in certain neuroendocrine cells found in the intestinal mucosa and it has been suggested that it may play an important role in the processing and secretion of neuropeptides. Alteration of P3H2 could be related to changes in intestinal neuropeptide production that could be key in this and other inflammatory bowel diseases.

Most affected breeds

Lundehund

Bibliography

Metzger J, Pfahler S, Distl O. Variant detection and runs of homozygosity in next generation sequencing data elucidate the genetic background of Lundehund syndrome. BMC Genomics. 2016 Aug 2;17:535.