Feline Radiograph Techniques for Sedation-Free Imaging

X-rays are a commonly used diagnostic tool in many veterinary clinics for our feline patients. Radiographs can provide a wealth of diagnostic information, as long as they are of good quality and well-positioned.

However, cats aren’t known for their trainability, or their propensity to lie perfectly still for periods of time in a veterinary hospital, to allow veterinarians and technicians to work around them! So how do you get an X-ray of good diagnostic quality in a cat without sedation?

Do you need X-rays without sedation?

The first question to be asked is if the radiographs really need to be taken without sedation or anesthesia. Safety is paramount – for both patients and veterinary staff.

Taking X-rays conscious is not worthwhile if the process ends up having to be repeated multiple times due to poor positioning or movement blur, increasing both stress and levels of radiographic exposure to the patient and staff alike.


In many cases, a short-acting sedation or anaesthesia is the safest option to gain radiographs.1 There are many protocols now in use for a variety of situations, including drugs which are more cardiac-safe, those which avoid either renal or hepatic metabolism, and those with short half-lives for those quick X-ray procedures.

However, there are scenarios in which a veterinarian may prefer to attempt a conscious X-ray. These may include:

  • Cats with advanced cardiac disease

  • Cats with severe renal or hepatic impairment 

  • If a cat has eaten recently and there is concern for aspiration, but needs urgent X-rays

  • A known previous reaction to sedation or anesthesia

  • A moribund patient who requires urgent assessment but is clinically unstable

Techniques for conscious radiographs in cats


If you have a feline patient requiring X-rays in your veterinary hospital, there are a few ways to make the procedure safer and less stressful for all involved.

The welfare of the cat, and the safety of all involved, should always be at the forefront of decision making in a veterinary clinic.

Preparation

When taking X-rays conscious, it’s hugely important to be prepared – time is of the essence. Use an exposure chart to predict your kV and mA settings,1 have restraint equipment ready to go and veterinary staff primed as to their roles. Have a plan of which order the radiographs will be taken in, and how positioning is going to be achieved. 

The process with be smoother if both staff and patient are relaxed. Practice feline-centric protocols: calm voices, quiet areas, pheromone diffusers, and minimal handling. Speed is helpful, but not to the detriment of calm handling and a low-stress environment.

Positioning


Firstly, keep the X-ray area secure by closing or locking doors: as well as being a distraction, doors opening suddenly can be an escape route for a stressed cat!

Positioning aids will be required

These may include:

  1. Perspex box – if it is not possible to restrain the cat in a specific position, or the cat is very sick and/or recumbent, a clear Perspex box can be used to gain rapid radiographic assessment. Specific positioning will not be achieved, but a radiographic overview of a certain area – or even a full ‘catogram’ – can be achieved very quickly without the need for chemical or more aggressive physical restraint. Some boxes also allow oxygen to be piped in for those cats with respiratory concerns.  

  2. Sandbags, troughs, and foam wedges – cats who are mobile will require physical restraint. Wedges can be used to elevate anatomic areas, or to ensure correct alignment. Sandbags are useful mostly for limb restraint – they are heavy, so avoid placing them across the thorax as this can affect respiration. Always try and ensure positioning is comfortable for the patient, as this will aid them to lie still and not panic. 

Be aware that “less is more” when restraining cats; and that cats with dyspnoea are brittle and require minimal restraint. In these patients, initial stabilization, thoracic ultrasonography, and general anesthesia for radiography (if cardiac failure can be excluded) is often the most appropriate approach.3

Taking the radiographs

A veterinary team member can stay with the cat until the machine is ready to go and the positioning is perfect, providing reassurance and extra restraint. Once the area is safe, personnel can exit and take the radiograph. The ‘beep’ or ‘click’ of the X-ray machine can cause cats to move, so you may need some background music or white noise to distract from this. 

Allow the cat to rest and hide in a covered box in between X-rays. Provide reassurance, and reward (if clinically appropriate). If the patient is becoming distressed, consider moving to chemical restraint or postponing the radiographs. 

There are many potential pitfalls when taking conscious radiographs, and it is more likely that these X-rays will be affected by poor positioning, movement blur or sub-optimal exposure. Wherever possible, sedation or anesthesia is preferable to achieve radiographs safely. 

References

  1. Larson, M. Feline Diagnostic Imaging. Published 2020 John Wiley. Ed. Holland & Hudson. ISBN:9781118840948

  2. Lavin L: Small animal soft tissue, in Lavin L (ed): Radiology in Veterinary Technology, ed 3. Philadelphia, WB Saunders, 2003

  3. Borgeat, K. and Pack, M. (2021), Approach to the acutely dyspnoeic cat. In Practice, 43: 60-70. https://doi.org/10.1002/inpr.15