# Urinary Calculi--Causes and Types of Stones



## sweetgoatmama (Dec 10, 2008)

The following was published in Wool & Wattles, the current quarterly magazine of the American Assn of Small Ruminant Practitioners (Vol. 37, Issue 1). The article's author granted me permission to reprint on various discussion lists and publications. I hope you find it useful. - Maxine Kinne (Also printed here with permission.--Carolyn )

Urolithiasis in Small Ruminants (Seminar Notes)
Marie Bulgin, DVM, University of Idaho Caine Veterinary Teaching Center

Because questions about urolithiasis come up fairly often, I thought it might be helpful to summarize a talk I gave on the subject a couple of years ago. here are some of the points I made.

Calcium carbonate (smooth, round, gold stones; look like B-B pellets) are common in pastured goats particularly on clover-rich pastures or where oxalate-containing plants occur (halogeton, spinach, rhubarb, Swiss chard, dock, lamb's quarter, pig weed, antifreeze, excessive use of ascorbic acid (vitamin C)). Oxalates bind calcium, which comes unglued in urine, allowing the calcium to then bind with carbonate. It is the most common stone found in goats in my area of Southern Idaho.

Struvite crystals or magnesium ammonium phosphate crystals (look like sand) are most common in feedlot animals (sheep & cattle).
* High phosphate diets (grains are high in phosphorus; when too high, phosphorus combines with magnesium and ammonium and forms a "sand-like" deposit.
* High magnesium is >0.6% even when Ca is balanced (2:2.5:1).

Silicate stones. I've never actually seen these. I think they are reported in range cattle.

A high pH (alkaline) facilitates the precipitation of stones in the urine. Forage eaters normally have urine with a high pH. A low urine pH aids in the solubility of phosphate, carbonate and silica compounds.

Mucopolysaccharides are associated with rapid body growth and are often correlated with stone formation. They are increased when feeding certain feeds - cottonseed meal, milo.

Pelleted feeds increase mucoproteins in the urine which act as a matrix and cementing substance.

Vitamin A deficiency causes desquamation of bladder lining cells. Dead cells act as a nidus on which stone will begin to form.

Diameter of urethra: Wethers and steers are more at risk because castrated males have smaller urethras. In cattle, the urethral diameter of late castrates ((6 months old, compared to early castrates, 2 months old) was found to be 8% larger and able to expel a calculus that was 14% larger. Bulls' urethras are twice as large as steers. Studies haven't been done in sheep or goats, but chances are it is a similar situation. Genetics also seem to play a part in urethral size.

Balanced CA and P, a 2:1 ratio is considered optimum for prevention of struvite crystals.

Increase water intake.

Feed NaCl (salt) up to 4% in the diet (most sodium (Na) mineral combinations are soluble and "water follows salt".

Tank heaters for the winter months. Be sure water is always clean, fresh easily accessible and enough for all individuals.


Treatments

Struvite crystals - Establish urine flow - catheterization, flushing, etc. Muscle relaxers. Acidifying the urine will dissolve the crystals in the bladder. Keep the animal on a urine acidifier as a preventative. Good prognosis.

Calcium carbonate stones do not dissolve in acid urine. Even if the stones in the urethra are removed, there are always more in the bladder. Tx: Urethrotomy, Cystotomy, Marsupialization. Long term outcome: Not good, urine scald, bladder and kidney infections. Acidified urine should prevent them from reforming.

Recommendations

* Quit feeding treats

*Since grass hay calcium and phosphate ratio is 1:1 and alfalfa hay is 5.7:1, feed a combination of half alfalfa and half grass hay which will give approximately a 2.3:1 ratio.

* Spray pasture with 2,4-D to kill broadleaf weeds, which tend to be oxalate accumulators.

* Castrate late, after 6 months of age, if you can stand to wait that long. Callicrate Banding is an option at an older age - no blood loss, no infections. Tetanus vaccination required. A Local anesthetic should be used. The scrotum should be removed 3-4 days after banding, leaving the band in place.

* Ammonium chloride or ammonium sulfate 1 gm/day. Goats eat salt at about 0.5 to 1 ounce per day. Mix 50 pounds of loose trace mineral salt with 2.5 lbs. of ammonium chloride and feed free choice.

* Biochlor or Soychlor. Feed approximately 1/4 .b or 1 measuring cup per head per day. Some goats do not like the taste. Can be mixed with cornmeal, cracked grains or dried molasses to entice them to eat it.

* Vitamin C - not recommended, as large doses irritate the bladder and the body compensates after several days and it no longer acidifies the urine.


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## sweetgoatmama (Dec 10, 2008)

Hi Carolyn,

A lot of private pharmacies will either have on hand or readily order pH test strips for you. You can also use litmus paper. The pH that you are seeking depends upon the individual situation and goal of the caretaker. 
A pH of 7 is neutral (that is what you want untreated water to be and not what a normal goat's urine will be).

A ruminant's urine is normally going to be quite alkaline if they are 
eating forage as their diet. My goats' urine always runs up about 8 -88.5 pH. The more recently they have eaten forage, the higher the urine pH seems to read. A goat's urine pH will usually drop when they are eating a high concentrate diet such as grains. But, feeding grains is not something you want to be doing to lower pH.. You will find differences in individual readings according to time of day and 
management practices. It's good to test a goat several times a day for a few days to learn what their pattern is.

When you acidify the urine, you are also pulling calcium from the goat's system. Whether the long term effects present a significant danger to the goat's structural integrity, teeth and general health or not is controversial. Dr. Marie Bulgin has stated that in her experience, the benefits of long-term urine acidification out-weigh the risks in goat herds prone to urinary calculi. A couple of local vets that I have spoken to here in MD have been much more leery of long term urine acidification due to bone loss seen in sheep.

Personally, I used a "flushing" regimen where I acidified the urine for 
several days in a row approximately once a month. During that time, my wether's urine pH would be dropped from his normal pH of 8.5 down to 
approx. 6 (AM test time before daily foraging). This method proved to work well in the case of my wether who had a history of urinary calculi. When he died (13.5+ years old), a necropsy showed his urinary tract completely healed and totally free of calculi.

Crossposted with permission from the Packgoat e-list.


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## Hasligrove (Dec 10, 2008)

Who was this cross post from? How did you "flush" the system once an month. What did you do to get the PH down to 6 for several days?

What type of stones did they have?

Thanks


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## sweetgoatmama (Dec 10, 2008)

Oops, I forgot to give credit. It was from Andy who posts on both the packgoat list and the GOAT list from WSU. She has a really good grasp of this particular problem. 
Becki said you guys were having some problems. I'll send you her email so you can talk to her direct.


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## rtdoyer (May 6, 2010)

In this original post (the seminar notes), it was stated, "Spray pasture with 2,4-D to kill broadleaf weeds, which tend to be oxalate accumulators"

We have an influx of clover this year (I'm blaming the horse lady across the road as she now has a clover problem) and on reading posts I realize we should probably get rid of the clover. We've done the mowing thing and that just isn't working very well so we thought about spraying. 

I looked up 2,4-D on the internet and about usage with animals and most of what I read said that as long as the animals weren't lactating or getting ready for slaughter, the spray is not harmful to animals. (Doesn't make sense as your goat is eating what the spray is targeting.)

Any thoughts out there or any experience out there with this spray and clover?

Tonia


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## bamboola (May 28, 2014)

Thank you for this information! I had read somewhere else that intermittent acidifying worked well, but this article is more helpful and specific about what is meant by "intermittent". 
Also, re: clover: unfortunately, we have some in our pasture, but fortunately, the goats seldom seem to eat it. It is very low on their list of "favorite foods".


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