Register kit
HIGH QUALITY DNA
TESTING YOU CAN TRUST
OUR PANELS
The tests in our DNA health testing panels are selected based on the scientific evidence available for disorders in the breed. Our scientists stay up to date with the latest developments and discoveries in the field to ensure that our testing panels are as up-to-date as possible.
DID YOU KNOW?
Our ISO-accredited testing services are relied upon by UK police forces for assessing the suitability of canine recruits for police duties.
TESTIMONIALS
approx. 2 weeks
Typical turnaround
4
Conditions screened
Simple cheek swab
At-home sampling
UK laboratory
Tested in-house
Collie Eye AnomalyCEA
Collie Eye Anomaly (CEA), also known as Choroidal Hypoplasia, is an inherited eye condition caused by a variant associated with the NHEJ1 gene. It affects the development of the eye and can range from no obvious vision problems to more serious changes that may lead to partial or complete blindness. CEA is inherited as an autosomal recessive condition, meaning a dog must inherit two copies of the associated variant to be genetically affected.
How it's inherited
Recessive
What your result means
Clear (N/N): no copies; not expected to develop CEA, nor pass it on.
Carrier (N/CEA): one copy. Healthy, but can pass it on. Breeding two carriers risks affected puppies.
Affected (CEA/CEA): two copies; expected to develop CEA. Discuss with your vet.
Multidrug ResistanceMDR1
Multidrug Resistance 1 (MDR1), or Invermectin Sensitivity, causes reactions to certain classes of drug. An inability to metabolise these drugs can cause severe reactions or death even at low doses, and so vets should be made aware of this disorder.
An autosomal recessive condition caused by a mutation in the ABCB1 gene.
How it's inherited
Incomplete Dominant
What your result means
Clear (N/N): your dog has no copies of the MDR1 variant and will not develop the condition, nor pass it on.
Carrier (N/MDR1): your dog has one copy. There is a high likelihood of your dog developing the disease. Discuss with your vet. Due to the dominant inheritance it is not recommended to breed carrier dogs, even to clear dogs.
Affected (MDR1/MDR1): your dog has two copies and is expected to develop the condition. Discuss with your vet.
Degenerative MyelopathyDM
Degenerative Myelopathy (DM) is a progressive disease of the spinal cord that usually appears in older dogs. It gradually weakens the hind limbs, leading to loss of coordination and eventually difficulty walking. It is not painful, but it is progressive. Knowing a dog's status supports breeding decisions and early awareness.
An autosomal recessive condition with variable expression between breeds caused by a mutation in the SOD1 gene.
Signs to look for
Usually from around 8 years old: wobbliness or dragging of the hind paws, loss of coordination in the back legs, worn nails, and gradually progressing hind-limb weakness.
How it's inherited
Recessive with incomplete penetrance — a dog needs two copies to be at risk, but not every at-risk dog develops signs.
What your result means
Clear (N/N): no copies of the variant; not expected to develop this inherited form.
Carrier (N/DM): one copy. Very unlikely to develop DM, but can pass the variant on.
At risk (DM/DM): two copies. At risk of developing DM, though not all at-risk dogs do.
Progressive Retinal Atrophy -PRCDPRA-PRCD
Progressive Retinal Atrophy, progressive rod-cone degeneration type (PRA-PRCD), is an inherited eye condition in which the light-sensing cells of the retina gradually break down. It leads to night blindness first, then progressive loss of vision, often ending in blindness. Onset and speed vary. Testing supports breeding choices and early awareness.
Signs to look for
Early night blindness or reluctance in the dark, bumping into things in low light, dilated pupils or a reflective 'shine' to the eyes, progressing to daytime vision loss.
How it's inherited
Recessive — a dog needs two copies of the variant to be affected.
What your result means
Clear (N/N): no copies; not expected to develop PRA-PRCD, nor pass it on.
Carrier (N/PRA): one copy. Healthy, but can pass it on. Breeding two carriers risks affected puppies.
Affected (PRA/PRA): two copies; expected to develop PRA-PRCD. Discuss with your vet.
Collie Eye AnomalyCEA
- Gene
- NHEJ1
- Variant
- 37:g.28,697,542–28,705,340del
- Inheritance
- autosomal recessive
- OMIA
- OMIA000218 9615
Molecular mechanism
Collie Eye Anomaly (CEA), now more broadly referred to as Choroidal Hypoplasia, is an inherited developmental disorder of the eye characterised primarily by underdevelopment of the choroid, with severity ranging from no detectable visual impairment to complete blindness. Affected dogs may also develop colobomas, retinal folds and, in more severe cases, retinal detachment and intraocular haemorrhage, which can result in permanent vision loss (Lowe et al., 2003; Fredholm et al., 2016).
Collie Eye Anomaly is inherited as an autosomal recessive condition with variable clinical expression. Parker et al., (2007) identified a 7.8 kb deletion (37.28,697,542–28,705,340del) associated with CEA within the NHEJ1 gene on canine chromosome 37 (CFA37), which is widely used as the genetic marker for CEA screening. Although subsequent studies have suggested that this deletion may be linked to, rather than be the causative variant in, some breed populations, it remains strongly associated with the disease and is widely used for genetic testing (Fredholm et al., 2016; Brown et al., 2018; Clark et al., 2023).
References
Brown, E.A., Thomasy, S.M., Murphy, C.J., Bannasch, D.L. : Genetic analysis of optic nerve head coloboma in the Nova Scotia Duck Tolling Retriever identifies discordance with the NHEJ1 intronic deletion (collie eye anomaly mutation). Vet Ophthalmol 21:144-150, 2018. Pubmed reference: 28702949. DOI: 10.1111/vop.12488.
Clark, J.A., Anderson, H., Donner, J., Pearce-Kelling, S., Ekenstedt, K.J. : Global frequency analyses of canine progressive rod-cone degeneration-progressive retinal atrophy and Collie eye anomaly using commercial genetic testing data. Genes (Basel) 14:2093, 2023. Pubmed reference: 38003037. DOI: 10.3390/genes14112093.
Fredholm, M., Larsen, R.C., Jönsson, M., Söderlund, M.A., Hardon, T., Proschowsky, H.F. : Discrepancy in compliance between the clinical and genetic diagnosis of choroidal hypoplasia in Danish Rough Collies and Shetland Sheepdogs. Anim Genet 47:250-2, 2016. Pubmed reference: 26732749. DOI: 10.1111/age.12405.
Lowe, JK., Kukekova, AV., Kirkness, EF., Langlois, MC., Aguirre, GD., Acland, GM., Ostrander, EA. : Linkage mapping of the primary disease locus for collie eye anomaly. Genomics 82:86-95, 2003. Pubmed reference: 12809679.
Parker, H.G., Kukekova, A.V., Akey, D.T., Goldstein, O., Kirkness, E.F., Baysac, K.C., Mosher, D.S., Aguirre, G.D., Acland, G.M., Ostrander, E.A. : Breed relationships facilitate fine-mapping studies: a 7.8-kb deletion cosegregates with Collie eye anomaly across multiple dog breeds. Genome Res 17:1562-71, 2007. Pubmed reference: 17916641. DOI: 10.1101/gr.6772807
Multidrug ResistanceMDR1
- Gene
- ABCB1
- Variant
- c.296_299del4
- Inheritance
- incomplete dominance
- OMIA
- OMIA001402 9615
Molecular mechanism
Multidrug resistance (MDR1), or Ivermectin sensitivity, is an inherited drug sensitivity disorder caused by a mutation in the ABCB1 (MDR1) gene. The condition is inherited in an autosomal incomplete dominant manner, meaning dogs carrying one copy of the mutation may show increased sensitivity to certain medications, while dogs with two copies are at the greatest risk of severe adverse reactions (Mealey et al., 2003; Mealey \u0026amp; Meurs, 2008). The causative variant, first identified by Mealey et al., (2001), is a 4 bp deletion (c.296_299del4) that causes a frameshift and premature stop codon, resulting in loss of normal P-glycoprotein function.
P-glycoprotein is responsible for preventing certain drugs from accumulating within the brain. Dogs carrying the MDR1 mutation are unable to effectively transport these medications out of the central nervous system, making them susceptible to drug toxicity. Clinical signs can include tremors, excessive salivation, lethargy, disorientation, weakness, ataxia, blindness, seizures, coma, and in severe cases, death following exposure to affected medications (Mealey et al., 2001; Bissonnette et al., 2009; Gaens et al., 2019).
The MDR1 mutation is most commonly found in herding breeds, although its frequency varies considerably between breeds and populations (Mealey \u0026amp; Meurs, 2008; Gramer et al., 2011; Lerdkrai et al., 2021). Genetic testing helps identify dogs at increased risk, allowing appropriate medication choices to reduce the likelihood of adverse drug reactions.
References
Bissonnette, S., Paradis, M., Daneau, I., Silversides, DW. : The ABCB1-1Delta mutation is not responsible for subchronic neurotoxicity seen in dogs of non-collie breeds following macrocyclic lactone treatment for generalized demodicosis. Vet Dermatol 20:60-6, 2009. Pubmed reference: 19152588. DOI: 10.1111/j.1365-3164.2008.00731.x.
Gaens, D., Leithäuser, C., Hamann, M., Geyer, J. : Adverse drug reactions after administration of emodepside/praziquantel (Profender®) in an MDR1-mutant Australian Shepherd dog: Case report. Front Vet Sci 6:296, 2019. Pubmed reference: 31555677. DOI: 10.3389/fvets.2019.00296.
Gramer, I., Leidolf, R., Doring, B., Klintzsch, S., Kramer, EM., Yalcin, E., Petzinger, E., Geyer, J. : Breed distribution of the nt230(del4) MDR1 mutation in dogs. Vet J 189:67-71, 2011. Pubmed reference: 20655253. DOI: 10.1016/j.tvjl.2010.06.012.
Lerdkrai, C., Phungphosop, N. : Prevalence of the MDR1 gene mutation in herding dog breeds and Thai Ridgebacks in Thailand. Vet World 14:3015-3020, 2021. Pubmed reference: 35017851. DOI: 10.14202/vetworld.2021.3015-3020.
Mealey, K.L., Meurs, K.M. : Breed distribution of the ABCB1-1Delta (multidrug sensitivity) polymorphism among dogs undergoing ABCB1 genotyping. J Am Vet Med Assoc 233:921-4, 2008. Pubmed reference: 18795852. DOI: 10.2460/javma.233.6.921.
Mealey, KL., Northrup, NC., Bentjen, SA. : Increased toxicity of P-glycoprotein-substrate chemotherapeutic agents in a dog with the MDR1 deletion mutation associated with ivermectin sensitivity. J Am Vet Med Assoc 223:1453-5, 1434, 2003. Pubmed reference: 14627096.
Mealey, KL., Bentjen, SA., Gay, JM., Cantor, GH. : Ivermectin sensitivity in collies is associated with a deletion mutation of the mdr1 gene. Pharmacogenetics 11:727-33, 2001. Pubmed reference: 11692082. DOI: 10.1097/00008571-200111000-00012.
Degenerative MyelopathyDM
- Gene
- SOD1
- Variant
- c.118G>A (p.Glu40Lys)
- Inheritance
- autosomal recessive
- OMIA
- OMIA 000263 9615
- Reported frequency
- One of the most widespread canine disease variants, reported across very many breeds with varying penetrance.
Molecular mechanism
Degenerative Myelopathy (DM) is a progressive neurodegenerative disease of the spinal cord that typically affects dogs older than 8 years of age. The condition is characterised by progressive muscle atrophy and weakness of the limbs, advancing to tetraparesis (Awano et al., 2009) and eventually respiratory muscle failure (Nardone et al., 2016). DM is inherited as an autosomal recessive condition with variable expression between breeds. Missense mutation (c.118G\u0026gt;A; p.E40K) in exon 2 of the SOD1 gene on canine chromosome 31 (CFA31) was identified as the primary genetic risk factor by Awano et al., (2009). However, some dogs homozygous for the variant remain clinically unaffected, demonstrating incomplete penetrance. The SOD1.118G\u0026gt;A risk allele has been identified in 222 dog breeds. Burnese Mountain Dogs are also susceptible to this version of DM in addition to their breed-specific variant of DM, see DM- BMD variant for further information.
References
Awano, T., Johnson, GS., Wade, CM., Katz, ML., Johnson, GC., Taylor, JF., Perloski, M., Biagi, T., Baranowska, I., Long, S., March, PA., Olby, NJ., Shelton, GD., Khan, S., O\u0026#39;Brien, DP., Lindblad-Toh, K., Coates, JR. : Genome-wide association analysis reveals a SOD1 mutation in canine degenerative myelopathy that resembles amyotrophic lateral sclerosis. Proc Natl Acad Sci U S A 106:2794-9, 2009. Pubmed reference: 19188595. DOI: 10.1073/pnas.0812297106.
Nardone, R., Höller, Y., Taylor, A.C., Lochner, P., Tezzon, F., Golaszewski, S., Brigo, F., Trinka, E. : Canine degenerative myelopathy: a model of human amyotrophic lateral sclerosis. Zoology (Jena) 119:64-73, 2016. Pubmed reference: 26432396. DOI: 10.1016/j.zool.2015.09.003.
Zeng, R., Coates, J.R., Johnson, G.C., Hansen, L., Awano, T., Kolicheski, A., Ivansson, E., Perloski, M., Lindblad-Toh, K., O\u0026#39;Brien, D.P., Guo, J., Katz, M.L., Johnson, G.S. : Breed distribution of SOD1 alleles previously associated with canine degenerative myelopathy. J Vet Intern Med 28:515-21, 2014. Pubmed reference: 24524809. DOI: 10.1111/jvim.12317.
Progressive Retinal Atrophy -PRCDPRA-PRCD
- Gene
- PRCD
- Variant
- c.5G>A (p.Cys2Tyr)
- Inheritance
- autosomal recessive
- OMIA
- OMIA 001298 9615
- Reported frequency
- A single PRCD variant is shared across a large number of breeds, making it one of the most commonly tested PRA forms.
Molecular mechanism
Progressive retinal atrophy (PRA) encompasses a genetically heterogeneous group of inherited retinal degenerative disorders characterised by the progressive loss of photoreceptor function, ultimately resulting in irreversible blindness. Although the clinical presentation is broadly similar across affected breeds, with initial degeneration of rod photoreceptors causing night blindness followed by cone degeneration and progressive loss of daylight vision, numerous genetically distinct forms of PRA have been identified (Miyadera et al., 2012; Mowat et al., 2024). Advances in canine molecular genetics have demonstrated that variants in multiple genes involved in photoreceptor development, maintenance and function can produce clinically similar retinal phenotypes. Consequently, breed-specific genetic testing is required, as different forms of PRA are associated with different causative variants.
PRA-PRCD is an autosomal recessive form of progressive retinal atrophy caused by a missense variant in the PRCD gene. PRCD Zangerl et al., (2006) identified a c.5G\u0026gt;A (p.Cys2Tyr) variant that has been reported across numerous dog breeds. Affected dogs are born with normal vision but gradually develop night blindness, progressing to complete blindness as both rod and cone photoreceptors degenerate. Widespread genetic testing has substantially reduced the frequency of this variant in several breeds, although carriers and affected dogs continue to be identified (Zangerl et al., 2006; Lewis \u0026amp; Mellersh, 2019; Clark et al., 2023).
The expanding number of recognised PRA-associated variants highlights the marked genetic heterogeneity underlying inherited retinal degeneration in dogs. While many of these variants are breed-specific, others are shared across multiple breeds through historical founder events. Genetic testing enables accurate identification of affected and carrier dogs, supporting informed breeding decisions aimed at reducing disease prevalence while preserving genetic diversity. As additional causative variants continue to be identified, molecular testing will remain an important tool for improving the diagnosis, management and long-term control of progressive retinal atrophy in canine populations (Lewis \u0026amp; Mellersh, 2019; Mowat et al., 2024).
References
References
Aguirre, G.D., Lohi, H., Kaukonen, M., Murgiano, L. : Formal commentary. PLoS Genet 16:e1009059, 2020. Pubmed reference: 33151924. DOI: 10.1371/journal.pgen.1009059.
Clark, J.A., Anderson, H., Donner, J., Pearce-Kelling, S., Ekenstedt, K.J. : Global frequency analyses of canine progressive rod-cone degeneration-progressive retinal atrophy and Collie eye anomaly using commercial genetic testing data. Genes (Basel) 14:2093, 2023. Pubmed reference: 38003037. DOI: 10.3390/genes14112093.
Downs, L.M., Wallin-Håkansson, B., Boursnell, M., Marklund, S., Hedhammar, Å., Truvé, K., Hübinette, L., Lindblad-Toh, K., Bergström, T., Mellersh, C.S. : A frameshift mutation in golden retriever dogs with progressive retinal atrophy endorses SLC4A3 as a candidate gene for human retinal degenerations. PLoS One 6:e21452, 2011. Pubmed reference: 21738669. DOI: 10.1371/journal.pone.0021452.
Downs, L.M., Bell, J.S., Freeman, J., Hartley, C., Hayward, L.J., Mellersh, C.S. : Late-onset progressive retinal atrophy in the Gordon and Irish Setter breeds is associated with a frameshift mutation in C2orf71. Anim Genet 44:169-77, 2013. Pubmed reference: 22686255. DOI: 10.1111/j.1365-2052.2012.02379.x.
Downs, L.M., Mellersh, C.S. : An intronic SINE insertion in FAM161A that causes exon-skipping is associated with progressive retinal atrophy in Tibetan Spaniels and Tibetan Terriers. PLoS One 9:e93990, 2014. Pubmed reference: 24705771. DOI: 10.1371/journal.pone.0093990.
Downs, L.M., Wallin-Håkansson, B., Bergström, T., Mellersh, C.S. : A novel mutation in TTC8 is associated with progressive retinal atrophy in the golden retriever. Canine Genet Epidemiol 1:4, 2014. Pubmed reference: 26401321. DOI: 10.1186/2052-6687-1-4.
Goldstein, O., Mezey, JG., Boyko, AR., Gao, C., Wang, W., Bustamante, CD., Anguish, LJ., Jordan, JA., Pearce-Kelling, SE., Aguirre, GD., Acland, GM. : An ADAM9 mutation in canine cone-rod dystrophy 3 establishes homology with human cone-rod dystrophy 9. Mol Vis 16:1549-69, 2010. Pubmed reference: 20806078.
Karlskov-Mortensen, P., Proschowsky, H.F., Gao, F., Fredholm, M. : Identification of the mutation causing progressive retinal atrophy in Old Danish Pointing Dog. Anim Genet 49:237-241, 2018. Pubmed reference: 29624701. DOI: 10.1111/age.12659.
Kaukonen, M., Quintero, I.B., Mukarram, A.K., Hytönen, M.K., Holopainen, S., Wickström, K., Kyöstilä, K., Arumilli, M., Jalomäki, S., Daub, C.O., Kere, J., Lohi, H. : A putative silencer variant in a spontaneous canine model of retinitis pigmentosa. PLoS Genet 16:e1008659, 2020. Pubmed reference: 32150541. DOI: 10.1371/journal.pgen.1008659.
Kropatsch, R., Petrasch-Parwez, E., Seelow, D., Schlichting, A., Gerding, WM., Akkad, DA., Epplen, JT., Dekomien, G. : Generalized progressive retinal atrophy in the Irish Glen of Imaal Terrier is associated with a deletion in the ADAM9 gene. Mol Cell Probes 24:357-63, 2010. Pubmed reference: 20691256. DOI: 10.1016/j.mcp.2010.07.007.
Lewis, T.W., Mellersh, C.S. : Changes in mutation frequency of eight Mendelian inherited disorders in eight pedigree dog populations following introduction of a commercial DNA test. PLoS One 14:e0209864, 2019. Pubmed reference: 30650096. DOI: 10.1371/journal.pone.0209864.
Mellersh, CS., Boursnell, ME., Pettitt, L., Ryder, EJ., Holmes, NG., Grafham, D., Forman, OP., Sampson, J., Barnett, KC., Blanton, S., Binns, MM., Vaudin, M. : Canine RPGRIP1 mutation establishes cone-rod dystrophy in miniature longhaired dachshunds as a homologue of human Leber congenital amaurosis. Genomics 88:293-301, 2006. Pubmed reference: 16806805. DOI: 10.1016/j.ygeno.2006.05.004.
Mowat, F.M., Iwabe, S., Aguirre, G.D., Petersen-Jones, S.M. : Consensus guidelines for nomenclature of companion animal inherited retinal disorders. Vet Ophthalmol 28:663-667, 2024. Pubmed reference: 38334230. DOI: 10.1111/vop.13185.
Miyadera, K., Acland, G.M., Aguirre, G.D. : Genetic and phenotypic variations of inherited retinal diseases in dogs: the power of within- and across-breed studies. Mamm Genome 23:40-61, 2012. Pubmed reference: 22065099. DOI: 10.1007/s00335-011-9361-3.
Murgiano, L., Becker, D., Torjman, D., Niggel, J.K., Milano, A., Cullen, C., Feng, R., Wang, F., Jagannathan, V., Pearce-Kelling, S., Katz, M.L., Leeb, T., Aguirre, G.D. : Complex structural PPT1 variant associated with non-syndromic canine retinal degeneration. G3 (Bethesda) 9:425-437, 2019. Pubmed reference: 30541930. DOI: 10.1534/g3.118.200859.
Petersen-Jones, S.M., Entz, D.D., Sargan, D.R. : CGMP phosphodiesterase-alpha mutation causes progressive retinal atrophy in the Cardigan Welsh corgi dog Investigative Ophthalmology \u0026amp; Visual Science 40:1637-1644, 1999. Pubmed reference: 10393029.
Suber, M.L., Pittler, S.J., Qin, N., Wright, G.C., Holcombe, V., Lee, R.H., Craft, C.M., Lolley, R.N., Baehr, W., Hurwitz, R.L. : Irish Setter Dogs Affected with Rod/Cone Dysplasia Contain a Nonsense Mutation in the Rod cGMP Phosphodiesterase beta- Subunit Gene Proceedings of the National Academy of Sciences of the United States of America 90:3968-3972, 1993. Pubmed reference: 8387203.
Svensson, M., Olsén, L., Winkler, P.A., Petersen-Jones, S.M., Bergström, T., Garncarz, Y., Narfström, K. : Progressive retinal atrophy in the Polski Owczarek Nizinny dog: a clinical and genetic study. Vet Ophthalmol 19:195-205, 2016. Pubmed reference: 26009980. DOI: 10.1111/vop.12284.
Wiik, A.C., Ropstad, E.O., Ekesten, B., Karlstam, L., Wade, C.M., Lingaas, F. : Progressive retinal atrophy in Shetland sheepdog is associated with a mutation in the CNGA1 gene. Anim Genet 46:515-21, 2015. Pubmed reference: 26202106. DOI: 10.1111/age.12323.
Winkler, P.A., Ekenstedt, K.J., Occelli, L.M., Frattaroli, A.V., Bartoe, J.T., Venta, P.J., Petersen-Jones, S.M. : A large animal model for CNGB1 autosomal recessive retinitis pigmentosa. PLoS One 8:e72229, 2013. Pubmed reference: 23977260. DOI: 10.1371/journal.pone.0072229.
Zangerl, B., Goldstein, O., Philp, AR., Lindauer, SJ., Pearce-Kelling, SE., Mullins, RF., Graphodatsky, AS., Ripoll, D., Felix, JS., Stone, EM., Acland, GM., Aguirre, GD. : Identical mutation in a novel retinal gene causes progressive rod-cone degeneration in dogs and retinitis pigmentosa in humans. Genomics 88:551-563, 2006. Pubmed reference: 16938425. DOI: 10.1016/j.ygeno.2006.07.007.
