You may recall that last week we decided to deal with that which is normal before embarking on the pathological. We dwelt on the normal amount of teeth in the kitten/puppy and the adult cat/dog, and with the fact that the “milk” teeth (also called “baby” teeth or “deciduous” teeth) drop out at four-five months of age.
Today, let’s look at the time when these “milk” teeth emerge (“erupt” is the technical term) from the gums. In the puppy, the incisors erupt when the animal is between four to six weeks old. The kitten must be two to four weeks old before the incisors emerge.
The permanent incisors start coming out when the pup/kitten is about two months old. When the pup and kitten are five months and four-and-a-half months old, respectively, the permanent incisors should all be in place.
The “baby” canine teeth (the long ones on the side) are quite visible at three to four weeks of age in both the dogs and cats. The permanent canines are quite obvious when the animals have reached five to six months.
The deciduous premolars emerge between four and eight weeks of age in the puppy and kitten. One should note that in the lower jaw of the kitten, the first premolar teeth are absent in the beginning.
The permanent premolars come to being between the ages of four to six months in both dogs and cats. Remember that the cat only has four permanent premolar teeth in the lower jaw (two on each side) as compared with the dog which has eight in the lower mandible.
Also the dog has eight premolars in the upper jaw while the cat has six (see the dental formula in last week’s Pet Corner).
Neither cats nor dogs have “baby” molar teeth. The adult dog has four molar teeth in the top jaw and six in the lower jaw, while the cat only has four molars in all (one on each side of both the top and bottom jaw). The eruption of the molar teeth begins when the animals are about four to five months old and is completed two to three months later.
From the very outset, let me make it clear that only the observation of a dog’s teeth to ascertain its true age is not an accurate method.
There are several factors that impact on the accuracy. Let’s look at some of these influences.
Breed: Those short-faced dogs e.g. Pekinese, (another example is the now popular Pom-Pek – not Pumpick as one gentleman advised me recently), who characteristically have a prognathic bottom jaw (the bottom jaw is protruding much more forward than the top jaw; also described as “undershot”), do not have a closed bite. In other words the front teeth of the top jaw do not mesh with the incisors of the lower jaw.
As a result there is not the same amount of wear on the cutting edges (cusps) of the incisors as would be the case if the upper and lower jaws were to close correctly. natomical abnormalities: One result of incest (close relatives mating and producing offspring) is the malformation (deformity) of the jaws. In some cases the top jaw protrudes far forward (“Overshot”, “Parrot Bite”), and in others the bottom jaw is prognathic (see paragraph above).
These genetic defects (malformation of the jaws) result in an uneven wear of the teeth, especially the incisors.
Nutrition and dental hygiene: poor diets will result in a depression of tooth growth; the strength and health of the teeth are also compromised.
Furthermore, inappropriate diets could cause teeth to drop out permanently. Also, teeth will be lost ahead of time, if no proper dental hygiene is maintained.
Disease: A few of the many diseases which we discussed over the past few months (e.g. gingivitis, stomatitis, tartar build-up, tooth decay, etc) could lead to the demise of teeth. The wear on those remaining will therefore be altered, thus making it difficult to gauge the age.
Chewing habits: Dogs really don’t chew too much. They tend more to bite and swallow. However, if they get a big beef bone, they will gnaw.
Obviously, if the dog gets into the habit of gnawing and chewing, the wear on the cusps (the biting edges) of the teeth will be increased.
Below are guidelines which could assist in the age determination of large dogs, bearing in mind inherent variations and the factors mentioned above.
– See eruption and change of “milk” teeth in puppies (The Pet Corner October 18th, 2009).
– 1½ years – Cusps are worn flat on the lower middle incisors; tartar begins to form on the canines.
– 2½ years – Cusps are worn flat on the lower intermediate incisors; tartar is quite noticeable on the canines.
– 3½ years – Cusps are worn flat on the upper middle incisors.
– 4½ years – Cusps are worn flat on the lower middle incisors; tartar begins to form on the canines.
– 5 years – Cusps are worn flat on the last incisor. The Canine teeth begin to show wear.
– 6 years – All the lower incisors are worn flat and the canine teeth appear blunted.
After seven years of age incisors tend to fall out and one has a difficult time judging the age accurately. The remaining incisors tend to bend forward and their surfaces start to take on an elliptical shape.
Later still (10-12 years of age), the canines show great wear and all the incisors have disappeared.
Please implement disease preventative measures (vaccinations, routine dewormings, monthly anti-Heartworm medication, etc) and adopt-a-pet from the GSPCA’s Animal Clinic and Shelter at Robb Street and Orange Walk, if you have the wherewithal to care well for the animals. Do not stray your unwanted pets, take them to the GSPCA’s Clinic and Shelter instead. If you do not wish your pet to have puppies or kittens, you may exploit the GSPCA’s free spay and neutering programme. If you see anyone being cruel to an animal, or if you need any technical information, please get in touch with the Clinic and Shelter by calling 226-4237.