If you are concerned that your horse is not feeling their normal self or is ‘under the weather’ then it can be a good idea to check their TPR (temperature, pulse, respiration) as a helpful indicator to the source of the problem, it can be very helpful to the vet if you can give these extra details when you speak them about your horse. If your horse regularly mixes with other horses at competitions/lessons/out hunting they are at a greater risk of contracting a virus and monitoring can help you pick up problems before they become severe. For example, if your horse has a nasal discharge and an increased temperature this may indicate a respiratory virus; you can then isolate this horse from others as quickly as possible to try and avoid spread. It can also be useful to check your horse’s vital signs when they start on a new medication in case they suffer any unexpected side effects.
Pulse rate – The pulse is taken most easily from the mandibular artery under the jaw (see left), the artery will feel like a spongy cylinder against the inside of the jaw bone and you will feel the pulse through it when you place your middle and index finger over it. Take your time to wait and feel the beats as the horse’s pulse is slow; count the number of beats in 15 seconds and multiply by 4 to get beats per minute. Normal is around 30-44 beats per minute in a healthy adult horse. It is slightly higher in small ponies and in foals.
Respiratory rate – number of breaths per minute. Stand to the side and back of your horse and watch the abdomen rise and fall, this should be barely perceptible with minimal effort and only mild movement of the nostrils. In an adult horse, 8-16 breaths per minute is normal, again it can be higher in small ponies and foals.
Mucous membrane colour and capillary refill time – raise your horse’s upper lip to view the mucous membranes which should be pink and moist. Gently press your finger onto the membrane surface (to push the blood out from the capillary vessels) and count how long it takes for the area to become pink again, this should be less than 2 seconds.
Temperature – this is taken by placing a thermometer (digital is easier as it will beep when ready!) just through the anus and holding it gently against the rectal wall. The temperature should lie between 37-38.5⁰c in a healthy adult horse. Temperature can vary between horses but each individual’s temperature is normally pretty stable and it can be a good idea to take it a few times when the horse is well to know what is normal for them.
What Changes are Significant?
If your horse’s pulse rate or respiratory rate is elevated then first be sure this is not due to excitement/exercise/fear, if you are unsure take it again when the horse seems more settled. A truly elevated heart rate does indicate a problem and is usually accompanied by another clinical sign.
An elevated respiratory rate is most significant if there is also an increased effort to inspiration/expiration with excessive abdominal movement (they may even show a ‘heave’ line) especially if this is coupled with flaring nostrils, a wheeze and coughing. This can be due to allergic airway disease or a respiratory infection and should be investigated.
Mucous membrane colour can vary between horses and often can appear pale without any clinical problem; however bright red or purple/grey mucous membranes indicate a sick horse that is in need of veterinary attention. A slow capillary refill time combined with pale mucous membranes can indicate a circulatory problem.
A high temperature is almost always significant (provided you haven’t just exercised the horse hard!) and you should contact the vet if it is over 39⁰c especially if accompanied by dullness and inappetence.
An increase in faecal production indicates an increased intake. Decreased output can be due to decreased input or may be an early indicator of an impaction especially if those faeces produced are small and dry/firm. Increased water content of faeces (diarrhoea) often relates to stress, change in diet or rich pasture but if prolonged or accompanied by other signs of poor health then should be investigated. Increased drinking may be normal in hot weather but if prolonged/excessive can indicate a problem, such as Cushing’s or kidney disease; this may be accompanied by increased urination. Decrease urination may indicate dehydration whilst anuria (no urine) is a veterinary emergency.