Results: 2018 General Health Survey
Eyes
Conditions listed in the Eye category were reported in 16.3% (191) of 1,171 surveys completed across all breeds/varieties surveyed, making it the fourth most reported among physical health categories.
Considering the entire population surveyed:
*When reviewing results for this category, please keep in mind that some conditions listed lend themselves to higher rates of owner diagnosis based on descriptions provided. This is particularly true of night blindness and cataracts, as age-related nuclear sclerosis and cataracts are frequently confused. As no information was collected on whether diagnoses were made by a veterinarian, we must consider that reporting of these conditions may not be as accurate as reports of conditions that are less likely to be solely owner identified.
Considering the entire population surveyed:
- As expected, “eye/sight changes related to advanced age” were reported at significantly higher rates in Toy Manchesters (12.5%) and Standard Manchesters (11.3%) as compared to Manchester Terriers (3.3%) and English Toy Terriers (3.1%). The difference observed is due in large part to the demographics of the surveyed population. Median age at onset for age-related eye/vision changes was consistent across all breeds/varieties surveyed at 11-12 years, however just 10% of English Toy Terriers and 19% of Manchesters reported on were 11 years of age or older, compared to 35% of TMTs and 34% of SMTs.
- Conjunctivitis was reported at slightly elevated rates in the Manchester Terrier (UK/FCI) population with 4% of owners reporting at least one eye infection during their dog’s lifetime as compared to 1% in TMTs, 0.4% in ETTs, and 0.3% in SMTs.
- Rates of all eye diseases in this category are likely heavily affected by the amount of standard eye screening done by breeders/exhibitors as part of breeding clearances. As respondents who completed the survey were not asked whether testing was associated with clearances or in response to observed symptoms, it is impossible to measure the impact of eye issues reported on a wide scale.
*When reviewing results for this category, please keep in mind that some conditions listed lend themselves to higher rates of owner diagnosis based on descriptions provided. This is particularly true of night blindness and cataracts, as age-related nuclear sclerosis and cataracts are frequently confused. As no information was collected on whether diagnoses were made by a veterinarian, we must consider that reporting of these conditions may not be as accurate as reports of conditions that are less likely to be solely owner identified.
Conditions
The following conditions are referenced below in the analysis for this section. The explanation for each disease/condition provided in the survey is included for reference:
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Toy Manchester Terriers
The most common conditions affecting Toy Manchester Terriers in the Eye category were “eye/sight changes related to advanced age,” which affected 12.5% (37) of Toy Manchesters, and Cataracts, which were reported in 10.5% (32) of Toy Manchesters. Additional conditions reported included seven cases each of Night blindness and Persistent Pupillary Membrance (2.3%), four cases of Keratoconjunctivitis Sicca (1.3%), three cases of Conjunctivitis (1%), two cases of Glaucoma (0.7%), and one case each of Lens Luxation, Progressive Retinal Atrophy, Ulcerated Cornea, and Vitreous Degeneration (0.3%).
In the ‘other’ section, owners reported one case of hyperpigmentation in the eye, one case of uveitis (inflammation of the uvea--middle layer of the eye), and one eye injury.
32 of 38 owners who reported “eye/sight changes related to advanced age” provided information pointing to a median overall age at onset for eye changes of 12 years, with reported ages ranging from a low of eight years to a high of 15 years. Eye sight changes related to age accounted for at least half of all reported cases of cataracts, three of the seven cases of nightblindness, and one case of glaucoma and ulcerated cornea (both noted in the same dog).
Among the 16 reports of cataracts associated with age-related changes to the eye, the median age at onset was 11 years. In the remaining 16 reports of cataracts, age of onset was provided for just two dogs (affected at ages three and six), however it is interesting to note that an additional five dogs reported to have cataracts were aged 4-6 years as of the date the survey was completed. From this ancillary data we can confirm with confidence that at least seven of the 32 Toy Manchesters reporting cataracts (22% of all cases) were affected at less than six years of age. In the ‘other’ space provided, one of these owners linked the dog’s cataracts to prolonged steroid use while another noted a diagnosis of juvenile cataracts at age three.
Looking more closely, all seven cases of Persistent Pupillary Membrane, 11 of the 16 cases of cataracts where age-related changes were not also selected, and the only cases of Lens Luxation, Progressive Retinal Atrophy and Ulcerated Cornea were identified in dogs owned by Breeders/Exhibitors. These findings may suggest diagnosis through screening aids like the Canine Eye Registration Foundation (CERF) rather than based on symptoms alone--findings supported by testing habits reported in the 2017 Breeder's Survey. This is important as it may point to additional sources of detailed information on eye health. Because only a small number of breeders/exhibitors provided information on “age of onset”, it is also possible that eye conditions diagnosed through screening at a young age do not have/have little impact on the dog’s day-to-day life. Determining when or if diagnosed conditions begin to affect dogs would be an important indicator of the impact of conditions for which testing is available.
Finally, it should be noted that Toy Manchester owners tended to report multiple eye conditions in the same dog at a higher rate in the eye category than is typical in other categories and at a higher rate for this category as compared to other breeds or varieties surveyed. Not including reports of “eye changes related to age”, 14 of 46 dogs reported multiple eye conditions with 11 reporting two conditions, two reporting three conditions and one owner reporting five eye conditions. As a result, these 14 dogs reported almost half of all specific eye conditions noted in the TMT survey results above.
Follow-up
The most common conditions affecting Toy Manchester Terriers in the Eye category were “eye/sight changes related to advanced age,” which affected 12.5% (37) of Toy Manchesters, and Cataracts, which were reported in 10.5% (32) of Toy Manchesters. Additional conditions reported included seven cases each of Night blindness and Persistent Pupillary Membrance (2.3%), four cases of Keratoconjunctivitis Sicca (1.3%), three cases of Conjunctivitis (1%), two cases of Glaucoma (0.7%), and one case each of Lens Luxation, Progressive Retinal Atrophy, Ulcerated Cornea, and Vitreous Degeneration (0.3%).
In the ‘other’ section, owners reported one case of hyperpigmentation in the eye, one case of uveitis (inflammation of the uvea--middle layer of the eye), and one eye injury.
32 of 38 owners who reported “eye/sight changes related to advanced age” provided information pointing to a median overall age at onset for eye changes of 12 years, with reported ages ranging from a low of eight years to a high of 15 years. Eye sight changes related to age accounted for at least half of all reported cases of cataracts, three of the seven cases of nightblindness, and one case of glaucoma and ulcerated cornea (both noted in the same dog).
Among the 16 reports of cataracts associated with age-related changes to the eye, the median age at onset was 11 years. In the remaining 16 reports of cataracts, age of onset was provided for just two dogs (affected at ages three and six), however it is interesting to note that an additional five dogs reported to have cataracts were aged 4-6 years as of the date the survey was completed. From this ancillary data we can confirm with confidence that at least seven of the 32 Toy Manchesters reporting cataracts (22% of all cases) were affected at less than six years of age. In the ‘other’ space provided, one of these owners linked the dog’s cataracts to prolonged steroid use while another noted a diagnosis of juvenile cataracts at age three.
Looking more closely, all seven cases of Persistent Pupillary Membrane, 11 of the 16 cases of cataracts where age-related changes were not also selected, and the only cases of Lens Luxation, Progressive Retinal Atrophy and Ulcerated Cornea were identified in dogs owned by Breeders/Exhibitors. These findings may suggest diagnosis through screening aids like the Canine Eye Registration Foundation (CERF) rather than based on symptoms alone--findings supported by testing habits reported in the 2017 Breeder's Survey. This is important as it may point to additional sources of detailed information on eye health. Because only a small number of breeders/exhibitors provided information on “age of onset”, it is also possible that eye conditions diagnosed through screening at a young age do not have/have little impact on the dog’s day-to-day life. Determining when or if diagnosed conditions begin to affect dogs would be an important indicator of the impact of conditions for which testing is available.
Finally, it should be noted that Toy Manchester owners tended to report multiple eye conditions in the same dog at a higher rate in the eye category than is typical in other categories and at a higher rate for this category as compared to other breeds or varieties surveyed. Not including reports of “eye changes related to age”, 14 of 46 dogs reported multiple eye conditions with 11 reporting two conditions, two reporting three conditions and one owner reporting five eye conditions. As a result, these 14 dogs reported almost half of all specific eye conditions noted in the TMT survey results above.
Follow-up
- Additional investigation of reports available through organized health registries or databases is recommended;
- If additional surveying on eye conditions is pursued, an effort should be made to distinguish between age at diagnosis and age at which symptoms are observed for cataracts in Toy Manchesters.
Standard Manchester Terriers
The most common conditions affecting Standard Manchester Terriers in the Eye category were Cataracts, which were reported in 11.8% (22) of Standard Manchesters, and “eye/sight changes related to advanced age,” which affected 11.3% (21) of Standard Manchesters. Additional conditions reported included two cases of Keratoconjunctivitis Sicca and Night blindness (1.1%) and one case each of Conjunctivitis, Ectropian, Persistent Pupillary Membrane, and Trichiasis (0.3%). No conditions were reported in the ‘other’ category.
16 of 22 owners who reported “eye/sight changes related to advanced age” provided information pointing to a median overall age at onset of 11 years, with ages ranging from a low of nine years to a high of 14 years. Eye sight changes related to age accounted for at least 1/3 of all reported cases of cataracts.
Among the seven reports of cataracts associated with age-related changes to the eye, the median age at onset was 10 years. In the remaining 15 reports of cataracts, age of onset was provided for zero (0) dogs. In the ‘other’ space provided, one of these owners noted eye changes were associated with diabetes.
Looking more closely at results reported, it should be noted that the only cases of Ectropian, Persistent Pupillary Membrane and Trichiasis were reported by Breeders/Exhibitors, suggesting diagnosis through screening aids like the Canine Eye Registration Foundation (CERF) rather than based on symptoms alone. This is important as it may point to additional sources of detailed information on eye health. Additionally, just two of the 15 cases of cataracts not related to age were reported by Breeders/Exhibitors, which may be significant when it is considered that 100% of SMT breeders who responded to the 2017 Breeder’s Survey indicate that they ‘always’ or ‘most always’ complete eye exams as part of regular screening. Even so, because no information on age of onset for non-age related cataracts was provided, the impact of the condition on quality mof life cannot be assessed. Determining when or if diagnosed conditions begin to affect dogs would be an important indicator of the impact of conditions for which testing is available.
Follow-up
The most common conditions affecting Standard Manchester Terriers in the Eye category were Cataracts, which were reported in 11.8% (22) of Standard Manchesters, and “eye/sight changes related to advanced age,” which affected 11.3% (21) of Standard Manchesters. Additional conditions reported included two cases of Keratoconjunctivitis Sicca and Night blindness (1.1%) and one case each of Conjunctivitis, Ectropian, Persistent Pupillary Membrane, and Trichiasis (0.3%). No conditions were reported in the ‘other’ category.
16 of 22 owners who reported “eye/sight changes related to advanced age” provided information pointing to a median overall age at onset of 11 years, with ages ranging from a low of nine years to a high of 14 years. Eye sight changes related to age accounted for at least 1/3 of all reported cases of cataracts.
Among the seven reports of cataracts associated with age-related changes to the eye, the median age at onset was 10 years. In the remaining 15 reports of cataracts, age of onset was provided for zero (0) dogs. In the ‘other’ space provided, one of these owners noted eye changes were associated with diabetes.
Looking more closely at results reported, it should be noted that the only cases of Ectropian, Persistent Pupillary Membrane and Trichiasis were reported by Breeders/Exhibitors, suggesting diagnosis through screening aids like the Canine Eye Registration Foundation (CERF) rather than based on symptoms alone. This is important as it may point to additional sources of detailed information on eye health. Additionally, just two of the 15 cases of cataracts not related to age were reported by Breeders/Exhibitors, which may be significant when it is considered that 100% of SMT breeders who responded to the 2017 Breeder’s Survey indicate that they ‘always’ or ‘most always’ complete eye exams as part of regular screening. Even so, because no information on age of onset for non-age related cataracts was provided, the impact of the condition on quality mof life cannot be assessed. Determining when or if diagnosed conditions begin to affect dogs would be an important indicator of the impact of conditions for which testing is available.
Follow-up
- Additional investigation of reports available through organized health registries or databases is recommended;
- If additional surveying on eye conditions is pursued, information on age at diagnosis and age at which symptoms are observed will provide important insight into cataracts in Standard Manchester Terriers.
Flashback to 2002
When results of the 2018 health survey are compared to results of the 2002 survey, reported cases of cataracts in the combined Toy and Standard Manchester population increased from 1.4% to 11%, and night blindness increased from 0.7% to 1.8%. Reports of most other conditions measured in both studies remained consistent.
Several factors may have impacted results relating to cataracts. First, the 2002 survey was conducted almost entirely among breeders/exhibitors, with little to no input from companion owners. Second, eye changes related to age was not offered as an option on the original survey. A 2003 follow-up study focusing specifically on cataracts, however, concluded that average age of onset for cataract symptoms was 9 years. Finally, the use of eye testing as a screening tool for breeder/ exhibitors has dramatically increased since 2002, when 58% of breeders indicated they never CERF’d eyes as compared to the 2017 Breeder Survey, where 88% of TMT breeders and 100% of the SMT breeder indicate that they always or most always CERF eyes.
As the old saying goes... you won’t know something is there if you never look for it! Given the dramatic increase in screening, it would not be surprising if there were an increase in the reported number of minor issues with little impact on sight OR issues that can only be observed by an opthalmologist that may otherwise have gone unnoticed.
Several factors may have impacted results relating to cataracts. First, the 2002 survey was conducted almost entirely among breeders/exhibitors, with little to no input from companion owners. Second, eye changes related to age was not offered as an option on the original survey. A 2003 follow-up study focusing specifically on cataracts, however, concluded that average age of onset for cataract symptoms was 9 years. Finally, the use of eye testing as a screening tool for breeder/ exhibitors has dramatically increased since 2002, when 58% of breeders indicated they never CERF’d eyes as compared to the 2017 Breeder Survey, where 88% of TMT breeders and 100% of the SMT breeder indicate that they always or most always CERF eyes.
As the old saying goes... you won’t know something is there if you never look for it! Given the dramatic increase in screening, it would not be surprising if there were an increase in the reported number of minor issues with little impact on sight OR issues that can only be observed by an opthalmologist that may otherwise have gone unnoticed.
Manchester Terriers (UK/FCI)
The most common conditions affecting Manchester Terriers (UK/FCI) in the Eye category were Conjunctivitis, which affected 4% (18) MTs, and “eye/sight changes related to advanced age” and Cataracts, which both affected 3.3% (15) of Manchesters.
Additional conditions reported included six cases of Glaucoma (1.3%), five cases of Keratoconjunctivitis Sicca (1.1%), two cases each of Night blindness and Ulcerated Cornea (0.4%), and one case each of Detached Retina, Persistent Pupillary Membrane, and Vitreous Degeneration (0.2%).
In the ‘other’ section, owners reported one case of “Third eyelid is too tight (hair and dirt gets stuck under and causes infections),” and one case of “dry eye syndrome, and skin allergy to certain meadow plants.”
Nine of 15 owners who reported “eye/sight changes related to advanced age” provided information pointing to a median overall age at onset for eye changes of 11 years, with reported ages ranging from a low of nine years to a high of 16 years.
Eye sight changes related to age was selected as an option for just two of all reported cases of cataracts. Among the 13 reports of cataracts where age-related changes to the eye was not selected, age of onset was provided for zero (0) dogs. Advanced age was noted in four of six cases of glaucoma.
It should be noted that reports of eye issues were low among Manchester breeder/exhibitors as compared to other breeds/varieties examined in this study. While it is possible this may indicate fewer eye problems in this breed/variety, it may also reflect lower rates of standardized eye clearances as part of pre-breeding testing, which is consistent with results of the 2017 Breeder’s Survey.
The most common conditions affecting Manchester Terriers (UK/FCI) in the Eye category were Conjunctivitis, which affected 4% (18) MTs, and “eye/sight changes related to advanced age” and Cataracts, which both affected 3.3% (15) of Manchesters.
Additional conditions reported included six cases of Glaucoma (1.3%), five cases of Keratoconjunctivitis Sicca (1.1%), two cases each of Night blindness and Ulcerated Cornea (0.4%), and one case each of Detached Retina, Persistent Pupillary Membrane, and Vitreous Degeneration (0.2%).
In the ‘other’ section, owners reported one case of “Third eyelid is too tight (hair and dirt gets stuck under and causes infections),” and one case of “dry eye syndrome, and skin allergy to certain meadow plants.”
Nine of 15 owners who reported “eye/sight changes related to advanced age” provided information pointing to a median overall age at onset for eye changes of 11 years, with reported ages ranging from a low of nine years to a high of 16 years.
Eye sight changes related to age was selected as an option for just two of all reported cases of cataracts. Among the 13 reports of cataracts where age-related changes to the eye was not selected, age of onset was provided for zero (0) dogs. Advanced age was noted in four of six cases of glaucoma.
It should be noted that reports of eye issues were low among Manchester breeder/exhibitors as compared to other breeds/varieties examined in this study. While it is possible this may indicate fewer eye problems in this breed/variety, it may also reflect lower rates of standardized eye clearances as part of pre-breeding testing, which is consistent with results of the 2017 Breeder’s Survey.
English Toy Terriers
The most common conditions affecting English Toy Terriers in the Eye category were Cataracts, which affected 7.4% (17) of ETTs and “eye/sight changes related to advanced age,” which affected 3.1% (7) of ETTs. Cataracts were the fourth most common health-related condition reported among ETTs in the survey.
Additional conditions reported included two cases of Night blindness (0.87), and one case each of Conjunctivitis, Distichiasis, Keratoconjunctivitis Sicca, and Vitreous Degeneration (0.4%).
In the ‘other’ section, owners reported one case of episcleritis (inflammation of the episclara tissue of the eye), one case of anisocoria (unequal size pupils), one dog with iris atrophy (associated with vitreous degeneration), and one report of an “eye removed due to trauma”.
5 of 7 owners who reported “eye/sight changes related to advanced age” provided information pointing to a median overall age at onset of 12 years, with reported ages ranging from a low of 11 years to a high of 15 years.
Eye sight changes related to age was selected as an option for just four of all reported cases of cataracts. Among the 13 reports of cataracts where age-related changes to the eye was not selected, age of onset was provided for zero (0) dogs.
As has been noted in other areas of the survey, the low overall age of ETTs reported on in the survey is expected to affect results for this category. Because just 10% of dogs reported on were over age 11, for example, lower rates of age-related eye issues should be expected in comparison to other breeds/varieties surveyed.
Follow-up
The most common conditions affecting English Toy Terriers in the Eye category were Cataracts, which affected 7.4% (17) of ETTs and “eye/sight changes related to advanced age,” which affected 3.1% (7) of ETTs. Cataracts were the fourth most common health-related condition reported among ETTs in the survey.
Additional conditions reported included two cases of Night blindness (0.87), and one case each of Conjunctivitis, Distichiasis, Keratoconjunctivitis Sicca, and Vitreous Degeneration (0.4%).
In the ‘other’ section, owners reported one case of episcleritis (inflammation of the episclara tissue of the eye), one case of anisocoria (unequal size pupils), one dog with iris atrophy (associated with vitreous degeneration), and one report of an “eye removed due to trauma”.
5 of 7 owners who reported “eye/sight changes related to advanced age” provided information pointing to a median overall age at onset of 12 years, with reported ages ranging from a low of 11 years to a high of 15 years.
Eye sight changes related to age was selected as an option for just four of all reported cases of cataracts. Among the 13 reports of cataracts where age-related changes to the eye was not selected, age of onset was provided for zero (0) dogs.
As has been noted in other areas of the survey, the low overall age of ETTs reported on in the survey is expected to affect results for this category. Because just 10% of dogs reported on were over age 11, for example, lower rates of age-related eye issues should be expected in comparison to other breeds/varieties surveyed.
Follow-up
- As results of the 2017 Breeder’s Survey indicate that eye testing/screening is widely practices b y English Toy Terrier breeders/exhibitors, additional investigation of reports available through organized health registries or databases is recommended