Cause and occurence of kidney cysts in Swedish Siberian and Neva Masquerade cats

Last changed: 02 July 2021
Close up picture of a cat of the breed neva masquerade

Chronic kidney disease is common in cats and mainly affects the older feline population. The cause for failing renal function is often unknown. The aim of this project is to evaluate the presence of renal cysts observed in Swedish Siberian and Neva Masquerade cats and investigate if there is a genetic predisposition for the disease in these breeds.

The Siberian cat (SIB), and its sister breed Neva Masquerade (NEM), are native domestic cat breeds from Russia. Their Swedish popularity is increasing fast from 12 registered cats in SVERAK in 2000, to about 2000 cats in 2019. Lately Swedish SIB/NEM-breeders have observed an increasing number of cats presenting with renal cysts similar to those observed for PKD. These cysts do not appear to be caused by the mutation identified in Persians. Therefore, they addressed researchers at the Swedish University of Agricultural Sciences (SLU) in Uppsala to help them setup a survey for the situation within these breeds and to evaluate if any conclusions about patterns of inheritance can be drawn. 

Genetic mutations can cause kidney disease

For some forms of kidney disease in cats more is known about the causes behind the disease. 

Polycystic kidney disease (PKD) is such an example (for details see facts below). PKD presents already at a young age. The clinical findings include several cysts in both kidneys, which grow larger as the disease progresses. When those cysts progress into larger cysts they will damage the renal tissue and disrupt the function of the organ over time.

Clinical signs can be observed already at an age of 7-8 years and are close to identical to chronic kidney disease of unknown causes, e.g. polydipsia, anorexia, loss of weight and vomiting. Clinical assessment of PKD is performed by ultrasound, which will identify cysts of different sizes and numbers, usually in both kidneys. Ultrasound is only useful for assessing PKD once the cysts have developed, and a kitten (less than 6 months of age) could, hence, still present with normal kidneys at an evaluation but will develop disease over time. 

The renal cysts that have been observed in SIB and NEM are similar to those that present in PKD. The cysts are however negative for the previously described genetic mutation in Persian cats. 

The aim of this project is to evaluate the presence of renal cysts observed in Swedish Siberian and Neva Masquerade cats and investigate if there is a genetic predisposition for the disease in these breeds. 

Researcher Åsa Ohlsson with a siberian cat in her arms
Researcher Åsa Ohlsson with a siberian cat. Photo: Kristin Johansson, UDS

This project has received funding through a research stipend from Svelands stiftelse för djurens hälsa och livskvalité (Sveland foundation for animal health and quality of life) and Stiftelsen Svenska Kvinnors Djurskyddsförening (Swedish Women's Association for the Protection of Animals). 

Generous donations to the project has been provided by breeders, owners and cat fanciers through the projects crowd-funding. Some of the donations have been encouraged through the following platforms or clubs:

Vår sibiriska katt

SIgNE-ringen

Sällskapet Sibirisk Katt (SäSK)

Föreningen Neva Masquerade Sverige (FörNEM)

We would like to sincerely thank everyone of you that has made a contribution to the project in any form!

Do you want to contribute with a donation?

You can still contribute to the project even if the costs for the project are now covered. With more funding more cats can be evaluated in the project. The researchers would highly appreciate more samples from cats that are positive with kidney cysts. Please contact the researchers if you have questions about how to send a sample!

You can send a donation by Swish to nr: 123 322 23 38

Mark your contribution with: ”SIB & NEM” or ”kidney cysts cat”

Thank you for your support!

Facts:

Different forms of Polycystic kidney disease (PKD)

  • Dominant forms of PKD are described in humans, dogs and cats, where mutations in the gene for polycystin 1 (PKD1) is common for all.
  • Mutations in polycystin 2 (PKD2) is also associated with human PKD, but is less common than mutations in PKD1.
  • Human recessive forms of PKD has been linked to mutations in the gene for fibrocystin (PKHD1).
  • In cats, a dominant mutation has been described in PKD1. This mutation is observed in Persians and related sister breeds (such as Exotic and Scottish Fold), for which a genetic test has been developed.
  • The test makes it possible for breeders to exclude carriers from breeding, thereby improving feline health, before they present with renal cysts and clinical signs.
  • However, renal cysts have been observed in cats that are negative for the described mutation in PKD1, which indicates there are likely multiple causes of PKD in cats.

Contact

Åsa Ohlsson, researcher

Department of Animal Breeding and Genetics, SLU

asa.ohlsson@slu.se, 018-671352.

Lena Pelander
Lecturer at the Department of Clinical Sciences

Telephone: 018-671498
E-mail: lena.pelander@slu.se

Page editor: natalie.von.der.lehr@slu.se