Pentosan polysulfate sodium (Zycosan): adverse event reports that FDA received

Name: Pentosan polysulfate sodium: adverse event reports that FDA received, by year and species
Creator: Pet Drug Reports
License: https://creativecommons.org/publicdomain/zero/1.0/

Active ingredient

The name in brackets is a brand name with this active ingredient.

The openFDA records give the value "MSK" for the brand name and for the manufacturer name of each drug. FDA says that MSK means "masked". So the site cannot count a report for a brand.

Read this first. FDA says this about the data:

An API dataset query result cannot be used to estimate the risk associated with the product or compare one drug or device product with another. When looking at the results, be aware that there is no certainty that the reported drug or device caused the adverse event. This dataset should not be the sole source of information for clinical decision-making or other assumptions about the safety or effectiveness of a product. The adverse event may have been related to an underlying disease, other drugs used at the same time or other non-drug related sources.
FDA Center for Veterinary Medicine publishes these words. Source: Adverse Event Reports for Animal Drugs and Devices, read on 2 Oct 2026. The data have the reports that FDA received through 26 Jun 2026.

This page is not veterinary advice. For an animal that is ill, speak to a veterinarian.

Contacting a veterinarian How to report to FDA

From July 2008 to June 2026, FDA received 217 adverse event reports that name a drug with pentosan polysulfate sodium as its active ingredient. Of the 217 reports, 203 (93.5%) are about horses. 10 reports are about dogs (4.6%).

In January to March 2026, FDA received 25 reports that name this drug. The signs that appear in the largest number of the 217 reports are "Injection site swelling", "Injection site hair change" and "Hives". A report is not proof that a drug caused a sign.

Reports that name this drug rose by 2.5% in the 12 months to June 2026, compared with the 12 months before. Reports for all animal drugs fell by 4.6% in the same periods. The newest months can get more reports in a later update. Reports about horses are 93.5% of the reports that name this drug, and 1.4% of all reports.

Search engines list a drug page with 500 reports or more in all years. The page also needs 30 reports or more in the 12 months to June 2026. This page is under one of these numbers. The site keeps the page and keeps it out of search engines.

Since the last update of the FDA data

The latest update of the FDA data, recorded on 11 Oct 2026, changed no count of this page.

January to March 2026 is the latest closed quarter in the data. In that quarter FDA received 25 reports that name pentosan polysulfate sodium: 0 dog, 0 cat, 22 horse, 3 other or not given.

All updates Feed of updates (RSS)

Signs that the reports list

A sign is a coded term from the report. The words in brackets are a plain gloss of the term. The percentage is the share of the 217 reports that list the sign. One report can list more than one sign.

The sign that is in the largest number of the reports comes first.

Injection site swelling[swelling where the injection was given]30%65 reports
Injection site hair change[hair change where the injection was given]13.8%30 reports
Hives12.9%28 reports
Injection site pain[pain where the injection was given]9.7%21 reports
Colic6.5%14 reports
Lethargy[unusually tired or inactive]6%13 reports
Reluctant to move6%13 reports
Injection site reaction NOS[reaction nos where the injection was given]5.5%12 reports
Injection site hair loss[hair loss where the injection was given]4.1%9 reports
Muscle stiffness4.1%9 reports
Agitation3.7%8 reports
Behavioural disorder NOS[behaviour change, type not specified]3.7%8 reports
Injection site tenderness[tenderness where the injection was given]3.7%8 reports
Pawing3.7%8 reports

Show the next 16 signs

Fever3.2%7 reports
Injection site alopecia[hair loss where the injection was given]3.2%7 reports
Injection site lump[lump where the injection was given]3.2%7 reports
Itching3.2%7 reports
Lameness3.2%7 reports
Lying down3.2%7 reports
Not himself/herself3.2%7 reports
Injection site stiffness[stiffness where the injection was given]2.8%6 reports
Not eating2.8%6 reports
Decreased appetite2.3%5 reports
Rubbing2.3%5 reports
Stiffness NOS[NOS: not otherwise specified]2.3%5 reports
Uncomfortable2.3%5 reports
Discomfort NOS[NOS: not otherwise specified]1.8%4 reports
Fasciculation1.8%4 reports
Hair coat discolouration1.8%4 reports

The list shows 30 of 226 coded signs. A report is not proof that a drug caused a sign. Download all signs (CSV)

Reports by species

Horse93.5%203
Dog4.6%10
Human exposure0.5%1

The share is of all 217 reports that name pentosan polysulfate sodium. The other reports give a different species or no species.

Reports for each month, Jul 2021 to Jun 2026

Dog6 reports

No chart: no month has 5 or more reports.

Cat0 reports

No chart: no month has 5 or more reports.

Horse203 reports. Largest count in one month: 11 (Mar 2026)

Other or not given4 reports

No chart: no month has 5 or more reports.

The month is the month in which FDA received the report. Each chart has its own scale. FDA says that a report can take 3 to 6 months to reach the public data. The newest months can get more reports in a later update.

Reports by year

Dog
Cat
Horse
Other or not given

Reports that name pentosan polysulfate sodium, by the year in which FDA received them and by species
Year	Dog	Horse	Other or not given	All species
2026	0	41	3	44
2025	1	79	0	80
2024	2	65	1	68
2023	1	18	0	19
2022	2	0	0	2
2016	1	0	0	1
2015	2	0	0	2
2008	1	0	0	1

2026 has the reports that FDA received through Jun 2026. Download the years (CSV)

What the reports record

Outcome at the time of the report

Recovered/Normal48.4%105
Recovered with Sequela[recovered, with a lasting effect]1.4%3
Ongoing5.1%11
Died1.4%3
Euthanized0.5%1
Outcome Unknown43.3%94

An outcome in a report is not proof that the drug caused it. The person who sends the report gives the outcome. Each share is of the 217 reports that name pentosan polysulfate sodium.

A report about more than one animal can have more than one outcome.

Kind of report

Safety issue97.2%211
Lack of expected effectiveness0%0
Both safety and lack of expected effectiveness1.4%3
Manufacturing or product defect1.4%3
Other0%0

212 reports say if the event was serious. 54.7% of them have the serious flag. The person who sends the report sets the flag.

Show age, weight, breed and route

Age of the animal

Under 1 year0.5%1
1 to 3 years1.8%4
4 to 7 years11.1%24
8 to 11 years24%52
12 years and over46.5%101
Age not given16.1%35

Weight of the animal

Under 5 kg (11 lb)0.5%1
5 to 9.9 kg (11 to 22 lb)0.9%2
10 to 24.9 kg (22 to 55 lb)0.9%2
25 to 44.9 kg (55 to 99 lb)0.9%2
45 kg and over (99 lb and over)66.4%144
Weight not given30.4%66

Breed, where the report gives one breed

Quarter Horse26.7%58
Thoroughbred8.8%19
Dutch Warmblood7.8%17
Appaloosa2.3%5
Arab2.3%5
Hanovarian2.3%5
Morgan1.8%4
Selle Français1.4%3

A breed with many animals has many reports.

Route in the report

Intramuscular82.9%180
Other0.9%2
Subcutaneous0.9%2
Intra-Articular0.5%1
Intravenous0.5%1

Each bar is on a scale of 0 to 100%.

Approved animal drugs with this active ingredient (FDA Green Book)

This section is reference data. It has no report count.

The openFDA records give the value "MSK" for the brand name and for the manufacturer name of each drug. FDA says that MSK means "masked". So the site cannot count a report for a brand.

Brand names

Zycosan

What the Green Book records give

Applications with an approval in force: 1
Approved species: Horses
Dose forms: Injectable Solution
Routes: Intramuscular
Sale: RX (prescription)
Earliest approval date in the records: 20 Dec 2022

The species, dose forms and routes are the words of the Green Book records for all the applications together. One product can have fewer. The label of a product gives its approved use.

Applications in the Green Book of 2 Nov 2026, pioneer applications (NADA) first
Brand name	Active ingredients	Sponsor	Approved species	Application
Zycosan	Pentosan polysulfate sodium	Dechra Veterinary Products LLC	Horses	NADA 141-559

Next in the A to Z list

All drugs by active ingredient. Brand names A to Z

FDA pages for this drug

How to Report Animal Drug and Device Side Effects and Product ProblemsThe FDA page that tells an owner or a veterinarian how to send a report.
Green Book record of NADA 141-559The FDA record of the application for Zycosan.
Animal Drugs @ FDAThe search page of the Green Book, the FDA list of approved animal drugs.

The site checked these addresses on 2 Oct 2026. The links open in a new tab.

Cite this page

Pet Drug Reports. Pentosan polysulfate sodium: adverse event reports that FDA received. https://petdrugreports.com/drug/pentosan-polysulfate-sodium/ Source: FDA Center for Veterinary Medicine, openFDA Animal and Veterinary adverse event reports, export of 30 Oct 2026. Reports received through 26 Jun 2026.

Where the data come from

The counts come from the openFDA Animal and Veterinary adverse event files, export of 30 Oct 2026. The files have the reports that the FDA Center for Veterinary Medicine received through 26 Jun 2026. The files mask brand and manufacturer names. The site counts a drug by the active ingredients that each record gives, and gives no count to a brand, an application or a company. Ingredient names and the lists of approved products follow the FDA Green Book of 2 Nov 2026. The site does not use the application number that a record has.

The site does not publish report text, lot numbers or details of a reporter. FDA's record is the authority. See how the site counts reports, the data sources and the corrections page.

Questions about these reports

Which brand are these reports about?: The openFDA records give the value "MSK" for the brand name and for the manufacturer name of each drug. FDA says that MSK means "masked". So the site cannot count a report for a brand. The Green Book section of this page lists the brand names with this active ingredient.
Do the reports show that the drug caused the signs?: No. FDA states this about the data.
When looking at the results, be aware that there is no certainty that the reported drug or device caused the adverse event.
The adverse event may have been related to an underlying disease, other drugs used at the same time or other non-drug related sources.
FDA Center for Veterinary Medicine. Source: Adverse Event Reports for Animal Drugs and Devices
How many reports did FDA receive in the latest 12 months?: FDA received 81 reports in the 12 months to June 2026. It received 79 reports in the 12 months before. FDA says that a report can take 3 to 6 months to reach the public data. The newest months can get more reports in a later update.
What kinds of report are in the count?: Of the 217 reports received from July 2008 to June 2026, 97.2% are about a safety issue only. 1.4% are about a lack of expected effectiveness, alone or with a safety issue. 1.4% are about a defect of the product or its package.