Looking for advice please as so confused and only want what is best for precious cat who has recently become part of our family. Will try to make this simple - I have blood test results here but cannot read/ understand them.
Hyperthyroid old cat (nearly 15 years) who has been on 10mg vidalta since March 2015. Increased to 15mg Vidalta in March 2017.
Cat had full medical check at end 2017 - very skinny, continuously crying for food and increased heart rate. Thyroid fuction was at 46 (ideal range 7.5- 55) so increased to 20mg Vidalta which has been taking for 50 days.
Recent check up - good news is he has put on 10% body weight in 7 weeks and does not cry for food now BUT thyroid levels has gone up, goitre bigger than it was which suggests Vidalta not working as effectively and which should mean he would not put on weight but he has and vet cannot explain this. Heart rate has gone down, goitre is bigger then it was and bloods show signs of early renal failure (which part of the blood test is this?), some teeth need removing and vet can now hear a slight heart murmur - none of which were apparent on examination 7 weeks ago
I am very confused. It seems hyperthyroidism can mask renal failure as the increased blood pressure it causes can hide poorly functioning kidneys. However am confused as blood results suggest that hyperthyroidism is worse (level has gone up) but (a) cat has put weight on and (b) renal damage apparent now but was not in blood tests 7 weeks ago which should not be the case if hyperthyroid is worse (as blood pressure should be higher and masking renal damage but it is not).
Vet wants to up the vidalta to 25 mg now but I am not sure that makes sense if it is becoming less effective? Need to consider hyperthyroid, early renal faiure (diet?) and to a lesser extent teeth issue.
Please can someone advise - we love him and are very confused.