Recording and scoring animals

Score sheets

Careful records of what is abnormal in an animal, and also what is normal need to be made. You can keep records in a reproducible way by using a score sheet. By giving scores to the different abnormalities you identify, using some carefully defined criteria, you should be able to track the progress of an animal’s welfare.

If you treat the animals or carry out some other remedial measures, such as giving softened diet, then be sure to also record this, and the animals’ response.

You can combine use of a scoring system with video or still images to record specific features of your examination.If you give an animal an overall low score but you scored one sign high then you should seek veterinary or other specialist advice, and monitor the animal more closely. You should check the study protocol to see what signs of poor welfare were anticipated, and what actions should be taken.

Improving score sheets

You could improve consistency in scoring animals, and the agreement between different people carrying out the scoring, by discussing and comparing your observations. If you do this, you can agree how to grade each clinical sign. You may also identify some very specific changes that are of importance in a particular study. Score sheets can be used to help you apply humane endpoints consistently. The most effective method is to adapt score sheets for each specific model. For example, this score sheet has been adapted for mice with liver disease. As well as the general signs of poor welfare, it includes assessment of the degree of jaundice.

Characteristic	Score
	1	2	3	4
Coat – general	Normal	Slight lack of grooming	Starey	–
Skin tone	Normal	Mildly dehydrated	Moderately dehydrated	Severely dehydrated
Behaviour	Normal	Slightly dull or lethargic	Aggressive or apathetic and inactive	Very aggressive or immobile and unresponsive
Abdominal distension	None	Mild ascites	Obvious ascites	–
Jaundice	None	Slightly jaundiced appearance	Mild jaundice present	Moderate jaundice present
Body weight	Normal weight gain or weight loss less than 5%	Weight loss <=10%	Weight loss <=15%	Weight loss <=20%

The maximum score is 22, but you should adjust your humane endpoint so that the degree of distress is the minimum needed to achieve the scientific objectives of the study and could be set at any point on this scale.

For example: Mice scoring 6-7 might be considered normal (or sub-threshold), those scoring 8-9 could be mild, those scoring 10-14 moderate, and 15-22 severe and euthanasia may be required, depending upon the Project Licence endpoints).

We might also set out some interventions such as giving fluids or feeding soaked diet if the score exceeded 8.

This scoresheet was devised for mice with tumours and includes measurement of tumour mass in the scoring system.

Characteristic	Score
	1	2	3	4
Coat – general	Normal	Slight lack of grooming	Starey	–
Skin tone	Normal	Mildly dehydrated	Moderately dehydrated	Severely dehydrated
Behaviour	Normal	Slightly dull or lethargic	Apathetic and inactive	Immobile and unresponsive (for tumour interfering with normal behaviour and activities
Tumour size and appearance	Very small (<3mm)	Tumour small (<=5mm) with no necrosis or ulceration	Tumour intermediate size (<=8mm) with no necrosis or ulceration	Tumour large (>=12mm) Ulceration of tumour of any size
Bodyweight	Normal weight gain or weight loss less than 5%	Weight loss <=10%	Weight loss <=15%	Weight loss <=20%

The maximum score is 19, and we should again adjust our humane endpoint so that the degree of distress is the minimum needed to achieve the scientific objectives of the study.

For example: Mice scoring 5-6 might be considered normal (or sub-threshold), those scoring 7-8 could be mild, those scoring 9-13 moderate, and 15-19 severe (and euthanasia may be required, depending upon the Project Licence endpoints).

We might also again set out some interventions such as giving fluids or feeding soaked diet if the score exceeded 8.

Developing scoresheets

Both of those scoresheets included monitoring of body weight. If we include bodyweight in our scoring, we should also record the weight of normally growing control animals. If our study doesn’t include a normal control group, then we may be able to use data from previous studies, or normal growth curves from the animal breeder or supplier. It is helpful to plot graphs of bodyweight of each animal and update these regularly so that trends are identified as rapidly as possible.

When developing a scoresheet, you can either use grading from 0-3, or 0-10, or simply note the presence or absence of a clinical sign. It is important to appreciate that the scales used for the clinical signs on your scoresheet may not be linear – for example, a score of coat condition from 1 to 2 may not mean the animal’s welfare is now twice as bad as before.

Many scoring systems incorporate some objective measures, such as food and water consumption or body weight. It can be difficult to measure food and water consumption in group-housed animals such as rodents, but bodyweight is easy to record.

Remember that the rate of loss or lack of weight gain can be as important as the absolute change. It is also important to weigh the animal at appropriate intervals. If you are not certain, then weigh the first group of animals on a study frequently, then adjust this on future studies.

It is often helpful to combine the use of bodyweight with a body condition score (Ullman-Culleré et al, 1999¹, Hickman and Swan, 2010²).

Scoresheet limitations

Scoresheets help to provide a consistent means of examining animals, they can help provide consistency between different individuals who assess the animals, and they encourage regular, careful examination of animals.

Remember, however that scoresheets and scoring systems have significant limitations. It is not always clear which clinical signs best reflect changes in the animal’s welfare.

When scoring pain following surgery, a number of specific pain assessment schemes have been developed, and these are described in EU Module 21 – Advanced Anaesthesia.

Scoresheets are useful not only to monitor deterioration in the welfare of a group of animals but can also be used to assess the positive effects of treatment.

Scoresheet summary

To summarise, monitoring scoresheets should include:

• General signs of good and poor health and welfare that we can identify for that species, strain or individual.
• Specific signs to be used to recognise if problems have occurred as a result of the particular procedure that has been carried out.
• A guide as to what interventions should be made, and when.
• An indication of the signs that would indicate euthanasia is needed (the humane endpoint).
• A record of any treatments given, so that their effects can be assessed.

1. H Ullman-Culleré, M & Foltz, Charmaine. (1999). Body Condition Scoring: A Rapid and Accurate Method for Assessing Health Status in Mice. Laboratory animal science. 49. 319-23.
2. Hickman DL, Swan M. 2010. Use of a body condition score technique to assess health status in a rat model of polycystic kidney disease. J Am Assoc Lab Anim Sci 49:155–159