First, with respect to your spreadsheet, the convention here is that the older numbers are at the top. The most current numbers are at the bottom. It will make those of us who have been looking at spreadsheets for years very confused since for this site, your spreadsheet is upside down. When you have a chance, can you rearrange the page?
If you decide to ditch the pet meter, you may want to consider buying a blood ketone meter. The strips are pricey but you don't have to wait hours for your cat to urinate in order to test for ketones. NovaMax makes a good ketone meter, as dose Precision Xtra and they are available on the ADW website. 
Did your vet run labs when treating Ty's DKA. If so, get a copy. The recipe for DKA is an infection/inflammation + not enough calories + not enough insulin. If Ty wasn't given an antibiotic, I'd be very surprised unless the white count was normal and there was no indication of a UTI. Do you know if your kitty has any dental issues like gingivitis? It can also contribute to the infection/inflammation issue. When Gabby was diagnosed with DKA, she was discharged from the ICU with an antibiotic, an anti-nausea med, an appetite stimulant and something else. (It was a long time ago an I didn't put the meds on her spreadsheet at the time.) Please keep in mind that water is good but food is necessary. Ketones develop when a cat is burning stored fat rather than metabolizing newly ingested food. 
The other anti-nausea med is ondansetron (Zofran). It's a human med. The tablets are expensive. The injectable form is much less costly but it stings when injected. Some cats need both Cerenia and ondansetron to get past nausea. 
You might want to try giving Ty baby food. Many cats love the stuff and it's a great way to get a cat eating. You would want to find a Stage 2 food that is only a protein and broth. The downside is that it's fairly low in calories. 
		
		
	 
Here was an update I received while he was in the hospital.
Physical Exam:
Wt: 4.44 kilograms
Temp: 102.5 F Pulse: 188 bpm Resp: 40 rpm
Mentation: QAR
MM/CRT: Pale pink/<2 sec
Pulse Quality: Moderate
Body Condition Score: 4/9
CSU Pain Score: 0/4
Hydration: persistent 3-5% dehydrated
EENT: Clear AU. No ocular or nasal discharge. Normal menace and palpebral responses OU. Pupils equal and reactive. Fundic
examination not performed. Oral examination not performed due to demeanor. No palpable thyroid slip
LYMPH NODES: No peripheral lymphadenopathy
CARDIOVASCULAR: Grade II/VI parasternal heart murmur NOT auscultated today. Femoral pulses strong, synchronous, symmetrical
RESPIRATORY: Resolved increase respiratory rate, with normal respiratory effort. No crackles/wheezes. Normal bronchovesicular
sounds
INTEGUMENT: No significant findings
ABDOMEN: No pain or masses noted
MUSCULOSKELETAL: Ambulatory x 4 but generalized weakness, full orthopedic examination not performed
NEUROLOGIC: Quiet,Alert and mentally appropriate. Generalized weakness. Full Neurological exam not performed
UROGENITAL: External normal
RECTAL: Not performed.
Working Diagnosis/Problems:
Lethargy
Hyporexia
Diabetes, ketoacidosis
Chronic nephropathy
Hyperechoic hepatomegaly
Heart murmur (Not auscultated 6/9/19)
Stress leukogram
Thrombocytopenia: resolved
Mild hypokalemia
Mild hypocalcemia
Diagnostics:
ER 6/8/2019:
Serum Ketones: 80 mg/dL
Glucose: 500 mg/dL
CBC:RBC 8.17, Hct 41.48, Hgb 14.8, WBC 18.92, Neut 16.66, Lymph 1.11, Mono 0.70, Plt 274 (L)
Chemistry: Glu 345 (H), BUN 27, Crea 0.9, Phos 3.8, Ca 7.6 (L), Na 149, K 3.6 (L), TP 7.5, Alb 4.5, Glob 3.0, ALT 75, ALP 47, tbil 0.2,
amyl 313
CG8: pH 7.178 (L), pCO2 17.6 (L), PO2 126, BE -22, HCO3 6.8, TCO2 7, SO2 98, Na 149, K 3.7, iCa 1.27, Glu 361 (H), PCV 38, TP 11.2, L
fPL: Negative
NIBP: 142 mmHg
UA:SG >1.050, Pro 30 mg/dL, pH 6.0, Ket 80 mg/dL, Gluc 1000 mg/dL, Neg bld, bil, rbc 0-3 hpf, 0-2 wbc hpf, no casts, crystals,
bacteria obs; epithelial 0-2 hpf
UCS: Idexx
TXR:
Findings
Thorax (Right lateral, Left lateral, VD images; 3 total images):
The cardiac silhouette and pulmonary vessels are normal in size and appearance. The pulmonary parenchyma is normal and there is
no evidence of soft tissue pulmonary nodules or pulmonary infiltrates. No abnormalities noted within the pleural space or
cranial mediastinum. Included portion of the abdomen is normal. The osseous and extra-thoracic soft tissue structures are
normal.
Conclusions
Unremarkable thoracic study however chronic lower airway inflammation (i.e. asthma) cannot be ruled out.
Treatments:
NormR 12 ml/hr (45 ml/kg/d + 1 ml/kg/hr losses) + 10 mEq KCL + 10 mEq KPhos
Maropitant 1 mg/kg IV once
Ondansetron 0.5 mg/kg IV BID
Insulin CRI after 4-6 hr on IVF ***Total IV rate IVF plus Insulin CRI to equal 15ml/Hr***
Serial BGs
Recheck Lytes, serum ketones
Monitor for fluid overload (Increase RR/RE, weight gain, serous ocular or nasal discharge, chemosis, etc)
Daily update to owner:
9:50a: Called owners with an update. Ty is doing fairly well. Still a bit weak but is eating. Still a bit dehydrated. I do not hear a
murmur on auscultation today. No abdominal pain or discomfort. Plan is to restart unasyn pending urine culture submitted by
2 of 3ER, continue to monitor BG q 2 hours and adjust insulin CRI, then re-evaluate general labs and serum ketones in am. Owners are happy with todays plan.