IPD in Rough Collies

The Inflammatory Pulmonary Disease (IPD) is an inherited lung disease affecting the Rough Collie and is characterized by recurrent pneumonia.

The first symptoms of the disease occur only several days after birth. The typical symptoms are foamy vomiting, shallow breathing, cough, increased breathing sounds, yellowish nasal discharge and fever. It is caused by inflammation of bronchi and lungs.  Although the affected dogs respond well to the treatment with antibiotics and secretolytics, the bronchopneumonia has the tendency to recur. The disease itself is not fatal (There are known some cases where dogs lived even several years); however the frequent nasal discharge and respiratory problems affect significantly the life comfort of the dog.

The disease is caused by a mutation in AKNA–gene (c.2717_2720delACAG).  There is a 4 bp deletion in the AKNA gene that causes a frame-shift introducing a premature stop codon that encodes the AT-hook transcription factor. The AT-hook transcription factor has a very important regulatory function in the immune system and this function is affected due to changes in the gene structure caused by the mutation.

The mutation is inherited in an autosomal recessive mode. It means that the disease develops when the dog inherits the mutated gene from both parents (recessive homozygotes) The carriers of this gene (heterozygotes) inherit the mutated gene from one parent only and are clinically healthy as well as the non-affected homozygotes.

The genetic test can determine the genotype of the given individual and can help you to select the breeding pair so that it is ensured that no affected puppies are born again.

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Reference:

Hug, P., Anderegg, L., Kehl, A., Jagannathan, V., Leeb, T. : Frameshift Variant in Three Dogs with Recurrent Inflammatory Pulmonary Disease. Genes (Basel) 10:, 2019. Pubmed reference: 31357536.