Here is a process you can follow to research whether you would like to acquire a puppy from a specific breeder:

At a minimum, good breeders test for the most common heritable diseases in their breed.  Except for a very tiny handful of breeds that do not seem to be plagued with Hip Dysplasia, most breeders test for HD.  In the USA, they may use the OFA, PennHip or a report from a University Veterinary school to provide evidence of their dogs’ hip results.  There are different eye diseases in different breeds, and some breeds don't have a serious problem with heritable eye conditions, so no testing is performed.  Other common heritable conditions for which testing is often performed include elbow dysplasia,  patellar luxation (knee problems), thyroid or cardiac conditions.   Some breeds (Doberman Pinchers, as an example), present with a bleeding disorder, and quality breeders routinely test for that condition.   At the OFA website, you can see the list of health screen tests listed on the search page - some apply just to one, or a few breeds.  OFA does not provide tracking / testing results on all heritable conditions, so consider the OFA website just a beginning for your research:  www.offa.org

To determine what may be necessary testing for a specific breed, consider the following:

1.  Do some research on the breed's general health by visiting the breed’s AKC parent club website, or another non-biased breed organization.

 2.  To find the AKC parent club go to www.akc.org , then do a search of the breed, and find the link to the parent club:  http://www.akc.org/clubs/search/index.cfm?action=national&display=on&breed=117

3.  Go to the AKC parent club or other national breed organization:  http://www.essfta.org/

4.  Look for a link to "Heath & Research" or something similar:  http://www.essfta.org/essfta/health_research.htm

5.  Review the health conditions and current research and testing that is available for the diseases.

6.  At the parent breed website, look for something like Breeder Guidelines.  Read the Breeder Guidelines to see if there is mention of heritable disease testing that is recommended for breeders.

7.  Check out the parent club’s Breeder Referral as a starting point to search for a quality puppy.  Once you look at some of those breeder’s websites (even if they are in a State so far away that you know you won't acquire a puppy directly from them), you will get a sense of the sort of information that some breeders post on their site regarding their breeding dogs' health screens, performance titles, etc....

8.  Once you know what health conditions are most important to review when selecting a breeder, use the OFA website to determine a fairly accurate snapshot of your breed's general health by going to www.offa.org  and clicking on "Statistics and Data"

9.  At "Statistics and Data" the diseases that OFA tracks are listed.  Click on Hip Dysplasia.

At the top of the columns, click on 'Breed' to get an alphabetical listing of the breeds, so that you can find your breed's rank, and statistics.  Ranked as 1st (meaning the WORST percentage of dysplastic dogs), is the Bulldog with a 73% HD rate.  English Springer Spaniels are ranked 67th out of 153 breeds, with a 13.5% HD value (the number of x-rays submitted to OFA that are scored dysplastic).  The ranking by breed is a combination of percent dysplastic versus percent Excellent rated individuals (8.2% for Springer Spaniels). 

As a comparison, my breed, Border Collies are ranked 87 (slightly better than the ESS), with 12.3%  Excellent rated and 11.1% dysplastic rated.  So, more individuals have Excellent hips but more records are submitted that get dysplastic ratings, than ESS.  This is OFA’s method of ranking breeds based on their experience with the disease.  Others in the field may do a different analysis to assess the breed's health for hip conformation.

10.  While at the OFA website, check other potential diseases that may be of concern in your breed, by going back to "Statistics and Data" and clicking on, say, Elbow Displasia.  ESS have a 13% elbow dysplastic rate.  On the contrary, in Border Collies, elbow dysplasia is not at all common.  Ranked 78 out of 95 breeds, there's a 98.5% normal and 1.3% dysplastic in BCs.  I don't do elbow x-rays on my dogs.  To me, it's not worth the money based on the risk.  Someone else may have a different opinion.  

Each breed has a unique general health status and the potential buyer needs to assess the risk of purchasing a puppy whose parents have / have not been tested for certain conditions.  Some breeders do every single test that is available, at great expense, however they don’t test their breeding stock to determine whether they can perform the work for which the breed was originally designed and / or do not work with their dogs in any performance events (both  are a good way to determine temperament in an animal since working places stress on the dog to perform and work with a human partner).  I would rather put resources into herding with my dogs to assess their value as breeding stock, rather than spending money to do tests for diseases that are uncommon in the breed, and therefore lower risk.  That’s my personal choice and each breeder has an opinion as to what is important when producing puppies.  The buyer’s responsibility is to determine whether the breeder has similar values regarding breeding dogs as he does.

11.  Based on the general health information at the ESS National Breed club's website, review other health conditions that may not be reported at the OFA website.  Some diseases can now be confirmed using DNA markers.  A large DNA testing company is www.Optigen.com   Click on "Tests" to find a list of conditions versus breed name.   Some DNA marker tests are performed by the University where the test was first developed.  The parent club’s website should have links to main organizations which perform DNA tests for heritable conditions found in the breed.   Here's a test that is available for ESS:  http://www.optigen.com/opt9_test_pfk.html  at Optigen.  It would be worth doing additional research to determine the prevalence in the breed to assess how important one finds having the parents of a litter tested for the condition.

14. Once your research helps to uncover which are the "reasonable" health screens that a breeder should perform, you should check out the breeder's website for proof of the testing.  I, personally, post the health screens on my website, so that it is available for anyone to view.   Here's an example:  http://www.darnfar.com/Dog%20Profiles/darnfar_switch.htm

On my “dog profile” pages, I provide a direct link to view the dog's OFA records (which allows them to see if the dog has relatives with OFA health screens, as well). The OFA suggests that it is a better breeding practice to “breed dogs whose relatives have normal hips”.  If a breeder “claims” that a dog has OFA hips but doesn’t provide proof on the website, I would go to OFA and do a search on the dog’s official name (in some breeds, like Border Collies, where there are many dual-registered dogs, the dog may have two "official" names and if you are not aware of both of them, you may not find the dog listed at OFA, when, it is in fact listed but under a different designation).  If the information is not at the OFA website, then I would ask to see a copy of the original form that OFA (or other testing organization) provides with the hip score, or as the breeder to direct me to the link at OFA, if the dog's official name is not listed on her website.  For CEA/CH (the heritable eye condition in my breed), I post the official DNA test report, since Optigen doesn’t maintain a database like OFA does.

Based on the information at the OFA website, I would suggest that English Springer Spaniels are a breed that should be tested for hip dysplasia - so, I would not permit a breeder to convince me that she doesn't have a reason to test her dogs.   Not having had a problem in the past does not preclude the fact that with HD, even OFA cleared parents can produce a puppy that presents with the disease. 

I didn't know the potential eye diseases in the English Springer Spaniel breed, but based on the breeder's website link that was provided, I noted that there was a dog listed with a CERF eye test result.  That information suggested there was a point to have ESS eyes tested.   CERF http://www.vmdb.org/cerf.html is the Canine Eye Registry Foundation, and provides a method of registering the results of eye tests performed by board certified ophthalmologists as a means of reducing heritable eye conditions in dogs.  Some of the eye conditions are now verifiable via DNA testing, so a CERF exam is no longer as important.  Knowing the dog’s genotype is more valuable than knowing its phenotype (which is all that an ophthalmologist is capable of determining via a physical exam).  However, when one sees a CERF test associated with a breeding dog, it’s obvious that there is an eye condition that the breeder was assessing.   

Since I did not know what eye conditions exist in ESS, I did a quick search and found this link:

http://www.sesss.org/#/inherited-eye-diseases/4535543588

Even before I went to the parent breed club’s website, I was able to determine something about heritable eye conditions via a simple search.  This is the sort of research that can be very valuable for a potential puppy buyer and doesn't require must background information.  It just requires typing "English Springer Spaniel eye disease" into a search engine.

I hope this information helps you find a wonderful puppy.  To tie the bow on this subject: