Comprehensive Health Testing for Dogs: Cerf and BAER Tests, Patella Luxation, and More

Health Testing for Dogs plays a vital role in ensuring the well-being of our furry companions. All dogs at Happy Trails Havanese are health screened with the following test, Cerf of the eyes for the juvenile cataracts BAER hearing test to rule out the possibility of bilateral hearing loss patella’s checked OFA for hip dysplasia.

On this page I hope to shed some light on what the testing is and what is involved in getting the testing done, I have always found it is more painful upon myself to get all the testing done rather than hard on the dogs.

Ensuring Canine Eye Health: Cerf Testing

In this section I am showing some pictures of the Cerf being done at Iowa State with Dr Betts and his students, (thank you Dr. Betts for letting me post these pictures). As you suggested, it may help educate people and hopefully they will see how easy it is to do the testing.

eye cerf

This is Dr Betts at Iowa State University with his students checking Miffy’s eyes for juvenile cataracts. With this testing we are able to see who is a carrier of the juvenile cataracts and eliminate those bloodlines from all breeding programs.

havanese cerf test

An eye Cerf must be performed by a State licensed Ophthalmologist , it cannot be performed by your regular veterinarian. The hardest part of this test is traveling to get the test done.

havanese eye cerf

Dr Betts checking Biscuit’s eyes for juvenile cataracts. The Cerf exams needs to be done every year until the age of 8.

havanese cerf

Thank you Dr Betts for letting me photograph you while teaching your students. 🙂

Assessing Hearing Health: The BAER Hearing Test

BAER hearing test performed by Dr. Kline at Iowa state university, the BAER hearing test is used to check for unilateral deafness in dogs, with this test we are able to screen breeding adults to eliminate hearing problems in our puppies.

baer hearing test

This is a picture of Biscuit getting her hearing test by Dr Kline and her students at Iowa State University. The dogs in these photos do not look alert or very cuddly, this is because they have been sedated with IV drugs. The small needles that are inserted in ear canal are somewhat painful, to get them to hold perfectly still for the hearing test Dr. Kline felt it was best to sedate them.

hearing test in havanese

The BAER hearing test is a test to see if a dog has normal hearing , this test is the only way to determine unilateral deafness in dogs. This is a test that cannot be done by your regular family veterinarian and needs to be done at an approved neurological lab.

The needles in the ear are connected to small wires which are connected to the computer screen. When the ear drum hears the noise, it moves, which signals the brain and shows up on the graph on the computer screen.

BAER hearing test - Photo 2

Yogi getting her BAER hearing test, she is very groggy as you can see her little head is being held upright for the test.

These pictures are of Yogi getting her BAER hearing test. She has been completely sedated, note the hand holding up her head.

havanese baer hearing test

The equipment is hooked up to the computer screen showing her results which becomes a permanent part of her health records, showing she passed.

It was my job to watch over everyone as they were finished with their test, until they were once again awake and ready for our trip home. The whole thing was a very speedy process, and the staff at Iowa State were very helpful and informative.

Thank you Dr Kline for taking some great pictures for me and allowing me to post them on my website 🙂

The BAER hearing test is a test that needs to be performed only once in the lifetime of the animal. It can be done as young as 5 weeks of age or older.

health testing

Here is a picture of Carter in one of my carriers, waiting his turn for the hearing test. He wasn’t sure where everyone else was going but was sure he wanted to be next.

Understanding Luxating Patellas: Causes and Diagnosis

Luxating Patella’s, the patella’s are the knee caps located on the hind legs.

luxating patella in havanese

Look closely, you can see the kneecap on the left leg slid to the inside of the leg and the knee on the right with the kneecap (patella) located in the center of the joint.

Here I hope to shed some light on what are luxating patella’s. The patella’s are located on the back legs of the dog, in the knee joint, of course they are located on both hind legs.

Luxating patella are the most common reason for lameness in small dogs. The knee cap strays out of joint, causing pain and instability that will lead to arthritis.

A normal positioned patella slides up and down in the groove at the bottom of the femur (the large leg bone). If the groove is to shallow or if the ligaments that support the patella are improperly aligned, the patella wanders out of place.

In the majority of all cases, the patella (knee cap) slides to the inside of the leg – called a medial luxation. When the patella is displaced, it damages the cartilage and causing inflammation and ultimately osteoarthritis. Dogs with patella luxation (PL) exhibit varying degrees of lameness.

Veterinarians diagnose patella luxation (PL) by performing a orthopedic exam, this can be performed by your regular veterinarian. They determine if the patella is in or out of the groove and whether it is freely mobile. With this information they assign a grade to the disorder. The veterinarian assign a grade from 1 to 4.

In grade 1 PL, there is just enough looseness in the fibrous tissues surrounding the joint to allow the patella to be pushed out of the groove. When released, the patella quickly goes back into joint. In grade 2 PL, is similar to grade 1, except that if pushed out of the groove, it stays luxated. In grade 3 PL, the patella’s resting position is out of the groove.

It prefers to stay there and although it can be pushed into the groove it quickly returns to the out of joint position. In grade 4 PL, this is the most serious form of patella luxation. The patella is permanently out of the groove, it can be pushed into place but will not stay there.

Dogs with patella luxation may have one knee that is normal and the other a grade 3. In fact it is not uncommon for one knee to be worse than the other and that is why many dogs limp only on one leg. If both knees are affected then the dog cannot limp since both knees are sore. This dog will have difficulty running or jumping properly.

What causes patella luxation, most agree that the groove in small puppies is to shallow. Also there is the possibility that improper hip conformation induces secondary changes in the knee. Lastly there is the possibility of a muscle problem-atrophy or poor development-that allows the patella to move medially.
Most veterinarians agree that if a dog is asymptotic, treatment is not required. In contrast when a dog exhibits significant clinical signs, surgery or medication should be administered.

Managing Patella Luxation: Treatment Options

Dogs can be given painkillers as well as supplements to decrease joint inflammation. If these are of no help, then surgery is required.

The best possible choice for slipped patella’s is to screen our adult dogs (9 months and older) so they do not pass this condition on to their young. It is a painless procedure requiring no sedating and can be performed by your local veterinarian.


In conclusion, health testing for dogs is not just a responsibility but a commitment to providing our beloved pets with the best quality of life. Regular screenings, such as Cerf and BAER tests, along with early detection and appropriate management of conditions like patella luxation, contribute to a happier and healthier canine companionship