We do have to consider that this calf may have colic issues, but you haven't noticed any constipation or abomasal bloating, so I would be reluctant to assume a sensitive stomach in this wee one's case.
In regards XXXXX XXXXX white fecal production, this usually is a characteristic of inadequate absorption of the milk. In a ‘normal situation’, we can see this arise if the mother has experienced diet change post-calving thus changing the milk’s content. In this little one’s case, a change of ‘mother’ could cause similar signs. That said, often the calves do settle down within a few weeks of introduction to the alteration in their milk diet. And if it hasn’t then we do need to be concerned that he isn’t just a sensitive soul, and while he isn’t scouring, we should rule out cyrptosporidia. This is a protozoa that can often compromise GI absorption and function and notoriously will cause a past white/grey feces. Ruling this out usually is a case of fecal sample examination.
Turning to the more worrying issue, we must address this teeth grinding behavior. This coupled with the intermittent days of lethargy and poor appetite are all red flags that this calf is experiencing pain/discomfort. With the other GI signs, it is highly likely that this calf’s pain is based in the gastrointestinal tract.
I am relieved that we don’t have a strangulating hernia in this case, as we can see gut loops slip into hernias and become entrapped (early stage animals can present as intermittent gut pain until the loops become to edematous to slip back into the body). That said, we still have to keep intestinal twists, torsions and intusseceptions in the back of our mind. That said, a very common source of pain in an individual milk fed calf with GI absorption issues is the abomasal ulcer and we would have to put this on the top of our differential list for this calf. Abomasal ulcers are very common in milk-fed calves of this calf’s age.
You have mentioned that he did respond to antibiotics and this would be fine to continue. That said, the most important treatment is to keep him eating, since food is an excellent buffer against stomach acid and continual flow of forestomach contents (pH 6.0-7.0) into the abomasum helps increase abomasal pH.This may mean supplementing him with more feedings with his adopted mum, or adding in a bottle or even seeing if you can get him to consider some feed.
In regards XXXXX XXXXX antibiotic use in this case, broad-spectrum antibiotic therapy is indicated for ulcers. Usually we give them for 5 days (or until the rectal temperature is normal for 48 hr). Additionally, antacids can be effective in increasing abomasal pH in milk-fed calves but usually needs to be given every 4-6 hours. H2 -receptor antagonists are effective in increasing abomasal pH in milk-fed calves; however, the oral doses required for cimetidine (100 mg/kg, tid) and ranitidine (50 mg/kg, tid) are high. And while he is showing pain, do avoid using NSAIDS since their side effects can increase the severity of ulceration.
Overall, it does sound suspicious that this calf has a malabsorption issue (possibly crypto, possibly nutritional) and we do need to rule out and address an associated abomasal ulcer. You will want to address this situation as outlined above, but do keep a close eye on this wee one. This is because any deterioration may suggest perforation of the ulcer and if this occurs you will need immediate veterinary intervention (as untreated perforated ulcers are often fatal).
I hope this information is helpful. Please let me know if you have any further questions. If you have no further questions, I would be grateful if you would press the wee green accept.