What is a COHAT?

Dr. Hannah Godfrey

A tan and black pug tilts its head in front of a yellow background

Your veterinarian may have recommended a COHAT. But what is a COHAT and why is it important?

What does COHAT stand for?

COHAT stands for Comprehensive Oral Health Assessment and Treatment. Your veterinarian will have checked your pet’s teeth regularly at their vaccinations visits and other check-ups. If you or your veterinarian have noticed any concerns with your pet’s oral health, they will likely recommend a COHAT.

Why does my pet need a COHAT when my veterinarian has already had a look in his mouth? Is it really necessary?

Assessing your pet’s mouth while they are conscious will only give a small amount of information. Even in the most tolerant pets, your veterinarian will be unable to do a full assessment and get an idea of the treatment required. Examining under anesthetic allows the entire mouth to be examined, including the teeth, gums, palate, tongue, and other soft tissues. It also allows additional tests to be performed, including taking radiographs (x-rays) of the teeth and probing the gum line to assess the gum and root health.

Damage and disease are often hidden below the gum line or within the tooth or root, so without the additional testing performed in a COHAT, many mouth issues would be missed, which might leave your pet in pain or unwell. A COHAT will also allow earlier detection of any dental problems, meaning a reduced need for tooth extractions.

What does a COHAT involve?

Initial Assessment

If your pet has a COHAT, your veterinarian will first give an anesthetic to allow a thorough examination of the mouth and teeth. Once under anesthetic, the veterinarian will visualize the mouth thoroughly, looking for any noticeable abnormalities, injuries, or growths.


Once the initial check is complete, the tartar will be gently removed from the tooth surfaces, gum lines, and between the teeth, using an ultrasonic scaler. The removal of the tartar and any debris allow a proper assessment of the teeth and the gum line surrounding each tooth.


Probing is performed using a periodontal probe, which measures the depth of the pocket between the teeth and gums, checking for any excessive pockets or areas of detachments. If there are pockets and they are left, they will accumulate food and other debris and become a breeding ground for infection, leading to tooth decay and tooth loss. The veterinarian will check the depth of any pockets and any loss of gum attachment and keep the findings in your pet’s dental records.

While assessing the gum line for issues, your veterinarian will also be using a probe to check for any damage to the tooth’s enamel. Sometimes teeth can snap or fracture, exposing the sensitive pulp cavity, which causes extreme pain and leaves your pet at risk of severe infection.

Cats are prone to tooth resorption, where holes appear in the teeth or roots. It’s thought this could be due to an overreaction of the immune system to normal levels of bacteria within the mouth.

A probe will pick up any uneven areas of enamel and any areas of pulp cavity exposure. This information will also be recorded in your pet’s dental health records.

Dental radiographs

Without dental radiographs, it is impossible to assess the tooth’s health thoroughly. A series of x-rays will be taken by your veterinarian, with an x-ray film being placed within your pet’s mouth, just like in humans. X-rays are taken to check for any ‘holes’ in the tooth or root and any changes to the jaw-bone surrounding the roots.

The other benefit of dental radiographs, particularly in cats, is that it allows better treatment planning. Before attempting to remove the tooth, visualizing the tooth root means that your veterinarian can predict how easy it will be to remove and what type of extraction procedure would be best.

Sometimes the root is so diseased that it becomes fused with the bone of the jaw and cannot be removed. Radiographs will show this fusion, which means that it’s safe to remove just the tooth’s crown – your veterinarian will not need to waste time or risk causing additional damage by trying to remove the root.


The final step in the COHAT is treatment.  If there have been issues identified during the assessment of your pet’s mouth often they can be addressed during the same anesthetic appointment.  Treatments could involve extracting teeth, application of antibiotic gel to deep pockets, or removal or biopsy of oral tumors.

If there is extensive treatment required, especially if it is surgical or time-consuming, your veterinarian may work with you to arrange a staged treatment plan. In this case, treatments are performed in a few installments to allow time for your pet to heal between surgeries.

As a pet parent, it can be frustrating when your pet needs extensive and potentially costly treatments that have to be performed in stages. However, your veterinarian will be able to discuss with you the reasons why your pet needs treatment. If you are concerned about costs, or repeated anesthetics, talk to your veterinarian as they will often be able to work with you to ensure that your pet is as comfortable and healthy as possible.

My pet has had a COHAT. What now?

After a COHAT your veterinarian will talk to you about home dental care and when a follow-up COHAT is recommended.  Depending on the overall health or your pet’s mouth, follow-up COHATs will often be recommended in 6-24 months.


It’s easy to understand why you may initially be confused or frustrated or surprised when your pet needs a COHAT. Dental disease is often missed because pets don’t always show signs of pain or discomfort. It’s important to remember that dental disease can lead to tooth loss, pain and infection, even if your pet doesn’t show signs right away. Being open with your veterinarian about your concerns will help them formulate the best treatment plan for you and your pet.