Low blood pressure in rabbits

Question
Hello Lee,

I recently took my 7 year old mini lop rabbit Jasper to the vet to have a blood test. Jasper has lost a fair amount of body mass in his advancing years, but I was told this is quite normal in an ageing rabbit, in much the same way as an ageing human will lose body mass in their senior years.

Although a blood test was not required for medical reasons (he seems to exhibit perfectly normal behaviour, eating frequently, and pelleting as normal), I wanted to be aware of any deterioration in his kidney/liver function at the earliest possible opportunity, in order to manage any deterioration in those organs.

However, when I took him to the vet, the vet was unable to to extract a sufficient amount of blood. The reason that was given for this was that Jasper was suffering from low blood pressure, due to old age. The vet seemed relatively unconcerned about this.

Having scoured the internet, I have been unable to find the reason for low blood pressure in rabbits. The material which does exist on the web seems to suggest that, a rabbits blood pressure usually increases with age, and that low blood pressure in rabbits is very uncommon.

Please could you give me an opinion on what might be causing the low blood pressure, if it is a more serious problem than my vet would lead me to believe, if it might be a consequence of another underlying condition, and what can be done to treat low blood pressure in rabbits.

Kind Regards
Angelo

Answer
Hi,

well, the good news is according to you, he is eating and drinking and has otherwise what you know to be, for him, NORMAL behaviors and normal intake and output.

This is the good news because generally speaking when you have all this, the bunny is doing okay and not in crisis.

Why the blood pressure being low.  Well it could be more than one thing.  If he's a little nervous at the vet and didn't drink as much as he normally does before going to the vet, he may be down a little in water and that makes drawing blood difficult.  If he was feeling cooler or had been in a cooler environment that would have an effect on size of blood vessels.  Given he's older and lost some weight his blood volume is probably less than it used to be.

For a indoor house rabbit, 7 is not old.  Technically vets may consider him to be older, but as house rabbits with good care routinely live 10-12 years, or more, he's not terribly old.  He's the "young" of the "old".  

I need to preface I'm not a vet and don't know his history other than what you've said here.  That said, there's several things I'd suggest talking with your good rabbit vet about for him.

First, as technically he is older (younger side of "old"), one thing you amy want to have checked is his kidneys and liver.  Kidneys play a part in regulating blood pressure in how they deal with sodium regulation in the body and they try to help keep blood pressure more or less stable.  I tie in the liver to this because liver problems can affect the kidney.  There are tests they can run to check for specific things that would point to high or low numbers that may indicate a problem.  I'd pick up the "Rabbit Health in the 21st Century" book I discuss because it discusses this and also has numbers for what's normal for a given enzyme, substance, etc.  Which would help decipher numbers, and it also discusses what decreasing values of something means in terms of a organ that's declining, etc.

If there does seem to be a problem, Milk Thistle and Dandelion are two great herbs you can get in health supply stores that are great for the liver and kidney which you could take a small part of a capsule, wet some lettuce he eats, and sprinkle on.

Second, if he seems to be eating less, and if he's lost weight, he is, you could try to see if you could stimulate his appetite if he seems to be losing too much weight.  THe seasick product called "Bonine" is useful for this.  The tablet drug name is Meclizine.  Generally they are 25 mg tablets and usually raspberry flavored.  Cut the tablet into 4 parts.  You can either crush and liquefy each quarter into 4 doses you can give with an oral syringe, or you can put each quarter into a dab of petromalt and feed that way. Generally rabbits love the flavor.  Meclizine can stimulate appetite in rabbits that are sick, or on antibiotics that cause a drop in appetite, or for rabbits who have a head/inner ear infection that could be making them feel nauseous, and also for cases where their sense of taste has been negatively affected.  You can try once a day and if it works, once a day is enough.  Otherwise you could try twice a day, every 12 hours.

If this seems to help, you may want to consider just making sure he's not suffering from some low level, chronic infection somewhere.

Third, if he's ever been on antibiotics for a period of time, you may want to consider giving him some probiotics - to replenish good gut bacteria and maybe help his gut work better and maybe being able to give him more energy from his food.  Bene-bac comes in a 15 mL oral syringe and it's the best form, because it's delivered in a tasty, fatty paste that allows the bacteria to survive the acid of the stomach.  Maybe try giving 1/2 mL 2-3 times a week to see if you notice any output results (bigger poops, more poops, etc).

Fourth you may want to see if it's just that he's lost some excitement for what he normally eats, in terms of taste.  If you had a poorer batch of hay, he may be eating less of it.  If they changed his pellet formula he liked from last year, but this year's formula is a little different, he may not like it so much.  You may even want to consider giving him a little alfalfa pellets or alfalfa piece of hay cube each day to see if that entices him to eat a little more.