By Stephen Ettinger, DVM, DACVIM (SAIM and Cardiology)
Identifying cardiac disease in the dog is important for the breeder, the dog’s seller (if not the breeder), and the new caretaker (owner), but it can be frightening for the owners and pets in question, who may be unfamiliar with the procedures or handling required. By assuring owners that cardiac exams are pain free and by handling animals in a gentle way that ensures minimal stress, veterinarians and veterinary cardiologists can contribute to early recognition of cardiac disease, identify dogs with potential genetic defects or traits that might be passed on to other dogs in future breedings, and uncover problems that may cause cardiac health issues in the dog in the future.
Cardiac disease certification is a highly dependable method for reducing the number of dogs that potentially have the ability to pass on defects to their offspring. Please note that in this outline for OFA cardiac examinations I will refer to puppies or kittens often or use just one of the names for brevity purposes. Regardless, the same standards apply to each species.
OFA certification is a two-part process. The first is to recognize a congenital heart disease condition in a new puppy, kitten, or newly obtained older animal. While an official congenital heart disease-free certification can occur after only 12 months of age, breeders or owners should ideally bring animals to the examining veterinarian at 8 to 12 weeks of age for an early evaluation before sale or immediately after purchase.
This portion of the examination may be done by any veterinarian with additional training in recognizing abnormal heart sounds. If possible, this examination may be completed by a board-certified veterinary cardiologist (DACVIM-Cardiology; DECVIM-Cardiology). Identifying a congenital heart defect at this age permits the new owner to decide if he/she wishes to keep a dog or cat who will not be accepted as CLEAR at the 12-month full examination point.
The second part of the process is registration of the results. OFA only accepts information submitted by the breeder or owner, does not disseminate this information, and maintains breeder/owner privacy.
The Puppy/Kitten Examination
The first examination requires only a careful auscultation of heart sounds. The room should be warm, comfortable, and quiet, without music or noise from other areas of the hospital. A veterinary nurse is there to help keep accurate records.
Do not let outside hospital noise interrupt this examination. Place a sign on the door or request in advance that others not enter the room or begin talking and disrupting the process. Ask all in the room, including owners, to turn off cell phones and refrain from unnecessary talking so heart sounds can be heard clearly.
Since this is an examination only with no discomfort, it is a good time to introduce the puppy to the Fear Free examination process. If animals are on the exam table, I recommend covering it with a warm blanket, towel, or bath mat with rubber backing so the pet does not slip around. This early introduction to the veterinarian helps develop less fear of and more comfort with being at the veterinary hospital or clinic.
Since most youngsters at this age have yet to be microchipped, it is important to separate puppies or kittens after examination so the process is not disturbed by picking the wrong animal from a crowded litter holder. There are numerous ways to do this: tying a piece of ribbon in a unique color around the neck of each puppy; clipping a small amount of hair in a specific spot to identify each animal; painting a different toenail on each animal with nail polish; or simply placing the microchip immediately after each exam.
Defects or Abnormalities
Some puppies/kittens will have very soft incidental murmur. Many puppies have questionable sounds that may be insignificant, and the veterinarian may ask to listen again after a few minutes when the puppy is a bit calmer. These sounds may be heard because of increased blood flow through the heart, an animal’s thin skin and body wall, or the ausculter’s keen hearing. Often, abnormal sounds diminish or resolve with a little more growth.
For animals with a potential congenital heart defect, a veterinary cardiologist will determine if there is an unequivocal defect or if the abnormal heart sound could be an incidental murmur that may resolve over two or three weeks (not months or years) of further growth. Some congenital diseases may appear without any obvious changes in the dog’s appearance and structure while others may cause the puppy or kitten to be smaller, fail to gain weight, or fatigue easily. Some of these diseases are correctable almost immediately, which is good news for the owner, but the breeder should be made aware of the problem since the new puppy or kitten may be returned for a healthy one or there may be a health guarantee for a congenital defect.
This is all that is required for the initial examination. If all dogs are without murmurs, that is good news and vaccine and other puppy/kitten protocols should continue as normal. Advise breeders or new owners to schedule an appointment with the veterinary cardiologist after puppies are one year old.
This article was reviewed/edited by board-certified veterinary behaviorist Dr. Kenneth Martin and/or veterinary technician specialist in behavior Debbie Martin, LVT.