Deciduous (baby) teeth that don’t fall out on their own are called persistent deciduous teeth. These extra teeth can cause problems if they are not removed surgically. Persistent deciduous teeth are most often seen in small-breed dogs and are uncommon in cats.
 
Deciduous Teeth
Like most mammals, dogs have 2 sets of teeth in their lifetime. Deciduous teeth erupt when puppies are a few weeks old and are replaced by permanent teeth from about 4 to 7 months of age. Dogs have 28 deciduous teeth and 42 permanent teeth.
 
Deciduous teeth are able to fall out on their own because their roots gradually resorb (dissolve). Think of how children’s baby teeth look after they fall out: instead of long roots, they have jagged edges.
 
Resorption of deciduous tooth roots is a complex process that is triggered, at least in part, by the pressure that erupting permanent teeth put on the deciduous tooth roots. As a permanent tooth starts to push toward the surface, the root of the deciduous tooth directly above it resorbs until the deciduous tooth falls away. The permanent tooth then emerges in the space left vacant by the deciduous tooth.
 
Sometimes a permanent tooth isn’t in the right position under the gum, so the root of the deciduous tooth above it doesn’t resorb as it should. The permanent tooth then erupts next to the deciduous tooth, which stays in place as a persistent deciduous tooth.
 
A common persistent deciduous tooth in dogs is the canine tooth, which is the long, sharpish tooth next to the incisors at the front of the mouth. Dogs with a persistent deciduous canine tooth have 2 canine teeth (1 deciduous and 1 permanent) right next to each other, usually touching.
 
Problems Caused by Persistent Deciduous Teeth
Two teeth crammed into a space meant for 1 tooth is never good. Overcrowding from a persistent deciduous tooth leads to a number of problems:

• Food trapped between the teeth, causing plaque and tartar buildup
• Gingivitis and periodontal disease around the crowded teeth
• Displacement of the permanent tooth
• Malocclusion (improper bite)
• Weakening of the structures that hold the permanent tooth in place

 
A permanent tooth that has been displaced by a persistent deciduous tooth is positioned incorrectly within the row of teeth. Displaced permanent teeth might be angled toward the lips or the tongue. A displaced lower canine tooth can hit the roof of the mouth when the mouth is closed.
 
Diagnosis
A persistent deciduous tooth is diagnosed when a deciduous tooth and the corresponding permanent tooth have both erupted but the deciduous tooth is still firmly fixed in place, not wiggly and getting ready to fall out. Dental radiographs are used to evaluate the tooth roots and look for other problems like impacted or missing teeth.
 
Treatment
A persistent deciduous tooth needs to be surgically removed as soon as it is diagnosed. The longer it stays in the mouth, the greater the risk of problems with the permanent tooth. If a persistent deciduous tooth is removed early, the permanent tooth will most likely move into the correct position on its own as the puppy grows.
 
Photo by Elena Mozhvilo on Unsplash

As COVID-19 cases increase, more pets are exposed to the virus, so it’s time to review what we know about COVID-19 and animals. The content of this article is current as of February 7, 2022.
 
Can animals get COVID-19?
A number of mammal species, including dogs and cats, can be infected with SARS-CoV-2 (the virus that causes COVID-19). Infection in animals is rare compared with infection in people. Most animals infected with the virus have had close contact with people who had COVID-19. Some species have been experimentally infected under controlled conditions; these species might or might not be able to get infected naturally. The virus has not been found in birds, reptiles, amphibians, or fish.
 
Animals infected with SARS-CoV-2 don’t necessarily get sick. Domestic cats, large cats, dogs, ferrets, hamsters, mink, and gorillas have developed symptoms after being infected. Infection with no symptoms has been found in rabbits, bats, white-tailed deer, and many other species.
 
Symptoms of SARS-CoV-2 infection in animals are usually mild and nonspecific (lots of other things cause the same symptoms):

• Fever
• Decreased activity
• Coughing
• Sneezing
• Difficulty breathing
• Vomiting or diarrhea

 
Can pets spread COVID-19 to people or other animals?
The risk of catching COVID-19 from a pet is very low. There is no evidence that animals are a significant source of infection for people or that animals carry the virus on their fur. An exception is that SARS-CoV-2 was found to spread in both directions between mink and humans on mink farms in Denmark.
 
Some animals can infect other animals of the same species. For example, SARS-CoV-2 spreads among white-tailed deer populations without causing symptoms.
 
Someone in my household has COVID-19. How should I protect my pets?
People with COVID-19 can spread the virus to dogs, cats, and ferrets, although serious illness is rare in animals. The CDC recommends that people with COVID-19 avoid close contact with pets, stay in a room away from pets as much as possible, and wear a mask if they need to be near pets. People carrying the infection should also wash their hands before and after handling animals, avoid sharing food with animals, and avoid kissing their pets or letting their pets lick them in the face. There is no reason to remove pets from the home unless their caregiver is unable to take care of them.
 
Don’t put a mask on an animal or do anything else that might block its airflow. Increase ventilation or use air filters instead. Don’t use hand sanitizer, disinfecting wipes, or surface cleaners on an animal.
 
I think my pet might have COVID-19. What should I do?
If your pet has symptoms that seem similar to COVID-19, call your veterinarian. If you have COVID-19, don’t take your pet to the clinic yourself. Your veterinarian will advise you on whether your pet should be seen at the clinic.
 
Can I have my pet tested for COVID-19?
Don’t use a home test on an animal. Routine animal testing for COVID-19 is not currently recommended because infection is rare in animals, the symptoms are more likely to be caused by something else, and animals aren’t a significant source of SARS-CoV-2 infection in humans. Decisions about animal testing are made by a veterinarian in consultation with public health officials. A veterinarian will need to rule out more common causes of the symptoms before considering SARS-CoV-2 testing. Testing might be done for animals that meet criteria like having exposure to an infected person and having symptoms compatible with SARS-CoV-2 infection (with no other cause found).
 
Can my pet be vaccinated for COVID-19?
Vaccines for dogs and cats are not available. According to the World Organisation for Animal Health, vaccines are being developed for some animal species that are susceptible to SARS-CoV-2 infection. An experimental COVID-19 vaccine has been given to zoo animals at risk of getting sick from the infection. Mink will likely also be a priority species for vaccine development because of their potential to spread the infection to humans.
 
Please see these sources for updates and more information:

• Centers for Disease Control and Prevention (CDC): https://www.cdc.gov/healthypets/covid-19/pets.html
• American Veterinary Medical Association: https://www.avma.org/resources-tools/animal-health-and-welfare/covid-19
• World Organisation for Animal Health: https://www.oie.int/en/what-we-offer/emergency-and-resilience/covid-19/#ui-id-2

 
Public domain image credit: National Institute of Allergy and Infectious Diseases, NIH. Source: NIH Image Gallery