Hypercalcaemia in a cat.

Re: Hypercalcaemia in a cat.

Richard Fox — Thu, 19 May 2011 12:58:47 GMT

Thanks for the update -

Re: Hypercalcaemia in a cat.

Kate Richardson — Wed, 18 May 2011 08:47:00 GMT

Sad result but at least they have a definitive answer. Shame they won't consider chemo given he is only 9

Re: Hypercalcaemia in a cat.

Clive Ansell — Wed, 18 May 2011 08:19:15 GMT

Lab results back, and show a lymphosarcoma. malignant with poor prognosis. He is holding his own on prednisolone at the moment, and the owners have decided upon PTS when he deteriorates again, and have declined surgery or chemotherapy.

Re: Hypercalcaemia in a cat.

Richard Fox — Tue, 17 May 2011 12:37:19 GMT

At least you have something to go on now !

Re: Hypercalcaemia in a cat.

Clive Ansell — Fri, 13 May 2011 18:45:51 GMT

Update: my colleague has found a mass on ultrasound in duodenum and taken a FNA, she thinks it is lymphoma(sarcoma) but has sent to lab for confirmation.

Re: Hypercalcaemia in a cat.

Alex Gough — Thu, 12 May 2011 12:02:17 GMT

well worth the tumour hunt and PTHrp first then

Re: Hypercalcaemia in a cat.

Clive Ansell — Thu, 12 May 2011 11:39:30 GMT

I'm now locuming a different practice, having to keep in touch by email, and so don't have the figures to hand. Cat is back today for repeat ultrasound with someone who is better at it than me, and they are going to run a PTHrp assay if no mass is found.

From memory: PTH levels were low end of normal range, Phos was mid range, calcium was about 3.5 mMol (2.0-3.0), and ionised calcium was 1.68 (1.0-1.4)

Re: Hypercalcaemia in a cat.

Alex Gough — Thu, 12 May 2011 08:33:29 GMT

When you say PTH was "normal", was it actually normal, or low? If something is pushing the calcium up eg PTHrP, physiologically PTH should be low. How high was the calcium. Usually idiopathic hypercalcaemias aren't that high. Also what's the phosphate - a phosphatexcalcium (in mmol/l) over 5-6 would suggest a need for emergency treatment to lower the calcium due to risk of renal failure (although some believe that the calcium level alone is more important than ca x P). I would definitely do a PTHrP, - lymphomas can sometimes be tricky to find, it might be in the CNS or bone marrow for example. The hormone tests are expensive, but you could also consider running vit D testing at Cambridge Specialist Labs, to look for vit D toxicosis (rat bait, psoriasis cream), and hypercalcaemia of granulomatous disease (eg TB or idiopathic).

Alex

Re: Hypercalcaemia in a cat.

Richard Fox — Thu, 12 May 2011 08:23:10 GMT

[quote]but not a PTHrp -maybe I should? I guess a positive would confirm malignancy, but would a negative exclude malignancy??[/quote]

Would support but not confirm and no a -ve would not exclude neoplasia

Re: Hypercalcaemia in a cat.

Clive Ansell — Thu, 12 May 2011 08:11:28 GMT

Many thanks for all the feedback so far.

No access to skin creams, rodenticides etc as far as I know. He is mainly an indoor cat feed a dried commercial diet, Hill's I think. No large amounts of oily fish either. He doesn't vomit very often, and has always done so, so not sure of the significance of this. No diarrhoea.

There is no sign of any neoplasm as far as I can see; none externally, anal sacs normal, LN's all normal. I am the first to admit that my ultrasound skills are not great, so a colleague is going to repeat that for me FOC and FNA any masses if she finds them.

I did run a PTH assay which was normal, but not a PTHrp -maybe I should? I guess a positive would confirm malignancy, but would a negative exclude malignancy??

I had considered idiopathic hypercalcaemia and malignancy to be the two remaining differentials, but my money is with a tumour somewhere given the degree of weight loss (5.5 Kg to 3.5Kg in 3 months) and cachexia, would one see this with idiopathic hypercalcaemia?

He is not insured and costs are a bit of an issue, but they are good clients and will do what they can. As referral for further imaging such as CT, MRI, ultrasound is unlikely we are probably going to go down the route of ex-lap. At the moment his demeanour and appetite have improved on low dose prednisolone.

Re: Hypercalcaemia in a cat.

Richard Fox — Thu, 12 May 2011 07:38:02 GMT

Anal sac tumours (they are rare in cats) & Lymphoma (can be difficult to find ) would be likely neoplastic causes of hypercalcaemia?

Re: Hypercalcaemia in a cat.

Christopher Saul — Wed, 11 May 2011 23:59:22 GMT

Have you considered idiopathic hypercalcaemia? The differentials for hypercalcaemia in the cat are similar to those in the dog, however this is an important consideration in the cat.

Diagnosis is basically by exclusion of other causes; I would always do PTHrp assay as well as PTH. Don't forget that for these you need special sample handling ( sample drawn into chilled EDTA tubes, centrifuged immedately, separated EDTA plasma placed in a plain tube then frozen for at least 24hr before sending in a special refrigiration pack by special delivery ) . Addison's is EXTREMELY rare in the cat but I'd do a basal cortisol to rule this out too. Any possile history of vitamin D exposure ( human skin creams etc) ??

Given the GI signs then GI lymphoma is a possibility, could be worth scoping/ intestinal biopsy if you have the facility.

If the cat is insured you could refer to a radiologist for a really thorough abdo scan + splenic/liver FNA to rule out lymphoma in these organs too.

If you rule everything else out, then it's probably idiopathic hypercalcaemia. Treatment is steroids in the first instance, if this doesnt work I've heard you can use bisphosphanates, though never tried them myself

Hope this helps

Chris

Re: Hypercalcaemia in a cat.

Mark Holmes — Tue, 10 May 2011 21:29:54 GMT

I would go with cancer and as a punt go for stomach. I only say that as accurate ultrasound of the stomach is difficult to have confidence in. Vomiting and reduced appetite would be consistent. I would exlap. You could scope I suppose but multiple abdominal biopsies are much more complete. Gastric lymphoma? It's a cat so let's face it, it's going to have lymphoma somewhere!