“Goodness, she’s biting them right off!”
This can be the unfortunate call we receive from a farmer when an animal is affected by a condition known as Ischaemic Teat necrosis (ITN).
ITN is a disease that specifically affects the teats causing intense irritation. This can result in excessive licking, sometimes to the point of cows removing entire teats from their udders.
The disease presents initially as discolouration and mild ulceration, most often on the inner wall of the teats (photo 1). This can progress to more significant ulceration with areas of skin sloughing off (photo 2) and then eventually complete removal of the teat (photo 3), often by means of the animal traumatising herself.
Unfortunately, the outcome for animals affected by this disease can be poor. A recent 2023 AHDB-funded report from Liverpool University found that out of 250 reported cases:
- 23% of animals were culled immediately
- 21% were seen to recover of those that weren’t culled and remained on farm
- 56% of these animals either lost the teat end or developed severe mastitis in that quarter
This disease seems to be of increasing importance in UK dairy herds with it being first officially reported in 2004.
Nearly half of farmers that have detected it in their herds had never seen it before until 2015.
We are still uncertain of what causes ITN. Investigations show there is often a reduction in the range of bacteria present on the ITN-affected teats compared to normal teats, a ‘dysbiosis’ with harmful bacteria being allowed to get the upper-hand.
We do know that the disease seems to be found more readily on farms with higher levels of chapped teats and teat oedema, and so milking machine maintenance and ensuring the teat is moisturised post milking remains the standard core advice. Interestingly there also seems to be an association with increased levels of Udder Cleft Dermatitis seen (see article below).
As mentioned above, response to treatment tends to be quite poor and is hampered by the high levels of antimicrobial resistance seen in the bacteria most commonly involved. The most vital aspect of managing these animals is having a clear plan in place with your vet – with welfare top of the agenda. Animals that are not showing signs of improvement must be dealt with quickly and adequately.
Written By Ben Barber, BVetMed (Hons) MSc Vet Epi MRCVS West Regional Lead
