A cleft palate in dogs is an opening between the mouth and the nose that forms when the tissues separating these two cavities don’t grow together properly during fetal development. It’s a birth defect most commonly seen in flat-faced (brachycephalic) breeds, and it can range from a small gap in the soft tissue at the back of the mouth to a wide opening that extends through the bony roof of the mouth and even into the lip. Puppies born with this condition can’t nurse normally because milk passes through the gap into the nasal passages, making early detection and specialized feeding critical to survival.
Types of Cleft Palate
There are two main categories. A primary cleft palate affects the lip and the front portion of the upper jaw. You might hear this called a cleft lip or harelip, and it’s usually visible the moment a puppy is born. A secondary cleft palate sits further back along the roof of the mouth and is harder to spot without opening the puppy’s mouth and looking inside.
Within the mouth, the cleft can involve the hard palate (the bony front portion), the soft palate (the flexible tissue toward the throat used in swallowing), or both. Clefts involving the soft palate alone are the easiest to miss because they’re hidden deep in the mouth, but they still interfere with a puppy’s ability to create the suction needed to nurse.
Causes and Risk Factors
Genetics is considered the primary driver. Brachycephalic breeds, including English Bulldogs, French Bulldogs, Pugs, and Boston Terriers, have a significantly higher incidence. The increase in commercial breeding and the inbreeding used to maintain breed-specific physical traits has made these malformations increasingly common in flat-faced dogs. In Nova Scotia Duck Tolling Retrievers, researchers at UC Davis identified a specific genetic mutation (inherited as a recessive trait) that accounts for about 62% of cleft palate cases in the breed. Roughly 15% of Tollers carry a single copy of this mutation without being affected themselves.
Environmental factors during pregnancy can also raise the risk. Nutritional deficiencies, viral infections, and exposure to certain toxins or medications while the mother is pregnant may interfere with normal palate development. The palate forms early in gestation, so the timing of these exposures matters. In many individual cases, though, no clear environmental trigger is identified and genetics is the likely explanation.
Signs in Newborn Puppies
A cleft lip is obvious at birth. A cleft palate hidden inside the mouth is harder to catch, but the signs show up quickly once the puppy tries to nurse. Milk leaks from the nostrils during or after feeding. The puppy may cough, gag, or sneeze while nursing. You’ll often notice the affected puppy gaining weight more slowly than its littermates, or failing to gain weight at all.
Breeders experienced with high-risk breeds typically check every puppy’s palate immediately after birth by gently opening the mouth and visually inspecting the roof. This is the fastest way to catch the problem before a puppy aspirates milk into its lungs.
Why Aspiration Pneumonia Is the Biggest Danger
The opening between the mouth and nasal cavity means food and liquid can easily enter the airway and lungs. This causes aspiration pneumonia, a lung infection triggered by inhaling foreign material. It’s the leading cause of death in puppies with unmanaged cleft palates. Signs include labored breathing, nasal discharge, lethargy, and a worsening cough. Without intervention, aspiration pneumonia can develop within the first few days of life.
Feeding a Puppy With a Cleft Palate
Affected puppies can’t create the suction needed to nurse from their mother, so they need to be fed by hand. Tube feeding is the most common approach. A small, flexible tube is passed directly into the stomach, bypassing the mouth entirely and dramatically reducing the chance of milk entering the airway. This needs to happen every few hours around the clock for the first several weeks of life, making it a serious time commitment.
In some cases, a veterinarian can create a prosthetic device, similar to a dental retainer, that temporarily covers the gap in the palate. This allows the puppy to eat more normally while waiting to grow large enough for surgery. Not every case is suited to a prosthesis, but when it works, it reduces the burden of round-the-clock tube feeding. Either way, the goal is the same: keep food out of the nasal passages and lungs while making sure the puppy gets enough nutrition to grow.
Surgery and What to Expect
Surgical repair is the definitive treatment, but puppies need to be old enough and large enough to tolerate general anesthesia safely. Most veterinary surgeons schedule cleft palate repair when a puppy is between 4 and 6 months old. Until then, the puppy depends entirely on assisted feeding.
The surgery involves rearranging the existing tissue in the mouth to close the gap between the oral and nasal cavities. The specific technique depends on the size and location of the cleft. Soft palate clefts and smaller hard palate defects tend to be more straightforward. Wide clefts through the hard palate are more challenging because there’s less tissue available to work with, and some dogs need more than one surgery to achieve full closure.
The most common complication after surgery is dehiscence, where the repaired tissue separates before it fully heals. This can happen if the repair is under too much tension, if the puppy chews on something hard too soon, or if infection develops at the surgical site. When dehiscence occurs, a second surgery is typically needed after the tissue has had time to recover. Soft food and restricted activity during the healing period help reduce this risk.
Breeds With Higher Incidence
Brachycephalic breeds top the list. English Bulldogs, French Bulldogs, Boston Terriers, and Pugs all show heightened susceptibility. The skull shape that defines these breeds appears to carry a genetic predisposition toward closure defects during fetal development. Nova Scotia Duck Tolling Retrievers have a well-documented genetic form of the condition, with a DNA test now available to identify carriers before breeding.
Cleft palate can occur in any breed and in mixed-breed dogs, but it’s far less common outside the high-risk groups. When it does appear in breeds without a known genetic predisposition, environmental factors during pregnancy are more likely to be involved.
Prevention Through Breeding and Nutrition
For breeders working with high-risk breeds, two strategies can reduce incidence: genetic testing and folic acid supplementation. In Tollers, the UC Davis DNA test allows breeders to identify carriers and avoid mating two carriers together. For breeds without a specific genetic test, tracking which pairings produce affected puppies and removing those dogs from breeding programs is the main tool.
Folic acid supplementation during pregnancy has shown striking results. A long-term study in Boston Terriers found that daily supplementation with 5 mg of folic acid reduced the incidence of cleft palates from 17.6% to 4.2% over roughly a decade. Similar studies in French Bulldogs confirmed the benefit. The timing is important: supplementation needs to start when the female comes into heat, about two weeks before mating, because the palate begins forming early in gestation. In dogs, the critical window closes before about day 33 of pregnancy, so starting supplementation after breeding has been confirmed may already be too late.
Pregnant dogs should also be kept away from known teratogens, including certain medications, pesticides, and other environmental toxins, particularly during the first half of gestation when the palate and other major structures are forming.