{"id":45101,"date":"2026-04-01T13:00:00","date_gmt":"2026-04-01T13:00:00","guid":{"rendered":"https:\/\/www.thefarmersdog.com\/digest\/?p=45101"},"modified":"2026-04-01T17:26:17","modified_gmt":"2026-04-01T17:26:17","slug":"what-dog-owners-need-to-know-about-ctt-stones","status":"publish","type":"post","link":"https:\/\/www.thefarmersdog.com\/digest\/what-dog-owners-need-to-know-about-ctt-stones\/","title":{"rendered":"What Dog Owners Need to Know About CTT Stones"},"content":{"rendered":"<?xml encoding=\"utf-8\" ?><p><strong>In this article:<\/strong><\/p><ul class=\"wp-block-list\">\n<li><a href=\"#h-what-are-ctt-stones\">What are CTT stones?<\/a><\/li>\n\n\n\n<li><a href=\"#h-how-do-ctt-stones-affect-dogs\">How do CTT stones affect dogs?<\/a><\/li>\n\n\n\n<li><a href=\"#h-how-common-are-ctt-stones\">How common are CTT stones?<\/a><\/li>\n\n\n\n<li><a href=\"#h-should-i-worry-about-ctt-stones-in-my-dog\">Should I worry about CTT stones in my dog?<\/a><\/li>\n<\/ul><div style=\"height:20px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div><hr class=\"wp-block-separator has-alpha-channel-opacity\"><div style=\"height:21px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div><p><em>This article was originally published in January of 2026, and has been updated.<\/em><\/p><p>You may already know that dogs can develop <a href=\"https:\/\/www.thefarmersdog.com\/digest\/bladder-stones-dogs\/\" target=\"_blank\" rel=\"noreferrer noopener\">bladder stones<\/a>, concentrated formations of minerals found in urine. Also known as uroliths or cystic calculi, bladder stones come in several types, all of which you can learn about in <a href=\"https:\/\/www.thefarmersdog.com\/digest\/bladder-stones-dogs\/\" target=\"_blank\" rel=\"noreferrer noopener\">this guide<\/a>.&nbsp;<\/p><p>These rock-like deposits range in composition and size, from a grain of sand to larger lumps that pose the threat of creating blockages that leave dogs straining or unable to urinate, which is a medical emergency.<\/p><p>In 2025, researchers from the University of Minnesota announced the discovery of a new, rare type of canine bladder stone composed of calcium tartrate tetrahydrate (CTT).<\/p><p>It&rsquo;s natural to worry about any risk to your dog&rsquo;s health, but the good news is that CTT stones are quite rare&nbsp;(.02% of bladder stones assessed)&mdash;and their health implications are not any different than those of the very common calcium oxalate stones (more than 30% of stones). Here&rsquo;s what you need to know about CTT stones, what causes them, how they affect dogs, and how veterinarians address them.&nbsp;<\/p><h4 class=\"wp-block-heading\" id=\"h-what-are-ctt-stones\">What are CTT stones?<\/h4><p>Canine CTT stones were recently discovered by researchers with the Minnesota Urolith Center at the University of Minnesota College of Veterinary Medicine. They detailed this finding in a <a href=\"https:\/\/onlinelibrary.wiley.com\/doi\/10.1111\/jvim.70093\" target=\"_blank\" rel=\"noreferrer noopener\">paper published in April 2025<\/a> in the <em>Journal of Veterinary Internal Medicine,<\/em> where they drew a potential link between the formation of CTT stones and ingestion of choline bitartrate, a common ingredient found in dog foods,&nbsp;including dry, fresh, and homemade foods.<\/p><p>However, choline bitartrate&rsquo;s presence in dog food far exceeds its super-rare presence in bladder stones. Adding cognitive and metabolic health benefits to a diet, choline bitartrate is a generally recognized as safe (<a href=\"https:\/\/www.fda.gov\/food\/food-ingredients-packaging\/generally-recognized-safe-gras\" target=\"_blank\" rel=\"noreferrer noopener\">GRAS<\/a>) ingredient that&rsquo;s commonly used in commercial dog foods.<\/p><h4 class=\"wp-block-heading\" id=\"h-how-do-ctt-stones-affect-dogs\">How do CTT stones affect dogs?<\/h4><p>Like other, more common types of uroliths, CTT stones may either pass on their own or, if they&rsquo;re larger and possibly obstructive, require veterinary intervention in the form of surgery.&nbsp;<\/p><p>Signs of bladder stones may include: straining to urinate, blood in urine, whimpering while urinating, or frequently urinating in small amounts. If you suspect bladder stones, or notice any unexplained change in your dog&rsquo;s behavior, call your veterinarian.<\/p><figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"682\" src=\"https:\/\/www.thefarmersdog.com\/digest\/wp-content\/uploads\/2026\/01\/what-to-know-about-CT-stones-in-dogs-1024x682.jpg\" alt=\"White shih tzu resting at living room couch during day .\" class=\"wp-image-45105\" srcset=\"https:\/\/www.thefarmersdog.com\/digest\/wp-content\/uploads\/2026\/01\/what-to-know-about-CT-stones-in-dogs-1024x682.jpg 1024w, https:\/\/www.thefarmersdog.com\/digest\/wp-content\/uploads\/2026\/01\/what-to-know-about-CT-stones-in-dogs-300x200.jpg 300w, https:\/\/www.thefarmersdog.com\/digest\/wp-content\/uploads\/2026\/01\/what-to-know-about-CT-stones-in-dogs-768x512.jpg 768w, https:\/\/www.thefarmersdog.com\/digest\/wp-content\/uploads\/2026\/01\/what-to-know-about-CT-stones-in-dogs-1536x1024.jpg 1536w, https:\/\/www.thefarmersdog.com\/digest\/wp-content\/uploads\/2026\/01\/what-to-know-about-CT-stones-in-dogs.jpg 1733w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure><h4 class=\"wp-block-heading\" id=\"h-how-common-are-ctt-stones\">How common are CTT stones?<\/h4><p>CTT stones in dogs are exceedingly rare.&nbsp;<\/p><p>The University of Minnesota team analyzed 318,147 canine bladder stones between January 1, 2020 and December 31, 2024. CTT was identified in stones from only 63 dogs, or 0.02% of those assessed.&nbsp;<\/p><p>Of these dogs, the most represented breeds encompassed eight shih tzus, six Pomeranians, six Chihuahuas, six Maltese, six Yorkshire terriers, and six miniature schnauzers, all of which have known predispositions to form calcium-based urinary stones according to <a href=\"https:\/\/pubmed.ncbi.nlm.nih.gov\/31471926\/\" target=\"_blank\" rel=\"noreferrer noopener\">previous research<\/a>. These stones were also more prevalent in male dogs, with 84% of CTT stones originating from males.<\/p><p>To better understand potential causes of CTT stones in these dogs, the team requested additional information from their owners, including information about diet; 33 completed surveys were returned, 29 of which detailed the dogs&rsquo; diet prior to urolith diagnosis. <\/p><p>Even among this tiny group, not all the dogs who developed CTT stones were fed a diet containing choline bitartrate. Owners fed seventeen commercially formulated diets to 23 of these dogs, but only 12 diets contained choline bitartrate. Twenty dogs in all ate these diets. That is: 30% of the dogs that had developed CTT stones did not even have choline bitartrate in their diets. Also, in conjunction with both homemade and commercial diets, the choline bitartrate was given as a supplement in addition to the main diet in some cases.<\/p><h4 class=\"wp-block-heading\" id=\"h-should-i-worry-about-ctt-stones-in-my-dog\">Should I worry about CTT stones in my dog?<\/h4><p>CTT stones are quite uncommon in dogs, and in the study&rsquo;s context only a small subset of an already high-risk group of dogs had them. Since these stones have only just been identified in dogs, there&rsquo;s still much research to be done on how to best prevent and treat them. You should always ask your veterinarian any questions about your dog&rsquo;s health&mdash;they&rsquo;re the most qualified to weigh their history and risk factors&mdash;but the prevalence of CTT stones is infinitesimally low, and they are very unlikely to arise in most dogs.<\/p><p>Dog owners can also take steps to help prevent bladder stones in general. A complete and balanced diet can support balanced pH levels in your dog&rsquo;s urine, and a urinalysis test at the vet can verify this balance. Keeping your dog hydrated with fresh water can also help reduce the likelihood of developing stones.<\/p><p>If you&rsquo;re worried about your dog&rsquo;s risk for bladder stones, CTT or otherwise, consult your veterinarian. They&rsquo;re your best, most qualified partner in keeping your best friend healthy.<br><\/p><script type=\"application\/ld+json\">\n\n{\n    \"@context\": \"https:\/\/schema.org\",\n    \"@type\": \"FAQPage\",\n    \"mainEntity\": [\n      {\n        \"@type\": \"Question\",\n        \"name\": \"What are CTT stones in dogs?\",\n        \"acceptedAnswer\": {\n          \"@type\": \"Answer\",\n          \"text\": \"CTT stones are a newly discovered, rare type of canine bladder stone composed of calcium tartrate tetrahydrate. They were identified by researchers at the University of Minnesota.\"\n        }\n      },\n      {\n        \"@type\": \"Question\",\n        \"name\": \"How are CTT stones formed?\",\n        \"acceptedAnswer\": {\n          \"@type\": \"Answer\",\n          \"text\": \"Research suggests a link between the formation of CTT stones and the ingestion of choline bitartrate, an ingredient commonly found in dog foods. However, choline bitartrate is a generally recognized as safe ingredient used for cognitive and metabolic health benefits.\"\n        }\n      },\n      {\n        \"@type\": \"Question\",\n        \"name\": \"How do CTT stones affect dogs?\",\n        \"acceptedAnswer\": {\n          \"@type\": \"Answer\",\n          \"text\": \"Like other bladder stones, CTT stones can either pass on their own or, if they become large or obstructive, may require veterinary intervention such as surgery. Signs include straining to urinate, blood in urine, whimpering while urinating, or frequent urination in small amounts.\"\n        }\n      },\n      {\n        \"@type\": \"Question\",\n        \"name\": \"How common are CTT stones in dogs?\",\n        \"acceptedAnswer\": {\n          \"@type\": \"Answer\",\n          \"text\": \"CTT stones are exceedingly rare, accounting for only 0.02% of canine bladder stones assessed in a study by the University of Minnesota, which identified them in only 63 out of 318,147 stones.\"\n        }\n      },\n      {\n        \"@type\": \"Question\",\n        \"name\": \"Should I be worried about CTT stones in my dog?\",\n        \"acceptedAnswer\": {\n          \"@type\": \"Answer\",\n          \"text\": \"You generally should not worry about CTT stones as they are very uncommon and unlikely to arise in most dogs. If you have concerns about your dog's health or risk factors for bladder stones, consult your veterinarian.\"\n        }\n      },\n      {\n        \"@type\": \"Question\",\n        \"name\": \"How can I help prevent bladder stones in my dog?\",\n        \"acceptedAnswer\": {\n          \"@type\": \"Answer\",\n          \"text\": \"To help prevent bladder stones in general, ensure your dog has a complete and balanced diet to support balanced urine pH levels, and keep them well-hydrated with fresh water. A urinalysis test at the vet can also verify urine balance.\"\n        }\n      }\n    ]\n}\n<\/script>\n","protected":false},"excerpt":{"rendered":"<p>Here are key facts about these newly discovered canine bladder stones.<\/p>\n","protected":false},"author":12,"featured_media":45104,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[416,418],"tags":[349,184,239,221],"class_list":["post-45101","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-health-wellness","category-science-research","tag-conditions","tag-dog-food","tag-research","tag-safety"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.thefarmersdog.com\/digest\/wp-json\/wp\/v2\/posts\/45101","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.thefarmersdog.com\/digest\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.thefarmersdog.com\/digest\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.thefarmersdog.com\/digest\/wp-json\/wp\/v2\/users\/12"}],"replies":[{"embeddable":true,"href":"https:\/\/www.thefarmersdog.com\/digest\/wp-json\/wp\/v2\/comments?post=45101"}],"version-history":[{"count":12,"href":"https:\/\/www.thefarmersdog.com\/digest\/wp-json\/wp\/v2\/posts\/45101\/revisions"}],"predecessor-version":[{"id":45863,"href":"https:\/\/www.thefarmersdog.com\/digest\/wp-json\/wp\/v2\/posts\/45101\/revisions\/45863"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.thefarmersdog.com\/digest\/wp-json\/wp\/v2\/media\/45104"}],"wp:attachment":[{"href":"https:\/\/www.thefarmersdog.com\/digest\/wp-json\/wp\/v2\/media?parent=45101"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.thefarmersdog.com\/digest\/wp-json\/wp\/v2\/categories?post=45101"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.thefarmersdog.com\/digest\/wp-json\/wp\/v2\/tags?post=45101"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}