Changes

Tachypnoea and tachychardia can be seen in the horse with colic. This is due to pain, but mainly due to decreased circulating volume, decreased preload, and endotoxemia. The puse can be palpated in the facial, digital, brachial and great metatarsal arteries. The heart rate should be measured over time, and its response to analgesic therapy ascertained. The pulse should be assessed at different sites.  The blood pressure can be assessed with the use of a blood pressure cuff and Doppler around the coccygeal artery. The normal systolic pressure of a an adult horse should be 100 to 125 mm Hg. Horses with colic that have a systolic pressure of less than 80 mm Hg had a poorer prognosis. A pulse that continues to rise in rate to 60 to 70 beats per minute and weaken in quality over 6 to 8 hours in the face of adequate analgesia is considered a surgical indication.  Infarctive disease is characterised by an increaseing, non-fluctuating heart rate.  

Tachypnoea and tachychardia can be seen in the horse with colic. This is due to pain, but mainly due to decreased circulating volume, decreased preload, and endotoxemia. The puse can be palpated in the facial, digital, brachial and great metatarsal arteries. The heart rate should be measured over time, and its response to analgesic therapy ascertained. The pulse should be assessed at different sites.  The blood pressure can be assessed with the use of a blood pressure cuff and Doppler around the coccygeal artery. The normal systolic pressure of a an adult horse should be 100 to 125 mm Hg. Horses with colic that have a systolic pressure of less than 80 mm Hg had a poorer prognosis. A pulse that continues to rise in rate to 60 to 70 beats per minute and weaken in quality over 6 to 8 hours in the face of adequate analgesia is considered a surgical indication.  Infarctive disease is characterised by an increaseing, non-fluctuating heart rate.  

Mucous membrane colour and moisture and capillary refil time (CRT) can be assessed to appreciate the severity of haemodynamic compromise. A reduced skin tent indicates dehydration. The normal colour is pale pink and the CRT is 1 to 2 seconds. The gingival mucous membranes change from pink and moist to red and dry as the circulating blood volume decreases. Reddening of the mucous membranes indicates haemoconcentration and worsens as the patient goes into shock. Reddening reflects worse prognosis, and cyanotic membranes indicate a very poor chance of a positive outcome as it it indicates that the horse is in endotoxic shock. The CRT will be prolonged with dehydration and endotoxaemia. A reduced skin tent indicates dehydration.

Mucous membrane colour and moisture and capillary refil time (CRT) can be assessed to appreciate the severity of haemodynamic compromise. The normal colour is pale pink and the CRT is 1 to 2 seconds. The gingival mucous membranes change from pink and moist to red and dry as the circulating blood volume decreases. The genital and conjunctival mucosa can also be assessed. Reddening of the mucous membranes indicates haemoconcentration and worsens as the patient goes into shock. Reddening reflects worse prognosis, and cyanotic membranes indicate a very poor chance of a positive outcome as it it indicates that the horse is in endotoxic shock. The CRT will be prolonged with dehydration and endotoxaemia.  

[[File:Ocular Mucous Membrane.jpg|thumb|200px|center| Picture of a horse's eye with congested conjunctical mucosa(Courtesy of Potter K, SPANA)]]

[[File:Skin Tent.jpg|thumb|200px|center| Picture of a dehydrated horse with a reduced skin tent underneath the intravenous jugular catheter(Courtesy of Potter K, SPANA)]]

[[File:Skin Tent.jpg|thumb|200px|center| Picture of a dehydrated horse with a reduced skin tent underneath the intravenous jugular catheter(Courtesy of Potter K, SPANA)]]