The National AG Law Center publishes very good information and has many animal laws catalogued by state. This is linked to animal cases by Circuit.
http://www.ncjw.org/content_370.cfm?navID=275 (map showing which states are in which Circuit)
http://www.nationalaglawcenter.org/assets/caseindexes/animalwelfare.html (showing cases within Circuits)
It does not do an exceptional amount of good to cite cases outside of your jurisdiction, although occasionally if hard pressed for relevant law, we may use a case to show contrast or to try and persuade that other courts may have taken a certain route. In general the 9th Circuit tends to be very liberal and many ARs love to file in Los Angeles and San Francisco (yes, HSUS has done this a lot.) We have read many, many HSUS cases.
And some key cases have come out of CA, such as the Fuller case involving the killing of a blue pitbull pet, simply because he was a pitbull. Judge Maxine Chesney wrongfully decided the case at trial level, SF Federal District Ct., then it was appealed and overturned and resulted in one of the largest published, precedential PROPERTY cases for owners nationwide. The Court held that killing the dog was a property deprivation/illegal seizure since there was no reason to kill the dog. It took the attorneys 5-7 years to get that decision.
Also in CA, we have the infamous Hells Angels case, where the SWAT team from San Jose wrecked the defendant’s property, mobile home, and killed the dogs, we believe they were rotties. There was no exigency, they just tore up the place and killed the dogs. The case took years, but ended up with a finding for the defendants near a million bucks. The normally conservative jurisdiction went awry with their illegal tactics and SWAT team. It does happen.
You should know your Court Circuit number (for example, CA is in 9th Circuit, the most overturned Circuit in the USA, and one of the largest Circuits)
Headquartered in San Francisco, California, the Ninth Circuit is by far the largest of the thirteen courts of appeals, with 29 active judgeships. The court’s regular meeting places are Seattle at the William K. Nakamura Courthouse, Portland at the Pioneer Courthouse, San Francisco at the James R. Browning U.S. Court of Appeals Building, and Pasadena at the Richard H. Chambers U.S. Court of Appeals, but panels of the court occasionally travel to hear cases in other locations within its territorial jurisdiction. Although the judges travel around the circuit, the court arranges its hearings so that cases from the northern region of the circuit are heard in Seattle or Portland, cases from southern California are heard in Pasadena, and cases from northern California, Nevada, Arizona, and Hawaii are heard in San Francisco. For lawyers who must come and present their cases to the court in person, this administrative grouping of cases helps to reduce the time and cost of travel.
Animal cases are also shown on animal law info but it is done with AR help, so in some instances they tend to have more details on the cases they think are better for animals, but in general they are not biased. http://www.animallaw.info/cases/statecases/causcaset.htm This site also has legislation,and AR topics, historical materials and case summaries.